diff --git a/linker/Android.bp b/linker/Android.bp
new file mode 100644
index 0000000..39f1da9
--- /dev/null
+++ b/linker/Android.bp
@@ -0,0 +1,148 @@
+cc_library_static {
+    name: "liblinker_malloc",
+    clang: true,
+
+    srcs: [
+        "linker_allocator.cpp",
+        "linker_memory.cpp",
+    ],
+
+    // We need to access Bionic private headers in the linker.
+    include_dirs: ["bionic/libc"],
+}
+
+cc_binary {
+    clang: true,
+
+    srcs: [
+        "dlfcn.cpp",
+        "linker.cpp",
+        "linker_block_allocator.cpp",
+        "linker_dlwarning.cpp",
+        "linker_gdb_support.cpp",
+        "linker_globals.cpp",
+        "linker_libc_support.c",
+        "linker_namespaces.cpp",
+        "linker_logger.cpp",
+        "linker_mapped_file_fragment.cpp",
+        "linker_phdr.cpp",
+        "linker_sdk_versions.cpp",
+        "linker_soinfo.cpp",
+        "linker_utils.cpp",
+        "rt.cpp",
+    ],
+
+    arch: {
+        arm: {
+            srcs: ["arch/arm/begin.S"],
+
+            cflags: ["-D__work_around_b_24465209__"],
+        },
+        arm64: {
+            srcs: ["arch/arm64/begin.S"],
+        },
+        x86: {
+            srcs: ["arch/x86/begin.c"],
+
+            cflags: ["-D__work_around_b_24465209__"],
+        },
+        x86_64: {
+            srcs: ["arch/x86_64/begin.S"],
+        },
+        mips: {
+            srcs: [
+                "arch/mips/begin.S",
+                "linker_mips.cpp",
+            ],
+        },
+        mips64: {
+            srcs: [
+                "arch/mips64/begin.S",
+                "linker_mips.cpp",
+            ],
+        },
+    },
+
+    // We need to access Bionic private headers in the linker.
+    include_dirs: ["bionic/libc"],
+
+    // -shared is used to overwrite the -Bstatic and -static
+    // flags triggered by LOCAL_FORCE_STATIC_EXECUTABLE.
+    // This dynamic linker is actually a shared object linked with static libraries.
+    ldflags: [
+        "-shared",
+        "-Wl,-Bsymbolic",
+        "-Wl,--exclude-libs,ALL",
+    ],
+
+    cflags: [
+        "-fno-stack-protector",
+        "-Wstrict-overflow=5",
+        "-fvisibility=hidden",
+        "-Wall",
+        "-Wextra",
+        "-Wunused",
+        "-Werror",
+    ],
+
+    // TODO: split out the asflags.
+    asflags: [
+        "-fno-stack-protector",
+        "-Wstrict-overflow=5",
+        "-fvisibility=hidden",
+        "-Wall",
+        "-Wextra",
+        "-Wunused",
+        "-Werror",
+    ],
+
+    conlyflags: ["-std=gnu99"],
+
+    cppflags: ["-Wold-style-cast"],
+
+    // we don't want crtbegin.o (because we have begin.o), so unset it
+    // just for this module
+    nocrt: true,
+
+    static_libs: [
+        "libc_nomalloc",
+        "libziparchive",
+        "libutils",
+        "libbase",
+        "libz",
+        "liblog",
+        "libdebuggerd_client",
+
+        // Important: The liblinker_malloc should be the last library in the list
+        // to overwrite any other malloc implementations by other static libraries.
+        "liblinker_malloc"
+    ],
+    static_executable: true,
+
+    name: "linker",
+    multilib: {
+        lib32: {
+            symlinks: ["linker_asan"],
+        },
+        lib64: {
+            suffix: "64",
+            symlinks: ["linker_asan64"],
+       },
+    },
+    target: {
+        android64: {
+            cflags: ["-DTARGET_IS_64_BIT"],
+        },
+    },
+    compile_multilib: "both",
+
+    // Leave the symbols in the shared library so that stack unwinders can produce
+    // meaningful name resolution.
+    strip: {
+        keep_symbols: true,
+    },
+
+    // Insert an extra objcopy step to add prefix to symbols. This is needed to prevent gdb
+    // looking up symbols in the linker by mistake.
+    prefix_symbols: "__dl_",
+}
diff --git a/linker/Android.mk b/linker/Android.mk
new file mode 100644
index 0000000..ea7451c
--- /dev/null
+++ b/linker/Android.mk
@@ -0,0 +1,3 @@
+LOCAL_PATH := $(call my-dir)
+
+include $(call first-makefiles-under,$(LOCAL_PATH))
diff --git a/linker/MODULE_LICENSE_APACHE2 b/linker/MODULE_LICENSE_APACHE2
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/linker/MODULE_LICENSE_APACHE2
diff --git a/linker/NOTICE b/linker/NOTICE
new file mode 100644
index 0000000..3ba0ff9
--- /dev/null
+++ b/linker/NOTICE
@@ -0,0 +1,220 @@
+Copyright (C) 2007 The Android Open Source Project
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+-------------------------------------------------------------------
+
+Copyright (C) 2008 The Android Open Source Project
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+ * Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in
+   the documentation and/or other materials provided with the
+   distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGE.
+
+-------------------------------------------------------------------
+
+Copyright (C) 2012 The Android Open Source Project
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+ * Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in
+   the documentation and/or other materials provided with the
+   distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGE.
+
+-------------------------------------------------------------------
+
+Copyright (C) 2013 The Android Open Source Project
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+-------------------------------------------------------------------
+
+Copyright (C) 2013 The Android Open Source Project
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+ * Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in
+   the documentation and/or other materials provided with the
+   distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGE.
+
+-------------------------------------------------------------------
+
+Copyright (C) 2014 The Android Open Source Project
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+-------------------------------------------------------------------
+
+Copyright (C) 2015 The Android Open Source Project
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+-------------------------------------------------------------------
+
+Copyright (C) 2015 The Android Open Source Project
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+ * Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in
+   the documentation and/or other materials provided with the
+   distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGE.
+
+-------------------------------------------------------------------
+
+Copyright (C) 2016 The Android Open Source Project
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+-------------------------------------------------------------------
+
+Copyright (C) 2016 The Android Open Source Project
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+ * Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in
+   the documentation and/or other materials provided with the
+   distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGE.
+
+-------------------------------------------------------------------
+
diff --git a/linker/arch/arm/begin.S b/linker/arch/arm/begin.S
new file mode 100644
index 0000000..8cb599b
--- /dev/null
+++ b/linker/arch/arm/begin.S
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <private/bionic_asm.h>
+
+ENTRY(_start)
+  mov r0, sp
+  bl __linker_init
+
+  /* linker init returns the _entry address in the main image */
+  mov pc, r0
+END(_start)
diff --git a/linker/arch/arm64/begin.S b/linker/arch/arm64/begin.S
new file mode 100644
index 0000000..a6ea583
--- /dev/null
+++ b/linker/arch/arm64/begin.S
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <private/bionic_asm.h>
+
+ENTRY(_start)
+  mov x0, sp
+  bl __linker_init
+
+  /* linker init returns the _entry address in the main image */
+  br x0
+END(_start)
diff --git a/linker/arch/mips/begin.S b/linker/arch/mips/begin.S
new file mode 100644
index 0000000..cbe1e37
--- /dev/null
+++ b/linker/arch/mips/begin.S
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+    .text
+    .align    4
+    .type    __start,@function
+
+    .ent    __start
+    .globl    __start
+    .globl    _start
+__start:
+_start:
+    .set    noreorder
+    bal    1f
+    nop
+1:  .cpload    $31
+    .set    reorder
+
+    /* Discover the load address */
+    la    $t0, 1f
+    bal    1f
+1:  subu    $t0, $ra, $t0
+
+#define DT_PLTGOT 3
+#define DT_MIPS_LOCAL_GOTNO 0x7000000a
+
+    /* Search dynamic table for DT_MIPS_LOCAL_GOTNO and DT_PLTGOT values */
+    la    $t1, _DYNAMIC
+    addu    $t1, $t0
+    li    $t3, DT_PLTGOT
+    li    $t4, DT_MIPS_LOCAL_GOTNO
+0:
+    lw    $t2, 0($t1)
+    beqz    $t2, .Lrelocate_local_got
+
+    bne    $t2, $t3, 1f    /* DT_PLTGOT? */
+    lw    $s0, 4($t1)
+    addu    $s0, $t0
+    b    2f
+
+1:  bne    $t2, $t4, 1f    /* DT_MIPS_LOCAL_GOTNO? */
+    lw    $s1, 4($t1)
+    b    2f
+
+1:
+2:  addu    $t1, 8
+    b    0b
+
+.Lrelocate_local_got:
+    /*
+     * Relocate the local GOT entries
+     * got[0] is address of lazy resolver function
+     * got[1] may be used for a GNU extension
+     */
+
+    addu    $s0, 4
+    subu    $s1, 1
+    lw    $t1, ($s0)
+    bgez    $t1, 9f
+    addu    $s0, 4
+    subu    $s1, 1
+    b    9f
+
+1:  lw    $t1, ($s0)
+    addu    $t1, $t0
+    sw    $t1, ($s0)
+    addu    $s0, 4
+9:  subu    $s1, 1
+    bgez    $s1, 1b
+
+    /* call linker_init */
+    move    $a0, $sp
+    addiu    $sp, -4*4        /* space for arg saves in linker_init */
+    la    $t9, __linker_init
+    jalr    $t9
+    move    $t9, $v0
+    addu    $sp, 4*4        /* restore sp */
+    j    $t9
+    .end    __start
diff --git a/linker/arch/mips64/begin.S b/linker/arch/mips64/begin.S
new file mode 100644
index 0000000..8f6b94a
--- /dev/null
+++ b/linker/arch/mips64/begin.S
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <private/bionic_asm.h>
+
+#if (_MIPS_SIM == _ABIO32) || (_MIPS_SIM == _ABI32)
+#define ELF_DYNSZ       8
+#define ELF_DYN_TAG     0
+#define ELF_DYN_VAL     4
+#define GOTENT_SZ       4
+#else
+#define ELF_DYNSZ       16
+#define ELF_DYN_TAG     0
+#define ELF_DYN_VAL     8
+#define GOTENT_SZ       8
+#endif
+
+    .text
+    .align	4
+    .type	__start,@function
+
+    .ent	__start
+    .globl	__start
+    .globl	_start
+__start:
+_start:
+    .set	noreorder
+    bal		1f
+     nop
+1:
+#if (_MIPS_SIM == _ABIO32) || (_MIPS_SIM == _ABI32)
+    .cpload	ra
+#else
+    .cpsetup	ra, $0, 1b
+#endif
+    .set	reorder
+
+    /* Discover the load address */
+    LA		t0, 1b
+    PTR_SUBU	t0, ra, t0
+
+#define DT_PLTGOT 3
+#define DT_MIPS_LOCAL_GOTNO 0x7000000a
+
+    /* Search dynamic table for DT_MIPS_LOCAL_GOTNO and DT_PLTGOT values */
+    LA		t1, _DYNAMIC
+    PTR_ADDU	t1, t0
+    LI		t3, DT_PLTGOT
+    LI		ta0, DT_MIPS_LOCAL_GOTNO
+0:
+    REG_L	t2, ELF_DYN_TAG(t1)
+    beqz	t2, .Lrelocate_local_got
+
+    bne		t2, t3, 1f	/* DT_PLTGOT? */
+    REG_L	s0, ELF_DYN_VAL(t1)
+    PTR_ADDU	s0, t0
+    b		2f
+
+1:
+    bne		t2, ta0, 2f    /* DT_MIPS_LOCAL_GOTNO? */
+    REG_L	s1, ELF_DYN_VAL(t1)
+
+2:  PTR_ADDU    t1, ELF_DYNSZ
+    b		0b
+
+.Lrelocate_local_got:
+    /*
+     * Relocate the local GOT entries
+     * got[0] is address of lazy resolver function
+     * got[1] may be used for a GNU extension
+     */
+
+    PTR_ADDU	s0, GOTENT_SZ
+    SUBU	s1, 1
+    PTR_L	t1, (s0)
+    bgez	t1, 9f
+    PTR_ADDU	s0, GOTENT_SZ
+    SUBU	s1, 1
+    b		9f
+
+1:  PTR_L	t1, (s0)
+    PTR_ADDU	t1, t0
+    PTR_S	t1, (s0)
+    PTR_ADDU	s0, GOTENT_SZ
+9:  SUBU	s1, 1
+    bgez	s1, 1b
+
+    /* call linker_init */
+    move	a0, sp
+#if (_MIPS_SIM == _ABIO32) || (_MIPS_SIM == _ABI32)
+    PTR_SUBU	sp, 4*REGSZ       /* space for arg saves in linker_init */
+#endif
+    jal		__linker_init
+#if (_MIPS_SIM == _ABIO32) || (_MIPS_SIM == _ABI32)
+    PTR_ADDU	sp, 4*REGSZ        /* restore sp */
+#endif
+    move	t9, v0
+    j		t9
+    .end    __start
diff --git a/linker/arch/x86/begin.c b/linker/arch/x86/begin.c
new file mode 100644
index 0000000..051a16a
--- /dev/null
+++ b/linker/arch/x86/begin.c
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <stdint.h>
+#include <sys/cdefs.h>
+
+extern unsigned __linker_init(void* raw_args);
+
+__LIBC_HIDDEN__ void _start() {
+  void (*start)(void);
+
+  void* raw_args = (void*) ((uintptr_t) __builtin_frame_address(0) + sizeof(void*));
+  start = (void(*)(void))__linker_init(raw_args);
+
+  /* linker init returns (%eax) the _entry address in the main image */
+  /* entry point expects sp to point to raw_args */
+
+  __asm__ (
+     "mov %0, %%esp\n\t"
+     "jmp *%1\n\t"
+     : : "r"(raw_args), "r"(start) :
+  );
+
+  /* Unreachable */
+}
+
+/* Since linker has its own version of crtbegin (this file) it should have */
+/* own version of __stack_chk_fail_local for the case when it's built with */
+/* stack protector feature */
+
+#include "arch-x86/bionic/__stack_chk_fail_local.h"
diff --git a/linker/arch/x86_64/begin.S b/linker/arch/x86_64/begin.S
new file mode 100644
index 0000000..7945a31
--- /dev/null
+++ b/linker/arch/x86_64/begin.S
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <private/bionic_asm.h>
+
+ENTRY(_start)
+  mov %rsp, %rdi
+  call __linker_init
+
+  /* linker init returns (%rax) the _entry address in the main image */
+  jmp *%rax
+END(_start)
diff --git a/linker/dlfcn.cpp b/linker/dlfcn.cpp
new file mode 100644
index 0000000..3ac61d7
--- /dev/null
+++ b/linker/dlfcn.cpp
@@ -0,0 +1,288 @@
+/*
+ * Copyright (C) 2007 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "linker.h"
+#include "linker_globals.h"
+#include "linker_dlwarning.h"
+
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <android/api-level.h>
+
+#include <bionic/pthread_internal.h>
+#include "private/bionic_tls.h"
+#include "private/ScopedPthreadMutexLocker.h"
+#include "private/ThreadLocalBuffer.h"
+
+/* This file hijacks the symbols stubbed out in libdl.so. */
+
+static pthread_mutex_t g_dl_mutex = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
+
+static char* __bionic_set_dlerror(char* new_value) {
+  char** dlerror_slot = &reinterpret_cast<char**>(__get_tls())[TLS_SLOT_DLERROR];
+
+  char* old_value = *dlerror_slot;
+  *dlerror_slot = new_value;
+  return old_value;
+}
+
+static void __bionic_format_dlerror(const char* msg, const char* detail) {
+  char* buffer = __get_thread()->dlerror_buffer;
+  strlcpy(buffer, msg, __BIONIC_DLERROR_BUFFER_SIZE);
+  if (detail != nullptr) {
+    strlcat(buffer, ": ", __BIONIC_DLERROR_BUFFER_SIZE);
+    strlcat(buffer, detail, __BIONIC_DLERROR_BUFFER_SIZE);
+  }
+
+  __bionic_set_dlerror(buffer);
+}
+
+char* dlerror() {
+  char* old_value = __bionic_set_dlerror(nullptr);
+  return old_value;
+}
+
+void android_get_LD_LIBRARY_PATH(char* buffer, size_t buffer_size) {
+  ScopedPthreadMutexLocker locker(&g_dl_mutex);
+  do_android_get_LD_LIBRARY_PATH(buffer, buffer_size);
+}
+
+void android_update_LD_LIBRARY_PATH(const char* ld_library_path) {
+  ScopedPthreadMutexLocker locker(&g_dl_mutex);
+  do_android_update_LD_LIBRARY_PATH(ld_library_path);
+}
+
+static void* dlopen_ext(const char* filename, int flags,
+                        const android_dlextinfo* extinfo, void* caller_addr) {
+  ScopedPthreadMutexLocker locker(&g_dl_mutex);
+  g_linker_logger.ResetState();
+  void* result = do_dlopen(filename, flags, extinfo, caller_addr);
+  if (result == nullptr) {
+    __bionic_format_dlerror("dlopen failed", linker_get_error_buffer());
+    return nullptr;
+  }
+  return result;
+}
+
+void* android_dlopen_ext(const char* filename, int flags, const android_dlextinfo* extinfo) {
+  void* caller_addr = __builtin_return_address(0);
+  return dlopen_ext(filename, flags, extinfo, caller_addr);
+}
+
+void* dlopen(const char* filename, int flags) {
+  void* caller_addr = __builtin_return_address(0);
+  return dlopen_ext(filename, flags, nullptr, caller_addr);
+}
+
+void* dlsym_impl(void* handle, const char* symbol, const char* version, void* caller_addr) {
+  ScopedPthreadMutexLocker locker(&g_dl_mutex);
+  g_linker_logger.ResetState();
+  void* result;
+  if (!do_dlsym(handle, symbol, version, caller_addr, &result)) {
+    __bionic_format_dlerror(linker_get_error_buffer(), nullptr);
+    return nullptr;
+  }
+
+  return result;
+}
+
+void* dlsym(void* handle, const char* symbol) {
+  void* caller_addr = __builtin_return_address(0);
+  return dlsym_impl(handle, symbol, nullptr, caller_addr);
+}
+
+void* dlvsym(void* handle, const char* symbol, const char* version) {
+  void* caller_addr = __builtin_return_address(0);
+  return dlsym_impl(handle, symbol, version, caller_addr);
+}
+
+int dladdr(const void* addr, Dl_info* info) {
+  ScopedPthreadMutexLocker locker(&g_dl_mutex);
+  return do_dladdr(addr, info);
+}
+
+int dlclose(void* handle) {
+  ScopedPthreadMutexLocker locker(&g_dl_mutex);
+  int result = do_dlclose(handle);
+  if (result != 0) {
+    __bionic_format_dlerror("dlclose failed", linker_get_error_buffer());
+  }
+  return result;
+}
+
+int dl_iterate_phdr(int (*cb)(dl_phdr_info* info, size_t size, void* data), void* data) {
+  ScopedPthreadMutexLocker locker(&g_dl_mutex);
+  return do_dl_iterate_phdr(cb, data);
+}
+
+void android_set_application_target_sdk_version(uint32_t target) {
+  // lock to avoid modification in the middle of dlopen.
+  ScopedPthreadMutexLocker locker(&g_dl_mutex);
+  set_application_target_sdk_version(target);
+}
+
+uint32_t android_get_application_target_sdk_version() {
+  return get_application_target_sdk_version();
+}
+
+void android_dlwarning(void* obj, void (*f)(void*, const char*)) {
+  ScopedPthreadMutexLocker locker(&g_dl_mutex);
+  get_dlwarning(obj, f);
+}
+
+bool android_init_namespaces(const char* public_ns_sonames,
+                             const char* anon_ns_library_path) {
+  ScopedPthreadMutexLocker locker(&g_dl_mutex);
+  bool success = init_namespaces(public_ns_sonames, anon_ns_library_path);
+  if (!success) {
+    __bionic_format_dlerror("android_init_namespaces failed", linker_get_error_buffer());
+  }
+
+  return success;
+}
+
+android_namespace_t* android_create_namespace(const char* name,
+                                              const char* ld_library_path,
+                                              const char* default_library_path,
+                                              uint64_t type,
+                                              const char* permitted_when_isolated_path,
+                                              android_namespace_t* parent_namespace) {
+  void* caller_addr = __builtin_return_address(0);
+  ScopedPthreadMutexLocker locker(&g_dl_mutex);
+
+  android_namespace_t* result = create_namespace(caller_addr,
+                                                 name,
+                                                 ld_library_path,
+                                                 default_library_path,
+                                                 type,
+                                                 permitted_when_isolated_path,
+                                                 parent_namespace);
+
+  if (result == nullptr) {
+    __bionic_format_dlerror("android_create_namespace failed", linker_get_error_buffer());
+  }
+
+  return result;
+}
+
+// name_offset: starting index of the name in libdl_info.strtab
+#define ELF32_SYM_INITIALIZER(name_offset, value, shndx) \
+    { name_offset, \
+      reinterpret_cast<Elf32_Addr>(value), \
+      /* st_size */ 0, \
+      ((shndx) == 0) ? 0 : (STB_GLOBAL << 4), \
+      /* st_other */ 0, \
+      shndx, \
+    }
+
+#define ELF64_SYM_INITIALIZER(name_offset, value, shndx) \
+    { name_offset, \
+      ((shndx) == 0) ? 0 : (STB_GLOBAL << 4), \
+      /* st_other */ 0, \
+      shndx, \
+      reinterpret_cast<Elf64_Addr>(value), \
+      /* st_size */ 0, \
+    }
+
+static const char ANDROID_LIBDL_STRTAB[] =
+  // 0000000 00011111 111112 22222222 2333333 3333444444444455555555556666666 6667777777777888888888899999 99999
+  // 0123456 78901234 567890 12345678 9012345 6789012345678901234567890123456 7890123456789012345678901234 56789
+    "dlopen\0dlclose\0dlsym\0dlerror\0dladdr\0android_update_LD_LIBRARY_PATH\0android_get_LD_LIBRARY_PATH\0dl_it"
+  // 00000000001 1111111112222222222 3333333333444444444455555555556666666666777 777777788888888889999999999
+  // 01234567890 1234567890123456789 0123456789012345678901234567890123456789012 345678901234567890123456789
+    "erate_phdr\0android_dlopen_ext\0android_set_application_target_sdk_version\0android_get_application_tar"
+  // 0000000000111111 111122222222223333333333 4444444444555555555566666 6666677 777777778888888888
+  // 0123456789012345 678901234567890123456789 0123456789012345678901234 5678901 234567890123456789
+    "get_sdk_version\0android_init_namespaces\0android_create_namespace\0dlvsym\0android_dlwarning\0"
+#if defined(__arm__)
+  // 290
+    "dl_unwind_find_exidx\0"
+#endif
+    ;
+
+static ElfW(Sym) g_libdl_symtab[] = {
+  // Total length of libdl_info.strtab, including trailing 0.
+  // This is actually the STH_UNDEF entry. Technically, it's
+  // supposed to have st_name == 0, but instead, it points to an index
+  // in the strtab with a \0 to make iterating through the symtab easier.
+  ELFW(SYM_INITIALIZER)(sizeof(ANDROID_LIBDL_STRTAB) - 1, nullptr, 0),
+  ELFW(SYM_INITIALIZER)(  0, &dlopen, 1),
+  ELFW(SYM_INITIALIZER)(  7, &dlclose, 1),
+  ELFW(SYM_INITIALIZER)( 15, &dlsym, 1),
+  ELFW(SYM_INITIALIZER)( 21, &dlerror, 1),
+  ELFW(SYM_INITIALIZER)( 29, &dladdr, 1),
+  ELFW(SYM_INITIALIZER)( 36, &android_update_LD_LIBRARY_PATH, 1),
+  ELFW(SYM_INITIALIZER)( 67, &android_get_LD_LIBRARY_PATH, 1),
+  ELFW(SYM_INITIALIZER)( 95, &dl_iterate_phdr, 1),
+  ELFW(SYM_INITIALIZER)(111, &android_dlopen_ext, 1),
+  ELFW(SYM_INITIALIZER)(130, &android_set_application_target_sdk_version, 1),
+  ELFW(SYM_INITIALIZER)(173, &android_get_application_target_sdk_version, 1),
+  ELFW(SYM_INITIALIZER)(216, &android_init_namespaces, 1),
+  ELFW(SYM_INITIALIZER)(240, &android_create_namespace, 1),
+  ELFW(SYM_INITIALIZER)(265, &dlvsym, 1),
+  ELFW(SYM_INITIALIZER)(272, &android_dlwarning, 1),
+#if defined(__arm__)
+  ELFW(SYM_INITIALIZER)(290, &dl_unwind_find_exidx, 1),
+#endif
+};
+
+// Fake out a hash table with a single bucket.
+//
+// A search of the hash table will look through g_libdl_symtab starting with index 1, then
+// use g_libdl_chains to find the next index to look at. g_libdl_chains should be set up to
+// walk through every element in g_libdl_symtab, and then end with 0 (sentinel value).
+//
+// That is, g_libdl_chains should look like { 0, 2, 3, ... N, 0 } where N is the number
+// of actual symbols, or nelems(g_libdl_symtab)-1 (since the first element of g_libdl_symtab is not
+// a real symbol). (See soinfo_elf_lookup().)
+//
+// Note that adding any new symbols here requires stubbing them out in libdl.
+static unsigned g_libdl_buckets[1] = { 1 };
+#if defined(__arm__)
+static unsigned g_libdl_chains[] = { 0, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 0 };
+#else
+static unsigned g_libdl_chains[] = { 0, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 0 };
+#endif
+
+static uint8_t __libdl_info_buf[sizeof(soinfo)] __attribute__((aligned(8)));
+static soinfo* __libdl_info = nullptr;
+
+// This is used by the dynamic linker. Every process gets these symbols for free.
+soinfo* get_libdl_info() {
+  if (__libdl_info == nullptr) {
+    __libdl_info = new (__libdl_info_buf) soinfo(&g_default_namespace, "libdl.so", nullptr, 0, RTLD_GLOBAL);
+    __libdl_info->flags_ |= FLAG_LINKED;
+    __libdl_info->strtab_ = ANDROID_LIBDL_STRTAB;
+    __libdl_info->symtab_ = g_libdl_symtab;
+    __libdl_info->nbucket_ = sizeof(g_libdl_buckets)/sizeof(unsigned);
+    __libdl_info->nchain_ = sizeof(g_libdl_chains)/sizeof(unsigned);
+    __libdl_info->bucket_ = g_libdl_buckets;
+    __libdl_info->chain_ = g_libdl_chains;
+    __libdl_info->ref_count_ = 1;
+    __libdl_info->strtab_size_ = sizeof(ANDROID_LIBDL_STRTAB);
+    __libdl_info->local_group_root_ = __libdl_info;
+    __libdl_info->soname_ = "libdl.so";
+    __libdl_info->target_sdk_version_ = __ANDROID_API__;
+    __libdl_info->generate_handle();
+#if defined(__work_around_b_24465209__)
+    strlcpy(__libdl_info->old_name_, __libdl_info->soname_, sizeof(__libdl_info->old_name_));
+#endif
+  }
+
+  return __libdl_info;
+}
diff --git a/linker/linked_list.h b/linker/linked_list.h
new file mode 100644
index 0000000..092e831
--- /dev/null
+++ b/linker/linked_list.h
@@ -0,0 +1,241 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __LINKED_LIST_H
+#define __LINKED_LIST_H
+
+#include "private/bionic_macros.h"
+
+template<typename T>
+struct LinkedListEntry {
+  LinkedListEntry<T>* next;
+  T* element;
+};
+
+// ForwardInputIterator
+template<typename T>
+class LinkedListIterator {
+ public:
+  LinkedListIterator() : entry_(nullptr) {}
+  LinkedListIterator(const LinkedListIterator<T>& that) : entry_(that.entry_) {}
+  explicit LinkedListIterator(LinkedListEntry<T>* entry) : entry_(entry) {}
+
+  LinkedListIterator<T>& operator=(const LinkedListIterator<T>& that) {
+    entry_ = that.entry_;
+    return *this;
+  }
+
+  LinkedListIterator<T>& operator++() {
+    entry_ = entry_->next;
+    return *this;
+  }
+
+  T* const operator*() {
+    return entry_->element;
+  }
+
+  bool operator==(const LinkedListIterator<T>& that) const {
+    return entry_ == that.entry_;
+  }
+
+  bool operator!=(const LinkedListIterator<T>& that) const {
+    return entry_ != that.entry_;
+  }
+
+ private:
+  LinkedListEntry<T> *entry_;
+};
+
+/*
+ * Represents linked list of objects of type T
+ */
+template<typename T, typename Allocator>
+class LinkedList {
+ public:
+  typedef LinkedListIterator<T> iterator;
+  typedef T* value_type;
+
+  LinkedList() : head_(nullptr), tail_(nullptr) {}
+  ~LinkedList() {
+    clear();
+  }
+
+  LinkedList(LinkedList&& that) {
+    this->head_ = that.head_;
+    this->tail_ = that.tail_;
+    that.head_ = that.tail_ = nullptr;
+  }
+
+  void push_front(T* const element) {
+    LinkedListEntry<T>* new_entry = Allocator::alloc();
+    new_entry->next = head_;
+    new_entry->element = element;
+    head_ = new_entry;
+    if (tail_ == nullptr) {
+      tail_ = new_entry;
+    }
+  }
+
+  void push_back(T* const element) {
+    LinkedListEntry<T>* new_entry = Allocator::alloc();
+    new_entry->next = nullptr;
+    new_entry->element = element;
+    if (tail_ == nullptr) {
+      tail_ = head_ = new_entry;
+    } else {
+      tail_->next = new_entry;
+      tail_ = new_entry;
+    }
+  }
+
+  T* pop_front() {
+    if (head_ == nullptr) {
+      return nullptr;
+    }
+
+    LinkedListEntry<T>* entry = head_;
+    T* element = entry->element;
+    head_ = entry->next;
+    Allocator::free(entry);
+
+    if (head_ == nullptr) {
+      tail_ = nullptr;
+    }
+
+    return element;
+  }
+
+  T* front() const {
+    if (head_ == nullptr) {
+      return nullptr;
+    }
+
+    return head_->element;
+  }
+
+  void clear() {
+    while (head_ != nullptr) {
+      LinkedListEntry<T>* p = head_;
+      head_ = head_->next;
+      Allocator::free(p);
+    }
+
+    tail_ = nullptr;
+  }
+
+  template<typename F>
+  void for_each(F action) const {
+    visit([&] (T* si) {
+      action(si);
+      return true;
+    });
+  }
+
+  template<typename F>
+  bool visit(F action) const {
+    for (LinkedListEntry<T>* e = head_; e != nullptr; e = e->next) {
+      if (!action(e->element)) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  template<typename F>
+  void remove_if(F predicate) {
+    for (LinkedListEntry<T>* e = head_, *p = nullptr; e != nullptr;) {
+      if (predicate(e->element)) {
+        LinkedListEntry<T>* next = e->next;
+        if (p == nullptr) {
+          head_ = next;
+        } else {
+          p->next = next;
+        }
+
+        if (tail_ == e) {
+          tail_ = p;
+        }
+
+        Allocator::free(e);
+
+        e = next;
+      } else {
+        p = e;
+        e = e->next;
+      }
+    }
+  }
+
+  template<typename F>
+  T* find_if(F predicate) const {
+    for (LinkedListEntry<T>* e = head_; e != nullptr; e = e->next) {
+      if (predicate(e->element)) {
+        return e->element;
+      }
+    }
+
+    return nullptr;
+  }
+
+  iterator begin() const {
+    return iterator(head_);
+  }
+
+  iterator end() const {
+    return iterator(nullptr);
+  }
+
+  iterator find(T* value) const {
+    for (LinkedListEntry<T>* e = head_; e != nullptr; e = e->next) {
+      if (e->element == value) {
+        return iterator(e);
+      }
+    }
+
+    return end();
+  }
+
+  size_t copy_to_array(T* array[], size_t array_length) const {
+    size_t sz = 0;
+    for (LinkedListEntry<T>* e = head_; sz < array_length && e != nullptr; e = e->next) {
+      array[sz++] = e->element;
+    }
+
+    return sz;
+  }
+
+  bool contains(const T* el) const {
+    for (LinkedListEntry<T>* e = head_; e != nullptr; e = e->next) {
+      if (e->element == el) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  static LinkedList make_list(T* const element) {
+    LinkedList<T, Allocator> one_element_list;
+    one_element_list.push_back(element);
+    return one_element_list;
+  }
+
+ private:
+  LinkedListEntry<T>* head_;
+  LinkedListEntry<T>* tail_;
+  DISALLOW_COPY_AND_ASSIGN(LinkedList);
+};
+
+#endif // __LINKED_LIST_H
diff --git a/linker/linker.cpp b/linker/linker.cpp
new file mode 100644
index 0000000..d2a6e7d
--- /dev/null
+++ b/linker/linker.cpp
@@ -0,0 +1,3678 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <android/api-level.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/param.h>
+#include <unistd.h>
+
+#include <new>
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+// Private C library headers.
+#include "private/bionic_globals.h"
+#include "private/bionic_tls.h"
+#include "private/KernelArgumentBlock.h"
+#include "private/ScopedPthreadMutexLocker.h"
+#include "private/ScopeGuard.h"
+
+#include "linker.h"
+#include "linker_block_allocator.h"
+#include "linker_gdb_support.h"
+#include "linker_globals.h"
+#include "linker_debug.h"
+#include "linker_dlwarning.h"
+#include "linker_namespaces.h"
+#include "linker_sleb128.h"
+#include "linker_phdr.h"
+#include "linker_relocs.h"
+#include "linker_reloc_iterators.h"
+#include "linker_utils.h"
+
+#include "android-base/strings.h"
+#include "android-base/stringprintf.h"
+#include "debuggerd/client.h"
+#include "ziparchive/zip_archive.h"
+
+extern void __libc_init_globals(KernelArgumentBlock&);
+extern void __libc_init_AT_SECURE(KernelArgumentBlock&);
+
+extern "C" void _start();
+
+// Override macros to use C++ style casts.
+#undef ELF_ST_TYPE
+#define ELF_ST_TYPE(x) (static_cast<uint32_t>(x) & 0xf)
+
+static android_namespace_t* g_anonymous_namespace = &g_default_namespace;
+
+static ElfW(Addr) get_elf_exec_load_bias(const ElfW(Ehdr)* elf);
+
+static LinkerTypeAllocator<soinfo> g_soinfo_allocator;
+static LinkerTypeAllocator<LinkedListEntry<soinfo>> g_soinfo_links_allocator;
+
+static LinkerTypeAllocator<android_namespace_t> g_namespace_allocator;
+static LinkerTypeAllocator<LinkedListEntry<android_namespace_t>> g_namespace_list_allocator;
+
+static soinfo* solist;
+static soinfo* sonext;
+static soinfo* somain; // main process, always the one after libdl_info
+
+#if defined(__LP64__)
+static const char* const kSystemLibDir     = "/system/lib64";
+static const char* const kVendorLibDir     = "/vendor/lib64";
+static const char* const kAsanSystemLibDir = "/data/lib64";
+static const char* const kAsanVendorLibDir = "/data/vendor/lib64";
+#else
+static const char* const kSystemLibDir     = "/system/lib";
+static const char* const kVendorLibDir     = "/vendor/lib";
+static const char* const kAsanSystemLibDir = "/data/lib";
+static const char* const kAsanVendorLibDir = "/data/vendor/lib";
+#endif
+
+static const char* const kDefaultLdPaths[] = {
+  kSystemLibDir,
+  kVendorLibDir,
+  nullptr
+};
+
+static const char* const kAsanDefaultLdPaths[] = {
+  kAsanSystemLibDir,
+  kSystemLibDir,
+  kAsanVendorLibDir,
+  kVendorLibDir,
+  nullptr
+};
+
+// Is ASAN enabled?
+static bool g_is_asan = false;
+
+static bool is_system_library(const std::string& realpath) {
+  for (const auto& dir : g_default_namespace.get_default_library_paths()) {
+    if (file_is_in_dir(realpath, dir)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+// Checks if the file exists and not a directory.
+static bool file_exists(const char* path) {
+  struct stat s;
+
+  if (stat(path, &s) != 0) {
+    return false;
+  }
+
+  return S_ISREG(s.st_mode);
+}
+
+// TODO(dimitry): The grey-list is a workaround for http://b/26394120 ---
+// gradually remove libraries from this list until it is gone.
+static bool is_greylisted(const char* name, const soinfo* needed_by) {
+  static const char* const kLibraryGreyList[] = {
+    "libandroid_runtime.so",
+    "libbinder.so",
+    "libcrypto.so",
+    "libcutils.so",
+    "libexpat.so",
+    "libgui.so",
+    "libmedia.so",
+    "libnativehelper.so",
+    "libskia.so",
+    "libssl.so",
+    "libstagefright.so",
+    "libsqlite.so",
+    "libui.so",
+    "libutils.so",
+    "libvorbisidec.so",
+    nullptr
+  };
+
+  // limit greylisting to apps targeting sdk version 23 and below
+  if (get_application_target_sdk_version() > 23) {
+    return false;
+  }
+
+  // if the library needed by a system library - implicitly assume it
+  // is greylisted
+
+  if (needed_by != nullptr && is_system_library(needed_by->get_realpath())) {
+    return true;
+  }
+
+  // if this is an absolute path - make sure it points to /system/lib(64)
+  if (name[0] == '/' && dirname(name) == kSystemLibDir) {
+    // and reduce the path to basename
+    name = basename(name);
+  }
+
+  for (size_t i = 0; kLibraryGreyList[i] != nullptr; ++i) {
+    if (strcmp(name, kLibraryGreyList[i]) == 0) {
+      return true;
+    }
+  }
+
+  return false;
+}
+// END OF WORKAROUND
+
+static const char* const* g_default_ld_paths;
+static std::vector<std::string> g_ld_preload_names;
+
+static std::vector<soinfo*> g_ld_preloads;
+
+static bool g_public_namespace_initialized;
+static soinfo_list_t g_public_namespace;
+
+int g_ld_debug_verbosity;
+abort_msg_t* g_abort_message = nullptr; // For debuggerd.
+
+#if STATS
+struct linker_stats_t {
+  int count[kRelocMax];
+};
+
+static linker_stats_t linker_stats;
+
+void count_relocation(RelocationKind kind) {
+  ++linker_stats.count[kind];
+}
+#else
+void count_relocation(RelocationKind) {
+}
+#endif
+
+#if COUNT_PAGES
+uint32_t bitmask[4096];
+#endif
+
+static void notify_gdb_of_load(soinfo* info) {
+  if (info->is_linker() || info->is_main_executable()) {
+    // gdb already knows about the linker and the main executable.
+    return;
+  }
+
+  link_map* map = &(info->link_map_head);
+
+  map->l_addr = info->load_bias;
+  // link_map l_name field is not const.
+  map->l_name = const_cast<char*>(info->get_realpath());
+  map->l_ld = info->dynamic;
+
+  CHECK(map->l_name != nullptr);
+  CHECK(map->l_name[0] != '\0');
+
+  notify_gdb_of_load(map);
+}
+
+static void notify_gdb_of_unload(soinfo* info) {
+  notify_gdb_of_unload(&(info->link_map_head));
+}
+
+LinkedListEntry<soinfo>* SoinfoListAllocator::alloc() {
+  return g_soinfo_links_allocator.alloc();
+}
+
+void SoinfoListAllocator::free(LinkedListEntry<soinfo>* entry) {
+  g_soinfo_links_allocator.free(entry);
+}
+
+LinkedListEntry<android_namespace_t>* NamespaceListAllocator::alloc() {
+  return g_namespace_list_allocator.alloc();
+}
+
+void NamespaceListAllocator::free(LinkedListEntry<android_namespace_t>* entry) {
+  g_namespace_list_allocator.free(entry);
+}
+
+static soinfo* soinfo_alloc(android_namespace_t* ns, const char* name,
+                            struct stat* file_stat, off64_t file_offset,
+                            uint32_t rtld_flags) {
+  if (strlen(name) >= PATH_MAX) {
+    DL_ERR("library name \"%s\" too long", name);
+    return nullptr;
+  }
+
+  soinfo* si = new (g_soinfo_allocator.alloc()) soinfo(ns, name, file_stat,
+                                                       file_offset, rtld_flags);
+
+  sonext->next = si;
+  sonext = si;
+
+  si->generate_handle();
+  ns->add_soinfo(si);
+
+  TRACE("name %s: allocated soinfo @ %p", name, si);
+  return si;
+}
+
+static void soinfo_free(soinfo* si) {
+  if (si == nullptr) {
+    return;
+  }
+
+  if (si->base != 0 && si->size != 0) {
+    if (!si->is_mapped_by_caller()) {
+      munmap(reinterpret_cast<void*>(si->base), si->size);
+    } else {
+      // remap the region as PROT_NONE, MAP_ANONYMOUS | MAP_NORESERVE
+      mmap(reinterpret_cast<void*>(si->base), si->size, PROT_NONE,
+           MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0);
+    }
+  }
+
+  soinfo *prev = nullptr, *trav;
+
+  TRACE("name %s: freeing soinfo @ %p", si->get_realpath(), si);
+
+  for (trav = solist; trav != nullptr; trav = trav->next) {
+    if (trav == si) {
+      break;
+    }
+    prev = trav;
+  }
+
+  if (trav == nullptr) {
+    // si was not in solist
+    DL_ERR("name \"%s\"@%p is not in solist!", si->get_realpath(), si);
+    return;
+  }
+
+  // clear links to/from si
+  si->remove_all_links();
+
+  // prev will never be null, because the first entry in solist is
+  // always the static libdl_info.
+  prev->next = si->next;
+  if (si == sonext) {
+    sonext = prev;
+  }
+
+  si->~soinfo();
+  g_soinfo_allocator.free(si);
+}
+
+static void parse_path(const char* path, const char* delimiters,
+                       std::vector<std::string>* resolved_paths) {
+  std::vector<std::string> paths;
+  split_path(path, delimiters, &paths);
+  resolve_paths(paths, resolved_paths);
+}
+
+static void parse_LD_LIBRARY_PATH(const char* path) {
+  std::vector<std::string> ld_libary_paths;
+  parse_path(path, ":", &ld_libary_paths);
+  g_default_namespace.set_ld_library_paths(std::move(ld_libary_paths));
+}
+
+static void parse_LD_PRELOAD(const char* path) {
+  g_ld_preload_names.clear();
+  if (path != nullptr) {
+    // We have historically supported ':' as well as ' ' in LD_PRELOAD.
+    g_ld_preload_names = android::base::Split(path, " :");
+    std::remove_if(g_ld_preload_names.begin(),
+                   g_ld_preload_names.end(),
+                   [] (const std::string& s) { return s.empty(); });
+  }
+}
+
+static bool realpath_fd(int fd, std::string* realpath) {
+  std::vector<char> buf(PATH_MAX), proc_self_fd(PATH_MAX);
+  __libc_format_buffer(&proc_self_fd[0], proc_self_fd.size(), "/proc/self/fd/%d", fd);
+  if (readlink(&proc_self_fd[0], &buf[0], buf.size()) == -1) {
+    PRINT("readlink(\"%s\") failed: %s [fd=%d]", &proc_self_fd[0], strerror(errno), fd);
+    return false;
+  }
+
+  *realpath = &buf[0];
+  return true;
+}
+
+#if defined(__arm__)
+
+// For a given PC, find the .so that it belongs to.
+// Returns the base address of the .ARM.exidx section
+// for that .so, and the number of 8-byte entries
+// in that section (via *pcount).
+//
+// Intended to be called by libc's __gnu_Unwind_Find_exidx().
+//
+// This function is exposed via dlfcn.cpp and libdl.so.
+_Unwind_Ptr dl_unwind_find_exidx(_Unwind_Ptr pc, int* pcount) {
+  uintptr_t addr = reinterpret_cast<uintptr_t>(pc);
+
+  for (soinfo* si = solist; si != 0; si = si->next) {
+    if ((addr >= si->base) && (addr < (si->base + si->size))) {
+        *pcount = si->ARM_exidx_count;
+        return reinterpret_cast<_Unwind_Ptr>(si->ARM_exidx);
+    }
+  }
+  *pcount = 0;
+  return nullptr;
+}
+
+#endif
+
+// Here, we only have to provide a callback to iterate across all the
+// loaded libraries. gcc_eh does the rest.
+int do_dl_iterate_phdr(int (*cb)(dl_phdr_info* info, size_t size, void* data), void* data) {
+  int rv = 0;
+  for (soinfo* si = solist; si != nullptr; si = si->next) {
+    dl_phdr_info dl_info;
+    dl_info.dlpi_addr = si->link_map_head.l_addr;
+    dl_info.dlpi_name = si->link_map_head.l_name;
+    dl_info.dlpi_phdr = si->phdr;
+    dl_info.dlpi_phnum = si->phnum;
+    rv = cb(&dl_info, sizeof(dl_phdr_info), data);
+    if (rv != 0) {
+      break;
+    }
+  }
+  return rv;
+}
+
+
+bool soinfo_do_lookup(soinfo* si_from, const char* name, const version_info* vi,
+                      soinfo** si_found_in, const soinfo_list_t& global_group,
+                      const soinfo_list_t& local_group, const ElfW(Sym)** symbol) {
+  SymbolName symbol_name(name);
+  const ElfW(Sym)* s = nullptr;
+
+  /* "This element's presence in a shared object library alters the dynamic linker's
+   * symbol resolution algorithm for references within the library. Instead of starting
+   * a symbol search with the executable file, the dynamic linker starts from the shared
+   * object itself. If the shared object fails to supply the referenced symbol, the
+   * dynamic linker then searches the executable file and other shared objects as usual."
+   *
+   * http://www.sco.com/developers/gabi/2012-12-31/ch5.dynamic.html
+   *
+   * Note that this is unlikely since static linker avoids generating
+   * relocations for -Bsymbolic linked dynamic executables.
+   */
+  if (si_from->has_DT_SYMBOLIC) {
+    DEBUG("%s: looking up %s in local scope (DT_SYMBOLIC)", si_from->get_realpath(), name);
+    if (!si_from->find_symbol_by_name(symbol_name, vi, &s)) {
+      return false;
+    }
+
+    if (s != nullptr) {
+      *si_found_in = si_from;
+    }
+  }
+
+  // 1. Look for it in global_group
+  if (s == nullptr) {
+    bool error = false;
+    global_group.visit([&](soinfo* global_si) {
+      DEBUG("%s: looking up %s in %s (from global group)",
+          si_from->get_realpath(), name, global_si->get_realpath());
+      if (!global_si->find_symbol_by_name(symbol_name, vi, &s)) {
+        error = true;
+        return false;
+      }
+
+      if (s != nullptr) {
+        *si_found_in = global_si;
+        return false;
+      }
+
+      return true;
+    });
+
+    if (error) {
+      return false;
+    }
+  }
+
+  // 2. Look for it in the local group
+  if (s == nullptr) {
+    bool error = false;
+    local_group.visit([&](soinfo* local_si) {
+      if (local_si == si_from && si_from->has_DT_SYMBOLIC) {
+        // we already did this - skip
+        return true;
+      }
+
+      DEBUG("%s: looking up %s in %s (from local group)",
+          si_from->get_realpath(), name, local_si->get_realpath());
+      if (!local_si->find_symbol_by_name(symbol_name, vi, &s)) {
+        error = true;
+        return false;
+      }
+
+      if (s != nullptr) {
+        *si_found_in = local_si;
+        return false;
+      }
+
+      return true;
+    });
+
+    if (error) {
+      return false;
+    }
+  }
+
+  if (s != nullptr) {
+    TRACE_TYPE(LOOKUP, "si %s sym %s s->st_value = %p, "
+               "found in %s, base = %p, load bias = %p",
+               si_from->get_realpath(), name, reinterpret_cast<void*>(s->st_value),
+               (*si_found_in)->get_realpath(), reinterpret_cast<void*>((*si_found_in)->base),
+               reinterpret_cast<void*>((*si_found_in)->load_bias));
+  }
+
+  *symbol = s;
+  return true;
+}
+
+class ProtectedDataGuard {
+ public:
+  ProtectedDataGuard() {
+    if (ref_count_++ == 0) {
+      protect_data(PROT_READ | PROT_WRITE);
+    }
+  }
+
+  ~ProtectedDataGuard() {
+    if (ref_count_ == 0) { // overflow
+      __libc_fatal("Too many nested calls to dlopen()");
+    }
+
+    if (--ref_count_ == 0) {
+      protect_data(PROT_READ);
+    }
+  }
+ private:
+  void protect_data(int protection) {
+    g_soinfo_allocator.protect_all(protection);
+    g_soinfo_links_allocator.protect_all(protection);
+    g_namespace_allocator.protect_all(protection);
+    g_namespace_list_allocator.protect_all(protection);
+  }
+
+  static size_t ref_count_;
+};
+
+size_t ProtectedDataGuard::ref_count_ = 0;
+
+// Each size has it's own allocator.
+template<size_t size>
+class SizeBasedAllocator {
+ public:
+  static void* alloc() {
+    return allocator_.alloc();
+  }
+
+  static void free(void* ptr) {
+    allocator_.free(ptr);
+  }
+
+ private:
+  static LinkerBlockAllocator allocator_;
+};
+
+template<size_t size>
+LinkerBlockAllocator SizeBasedAllocator<size>::allocator_(size);
+
+template<typename T>
+class TypeBasedAllocator {
+ public:
+  static T* alloc() {
+    return reinterpret_cast<T*>(SizeBasedAllocator<sizeof(T)>::alloc());
+  }
+
+  static void free(T* ptr) {
+    SizeBasedAllocator<sizeof(T)>::free(ptr);
+  }
+};
+
+class LoadTask {
+ public:
+  struct deleter_t {
+    void operator()(LoadTask* t) {
+      t->~LoadTask();
+      TypeBasedAllocator<LoadTask>::free(t);
+    }
+  };
+
+  static deleter_t deleter;
+
+  static LoadTask* create(const char* name, soinfo* needed_by,
+                          std::unordered_map<const soinfo*, ElfReader>* readers_map) {
+    LoadTask* ptr = TypeBasedAllocator<LoadTask>::alloc();
+    return new (ptr) LoadTask(name, needed_by, readers_map);
+  }
+
+  const char* get_name() const {
+    return name_;
+  }
+
+  soinfo* get_needed_by() const {
+    return needed_by_;
+  }
+
+  soinfo* get_soinfo() const {
+    return si_;
+  }
+
+  void set_soinfo(soinfo* si) {
+    si_ = si;
+  }
+
+  off64_t get_file_offset() const {
+    return file_offset_;
+  }
+
+  void set_file_offset(off64_t offset) {
+    file_offset_ = offset;
+  }
+
+  int get_fd() const {
+    return fd_;
+  }
+
+  void set_fd(int fd, bool assume_ownership) {
+    fd_ = fd;
+    close_fd_ = assume_ownership;
+  }
+
+  const android_dlextinfo* get_extinfo() const {
+    return extinfo_;
+  }
+
+  void set_extinfo(const android_dlextinfo* extinfo) {
+    extinfo_ = extinfo;
+  }
+
+  bool is_dt_needed() const {
+    return is_dt_needed_;
+  }
+
+  void set_dt_needed(bool is_dt_needed) {
+    is_dt_needed_ = is_dt_needed;
+  }
+
+  const ElfReader& get_elf_reader() const {
+    CHECK(si_ != nullptr);
+    return (*elf_readers_map_)[si_];
+  }
+
+  ElfReader& get_elf_reader() {
+    CHECK(si_ != nullptr);
+    return (*elf_readers_map_)[si_];
+  }
+
+  std::unordered_map<const soinfo*, ElfReader>* get_readers_map() {
+    return elf_readers_map_;
+  }
+
+  bool read(const char* realpath, off64_t file_size) {
+    ElfReader& elf_reader = get_elf_reader();
+    return elf_reader.Read(realpath, fd_, file_offset_, file_size);
+  }
+
+  bool load() {
+    ElfReader& elf_reader = get_elf_reader();
+    if (!elf_reader.Load(extinfo_)) {
+      return false;
+    }
+
+    si_->base = elf_reader.load_start();
+    si_->size = elf_reader.load_size();
+    si_->set_mapped_by_caller(elf_reader.is_mapped_by_caller());
+    si_->load_bias = elf_reader.load_bias();
+    si_->phnum = elf_reader.phdr_count();
+    si_->phdr = elf_reader.loaded_phdr();
+
+    return true;
+  }
+
+ private:
+  LoadTask(const char* name, soinfo* needed_by,
+           std::unordered_map<const soinfo*, ElfReader>* readers_map)
+    : name_(name), needed_by_(needed_by), si_(nullptr),
+      fd_(-1), close_fd_(false), file_offset_(0), elf_readers_map_(readers_map),
+      is_dt_needed_(false) {}
+
+  ~LoadTask() {
+    if (fd_ != -1 && close_fd_) {
+      close(fd_);
+    }
+  }
+
+  const char* name_;
+  soinfo* needed_by_;
+  soinfo* si_;
+  const android_dlextinfo* extinfo_;
+  int fd_;
+  bool close_fd_;
+  off64_t file_offset_;
+  std::unordered_map<const soinfo*, ElfReader>* elf_readers_map_;
+  // TODO(dimitry): needed by workaround for http://b/26394120 (the grey-list)
+  bool is_dt_needed_;
+  // END OF WORKAROUND
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(LoadTask);
+};
+
+LoadTask::deleter_t LoadTask::deleter;
+
+template <typename T>
+using linked_list_t = LinkedList<T, TypeBasedAllocator<LinkedListEntry<T>>>;
+
+typedef linked_list_t<soinfo> SoinfoLinkedList;
+typedef linked_list_t<const char> StringLinkedList;
+typedef std::vector<LoadTask*> LoadTaskList;
+
+
+// This function walks down the tree of soinfo dependencies
+// in breadth-first order and
+//   * calls action(soinfo* si) for each node, and
+//   * terminates walk if action returns false.
+//
+// walk_dependencies_tree returns false if walk was terminated
+// by the action and true otherwise.
+template<typename F>
+static bool walk_dependencies_tree(soinfo* root_soinfos[], size_t root_soinfos_size, F action) {
+  SoinfoLinkedList visit_list;
+  SoinfoLinkedList visited;
+
+  for (size_t i = 0; i < root_soinfos_size; ++i) {
+    visit_list.push_back(root_soinfos[i]);
+  }
+
+  soinfo* si;
+  while ((si = visit_list.pop_front()) != nullptr) {
+    if (visited.contains(si)) {
+      continue;
+    }
+
+    if (!action(si)) {
+      return false;
+    }
+
+    visited.push_back(si);
+
+    si->get_children().for_each([&](soinfo* child) {
+      visit_list.push_back(child);
+    });
+  }
+
+  return true;
+}
+
+
+static const ElfW(Sym)* dlsym_handle_lookup(soinfo* root, soinfo* skip_until,
+                                            soinfo** found, SymbolName& symbol_name,
+                                            const version_info* vi) {
+  const ElfW(Sym)* result = nullptr;
+  bool skip_lookup = skip_until != nullptr;
+
+  walk_dependencies_tree(&root, 1, [&](soinfo* current_soinfo) {
+    if (skip_lookup) {
+      skip_lookup = current_soinfo != skip_until;
+      return true;
+    }
+
+    if (!current_soinfo->find_symbol_by_name(symbol_name, vi, &result)) {
+      result = nullptr;
+      return false;
+    }
+
+    if (result != nullptr) {
+      *found = current_soinfo;
+      return false;
+    }
+
+    return true;
+  });
+
+  return result;
+}
+
+static const ElfW(Sym)* dlsym_linear_lookup(android_namespace_t* ns,
+                                            const char* name,
+                                            const version_info* vi,
+                                            soinfo** found,
+                                            soinfo* caller,
+                                            void* handle);
+
+// This is used by dlsym(3).  It performs symbol lookup only within the
+// specified soinfo object and its dependencies in breadth first order.
+static const ElfW(Sym)* dlsym_handle_lookup(soinfo* si, soinfo** found,
+                                            const char* name, const version_info* vi) {
+  // According to man dlopen(3) and posix docs in the case when si is handle
+  // of the main executable we need to search not only in the executable and its
+  // dependencies but also in all libraries loaded with RTLD_GLOBAL.
+  //
+  // Since RTLD_GLOBAL is always set for the main executable and all dt_needed shared
+  // libraries and they are loaded in breath-first (correct) order we can just execute
+  // dlsym(RTLD_DEFAULT, ...); instead of doing two stage lookup.
+  if (si == somain) {
+    return dlsym_linear_lookup(&g_default_namespace, name, vi, found, nullptr, RTLD_DEFAULT);
+  }
+
+  SymbolName symbol_name(name);
+  return dlsym_handle_lookup(si, nullptr, found, symbol_name, vi);
+}
+
+/* This is used by dlsym(3) to performs a global symbol lookup. If the
+   start value is null (for RTLD_DEFAULT), the search starts at the
+   beginning of the global solist. Otherwise the search starts at the
+   specified soinfo (for RTLD_NEXT).
+ */
+static const ElfW(Sym)* dlsym_linear_lookup(android_namespace_t* ns,
+                                            const char* name,
+                                            const version_info* vi,
+                                            soinfo** found,
+                                            soinfo* caller,
+                                            void* handle) {
+  SymbolName symbol_name(name);
+
+  auto& soinfo_list = ns->soinfo_list();
+  auto start = soinfo_list.begin();
+
+  if (handle == RTLD_NEXT) {
+    if (caller == nullptr) {
+      return nullptr;
+    } else {
+      auto it = soinfo_list.find(caller);
+      CHECK (it != soinfo_list.end());
+      start = ++it;
+    }
+  }
+
+  const ElfW(Sym)* s = nullptr;
+  for (auto it = start, end = soinfo_list.end(); it != end; ++it) {
+    soinfo* si = *it;
+    // Do not skip RTLD_LOCAL libraries in dlsym(RTLD_DEFAULT, ...)
+    // if the library is opened by application with target api level <= 22
+    // See http://b/21565766
+    if ((si->get_rtld_flags() & RTLD_GLOBAL) == 0 && si->get_target_sdk_version() > 22) {
+      continue;
+    }
+
+    if (!si->find_symbol_by_name(symbol_name, vi, &s)) {
+      return nullptr;
+    }
+
+    if (s != nullptr) {
+      *found = si;
+      break;
+    }
+  }
+
+  // If not found - use dlsym_handle_lookup for caller's
+  // local_group unless it is part of the global group in which
+  // case we already did it.
+  if (s == nullptr && caller != nullptr &&
+      (caller->get_rtld_flags() & RTLD_GLOBAL) == 0) {
+    return dlsym_handle_lookup(caller->get_local_group_root(),
+        (handle == RTLD_NEXT) ? caller : nullptr, found, symbol_name, vi);
+  }
+
+  if (s != nullptr) {
+    TRACE_TYPE(LOOKUP, "%s s->st_value = %p, found->base = %p",
+               name, reinterpret_cast<void*>(s->st_value), reinterpret_cast<void*>((*found)->base));
+  }
+
+  return s;
+}
+
+soinfo* find_containing_library(const void* p) {
+  ElfW(Addr) address = reinterpret_cast<ElfW(Addr)>(p);
+  for (soinfo* si = solist; si != nullptr; si = si->next) {
+    if (address >= si->base && address - si->base < si->size) {
+      return si;
+    }
+  }
+  return nullptr;
+}
+
+class ZipArchiveCache {
+ public:
+  ZipArchiveCache() {}
+  ~ZipArchiveCache();
+
+  bool get_or_open(const char* zip_path, ZipArchiveHandle* handle);
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ZipArchiveCache);
+
+  std::unordered_map<std::string, ZipArchiveHandle> cache_;
+};
+
+bool ZipArchiveCache::get_or_open(const char* zip_path, ZipArchiveHandle* handle) {
+  std::string key(zip_path);
+
+  auto it = cache_.find(key);
+  if (it != cache_.end()) {
+    *handle = it->second;
+    return true;
+  }
+
+  int fd = TEMP_FAILURE_RETRY(open(zip_path, O_RDONLY | O_CLOEXEC));
+  if (fd == -1) {
+    return false;
+  }
+
+  if (OpenArchiveFd(fd, "", handle) != 0) {
+    // invalid zip-file (?)
+    CloseArchive(handle);
+    close(fd);
+    return false;
+  }
+
+  cache_[key] = *handle;
+  return true;
+}
+
+ZipArchiveCache::~ZipArchiveCache() {
+  for (const auto& it : cache_) {
+    CloseArchive(it.second);
+  }
+}
+
+static int open_library_in_zipfile(ZipArchiveCache* zip_archive_cache,
+                                   const char* const input_path,
+                                   off64_t* file_offset, std::string* realpath) {
+  std::string normalized_path;
+  if (!normalize_path(input_path, &normalized_path)) {
+    return -1;
+  }
+
+  const char* const path = normalized_path.c_str();
+  TRACE("Trying zip file open from path \"%s\" -> normalized \"%s\"", input_path, path);
+
+  // Treat an '!/' separator inside a path as the separator between the name
+  // of the zip file on disk and the subdirectory to search within it.
+  // For example, if path is "foo.zip!/bar/bas/x.so", then we search for
+  // "bar/bas/x.so" within "foo.zip".
+  const char* const separator = strstr(path, kZipFileSeparator);
+  if (separator == nullptr) {
+    return -1;
+  }
+
+  char buf[512];
+  if (strlcpy(buf, path, sizeof(buf)) >= sizeof(buf)) {
+    PRINT("Warning: ignoring very long library path: %s", path);
+    return -1;
+  }
+
+  buf[separator - path] = '\0';
+
+  const char* zip_path = buf;
+  const char* file_path = &buf[separator - path + 2];
+  int fd = TEMP_FAILURE_RETRY(open(zip_path, O_RDONLY | O_CLOEXEC));
+  if (fd == -1) {
+    return -1;
+  }
+
+  ZipArchiveHandle handle;
+  if (!zip_archive_cache->get_or_open(zip_path, &handle)) {
+    // invalid zip-file (?)
+    close(fd);
+    return -1;
+  }
+
+  ZipEntry entry;
+
+  if (FindEntry(handle, ZipString(file_path), &entry) != 0) {
+    // Entry was not found.
+    close(fd);
+    return -1;
+  }
+
+  // Check if it is properly stored
+  if (entry.method != kCompressStored || (entry.offset % PAGE_SIZE) != 0) {
+    close(fd);
+    return -1;
+  }
+
+  *file_offset = entry.offset;
+
+  if (realpath_fd(fd, realpath)) {
+    *realpath += separator;
+  } else {
+    PRINT("warning: unable to get realpath for the library \"%s\". Will use given path.",
+          normalized_path.c_str());
+    *realpath = normalized_path;
+  }
+
+  return fd;
+}
+
+static bool format_path(char* buf, size_t buf_size, const char* path, const char* name) {
+  int n = __libc_format_buffer(buf, buf_size, "%s/%s", path, name);
+  if (n < 0 || n >= static_cast<int>(buf_size)) {
+    PRINT("Warning: ignoring very long library path: %s/%s", path, name);
+    return false;
+  }
+
+  return true;
+}
+
+static int open_library_on_paths(ZipArchiveCache* zip_archive_cache,
+                                 const char* name, off64_t* file_offset,
+                                 const std::vector<std::string>& paths,
+                                 std::string* realpath) {
+  for (const auto& path : paths) {
+    char buf[512];
+    if (!format_path(buf, sizeof(buf), path.c_str(), name)) {
+      continue;
+    }
+
+    int fd = -1;
+    if (strstr(buf, kZipFileSeparator) != nullptr) {
+      fd = open_library_in_zipfile(zip_archive_cache, buf, file_offset, realpath);
+    }
+
+    if (fd == -1) {
+      fd = TEMP_FAILURE_RETRY(open(buf, O_RDONLY | O_CLOEXEC));
+      if (fd != -1) {
+        *file_offset = 0;
+        if (!realpath_fd(fd, realpath)) {
+          PRINT("warning: unable to get realpath for the library \"%s\". Will use given path.", buf);
+          *realpath = buf;
+        }
+      }
+    }
+
+    if (fd != -1) {
+      return fd;
+    }
+  }
+
+  return -1;
+}
+
+static int open_library(android_namespace_t* ns,
+                        ZipArchiveCache* zip_archive_cache,
+                        const char* name, soinfo *needed_by,
+                        off64_t* file_offset, std::string* realpath) {
+  TRACE("[ opening %s ]", name);
+
+  // If the name contains a slash, we should attempt to open it directly and not search the paths.
+  if (strchr(name, '/') != nullptr) {
+    int fd = -1;
+
+    if (strstr(name, kZipFileSeparator) != nullptr) {
+      fd = open_library_in_zipfile(zip_archive_cache, name, file_offset, realpath);
+    }
+
+    if (fd == -1) {
+      fd = TEMP_FAILURE_RETRY(open(name, O_RDONLY | O_CLOEXEC));
+      if (fd != -1) {
+        *file_offset = 0;
+        if (!realpath_fd(fd, realpath)) {
+          PRINT("warning: unable to get realpath for the library \"%s\". Will use given path.", name);
+          *realpath = name;
+        }
+      }
+    }
+
+    return fd;
+  }
+
+  // Otherwise we try LD_LIBRARY_PATH first, and fall back to the default library path
+  int fd = open_library_on_paths(zip_archive_cache, name, file_offset, ns->get_ld_library_paths(), realpath);
+  if (fd == -1 && needed_by != nullptr) {
+    fd = open_library_on_paths(zip_archive_cache, name, file_offset, needed_by->get_dt_runpath(), realpath);
+    // Check if the library is accessible
+    if (fd != -1 && !ns->is_accessible(*realpath)) {
+      fd = -1;
+    }
+  }
+
+  if (fd == -1) {
+    fd = open_library_on_paths(zip_archive_cache, name, file_offset, ns->get_default_library_paths(), realpath);
+  }
+
+  // TODO(dimitry): workaround for http://b/26394120 (the grey-list)
+  if (fd == -1 && ns != &g_default_namespace && is_greylisted(name, needed_by)) {
+    // try searching for it on default_namespace default_library_path
+    fd = open_library_on_paths(zip_archive_cache, name, file_offset,
+                               g_default_namespace.get_default_library_paths(), realpath);
+  }
+  // END OF WORKAROUND
+
+  return fd;
+}
+
+static const char* fix_dt_needed(const char* dt_needed, const char* sopath __unused) {
+#if !defined(__LP64__)
+  // Work around incorrect DT_NEEDED entries for old apps: http://b/21364029
+  if (get_application_target_sdk_version() <= 22) {
+    const char* bname = basename(dt_needed);
+    if (bname != dt_needed) {
+      DL_WARN("library \"%s\" has invalid DT_NEEDED entry \"%s\"", sopath, dt_needed);
+      add_dlwarning(sopath, "invalid DT_NEEDED entry",  dt_needed);
+    }
+
+    return bname;
+  }
+#endif
+  return dt_needed;
+}
+
+template<typename F>
+static void for_each_dt_needed(const soinfo* si, F action) {
+  for (const ElfW(Dyn)* d = si->dynamic; d->d_tag != DT_NULL; ++d) {
+    if (d->d_tag == DT_NEEDED) {
+      action(fix_dt_needed(si->get_string(d->d_un.d_val), si->get_realpath()));
+    }
+  }
+}
+
+template<typename F>
+static void for_each_dt_needed(const ElfReader& elf_reader, F action) {
+  for (const ElfW(Dyn)* d = elf_reader.dynamic(); d->d_tag != DT_NULL; ++d) {
+    if (d->d_tag == DT_NEEDED) {
+      action(fix_dt_needed(elf_reader.get_string(d->d_un.d_val), elf_reader.name()));
+    }
+  }
+}
+
+static bool load_library(android_namespace_t* ns,
+                         LoadTask* task,
+                         LoadTaskList* load_tasks,
+                         int rtld_flags,
+                         const std::string& realpath) {
+  off64_t file_offset = task->get_file_offset();
+  const char* name = task->get_name();
+  const android_dlextinfo* extinfo = task->get_extinfo();
+
+  if ((file_offset % PAGE_SIZE) != 0) {
+    DL_ERR("file offset for the library \"%s\" is not page-aligned: %" PRId64, name, file_offset);
+    return false;
+  }
+  if (file_offset < 0) {
+    DL_ERR("file offset for the library \"%s\" is negative: %" PRId64, name, file_offset);
+    return false;
+  }
+
+  struct stat file_stat;
+  if (TEMP_FAILURE_RETRY(fstat(task->get_fd(), &file_stat)) != 0) {
+    DL_ERR("unable to stat file for the library \"%s\": %s", name, strerror(errno));
+    return false;
+  }
+  if (file_offset >= file_stat.st_size) {
+    DL_ERR("file offset for the library \"%s\" >= file size: %" PRId64 " >= %" PRId64,
+        name, file_offset, file_stat.st_size);
+    return false;
+  }
+
+  // Check for symlink and other situations where
+  // file can have different names, unless ANDROID_DLEXT_FORCE_LOAD is set
+  if (extinfo == nullptr || (extinfo->flags & ANDROID_DLEXT_FORCE_LOAD) == 0) {
+    auto predicate = [&](soinfo* si) {
+      return si->get_st_dev() != 0 &&
+             si->get_st_ino() != 0 &&
+             si->get_st_dev() == file_stat.st_dev &&
+             si->get_st_ino() == file_stat.st_ino &&
+             si->get_file_offset() == file_offset;
+    };
+
+    soinfo* si = ns->soinfo_list().find_if(predicate);
+
+    // check public namespace
+    if (si == nullptr) {
+      si = g_public_namespace.find_if(predicate);
+      if (si != nullptr) {
+        ns->add_soinfo(si);
+      }
+    }
+
+    if (si != nullptr) {
+      TRACE("library \"%s\" is already loaded under different name/path \"%s\" - "
+            "will return existing soinfo", name, si->get_realpath());
+      task->set_soinfo(si);
+      return true;
+    }
+  }
+
+  if ((rtld_flags & RTLD_NOLOAD) != 0) {
+    DL_ERR("library \"%s\" wasn't loaded and RTLD_NOLOAD prevented it", name);
+    return false;
+  }
+
+  if (!ns->is_accessible(realpath)) {
+    // TODO(dimitry): workaround for http://b/26394120 - the grey-list
+    const soinfo* needed_by = task->is_dt_needed() ? task->get_needed_by() : nullptr;
+    if (is_greylisted(name, needed_by)) {
+      // print warning only if needed by non-system library
+      if (needed_by == nullptr || !is_system_library(needed_by->get_realpath())) {
+        const soinfo* needed_or_dlopened_by = task->get_needed_by();
+        const char* sopath = needed_or_dlopened_by == nullptr ? "(unknown)" :
+                                                      needed_or_dlopened_by->get_realpath();
+        DL_WARN("library \"%s\" (\"%s\") needed or dlopened by \"%s\" is not accessible for the namespace \"%s\""
+                " - the access is temporarily granted as a workaround for http://b/26394120, note that the access"
+                " will be removed in future releases of Android.",
+                name, realpath.c_str(), sopath, ns->get_name());
+        add_dlwarning(sopath, "unauthorized access to",  name);
+      }
+    } else {
+      // do not load libraries if they are not accessible for the specified namespace.
+      const char* needed_or_dlopened_by = task->get_needed_by() == nullptr ?
+                                          "(unknown)" :
+                                          task->get_needed_by()->get_realpath();
+
+      DL_ERR("library \"%s\" needed or dlopened by \"%s\" is not accessible for the namespace \"%s\"",
+             name, needed_or_dlopened_by, ns->get_name());
+
+      PRINT("library \"%s\" (\"%s\") needed or dlopened by \"%s\" is not accessible for the"
+            " namespace: [name=\"%s\", ld_library_paths=\"%s\", default_library_paths=\"%s\","
+            " permitted_paths=\"%s\"]",
+            name, realpath.c_str(),
+            needed_or_dlopened_by,
+            ns->get_name(),
+            android::base::Join(ns->get_ld_library_paths(), ':').c_str(),
+            android::base::Join(ns->get_default_library_paths(), ':').c_str(),
+            android::base::Join(ns->get_permitted_paths(), ':').c_str());
+      return false;
+    }
+  }
+
+  soinfo* si = soinfo_alloc(ns, realpath.c_str(), &file_stat, file_offset, rtld_flags);
+  if (si == nullptr) {
+    return false;
+  }
+
+  task->set_soinfo(si);
+
+  // Read the ELF header and some of the segments.
+  if (!task->read(realpath.c_str(), file_stat.st_size)) {
+    soinfo_free(si);
+    task->set_soinfo(nullptr);
+    return false;
+  }
+
+  // find and set DT_RUNPATH and dt_soname
+  // Note that these field values are temporary and are
+  // going to be overwritten on soinfo::prelink_image
+  // with values from PT_LOAD segments.
+  const ElfReader& elf_reader = task->get_elf_reader();
+  for (const ElfW(Dyn)* d = elf_reader.dynamic(); d->d_tag != DT_NULL; ++d) {
+    if (d->d_tag == DT_RUNPATH) {
+      si->set_dt_runpath(elf_reader.get_string(d->d_un.d_val));
+    }
+    if (d->d_tag == DT_SONAME) {
+      si->set_soname(elf_reader.get_string(d->d_un.d_val));
+    }
+  }
+
+  for_each_dt_needed(task->get_elf_reader(), [&](const char* name) {
+    load_tasks->push_back(LoadTask::create(name, si, task->get_readers_map()));
+  });
+
+  return true;
+}
+
+static bool load_library(android_namespace_t* ns,
+                         LoadTask* task,
+                         ZipArchiveCache* zip_archive_cache,
+                         LoadTaskList* load_tasks,
+                         int rtld_flags) {
+  const char* name = task->get_name();
+  soinfo* needed_by = task->get_needed_by();
+  const android_dlextinfo* extinfo = task->get_extinfo();
+
+  off64_t file_offset;
+  std::string realpath;
+  if (extinfo != nullptr && (extinfo->flags & ANDROID_DLEXT_USE_LIBRARY_FD) != 0) {
+    file_offset = 0;
+    if ((extinfo->flags & ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET) != 0) {
+      file_offset = extinfo->library_fd_offset;
+    }
+
+    if (!realpath_fd(extinfo->library_fd, &realpath)) {
+      PRINT("warning: unable to get realpath for the library \"%s\" by extinfo->library_fd. "
+            "Will use given name.", name);
+      realpath = name;
+    }
+
+    task->set_fd(extinfo->library_fd, false);
+    task->set_file_offset(file_offset);
+    return load_library(ns, task, load_tasks, rtld_flags, realpath);
+  }
+
+  // Open the file.
+  int fd = open_library(ns, zip_archive_cache, name, needed_by, &file_offset, &realpath);
+  if (fd == -1) {
+    DL_ERR("library \"%s\" not found", name);
+    return false;
+  }
+
+  task->set_fd(fd, true);
+  task->set_file_offset(file_offset);
+
+  return load_library(ns, task, load_tasks, rtld_flags, realpath);
+}
+
+// Returns true if library was found and false in 2 cases
+// 1. (for default namespace only) The library was found but loaded under different
+//    target_sdk_version (*candidate != nullptr)
+// 2. The library was not found by soname (*candidate is nullptr)
+static bool find_loaded_library_by_soname(android_namespace_t* ns,
+                                          const char* name, soinfo** candidate) {
+  *candidate = nullptr;
+
+  // Ignore filename with path.
+  if (strchr(name, '/') != nullptr) {
+    return false;
+  }
+
+  uint32_t target_sdk_version = get_application_target_sdk_version();
+
+  return !ns->soinfo_list().visit([&](soinfo* si) {
+    const char* soname = si->get_soname();
+    if (soname != nullptr && (strcmp(name, soname) == 0)) {
+      // If the library was opened under different target sdk version
+      // skip this step and try to reopen it. The exceptions are
+      // "libdl.so" and global group. There is no point in skipping
+      // them because relocation process is going to use them
+      // in any case.
+      bool is_libdl = si == solist;
+      if (is_libdl || (si->get_dt_flags_1() & DF_1_GLOBAL) != 0 ||
+          !si->is_linked() || si->get_target_sdk_version() == target_sdk_version ||
+          ns != &g_default_namespace) {
+        *candidate = si;
+        return false;
+      } else if (*candidate == nullptr) {
+        // for the different sdk version in the default namespace
+        // remember the first library.
+        *candidate = si;
+      }
+    }
+
+    return true;
+  });
+}
+
+static bool find_library_internal(android_namespace_t* ns,
+                                  LoadTask* task,
+                                  ZipArchiveCache* zip_archive_cache,
+                                  LoadTaskList* load_tasks,
+                                  int rtld_flags) {
+  soinfo* candidate;
+
+  if (find_loaded_library_by_soname(ns, task->get_name(), &candidate)) {
+    task->set_soinfo(candidate);
+    return true;
+  }
+
+  if (ns != &g_default_namespace) {
+    // check public namespace
+    candidate = g_public_namespace.find_if([&](soinfo* si) {
+      return strcmp(task->get_name(), si->get_soname()) == 0;
+    });
+
+    if (candidate != nullptr) {
+      ns->add_soinfo(candidate);
+      task->set_soinfo(candidate);
+      return true;
+    }
+  }
+
+  // Library might still be loaded, the accurate detection
+  // of this fact is done by load_library.
+  TRACE("[ \"%s\" find_loaded_library_by_soname failed (*candidate=%s@%p). Trying harder...]",
+      task->get_name(), candidate == nullptr ? "n/a" : candidate->get_realpath(), candidate);
+
+  if (load_library(ns, task, zip_archive_cache, load_tasks, rtld_flags)) {
+    return true;
+  } else {
+    // In case we were unable to load the library but there
+    // is a candidate loaded under the same soname but different
+    // sdk level - return it anyways.
+    if (candidate != nullptr) {
+      task->set_soinfo(candidate);
+      return true;
+    }
+  }
+
+  return false;
+}
+
+static void soinfo_unload(soinfo* si);
+static void soinfo_unload(soinfo* soinfos[], size_t count);
+
+// TODO: this is slightly unusual way to construct
+// the global group for relocation. Not every RTLD_GLOBAL
+// library is included in this group for backwards-compatibility
+// reasons.
+//
+// This group consists of the main executable, LD_PRELOADs
+// and libraries with the DF_1_GLOBAL flag set.
+static soinfo_list_t make_global_group(android_namespace_t* ns) {
+  soinfo_list_t global_group;
+  ns->soinfo_list().for_each([&](soinfo* si) {
+    if ((si->get_dt_flags_1() & DF_1_GLOBAL) != 0) {
+      global_group.push_back(si);
+    }
+  });
+
+  return global_group;
+}
+
+// This function provides a list of libraries to be shared
+// by the namespace. For the default namespace this is the global
+// group (see make_global_group). For all others this is a group
+// of RTLD_GLOBAL libraries (which includes the global group from
+// the default namespace).
+static soinfo_list_t get_shared_group(android_namespace_t* ns) {
+  if (ns == &g_default_namespace) {
+    return make_global_group(ns);
+  }
+
+  soinfo_list_t shared_group;
+  ns->soinfo_list().for_each([&](soinfo* si) {
+    if ((si->get_rtld_flags() & RTLD_GLOBAL) != 0) {
+      shared_group.push_back(si);
+    }
+  });
+
+  return shared_group;
+}
+
+static void shuffle(std::vector<LoadTask*>* v) {
+  for (size_t i = 0, size = v->size(); i < size; ++i) {
+    size_t n = size - i;
+    size_t r = arc4random_uniform(n);
+    std::swap((*v)[n-1], (*v)[r]);
+  }
+}
+
+// add_as_children - add first-level loaded libraries (i.e. library_names[], but
+// not their transitive dependencies) as children of the start_with library.
+// This is false when find_libraries is called for dlopen(), when newly loaded
+// libraries must form a disjoint tree.
+static bool find_libraries(android_namespace_t* ns,
+                           soinfo* start_with,
+                           const char* const library_names[],
+                           size_t library_names_count, soinfo* soinfos[],
+                           std::vector<soinfo*>* ld_preloads,
+                           size_t ld_preloads_count, int rtld_flags,
+                           const android_dlextinfo* extinfo,
+                           bool add_as_children) {
+  // Step 0: prepare.
+  LoadTaskList load_tasks;
+  std::unordered_map<const soinfo*, ElfReader> readers_map;
+
+  for (size_t i = 0; i < library_names_count; ++i) {
+    const char* name = library_names[i];
+    load_tasks.push_back(LoadTask::create(name, start_with, &readers_map));
+  }
+
+  // Construct global_group.
+  soinfo_list_t global_group = make_global_group(ns);
+
+  // If soinfos array is null allocate one on stack.
+  // The array is needed in case of failure; for example
+  // when library_names[] = {libone.so, libtwo.so} and libone.so
+  // is loaded correctly but libtwo.so failed for some reason.
+  // In this case libone.so should be unloaded on return.
+  // See also implementation of failure_guard below.
+
+  if (soinfos == nullptr) {
+    size_t soinfos_size = sizeof(soinfo*)*library_names_count;
+    soinfos = reinterpret_cast<soinfo**>(alloca(soinfos_size));
+    memset(soinfos, 0, soinfos_size);
+  }
+
+  // list of libraries to link - see step 2.
+  size_t soinfos_count = 0;
+
+  auto scope_guard = make_scope_guard([&]() {
+    for (LoadTask* t : load_tasks) {
+      LoadTask::deleter(t);
+    }
+  });
+
+  auto failure_guard = make_scope_guard([&]() {
+    // Housekeeping
+    soinfo_unload(soinfos, soinfos_count);
+  });
+
+  ZipArchiveCache zip_archive_cache;
+
+  // Step 1: expand the list of load_tasks to include
+  // all DT_NEEDED libraries (do not load them just yet)
+  for (size_t i = 0; i<load_tasks.size(); ++i) {
+    LoadTask* task = load_tasks[i];
+    soinfo* needed_by = task->get_needed_by();
+
+    bool is_dt_needed = needed_by != nullptr && (needed_by != start_with || add_as_children);
+    task->set_extinfo(is_dt_needed ? nullptr : extinfo);
+    task->set_dt_needed(is_dt_needed);
+
+    if(!find_library_internal(ns, task, &zip_archive_cache, &load_tasks, rtld_flags)) {
+      return false;
+    }
+
+    soinfo* si = task->get_soinfo();
+
+    if (is_dt_needed) {
+      needed_by->add_child(si);
+    }
+
+    if (si->is_linked()) {
+      si->increment_ref_count();
+    }
+
+    // When ld_preloads is not null, the first
+    // ld_preloads_count libs are in fact ld_preloads.
+    if (ld_preloads != nullptr && soinfos_count < ld_preloads_count) {
+      ld_preloads->push_back(si);
+    }
+
+    if (soinfos_count < library_names_count) {
+      soinfos[soinfos_count++] = si;
+    }
+  }
+
+  // Step 2: Load libraries in random order (see b/24047022)
+  LoadTaskList load_list;
+  for (auto&& task : load_tasks) {
+    soinfo* si = task->get_soinfo();
+    auto pred = [&](const LoadTask* t) {
+      return t->get_soinfo() == si;
+    };
+
+    if (!si->is_linked() &&
+        std::find_if(load_list.begin(), load_list.end(), pred) == load_list.end() ) {
+      load_list.push_back(task);
+    }
+  }
+  shuffle(&load_list);
+
+  for (auto&& task : load_list) {
+    if (!task->load()) {
+      return false;
+    }
+  }
+
+  // Step 3: pre-link all DT_NEEDED libraries in breadth first order.
+  for (auto&& task : load_tasks) {
+    soinfo* si = task->get_soinfo();
+    if (!si->is_linked() && !si->prelink_image()) {
+      return false;
+    }
+  }
+
+  // Step 4: Add LD_PRELOADed libraries to the global group for
+  // future runs. There is no need to explicitly add them to
+  // the global group for this run because they are going to
+  // appear in the local group in the correct order.
+  if (ld_preloads != nullptr) {
+    for (auto&& si : *ld_preloads) {
+      si->set_dt_flags_1(si->get_dt_flags_1() | DF_1_GLOBAL);
+    }
+  }
+
+
+  // Step 5: link libraries.
+  soinfo_list_t local_group;
+  walk_dependencies_tree(
+      (start_with != nullptr && add_as_children) ? &start_with : soinfos,
+      (start_with != nullptr && add_as_children) ? 1 : soinfos_count,
+      [&] (soinfo* si) {
+    local_group.push_back(si);
+    return true;
+  });
+
+  // We need to increment ref_count in case
+  // the root of the local group was not linked.
+  bool was_local_group_root_linked = local_group.front()->is_linked();
+
+  bool linked = local_group.visit([&](soinfo* si) {
+    if (!si->is_linked()) {
+      if (!si->link_image(global_group, local_group, extinfo)) {
+        return false;
+      }
+    }
+
+    return true;
+  });
+
+  if (linked) {
+    local_group.for_each([](soinfo* si) {
+      if (!si->is_linked()) {
+        si->set_linked();
+      }
+    });
+
+    failure_guard.disable();
+  }
+
+  if (!was_local_group_root_linked) {
+    local_group.front()->increment_ref_count();
+  }
+
+  return linked;
+}
+
+static soinfo* find_library(android_namespace_t* ns,
+                            const char* name, int rtld_flags,
+                            const android_dlextinfo* extinfo,
+                            soinfo* needed_by) {
+  soinfo* si;
+
+  if (name == nullptr) {
+    si = somain;
+  } else if (!find_libraries(ns, needed_by, &name, 1, &si, nullptr, 0, rtld_flags,
+                             extinfo, /* add_as_children */ false)) {
+    return nullptr;
+  }
+
+  return si;
+}
+
+static void soinfo_unload(soinfo* root) {
+  if (root->is_linked()) {
+    root = root->get_local_group_root();
+  }
+
+  if (!root->can_unload()) {
+    TRACE("not unloading \"%s\" - the binary is flagged with NODELETE", root->get_realpath());
+    return;
+  }
+
+  soinfo_unload(&root, 1);
+}
+
+static void soinfo_unload(soinfo* soinfos[], size_t count) {
+  // Note that the library can be loaded but not linked;
+  // in which case there is no root but we still need
+  // to walk the tree and unload soinfos involved.
+  //
+  // This happens on unsuccessful dlopen, when one of
+  // the DT_NEEDED libraries could not be linked/found.
+  if (count == 0) {
+    return;
+  }
+
+  soinfo_list_t unload_list;
+  for (size_t i = 0; i < count; ++i) {
+    soinfo* si = soinfos[i];
+
+    if (si->can_unload()) {
+      size_t ref_count = si->is_linked() ? si->decrement_ref_count() : 0;
+      if (ref_count == 0) {
+        unload_list.push_back(si);
+      } else {
+        TRACE("not unloading '%s' group, decrementing ref_count to %zd",
+            si->get_realpath(), ref_count);
+      }
+    } else {
+      TRACE("not unloading '%s' - the binary is flagged with NODELETE", si->get_realpath());
+      return;
+    }
+  }
+
+  // This is used to identify soinfos outside of the load-group
+  // note that we cannot have > 1 in the array and have any of them
+  // linked. This is why we can safely use the first one.
+  soinfo* root = soinfos[0];
+
+  soinfo_list_t local_unload_list;
+  soinfo_list_t external_unload_list;
+  soinfo* si = nullptr;
+
+  while ((si = unload_list.pop_front()) != nullptr) {
+    if (local_unload_list.contains(si)) {
+      continue;
+    }
+
+    local_unload_list.push_back(si);
+
+    if (si->has_min_version(0)) {
+      soinfo* child = nullptr;
+      while ((child = si->get_children().pop_front()) != nullptr) {
+        TRACE("%s@%p needs to unload %s@%p", si->get_realpath(), si,
+            child->get_realpath(), child);
+
+        if (local_unload_list.contains(child)) {
+          continue;
+        } else if (child->is_linked() && child->get_local_group_root() != root) {
+          external_unload_list.push_back(child);
+        } else {
+          unload_list.push_front(child);
+        }
+      }
+    } else {
+#if !defined(__work_around_b_24465209__)
+      __libc_fatal("soinfo for \"%s\"@%p has no version", si->get_realpath(), si);
+#else
+      PRINT("warning: soinfo for \"%s\"@%p has no version", si->get_realpath(), si);
+      for_each_dt_needed(si, [&] (const char* library_name) {
+        TRACE("deprecated (old format of soinfo): %s needs to unload %s",
+            si->get_realpath(), library_name);
+
+        soinfo* needed = find_library(si->get_primary_namespace(),
+                                      library_name, RTLD_NOLOAD, nullptr, nullptr);
+
+        if (needed != nullptr) {
+          // Not found: for example if symlink was deleted between dlopen and dlclose
+          // Since we cannot really handle errors at this point - print and continue.
+          PRINT("warning: couldn't find %s needed by %s on unload.",
+              library_name, si->get_realpath());
+          return;
+        } else if (local_unload_list.contains(needed)) {
+          // already visited
+          return;
+        } else if (needed->is_linked() && needed->get_local_group_root() != root) {
+          // external group
+          external_unload_list.push_back(needed);
+        } else {
+          // local group
+          unload_list.push_front(needed);
+        }
+      });
+#endif
+    }
+  }
+
+  local_unload_list.for_each([](soinfo* si) {
+    si->call_destructors();
+  });
+
+  while ((si = local_unload_list.pop_front()) != nullptr) {
+    notify_gdb_of_unload(si);
+    soinfo_free(si);
+  }
+
+  while ((si = external_unload_list.pop_front()) != nullptr) {
+    soinfo_unload(si);
+  }
+}
+
+static std::string symbol_display_name(const char* sym_name, const char* sym_ver) {
+  if (sym_ver == nullptr) {
+    return sym_name;
+  }
+
+  return std::string(sym_name) + ", version " + sym_ver;
+}
+
+static android_namespace_t* get_caller_namespace(soinfo* caller) {
+  return caller != nullptr ? caller->get_primary_namespace() : g_anonymous_namespace;
+}
+
+void do_android_get_LD_LIBRARY_PATH(char* buffer, size_t buffer_size) {
+  // Use basic string manipulation calls to avoid snprintf.
+  // snprintf indirectly calls pthread_getspecific to get the size of a buffer.
+  // When debug malloc is enabled, this call returns 0. This in turn causes
+  // snprintf to do nothing, which causes libraries to fail to load.
+  // See b/17302493 for further details.
+  // Once the above bug is fixed, this code can be modified to use
+  // snprintf again.
+  size_t required_len = 0;
+  for (size_t i = 0; g_default_ld_paths[i] != nullptr; ++i) {
+    required_len += strlen(g_default_ld_paths[i]) + 1;
+  }
+  if (buffer_size < required_len) {
+    __libc_fatal("android_get_LD_LIBRARY_PATH failed, buffer too small: "
+                 "buffer len %zu, required len %zu", buffer_size, required_len);
+  }
+  char* end = buffer;
+  for (size_t i = 0; g_default_ld_paths[i] != nullptr; ++i) {
+    if (i > 0) *end++ = ':';
+    end = stpcpy(end, g_default_ld_paths[i]);
+  }
+}
+
+void do_android_update_LD_LIBRARY_PATH(const char* ld_library_path) {
+  parse_LD_LIBRARY_PATH(ld_library_path);
+}
+
+static std::string android_dlextinfo_to_string(const android_dlextinfo* info) {
+  if (info == nullptr) {
+    return "(null)";
+  }
+
+  return android::base::StringPrintf("[flags=0x%" PRIx64 ","
+                                     " reserved_addr=%p,"
+                                     " reserved_size=0x%zx,"
+                                     " relro_fd=%d,"
+                                     " library_fd=%d,"
+                                     " library_fd_offset=0x%" PRIx64 ","
+                                     " library_namespace=%s@%p]",
+                                     info->flags,
+                                     info->reserved_addr,
+                                     info->reserved_size,
+                                     info->relro_fd,
+                                     info->library_fd,
+                                     info->library_fd_offset,
+                                     (info->flags & ANDROID_DLEXT_USE_NAMESPACE) != 0 ?
+                                        (info->library_namespace != nullptr ?
+                                          info->library_namespace->get_name() : "(null)") : "(n/a)",
+                                     (info->flags & ANDROID_DLEXT_USE_NAMESPACE) != 0 ?
+                                        info->library_namespace : nullptr);
+}
+
+void* do_dlopen(const char* name, int flags, const android_dlextinfo* extinfo,
+                  void* caller_addr) {
+  soinfo* const caller = find_containing_library(caller_addr);
+  android_namespace_t* ns = get_caller_namespace(caller);
+
+  LD_LOG(kLogDlopen,
+         "dlopen(name=\"%s\", flags=0x%x, extinfo=%s, caller=\"%s\", caller_ns=%s@%p) ...",
+         name,
+         flags,
+         android_dlextinfo_to_string(extinfo).c_str(),
+         caller == nullptr ? "(null)" : caller->get_realpath(),
+         ns == nullptr ? "(null)" : ns->get_name(),
+         ns);
+
+  auto failure_guard = make_scope_guard([&]() {
+    LD_LOG(kLogDlopen, "... dlopen failed: %s", linker_get_error_buffer());
+  });
+
+  if ((flags & ~(RTLD_NOW|RTLD_LAZY|RTLD_LOCAL|RTLD_GLOBAL|RTLD_NODELETE|RTLD_NOLOAD)) != 0) {
+    DL_ERR("invalid flags to dlopen: %x", flags);
+    return nullptr;
+  }
+
+  if (extinfo != nullptr) {
+    if ((extinfo->flags & ~(ANDROID_DLEXT_VALID_FLAG_BITS)) != 0) {
+      DL_ERR("invalid extended flags to android_dlopen_ext: 0x%" PRIx64, extinfo->flags);
+      return nullptr;
+    }
+
+    if ((extinfo->flags & ANDROID_DLEXT_USE_LIBRARY_FD) == 0 &&
+        (extinfo->flags & ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET) != 0) {
+      DL_ERR("invalid extended flag combination (ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET without "
+          "ANDROID_DLEXT_USE_LIBRARY_FD): 0x%" PRIx64, extinfo->flags);
+      return nullptr;
+    }
+
+    if ((extinfo->flags & ANDROID_DLEXT_LOAD_AT_FIXED_ADDRESS) != 0 &&
+        (extinfo->flags & (ANDROID_DLEXT_RESERVED_ADDRESS | ANDROID_DLEXT_RESERVED_ADDRESS_HINT)) != 0) {
+      DL_ERR("invalid extended flag combination: ANDROID_DLEXT_LOAD_AT_FIXED_ADDRESS is not "
+             "compatible with ANDROID_DLEXT_RESERVED_ADDRESS/ANDROID_DLEXT_RESERVED_ADDRESS_HINT");
+      return nullptr;
+    }
+
+    if ((extinfo->flags & ANDROID_DLEXT_USE_NAMESPACE) != 0) {
+      if (extinfo->library_namespace == nullptr) {
+        DL_ERR("ANDROID_DLEXT_USE_NAMESPACE is set but extinfo->library_namespace is null");
+        return nullptr;
+      }
+      ns = extinfo->library_namespace;
+    }
+  }
+
+  std::string asan_name_holder;
+
+  const char* translated_name = name;
+  if (g_is_asan) {
+    if (file_is_in_dir(name, kSystemLibDir)) {
+      asan_name_holder = std::string(kAsanSystemLibDir) + "/" + basename(name);
+      if (file_exists(asan_name_holder.c_str())) {
+        translated_name = asan_name_holder.c_str();
+        PRINT("linker_asan dlopen translating \"%s\" -> \"%s\"", name, translated_name);
+      }
+    } else if (file_is_in_dir(name, kVendorLibDir)) {
+      asan_name_holder = std::string(kAsanVendorLibDir) + "/" + basename(name);
+      if (file_exists(asan_name_holder.c_str())) {
+        translated_name = asan_name_holder.c_str();
+        PRINT("linker_asan dlopen translating \"%s\" -> \"%s\"", name, translated_name);
+      }
+    }
+  }
+
+  ProtectedDataGuard guard;
+  soinfo* si = find_library(ns, translated_name, flags, extinfo, caller);
+  if (si != nullptr) {
+    failure_guard.disable();
+    si->call_constructors();
+    void* handle = si->to_handle();
+    LD_LOG(kLogDlopen,
+           "... dlopen successful: realpath=\"%s\", soname=\"%s\", handle=%p",
+           si->get_realpath(), si->get_soname(), handle);
+    return handle;
+  }
+
+  return nullptr;
+}
+
+int do_dladdr(const void* addr, Dl_info* info) {
+  // Determine if this address can be found in any library currently mapped.
+  soinfo* si = find_containing_library(addr);
+  if (si == nullptr) {
+    return 0;
+  }
+
+  memset(info, 0, sizeof(Dl_info));
+
+  info->dli_fname = si->get_realpath();
+  // Address at which the shared object is loaded.
+  info->dli_fbase = reinterpret_cast<void*>(si->base);
+
+  // Determine if any symbol in the library contains the specified address.
+  ElfW(Sym)* sym = si->find_symbol_by_address(addr);
+  if (sym != nullptr) {
+    info->dli_sname = si->get_string(sym->st_name);
+    info->dli_saddr = reinterpret_cast<void*>(si->resolve_symbol_address(sym));
+  }
+
+  return 1;
+}
+
+static soinfo* soinfo_from_handle(void* handle) {
+  if ((reinterpret_cast<uintptr_t>(handle) & 1) != 0) {
+    auto it = g_soinfo_handles_map.find(reinterpret_cast<uintptr_t>(handle));
+    if (it == g_soinfo_handles_map.end()) {
+      return nullptr;
+    } else {
+      return it->second;
+    }
+  }
+
+  return static_cast<soinfo*>(handle);
+}
+
+bool do_dlsym(void* handle, const char* sym_name, const char* sym_ver,
+              void* caller_addr, void** symbol) {
+#if !defined(__LP64__)
+  if (handle == nullptr) {
+    DL_ERR("dlsym failed: library handle is null");
+    return false;
+  }
+#endif
+
+  if (sym_name == nullptr) {
+    DL_ERR("dlsym failed: symbol name is null");
+    return false;
+  }
+
+  soinfo* found = nullptr;
+  const ElfW(Sym)* sym = nullptr;
+  soinfo* caller = find_containing_library(caller_addr);
+  android_namespace_t* ns = get_caller_namespace(caller);
+
+  version_info vi_instance;
+  version_info* vi = nullptr;
+
+  if (sym_ver != nullptr) {
+    vi_instance.name = sym_ver;
+    vi_instance.elf_hash = calculate_elf_hash(sym_ver);
+    vi = &vi_instance;
+  }
+
+  if (handle == RTLD_DEFAULT || handle == RTLD_NEXT) {
+    sym = dlsym_linear_lookup(ns, sym_name, vi, &found, caller, handle);
+  } else {
+    soinfo* si = soinfo_from_handle(handle);
+    if (si == nullptr) {
+      DL_ERR("dlsym failed: invalid handle: %p", handle);
+      return false;
+    }
+    sym = dlsym_handle_lookup(si, &found, sym_name, vi);
+  }
+
+  if (sym != nullptr) {
+    uint32_t bind = ELF_ST_BIND(sym->st_info);
+
+    if ((bind == STB_GLOBAL || bind == STB_WEAK) && sym->st_shndx != 0) {
+      *symbol = reinterpret_cast<void*>(found->resolve_symbol_address(sym));
+      return true;
+    }
+
+    DL_ERR("symbol \"%s\" found but not global", symbol_display_name(sym_name, sym_ver).c_str());
+    return false;
+  }
+
+  DL_ERR("undefined symbol: %s", symbol_display_name(sym_name, sym_ver).c_str());
+  return false;
+}
+
+int do_dlclose(void* handle) {
+  ProtectedDataGuard guard;
+  soinfo* si = soinfo_from_handle(handle);
+  if (si == nullptr) {
+    DL_ERR("invalid handle: %p", handle);
+    return -1;
+  }
+
+  soinfo_unload(si);
+  return 0;
+}
+
+bool init_namespaces(const char* public_ns_sonames, const char* anon_ns_library_path) {
+  if (g_public_namespace_initialized) {
+    DL_ERR("public namespace has already been initialized.");
+    return false;
+  }
+
+  if (public_ns_sonames == nullptr || public_ns_sonames[0] == '\0') {
+    DL_ERR("error initializing public namespace: the list of public libraries is empty.");
+    return false;
+  }
+
+  std::vector<std::string> sonames = android::base::Split(public_ns_sonames, ":");
+
+  ProtectedDataGuard guard;
+
+  auto failure_guard = make_scope_guard([&]() {
+    g_public_namespace.clear();
+  });
+
+  for (const auto& soname : sonames) {
+    soinfo* candidate = nullptr;
+
+    find_loaded_library_by_soname(&g_default_namespace, soname.c_str(), &candidate);
+
+    if (candidate == nullptr) {
+      DL_ERR("error initializing public namespace: a library with soname \"%s\""
+             " was not found in the default namespace", soname.c_str());
+      return false;
+    }
+
+    candidate->set_nodelete();
+    g_public_namespace.push_back(candidate);
+  }
+
+  g_public_namespace_initialized = true;
+
+  // create anonymous namespace
+  // When the caller is nullptr - create_namespace will take global group
+  // from the anonymous namespace, which is fine because anonymous namespace
+  // is still pointing to the default one.
+  android_namespace_t* anon_ns =
+      create_namespace(nullptr, "(anonymous)", nullptr, anon_ns_library_path,
+                       ANDROID_NAMESPACE_TYPE_REGULAR, nullptr, &g_default_namespace);
+
+  if (anon_ns == nullptr) {
+    g_public_namespace_initialized = false;
+    return false;
+  }
+  g_anonymous_namespace = anon_ns;
+  failure_guard.disable();
+  return true;
+}
+
+static void add_soinfos_to_namespace(const soinfo_list_t& soinfos, android_namespace_t* ns) {
+  ns->add_soinfos(soinfos);
+  for (auto si : soinfos) {
+    si->add_secondary_namespace(ns);
+  }
+}
+
+android_namespace_t* create_namespace(const void* caller_addr,
+                                      const char* name,
+                                      const char* ld_library_path,
+                                      const char* default_library_path,
+                                      uint64_t type,
+                                      const char* permitted_when_isolated_path,
+                                      android_namespace_t* parent_namespace) {
+  if (!g_public_namespace_initialized) {
+    DL_ERR("cannot create namespace: public namespace is not initialized.");
+    return nullptr;
+  }
+
+  if (parent_namespace == nullptr) {
+    // if parent_namespace is nullptr -> set it to the caller namespace
+    soinfo* caller_soinfo = find_containing_library(caller_addr);
+
+    parent_namespace = caller_soinfo != nullptr ?
+                       caller_soinfo->get_primary_namespace() :
+                       g_anonymous_namespace;
+  }
+
+  ProtectedDataGuard guard;
+  std::vector<std::string> ld_library_paths;
+  std::vector<std::string> default_library_paths;
+  std::vector<std::string> permitted_paths;
+
+  parse_path(ld_library_path, ":", &ld_library_paths);
+  parse_path(default_library_path, ":", &default_library_paths);
+  parse_path(permitted_when_isolated_path, ":", &permitted_paths);
+
+  android_namespace_t* ns = new (g_namespace_allocator.alloc()) android_namespace_t();
+  ns->set_name(name);
+  ns->set_isolated((type & ANDROID_NAMESPACE_TYPE_ISOLATED) != 0);
+  ns->set_ld_library_paths(std::move(ld_library_paths));
+  ns->set_default_library_paths(std::move(default_library_paths));
+  ns->set_permitted_paths(std::move(permitted_paths));
+
+  if ((type & ANDROID_NAMESPACE_TYPE_SHARED) != 0) {
+    // If shared - clone the parent namespace
+    add_soinfos_to_namespace(parent_namespace->soinfo_list(), ns);
+  } else {
+    // If not shared - copy only the shared group
+    add_soinfos_to_namespace(get_shared_group(parent_namespace), ns);
+  }
+
+  return ns;
+}
+
+ElfW(Addr) call_ifunc_resolver(ElfW(Addr) resolver_addr) {
+  typedef ElfW(Addr) (*ifunc_resolver_t)(void);
+  ifunc_resolver_t ifunc_resolver = reinterpret_cast<ifunc_resolver_t>(resolver_addr);
+  ElfW(Addr) ifunc_addr = ifunc_resolver();
+  TRACE_TYPE(RELO, "Called ifunc_resolver@%p. The result is %p",
+      ifunc_resolver, reinterpret_cast<void*>(ifunc_addr));
+
+  return ifunc_addr;
+}
+
+const version_info* VersionTracker::get_version_info(ElfW(Versym) source_symver) const {
+  if (source_symver < 2 ||
+      source_symver >= version_infos.size() ||
+      version_infos[source_symver].name == nullptr) {
+    return nullptr;
+  }
+
+  return &version_infos[source_symver];
+}
+
+void VersionTracker::add_version_info(size_t source_index,
+                                      ElfW(Word) elf_hash,
+                                      const char* ver_name,
+                                      const soinfo* target_si) {
+  if (source_index >= version_infos.size()) {
+    version_infos.resize(source_index+1);
+  }
+
+  version_infos[source_index].elf_hash = elf_hash;
+  version_infos[source_index].name = ver_name;
+  version_infos[source_index].target_si = target_si;
+}
+
+bool VersionTracker::init_verneed(const soinfo* si_from) {
+  uintptr_t verneed_ptr = si_from->get_verneed_ptr();
+
+  if (verneed_ptr == 0) {
+    return true;
+  }
+
+  size_t verneed_cnt = si_from->get_verneed_cnt();
+
+  for (size_t i = 0, offset = 0; i<verneed_cnt; ++i) {
+    const ElfW(Verneed)* verneed = reinterpret_cast<ElfW(Verneed)*>(verneed_ptr + offset);
+    size_t vernaux_offset = offset + verneed->vn_aux;
+    offset += verneed->vn_next;
+
+    if (verneed->vn_version != 1) {
+      DL_ERR("unsupported verneed[%zd] vn_version: %d (expected 1)", i, verneed->vn_version);
+      return false;
+    }
+
+    const char* target_soname = si_from->get_string(verneed->vn_file);
+    // find it in dependencies
+    soinfo* target_si = si_from->get_children().find_if([&](const soinfo* si) {
+      return si->get_soname() != nullptr && strcmp(si->get_soname(), target_soname) == 0;
+    });
+
+    if (target_si == nullptr) {
+      DL_ERR("cannot find \"%s\" from verneed[%zd] in DT_NEEDED list for \"%s\"",
+          target_soname, i, si_from->get_realpath());
+      return false;
+    }
+
+    for (size_t j = 0; j<verneed->vn_cnt; ++j) {
+      const ElfW(Vernaux)* vernaux = reinterpret_cast<ElfW(Vernaux)*>(verneed_ptr + vernaux_offset);
+      vernaux_offset += vernaux->vna_next;
+
+      const ElfW(Word) elf_hash = vernaux->vna_hash;
+      const char* ver_name = si_from->get_string(vernaux->vna_name);
+      ElfW(Half) source_index = vernaux->vna_other;
+
+      add_version_info(source_index, elf_hash, ver_name, target_si);
+    }
+  }
+
+  return true;
+}
+
+template <typename F>
+static bool for_each_verdef(const soinfo* si, F functor) {
+  if (!si->has_min_version(2)) {
+    return true;
+  }
+
+  uintptr_t verdef_ptr = si->get_verdef_ptr();
+  if (verdef_ptr == 0) {
+    return true;
+  }
+
+  size_t offset = 0;
+
+  size_t verdef_cnt = si->get_verdef_cnt();
+  for (size_t i = 0; i<verdef_cnt; ++i) {
+    const ElfW(Verdef)* verdef = reinterpret_cast<ElfW(Verdef)*>(verdef_ptr + offset);
+    size_t verdaux_offset = offset + verdef->vd_aux;
+    offset += verdef->vd_next;
+
+    if (verdef->vd_version != 1) {
+      DL_ERR("unsupported verdef[%zd] vd_version: %d (expected 1) library: %s",
+          i, verdef->vd_version, si->get_realpath());
+      return false;
+    }
+
+    if ((verdef->vd_flags & VER_FLG_BASE) != 0) {
+      // "this is the version of the file itself.  It must not be used for
+      //  matching a symbol. It can be used to match references."
+      //
+      // http://www.akkadia.org/drepper/symbol-versioning
+      continue;
+    }
+
+    if (verdef->vd_cnt == 0) {
+      DL_ERR("invalid verdef[%zd] vd_cnt == 0 (version without a name)", i);
+      return false;
+    }
+
+    const ElfW(Verdaux)* verdaux = reinterpret_cast<ElfW(Verdaux)*>(verdef_ptr + verdaux_offset);
+
+    if (functor(i, verdef, verdaux) == true) {
+      break;
+    }
+  }
+
+  return true;
+}
+
+bool find_verdef_version_index(const soinfo* si, const version_info* vi, ElfW(Versym)* versym) {
+  if (vi == nullptr) {
+    *versym = kVersymNotNeeded;
+    return true;
+  }
+
+  *versym = kVersymGlobal;
+
+  return for_each_verdef(si,
+    [&](size_t, const ElfW(Verdef)* verdef, const ElfW(Verdaux)* verdaux) {
+      if (verdef->vd_hash == vi->elf_hash &&
+          strcmp(vi->name, si->get_string(verdaux->vda_name)) == 0) {
+        *versym = verdef->vd_ndx;
+        return true;
+      }
+
+      return false;
+    }
+  );
+}
+
+bool VersionTracker::init_verdef(const soinfo* si_from) {
+  return for_each_verdef(si_from,
+    [&](size_t, const ElfW(Verdef)* verdef, const ElfW(Verdaux)* verdaux) {
+      add_version_info(verdef->vd_ndx, verdef->vd_hash,
+          si_from->get_string(verdaux->vda_name), si_from);
+      return false;
+    }
+  );
+}
+
+bool VersionTracker::init(const soinfo* si_from) {
+  if (!si_from->has_min_version(2)) {
+    return true;
+  }
+
+  return init_verneed(si_from) && init_verdef(si_from);
+}
+
+// TODO (dimitry): Methods below need to be moved out of soinfo
+// and in more isolated file in order minimize dependencies on
+// unnecessary object in the linker binary. Consider making them
+// independent from soinfo (?).
+bool soinfo::lookup_version_info(const VersionTracker& version_tracker, ElfW(Word) sym,
+                                 const char* sym_name, const version_info** vi) {
+  const ElfW(Versym)* sym_ver_ptr = get_versym(sym);
+  ElfW(Versym) sym_ver = sym_ver_ptr == nullptr ? 0 : *sym_ver_ptr;
+
+  if (sym_ver != VER_NDX_LOCAL && sym_ver != VER_NDX_GLOBAL) {
+    *vi = version_tracker.get_version_info(sym_ver);
+
+    if (*vi == nullptr) {
+      DL_ERR("cannot find verneed/verdef for version index=%d "
+          "referenced by symbol \"%s\" at \"%s\"", sym_ver, sym_name, get_realpath());
+      return false;
+    }
+  } else {
+    // there is no version info
+    *vi = nullptr;
+  }
+
+  return true;
+}
+
+#if !defined(__mips__)
+#if defined(USE_RELA)
+static ElfW(Addr) get_addend(ElfW(Rela)* rela, ElfW(Addr) reloc_addr __unused) {
+  return rela->r_addend;
+}
+#else
+static ElfW(Addr) get_addend(ElfW(Rel)* rel, ElfW(Addr) reloc_addr) {
+  if (ELFW(R_TYPE)(rel->r_info) == R_GENERIC_RELATIVE ||
+      ELFW(R_TYPE)(rel->r_info) == R_GENERIC_IRELATIVE) {
+    return *reinterpret_cast<ElfW(Addr)*>(reloc_addr);
+  }
+  return 0;
+}
+#endif
+
+template<typename ElfRelIteratorT>
+bool soinfo::relocate(const VersionTracker& version_tracker, ElfRelIteratorT&& rel_iterator,
+                      const soinfo_list_t& global_group, const soinfo_list_t& local_group) {
+  for (size_t idx = 0; rel_iterator.has_next(); ++idx) {
+    const auto rel = rel_iterator.next();
+    if (rel == nullptr) {
+      return false;
+    }
+
+    ElfW(Word) type = ELFW(R_TYPE)(rel->r_info);
+    ElfW(Word) sym = ELFW(R_SYM)(rel->r_info);
+
+    ElfW(Addr) reloc = static_cast<ElfW(Addr)>(rel->r_offset + load_bias);
+    ElfW(Addr) sym_addr = 0;
+    const char* sym_name = nullptr;
+    ElfW(Addr) addend = get_addend(rel, reloc);
+
+    DEBUG("Processing \"%s\" relocation at index %zd", get_realpath(), idx);
+    if (type == R_GENERIC_NONE) {
+      continue;
+    }
+
+    const ElfW(Sym)* s = nullptr;
+    soinfo* lsi = nullptr;
+
+    if (sym != 0) {
+      sym_name = get_string(symtab_[sym].st_name);
+      const version_info* vi = nullptr;
+
+      if (!lookup_version_info(version_tracker, sym, sym_name, &vi)) {
+        return false;
+      }
+
+      if (!soinfo_do_lookup(this, sym_name, vi, &lsi, global_group, local_group, &s)) {
+        return false;
+      }
+
+      if (s == nullptr) {
+        // We only allow an undefined symbol if this is a weak reference...
+        s = &symtab_[sym];
+        if (ELF_ST_BIND(s->st_info) != STB_WEAK) {
+          DL_ERR("cannot locate symbol \"%s\" referenced by \"%s\"...", sym_name, get_realpath());
+          return false;
+        }
+
+        /* IHI0044C AAELF 4.5.1.1:
+
+           Libraries are not searched to resolve weak references.
+           It is not an error for a weak reference to remain unsatisfied.
+
+           During linking, the value of an undefined weak reference is:
+           - Zero if the relocation type is absolute
+           - The address of the place if the relocation is pc-relative
+           - The address of nominal base address if the relocation
+             type is base-relative.
+         */
+
+        switch (type) {
+          case R_GENERIC_JUMP_SLOT:
+          case R_GENERIC_GLOB_DAT:
+          case R_GENERIC_RELATIVE:
+          case R_GENERIC_IRELATIVE:
+#if defined(__aarch64__)
+          case R_AARCH64_ABS64:
+          case R_AARCH64_ABS32:
+          case R_AARCH64_ABS16:
+#elif defined(__x86_64__)
+          case R_X86_64_32:
+          case R_X86_64_64:
+#elif defined(__arm__)
+          case R_ARM_ABS32:
+#elif defined(__i386__)
+          case R_386_32:
+#endif
+            /*
+             * The sym_addr was initialized to be zero above, or the relocation
+             * code below does not care about value of sym_addr.
+             * No need to do anything.
+             */
+            break;
+#if defined(__x86_64__)
+          case R_X86_64_PC32:
+            sym_addr = reloc;
+            break;
+#elif defined(__i386__)
+          case R_386_PC32:
+            sym_addr = reloc;
+            break;
+#endif
+          default:
+            DL_ERR("unknown weak reloc type %d @ %p (%zu)", type, rel, idx);
+            return false;
+        }
+      } else { // We got a definition.
+#if !defined(__LP64__)
+        // When relocating dso with text_relocation .text segment is
+        // not executable. We need to restore elf flags before resolving
+        // STT_GNU_IFUNC symbol.
+        bool protect_segments = has_text_relocations &&
+                                lsi == this &&
+                                ELF_ST_TYPE(s->st_info) == STT_GNU_IFUNC;
+        if (protect_segments) {
+          if (phdr_table_protect_segments(phdr, phnum, load_bias) < 0) {
+            DL_ERR("can't protect segments for \"%s\": %s",
+                   get_realpath(), strerror(errno));
+            return false;
+          }
+        }
+#endif
+        sym_addr = lsi->resolve_symbol_address(s);
+#if !defined(__LP64__)
+        if (protect_segments) {
+          if (phdr_table_unprotect_segments(phdr, phnum, load_bias) < 0) {
+            DL_ERR("can't unprotect loadable segments for \"%s\": %s",
+                   get_realpath(), strerror(errno));
+            return false;
+          }
+        }
+#endif
+      }
+      count_relocation(kRelocSymbol);
+    }
+
+    switch (type) {
+      case R_GENERIC_JUMP_SLOT:
+        count_relocation(kRelocAbsolute);
+        MARK(rel->r_offset);
+        TRACE_TYPE(RELO, "RELO JMP_SLOT %16p <- %16p %s\n",
+                   reinterpret_cast<void*>(reloc),
+                   reinterpret_cast<void*>(sym_addr + addend), sym_name);
+
+        *reinterpret_cast<ElfW(Addr)*>(reloc) = (sym_addr + addend);
+        break;
+      case R_GENERIC_GLOB_DAT:
+        count_relocation(kRelocAbsolute);
+        MARK(rel->r_offset);
+        TRACE_TYPE(RELO, "RELO GLOB_DAT %16p <- %16p %s\n",
+                   reinterpret_cast<void*>(reloc),
+                   reinterpret_cast<void*>(sym_addr + addend), sym_name);
+        *reinterpret_cast<ElfW(Addr)*>(reloc) = (sym_addr + addend);
+        break;
+      case R_GENERIC_RELATIVE:
+        count_relocation(kRelocRelative);
+        MARK(rel->r_offset);
+        TRACE_TYPE(RELO, "RELO RELATIVE %16p <- %16p\n",
+                   reinterpret_cast<void*>(reloc),
+                   reinterpret_cast<void*>(load_bias + addend));
+        *reinterpret_cast<ElfW(Addr)*>(reloc) = (load_bias + addend);
+        break;
+      case R_GENERIC_IRELATIVE:
+        count_relocation(kRelocRelative);
+        MARK(rel->r_offset);
+        TRACE_TYPE(RELO, "RELO IRELATIVE %16p <- %16p\n",
+                    reinterpret_cast<void*>(reloc),
+                    reinterpret_cast<void*>(load_bias + addend));
+        {
+#if !defined(__LP64__)
+          // When relocating dso with text_relocation .text segment is
+          // not executable. We need to restore elf flags for this
+          // particular call.
+          if (has_text_relocations) {
+            if (phdr_table_protect_segments(phdr, phnum, load_bias) < 0) {
+              DL_ERR("can't protect segments for \"%s\": %s",
+                     get_realpath(), strerror(errno));
+              return false;
+            }
+          }
+#endif
+          ElfW(Addr) ifunc_addr = call_ifunc_resolver(load_bias + addend);
+#if !defined(__LP64__)
+          // Unprotect it afterwards...
+          if (has_text_relocations) {
+            if (phdr_table_unprotect_segments(phdr, phnum, load_bias) < 0) {
+              DL_ERR("can't unprotect loadable segments for \"%s\": %s",
+                     get_realpath(), strerror(errno));
+              return false;
+            }
+          }
+#endif
+          *reinterpret_cast<ElfW(Addr)*>(reloc) = ifunc_addr;
+        }
+        break;
+
+#if defined(__aarch64__)
+      case R_AARCH64_ABS64:
+        count_relocation(kRelocAbsolute);
+        MARK(rel->r_offset);
+        TRACE_TYPE(RELO, "RELO ABS64 %16llx <- %16llx %s\n",
+                   reloc, sym_addr + addend, sym_name);
+        *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr + addend;
+        break;
+      case R_AARCH64_ABS32:
+        count_relocation(kRelocAbsolute);
+        MARK(rel->r_offset);
+        TRACE_TYPE(RELO, "RELO ABS32 %16llx <- %16llx %s\n",
+                   reloc, sym_addr + addend, sym_name);
+        {
+          const ElfW(Addr) min_value = static_cast<ElfW(Addr)>(INT32_MIN);
+          const ElfW(Addr) max_value = static_cast<ElfW(Addr)>(UINT32_MAX);
+          if ((min_value <= (sym_addr + addend)) &&
+              ((sym_addr + addend) <= max_value)) {
+            *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr + addend;
+          } else {
+            DL_ERR("0x%016llx out of range 0x%016llx to 0x%016llx",
+                   sym_addr + addend, min_value, max_value);
+            return false;
+          }
+        }
+        break;
+      case R_AARCH64_ABS16:
+        count_relocation(kRelocAbsolute);
+        MARK(rel->r_offset);
+        TRACE_TYPE(RELO, "RELO ABS16 %16llx <- %16llx %s\n",
+                   reloc, sym_addr + addend, sym_name);
+        {
+          const ElfW(Addr) min_value = static_cast<ElfW(Addr)>(INT16_MIN);
+          const ElfW(Addr) max_value = static_cast<ElfW(Addr)>(UINT16_MAX);
+          if ((min_value <= (sym_addr + addend)) &&
+              ((sym_addr + addend) <= max_value)) {
+            *reinterpret_cast<ElfW(Addr)*>(reloc) = (sym_addr + addend);
+          } else {
+            DL_ERR("0x%016llx out of range 0x%016llx to 0x%016llx",
+                   sym_addr + addend, min_value, max_value);
+            return false;
+          }
+        }
+        break;
+      case R_AARCH64_PREL64:
+        count_relocation(kRelocRelative);
+        MARK(rel->r_offset);
+        TRACE_TYPE(RELO, "RELO REL64 %16llx <- %16llx - %16llx %s\n",
+                   reloc, sym_addr + addend, rel->r_offset, sym_name);
+        *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr + addend - rel->r_offset;
+        break;
+      case R_AARCH64_PREL32:
+        count_relocation(kRelocRelative);
+        MARK(rel->r_offset);
+        TRACE_TYPE(RELO, "RELO REL32 %16llx <- %16llx - %16llx %s\n",
+                   reloc, sym_addr + addend, rel->r_offset, sym_name);
+        {
+          const ElfW(Addr) min_value = static_cast<ElfW(Addr)>(INT32_MIN);
+          const ElfW(Addr) max_value = static_cast<ElfW(Addr)>(UINT32_MAX);
+          if ((min_value <= (sym_addr + addend - rel->r_offset)) &&
+              ((sym_addr + addend - rel->r_offset) <= max_value)) {
+            *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr + addend - rel->r_offset;
+          } else {
+            DL_ERR("0x%016llx out of range 0x%016llx to 0x%016llx",
+                   sym_addr + addend - rel->r_offset, min_value, max_value);
+            return false;
+          }
+        }
+        break;
+      case R_AARCH64_PREL16:
+        count_relocation(kRelocRelative);
+        MARK(rel->r_offset);
+        TRACE_TYPE(RELO, "RELO REL16 %16llx <- %16llx - %16llx %s\n",
+                   reloc, sym_addr + addend, rel->r_offset, sym_name);
+        {
+          const ElfW(Addr) min_value = static_cast<ElfW(Addr)>(INT16_MIN);
+          const ElfW(Addr) max_value = static_cast<ElfW(Addr)>(UINT16_MAX);
+          if ((min_value <= (sym_addr + addend - rel->r_offset)) &&
+              ((sym_addr + addend - rel->r_offset) <= max_value)) {
+            *reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr + addend - rel->r_offset;
+          } else {
+            DL_ERR("0x%016llx out of range 0x%016llx to 0x%016llx",
+                   sym_addr + addend - rel->r_offset, min_value, max_value);
+            return false;
+          }
+        }
+        break;
+
+      case R_AARCH64_COPY:
+        /*
+         * ET_EXEC is not supported so this should not happen.
+         *
+         * http://infocenter.arm.com/help/topic/com.arm.doc.ihi0056b/IHI0056B_aaelf64.pdf
+         *
+         * Section 4.6.11 "Dynamic relocations"
+         * R_AARCH64_COPY may only appear in executable objects where e_type is
+         * set to ET_EXEC.
+         */
+        DL_ERR("%s R_AARCH64_COPY relocations are not supported", get_realpath());
+        return false;
+      case R_AARCH64_TLS_TPREL64:
+        TRACE_TYPE(RELO, "RELO TLS_TPREL64 *** %16llx <- %16llx - %16llx\n",
+                   reloc, (sym_addr + addend), rel->r_offset);
+        break;
+      case R_AARCH64_TLS_DTPREL32:
+        TRACE_TYPE(RELO, "RELO TLS_DTPREL32 *** %16llx <- %16llx - %16llx\n",
+                   reloc, (sym_addr + addend), rel->r_offset);
+        break;
+#elif defined(__x86_64__)
+      case R_X86_64_32:
+        count_relocation(kRelocRelative);
+        MARK(rel->r_offset);
+        TRACE_TYPE(RELO, "RELO R_X86_64_32 %08zx <- +%08zx %s", static_cast<size_t>(reloc),
+                   static_cast<size_t>(sym_addr), sym_name);
+        *reinterpret_cast<Elf32_Addr*>(reloc) = sym_addr + addend;
+        break;
+      case R_X86_64_64:
+        count_relocation(kRelocRelative);
+        MARK(rel->r_offset);
+        TRACE_TYPE(RELO, "RELO R_X86_64_64 %08zx <- +%08zx %s", static_cast<size_t>(reloc),
+                   static_cast<size_t>(sym_addr), sym_name);
+        *reinterpret_cast<Elf64_Addr*>(reloc) = sym_addr + addend;
+        break;
+      case R_X86_64_PC32:
+        count_relocation(kRelocRelative);
+        MARK(rel->r_offset);
+        TRACE_TYPE(RELO, "RELO R_X86_64_PC32 %08zx <- +%08zx (%08zx - %08zx) %s",
+                   static_cast<size_t>(reloc), static_cast<size_t>(sym_addr - reloc),
+                   static_cast<size_t>(sym_addr), static_cast<size_t>(reloc), sym_name);
+        *reinterpret_cast<Elf32_Addr*>(reloc) = sym_addr + addend - reloc;
+        break;
+#elif defined(__arm__)
+      case R_ARM_ABS32:
+        count_relocation(kRelocAbsolute);
+        MARK(rel->r_offset);
+        TRACE_TYPE(RELO, "RELO ABS %08x <- %08x %s", reloc, sym_addr, sym_name);
+        *reinterpret_cast<ElfW(Addr)*>(reloc) += sym_addr;
+        break;
+      case R_ARM_REL32:
+        count_relocation(kRelocRelative);
+        MARK(rel->r_offset);
+        TRACE_TYPE(RELO, "RELO REL32 %08x <- %08x - %08x %s",
+                   reloc, sym_addr, rel->r_offset, sym_name);
+        *reinterpret_cast<ElfW(Addr)*>(reloc) += sym_addr - rel->r_offset;
+        break;
+      case R_ARM_COPY:
+        /*
+         * ET_EXEC is not supported so this should not happen.
+         *
+         * http://infocenter.arm.com/help/topic/com.arm.doc.ihi0044d/IHI0044D_aaelf.pdf
+         *
+         * Section 4.6.1.10 "Dynamic relocations"
+         * R_ARM_COPY may only appear in executable objects where e_type is
+         * set to ET_EXEC.
+         */
+        DL_ERR("%s R_ARM_COPY relocations are not supported", get_realpath());
+        return false;
+#elif defined(__i386__)
+      case R_386_32:
+        count_relocation(kRelocRelative);
+        MARK(rel->r_offset);
+        TRACE_TYPE(RELO, "RELO R_386_32 %08x <- +%08x %s", reloc, sym_addr, sym_name);
+        *reinterpret_cast<ElfW(Addr)*>(reloc) += sym_addr;
+        break;
+      case R_386_PC32:
+        count_relocation(kRelocRelative);
+        MARK(rel->r_offset);
+        TRACE_TYPE(RELO, "RELO R_386_PC32 %08x <- +%08x (%08x - %08x) %s",
+                   reloc, (sym_addr - reloc), sym_addr, reloc, sym_name);
+        *reinterpret_cast<ElfW(Addr)*>(reloc) += (sym_addr - reloc);
+        break;
+#endif
+      default:
+        DL_ERR("unknown reloc type %d @ %p (%zu)", type, rel, idx);
+        return false;
+    }
+  }
+  return true;
+}
+#endif  // !defined(__mips__)
+
+// An empty list of soinfos
+static soinfo_list_t g_empty_list;
+
+bool soinfo::prelink_image() {
+  /* Extract dynamic section */
+  ElfW(Word) dynamic_flags = 0;
+  phdr_table_get_dynamic_section(phdr, phnum, load_bias, &dynamic, &dynamic_flags);
+
+  /* We can't log anything until the linker is relocated */
+  bool relocating_linker = (flags_ & FLAG_LINKER) != 0;
+  if (!relocating_linker) {
+    INFO("[ Linking \"%s\" ]", get_realpath());
+    DEBUG("si->base = %p si->flags = 0x%08x", reinterpret_cast<void*>(base), flags_);
+  }
+
+  if (dynamic == nullptr) {
+    if (!relocating_linker) {
+      DL_ERR("missing PT_DYNAMIC in \"%s\"", get_realpath());
+    }
+    return false;
+  } else {
+    if (!relocating_linker) {
+      DEBUG("dynamic = %p", dynamic);
+    }
+  }
+
+#if defined(__arm__)
+  (void) phdr_table_get_arm_exidx(phdr, phnum, load_bias,
+                                  &ARM_exidx, &ARM_exidx_count);
+#endif
+
+  // Extract useful information from dynamic section.
+  // Note that: "Except for the DT_NULL element at the end of the array,
+  // and the relative order of DT_NEEDED elements, entries may appear in any order."
+  //
+  // source: http://www.sco.com/developers/gabi/1998-04-29/ch5.dynamic.html
+  uint32_t needed_count = 0;
+  for (ElfW(Dyn)* d = dynamic; d->d_tag != DT_NULL; ++d) {
+    DEBUG("d = %p, d[0](tag) = %p d[1](val) = %p",
+          d, reinterpret_cast<void*>(d->d_tag), reinterpret_cast<void*>(d->d_un.d_val));
+    switch (d->d_tag) {
+      case DT_SONAME:
+        // this is parsed after we have strtab initialized (see below).
+        break;
+
+      case DT_HASH:
+        nbucket_ = reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr)[0];
+        nchain_ = reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr)[1];
+        bucket_ = reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr + 8);
+        chain_ = reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr + 8 + nbucket_ * 4);
+        break;
+
+      case DT_GNU_HASH:
+        gnu_nbucket_ = reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr)[0];
+        // skip symndx
+        gnu_maskwords_ = reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr)[2];
+        gnu_shift2_ = reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr)[3];
+
+        gnu_bloom_filter_ = reinterpret_cast<ElfW(Addr)*>(load_bias + d->d_un.d_ptr + 16);
+        gnu_bucket_ = reinterpret_cast<uint32_t*>(gnu_bloom_filter_ + gnu_maskwords_);
+        // amend chain for symndx = header[1]
+        gnu_chain_ = gnu_bucket_ + gnu_nbucket_ -
+            reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr)[1];
+
+        if (!powerof2(gnu_maskwords_)) {
+          DL_ERR("invalid maskwords for gnu_hash = 0x%x, in \"%s\" expecting power to two",
+              gnu_maskwords_, get_realpath());
+          return false;
+        }
+        --gnu_maskwords_;
+
+        flags_ |= FLAG_GNU_HASH;
+        break;
+
+      case DT_STRTAB:
+        strtab_ = reinterpret_cast<const char*>(load_bias + d->d_un.d_ptr);
+        break;
+
+      case DT_STRSZ:
+        strtab_size_ = d->d_un.d_val;
+        break;
+
+      case DT_SYMTAB:
+        symtab_ = reinterpret_cast<ElfW(Sym)*>(load_bias + d->d_un.d_ptr);
+        break;
+
+      case DT_SYMENT:
+        if (d->d_un.d_val != sizeof(ElfW(Sym))) {
+          DL_ERR("invalid DT_SYMENT: %zd in \"%s\"",
+              static_cast<size_t>(d->d_un.d_val), get_realpath());
+          return false;
+        }
+        break;
+
+      case DT_PLTREL:
+#if defined(USE_RELA)
+        if (d->d_un.d_val != DT_RELA) {
+          DL_ERR("unsupported DT_PLTREL in \"%s\"; expected DT_RELA", get_realpath());
+          return false;
+        }
+#else
+        if (d->d_un.d_val != DT_REL) {
+          DL_ERR("unsupported DT_PLTREL in \"%s\"; expected DT_REL", get_realpath());
+          return false;
+        }
+#endif
+        break;
+
+      case DT_JMPREL:
+#if defined(USE_RELA)
+        plt_rela_ = reinterpret_cast<ElfW(Rela)*>(load_bias + d->d_un.d_ptr);
+#else
+        plt_rel_ = reinterpret_cast<ElfW(Rel)*>(load_bias + d->d_un.d_ptr);
+#endif
+        break;
+
+      case DT_PLTRELSZ:
+#if defined(USE_RELA)
+        plt_rela_count_ = d->d_un.d_val / sizeof(ElfW(Rela));
+#else
+        plt_rel_count_ = d->d_un.d_val / sizeof(ElfW(Rel));
+#endif
+        break;
+
+      case DT_PLTGOT:
+#if defined(__mips__)
+        // Used by mips and mips64.
+        plt_got_ = reinterpret_cast<ElfW(Addr)**>(load_bias + d->d_un.d_ptr);
+#endif
+        // Ignore for other platforms... (because RTLD_LAZY is not supported)
+        break;
+
+      case DT_DEBUG:
+        // Set the DT_DEBUG entry to the address of _r_debug for GDB
+        // if the dynamic table is writable
+// FIXME: not working currently for N64
+// The flags for the LOAD and DYNAMIC program headers do not agree.
+// The LOAD section containing the dynamic table has been mapped as
+// read-only, but the DYNAMIC header claims it is writable.
+#if !(defined(__mips__) && defined(__LP64__))
+        if ((dynamic_flags & PF_W) != 0) {
+          d->d_un.d_val = reinterpret_cast<uintptr_t>(&_r_debug);
+        }
+#endif
+        break;
+#if defined(USE_RELA)
+      case DT_RELA:
+        rela_ = reinterpret_cast<ElfW(Rela)*>(load_bias + d->d_un.d_ptr);
+        break;
+
+      case DT_RELASZ:
+        rela_count_ = d->d_un.d_val / sizeof(ElfW(Rela));
+        break;
+
+      case DT_ANDROID_RELA:
+        android_relocs_ = reinterpret_cast<uint8_t*>(load_bias + d->d_un.d_ptr);
+        break;
+
+      case DT_ANDROID_RELASZ:
+        android_relocs_size_ = d->d_un.d_val;
+        break;
+
+      case DT_ANDROID_REL:
+        DL_ERR("unsupported DT_ANDROID_REL in \"%s\"", get_realpath());
+        return false;
+
+      case DT_ANDROID_RELSZ:
+        DL_ERR("unsupported DT_ANDROID_RELSZ in \"%s\"", get_realpath());
+        return false;
+
+      case DT_RELAENT:
+        if (d->d_un.d_val != sizeof(ElfW(Rela))) {
+          DL_ERR("invalid DT_RELAENT: %zd", static_cast<size_t>(d->d_un.d_val));
+          return false;
+        }
+        break;
+
+      // ignored (see DT_RELCOUNT comments for details)
+      case DT_RELACOUNT:
+        break;
+
+      case DT_REL:
+        DL_ERR("unsupported DT_REL in \"%s\"", get_realpath());
+        return false;
+
+      case DT_RELSZ:
+        DL_ERR("unsupported DT_RELSZ in \"%s\"", get_realpath());
+        return false;
+
+#else
+      case DT_REL:
+        rel_ = reinterpret_cast<ElfW(Rel)*>(load_bias + d->d_un.d_ptr);
+        break;
+
+      case DT_RELSZ:
+        rel_count_ = d->d_un.d_val / sizeof(ElfW(Rel));
+        break;
+
+      case DT_RELENT:
+        if (d->d_un.d_val != sizeof(ElfW(Rel))) {
+          DL_ERR("invalid DT_RELENT: %zd", static_cast<size_t>(d->d_un.d_val));
+          return false;
+        }
+        break;
+
+      case DT_ANDROID_REL:
+        android_relocs_ = reinterpret_cast<uint8_t*>(load_bias + d->d_un.d_ptr);
+        break;
+
+      case DT_ANDROID_RELSZ:
+        android_relocs_size_ = d->d_un.d_val;
+        break;
+
+      case DT_ANDROID_RELA:
+        DL_ERR("unsupported DT_ANDROID_RELA in \"%s\"", get_realpath());
+        return false;
+
+      case DT_ANDROID_RELASZ:
+        DL_ERR("unsupported DT_ANDROID_RELASZ in \"%s\"", get_realpath());
+        return false;
+
+      // "Indicates that all RELATIVE relocations have been concatenated together,
+      // and specifies the RELATIVE relocation count."
+      //
+      // TODO: Spec also mentions that this can be used to optimize relocation process;
+      // Not currently used by bionic linker - ignored.
+      case DT_RELCOUNT:
+        break;
+
+      case DT_RELA:
+        DL_ERR("unsupported DT_RELA in \"%s\"", get_realpath());
+        return false;
+
+      case DT_RELASZ:
+        DL_ERR("unsupported DT_RELASZ in \"%s\"", get_realpath());
+        return false;
+
+#endif
+      case DT_INIT:
+        init_func_ = reinterpret_cast<linker_ctor_function_t>(load_bias + d->d_un.d_ptr);
+        DEBUG("%s constructors (DT_INIT) found at %p", get_realpath(), init_func_);
+        break;
+
+      case DT_FINI:
+        fini_func_ = reinterpret_cast<linker_dtor_function_t>(load_bias + d->d_un.d_ptr);
+        DEBUG("%s destructors (DT_FINI) found at %p", get_realpath(), fini_func_);
+        break;
+
+      case DT_INIT_ARRAY:
+        init_array_ = reinterpret_cast<linker_ctor_function_t*>(load_bias + d->d_un.d_ptr);
+        DEBUG("%s constructors (DT_INIT_ARRAY) found at %p", get_realpath(), init_array_);
+        break;
+
+      case DT_INIT_ARRAYSZ:
+        init_array_count_ = static_cast<uint32_t>(d->d_un.d_val) / sizeof(ElfW(Addr));
+        break;
+
+      case DT_FINI_ARRAY:
+        fini_array_ = reinterpret_cast<linker_dtor_function_t*>(load_bias + d->d_un.d_ptr);
+        DEBUG("%s destructors (DT_FINI_ARRAY) found at %p", get_realpath(), fini_array_);
+        break;
+
+      case DT_FINI_ARRAYSZ:
+        fini_array_count_ = static_cast<uint32_t>(d->d_un.d_val) / sizeof(ElfW(Addr));
+        break;
+
+      case DT_PREINIT_ARRAY:
+        preinit_array_ = reinterpret_cast<linker_ctor_function_t*>(load_bias + d->d_un.d_ptr);
+        DEBUG("%s constructors (DT_PREINIT_ARRAY) found at %p", get_realpath(), preinit_array_);
+        break;
+
+      case DT_PREINIT_ARRAYSZ:
+        preinit_array_count_ = static_cast<uint32_t>(d->d_un.d_val) / sizeof(ElfW(Addr));
+        break;
+
+      case DT_TEXTREL:
+#if defined(__LP64__)
+        DL_ERR("text relocations (DT_TEXTREL) found in 64-bit ELF file \"%s\"", get_realpath());
+        return false;
+#else
+        has_text_relocations = true;
+        break;
+#endif
+
+      case DT_SYMBOLIC:
+        has_DT_SYMBOLIC = true;
+        break;
+
+      case DT_NEEDED:
+        ++needed_count;
+        break;
+
+      case DT_FLAGS:
+        if (d->d_un.d_val & DF_TEXTREL) {
+#if defined(__LP64__)
+          DL_ERR("text relocations (DF_TEXTREL) found in 64-bit ELF file \"%s\"", get_realpath());
+          return false;
+#else
+          has_text_relocations = true;
+#endif
+        }
+        if (d->d_un.d_val & DF_SYMBOLIC) {
+          has_DT_SYMBOLIC = true;
+        }
+        break;
+
+      case DT_FLAGS_1:
+        set_dt_flags_1(d->d_un.d_val);
+
+        if ((d->d_un.d_val & ~SUPPORTED_DT_FLAGS_1) != 0) {
+          DL_WARN("%s: unsupported flags DT_FLAGS_1=%p", get_realpath(), reinterpret_cast<void*>(d->d_un.d_val));
+        }
+        break;
+#if defined(__mips__)
+      case DT_MIPS_RLD_MAP:
+        // Set the DT_MIPS_RLD_MAP entry to the address of _r_debug for GDB.
+        {
+          r_debug** dp = reinterpret_cast<r_debug**>(load_bias + d->d_un.d_ptr);
+          *dp = &_r_debug;
+        }
+        break;
+      case DT_MIPS_RLD_MAP_REL:
+        // Set the DT_MIPS_RLD_MAP_REL entry to the address of _r_debug for GDB.
+        {
+          r_debug** dp = reinterpret_cast<r_debug**>(
+              reinterpret_cast<ElfW(Addr)>(d) + d->d_un.d_val);
+          *dp = &_r_debug;
+        }
+        break;
+
+      case DT_MIPS_RLD_VERSION:
+      case DT_MIPS_FLAGS:
+      case DT_MIPS_BASE_ADDRESS:
+      case DT_MIPS_UNREFEXTNO:
+        break;
+
+      case DT_MIPS_SYMTABNO:
+        mips_symtabno_ = d->d_un.d_val;
+        break;
+
+      case DT_MIPS_LOCAL_GOTNO:
+        mips_local_gotno_ = d->d_un.d_val;
+        break;
+
+      case DT_MIPS_GOTSYM:
+        mips_gotsym_ = d->d_un.d_val;
+        break;
+#endif
+      // Ignored: "Its use has been superseded by the DF_BIND_NOW flag"
+      case DT_BIND_NOW:
+        break;
+
+      case DT_VERSYM:
+        versym_ = reinterpret_cast<ElfW(Versym)*>(load_bias + d->d_un.d_ptr);
+        break;
+
+      case DT_VERDEF:
+        verdef_ptr_ = load_bias + d->d_un.d_ptr;
+        break;
+      case DT_VERDEFNUM:
+        verdef_cnt_ = d->d_un.d_val;
+        break;
+
+      case DT_VERNEED:
+        verneed_ptr_ = load_bias + d->d_un.d_ptr;
+        break;
+
+      case DT_VERNEEDNUM:
+        verneed_cnt_ = d->d_un.d_val;
+        break;
+
+      case DT_RUNPATH:
+        // this is parsed after we have strtab initialized (see below).
+        break;
+
+      default:
+        if (!relocating_linker) {
+          DL_WARN("%s: unused DT entry: type %p arg %p", get_realpath(),
+              reinterpret_cast<void*>(d->d_tag), reinterpret_cast<void*>(d->d_un.d_val));
+        }
+        break;
+    }
+  }
+
+#if defined(__mips__) && !defined(__LP64__)
+  if (!mips_check_and_adjust_fp_modes()) {
+    return false;
+  }
+#endif
+
+  DEBUG("si->base = %p, si->strtab = %p, si->symtab = %p",
+        reinterpret_cast<void*>(base), strtab_, symtab_);
+
+  // Sanity checks.
+  if (relocating_linker && needed_count != 0) {
+    DL_ERR("linker cannot have DT_NEEDED dependencies on other libraries");
+    return false;
+  }
+  if (nbucket_ == 0 && gnu_nbucket_ == 0) {
+    DL_ERR("empty/missing DT_HASH/DT_GNU_HASH in \"%s\" "
+        "(new hash type from the future?)", get_realpath());
+    return false;
+  }
+  if (strtab_ == 0) {
+    DL_ERR("empty/missing DT_STRTAB in \"%s\"", get_realpath());
+    return false;
+  }
+  if (symtab_ == 0) {
+    DL_ERR("empty/missing DT_SYMTAB in \"%s\"", get_realpath());
+    return false;
+  }
+
+  // second pass - parse entries relying on strtab
+  for (ElfW(Dyn)* d = dynamic; d->d_tag != DT_NULL; ++d) {
+    switch (d->d_tag) {
+      case DT_SONAME:
+        set_soname(get_string(d->d_un.d_val));
+        break;
+      case DT_RUNPATH:
+        set_dt_runpath(get_string(d->d_un.d_val));
+        break;
+    }
+  }
+
+  // Before M release linker was using basename in place of soname.
+  // In the case when dt_soname is absent some apps stop working
+  // because they can't find dt_needed library by soname.
+  // This workaround should keep them working. (applies only
+  // for apps targeting sdk version <=22). Make an exception for
+  // the main executable and linker; they do not need to have dt_soname
+  if (soname_ == nullptr && this != somain && (flags_ & FLAG_LINKER) == 0 &&
+      get_application_target_sdk_version() <= 22) {
+    soname_ = basename(realpath_.c_str());
+    DL_WARN("%s: is missing DT_SONAME will use basename as a replacement: \"%s\"",
+        get_realpath(), soname_);
+    // Don't call add_dlwarning because a missing DT_SONAME isn't important enough to show in the UI
+  }
+  return true;
+}
+
+bool soinfo::link_image(const soinfo_list_t& global_group, const soinfo_list_t& local_group,
+                        const android_dlextinfo* extinfo) {
+
+  local_group_root_ = local_group.front();
+  if (local_group_root_ == nullptr) {
+    local_group_root_ = this;
+  }
+
+  if ((flags_ & FLAG_LINKER) == 0 && local_group_root_ == this) {
+    target_sdk_version_ = get_application_target_sdk_version();
+  }
+
+  VersionTracker version_tracker;
+
+  if (!version_tracker.init(this)) {
+    return false;
+  }
+
+#if !defined(__LP64__)
+  if (has_text_relocations) {
+    // Fail if app is targeting sdk version > 22
+    if (get_application_target_sdk_version() > 22) {
+      PRINT("%s: has text relocations", get_realpath());
+      DL_ERR("%s: has text relocations", get_realpath());
+      return false;
+    }
+    // Make segments writable to allow text relocations to work properly. We will later call
+    // phdr_table_protect_segments() after all of them are applied.
+    DL_WARN("%s has text relocations. This is wasting memory and prevents "
+            "security hardening. Please fix.", get_realpath());
+    add_dlwarning(get_realpath(), "text relocations");
+    if (phdr_table_unprotect_segments(phdr, phnum, load_bias) < 0) {
+      DL_ERR("can't unprotect loadable segments for \"%s\": %s",
+             get_realpath(), strerror(errno));
+      return false;
+    }
+  }
+#endif
+
+  if (android_relocs_ != nullptr) {
+    // check signature
+    if (android_relocs_size_ > 3 &&
+        android_relocs_[0] == 'A' &&
+        android_relocs_[1] == 'P' &&
+        android_relocs_[2] == 'S' &&
+        android_relocs_[3] == '2') {
+      DEBUG("[ android relocating %s ]", get_realpath());
+
+      bool relocated = false;
+      const uint8_t* packed_relocs = android_relocs_ + 4;
+      const size_t packed_relocs_size = android_relocs_size_ - 4;
+
+      relocated = relocate(
+          version_tracker,
+          packed_reloc_iterator<sleb128_decoder>(
+            sleb128_decoder(packed_relocs, packed_relocs_size)),
+          global_group, local_group);
+
+      if (!relocated) {
+        return false;
+      }
+    } else {
+      DL_ERR("bad android relocation header.");
+      return false;
+    }
+  }
+
+#if defined(USE_RELA)
+  if (rela_ != nullptr) {
+    DEBUG("[ relocating %s ]", get_realpath());
+    if (!relocate(version_tracker,
+            plain_reloc_iterator(rela_, rela_count_), global_group, local_group)) {
+      return false;
+    }
+  }
+  if (plt_rela_ != nullptr) {
+    DEBUG("[ relocating %s plt ]", get_realpath());
+    if (!relocate(version_tracker,
+            plain_reloc_iterator(plt_rela_, plt_rela_count_), global_group, local_group)) {
+      return false;
+    }
+  }
+#else
+  if (rel_ != nullptr) {
+    DEBUG("[ relocating %s ]", get_realpath());
+    if (!relocate(version_tracker,
+            plain_reloc_iterator(rel_, rel_count_), global_group, local_group)) {
+      return false;
+    }
+  }
+  if (plt_rel_ != nullptr) {
+    DEBUG("[ relocating %s plt ]", get_realpath());
+    if (!relocate(version_tracker,
+            plain_reloc_iterator(plt_rel_, plt_rel_count_), global_group, local_group)) {
+      return false;
+    }
+  }
+#endif
+
+#if defined(__mips__)
+  if (!mips_relocate_got(version_tracker, global_group, local_group)) {
+    return false;
+  }
+#endif
+
+  DEBUG("[ finished linking %s ]", get_realpath());
+
+#if !defined(__LP64__)
+  if (has_text_relocations) {
+    // All relocations are done, we can protect our segments back to read-only.
+    if (phdr_table_protect_segments(phdr, phnum, load_bias) < 0) {
+      DL_ERR("can't protect segments for \"%s\": %s",
+             get_realpath(), strerror(errno));
+      return false;
+    }
+  }
+#endif
+
+  // We can also turn on GNU RELRO protection if we're not linking the dynamic linker
+  // itself --- it can't make system calls yet, and will have to call protect_relro later.
+  if (!is_linker() && !protect_relro()) {
+    return false;
+  }
+
+  /* Handle serializing/sharing the RELRO segment */
+  if (extinfo && (extinfo->flags & ANDROID_DLEXT_WRITE_RELRO)) {
+    if (phdr_table_serialize_gnu_relro(phdr, phnum, load_bias,
+                                       extinfo->relro_fd) < 0) {
+      DL_ERR("failed serializing GNU RELRO section for \"%s\": %s",
+             get_realpath(), strerror(errno));
+      return false;
+    }
+  } else if (extinfo && (extinfo->flags & ANDROID_DLEXT_USE_RELRO)) {
+    if (phdr_table_map_gnu_relro(phdr, phnum, load_bias,
+                                 extinfo->relro_fd) < 0) {
+      DL_ERR("failed mapping GNU RELRO section for \"%s\": %s",
+             get_realpath(), strerror(errno));
+      return false;
+    }
+  }
+
+  notify_gdb_of_load(this);
+  return true;
+}
+
+bool soinfo::protect_relro() {
+  if (phdr_table_protect_gnu_relro(phdr, phnum, load_bias) < 0) {
+    DL_ERR("can't enable GNU RELRO protection for \"%s\": %s",
+           get_realpath(), strerror(errno));
+    return false;
+  }
+  return true;
+}
+
+/*
+ * This function add vdso to internal dso list.
+ * It helps to stack unwinding through signal handlers.
+ * Also, it makes bionic more like glibc.
+ */
+static void add_vdso(KernelArgumentBlock& args __unused) {
+#if defined(AT_SYSINFO_EHDR)
+  ElfW(Ehdr)* ehdr_vdso = reinterpret_cast<ElfW(Ehdr)*>(args.getauxval(AT_SYSINFO_EHDR));
+  if (ehdr_vdso == nullptr) {
+    return;
+  }
+
+  soinfo* si = soinfo_alloc(&g_default_namespace, "[vdso]", nullptr, 0, 0);
+
+  si->phdr = reinterpret_cast<ElfW(Phdr)*>(reinterpret_cast<char*>(ehdr_vdso) + ehdr_vdso->e_phoff);
+  si->phnum = ehdr_vdso->e_phnum;
+  si->base = reinterpret_cast<ElfW(Addr)>(ehdr_vdso);
+  si->size = phdr_table_get_load_size(si->phdr, si->phnum);
+  si->load_bias = get_elf_exec_load_bias(ehdr_vdso);
+
+  si->prelink_image();
+  si->link_image(g_empty_list, soinfo_list_t::make_list(si), nullptr);
+#endif
+}
+
+/* gdb expects the linker to be in the debug shared object list.
+ * Without this, gdb has trouble locating the linker's ".text"
+ * and ".plt" sections. Gdb could also potentially use this to
+ * relocate the offset of our exported 'rtld_db_dlactivity' symbol.
+ * Note that the linker shouldn't be on the soinfo list.
+ */
+static void init_linker_info_for_gdb(ElfW(Addr) linker_base) {
+  static link_map linker_link_map_for_gdb;
+#if defined(__LP64__)
+  static char kLinkerPath[] = "/system/bin/linker64";
+#else
+  static char kLinkerPath[] = "/system/bin/linker";
+#endif
+
+  linker_link_map_for_gdb.l_addr = linker_base;
+  linker_link_map_for_gdb.l_name = kLinkerPath;
+
+  /*
+   * Set the dynamic field in the link map otherwise gdb will complain with
+   * the following:
+   *   warning: .dynamic section for "/system/bin/linker" is not at the
+   *   expected address (wrong library or version mismatch?)
+   */
+  ElfW(Ehdr)* elf_hdr = reinterpret_cast<ElfW(Ehdr)*>(linker_base);
+  ElfW(Phdr)* phdr = reinterpret_cast<ElfW(Phdr)*>(linker_base + elf_hdr->e_phoff);
+  phdr_table_get_dynamic_section(phdr, elf_hdr->e_phnum, linker_base,
+                                 &linker_link_map_for_gdb.l_ld, nullptr);
+
+  insert_link_map_into_debug_map(&linker_link_map_for_gdb);
+}
+
+static void init_default_namespace() {
+  g_default_namespace.set_name("(default)");
+  g_default_namespace.set_isolated(false);
+
+  const char *interp = phdr_table_get_interpreter_name(somain->phdr, somain->phnum,
+                                                       somain->load_bias);
+  const char* bname = basename(interp);
+  if (bname && (strcmp(bname, "linker_asan") == 0 || strcmp(bname, "linker_asan64") == 0)) {
+    g_default_ld_paths = kAsanDefaultLdPaths;
+    g_is_asan = true;
+  } else {
+    g_default_ld_paths = kDefaultLdPaths;
+  }
+
+  std::vector<std::string> ld_default_paths;
+  for (size_t i = 0; g_default_ld_paths[i] != nullptr; ++i) {
+    ld_default_paths.push_back(g_default_ld_paths[i]);
+  }
+
+  g_default_namespace.set_default_library_paths(std::move(ld_default_paths));
+};
+
+extern "C" int __system_properties_init(void);
+
+static const char* get_executable_path() {
+  static std::string executable_path;
+  if (executable_path.empty()) {
+    char path[PATH_MAX];
+    ssize_t path_len = readlink("/proc/self/exe", path, sizeof(path));
+    if (path_len == -1 || path_len >= static_cast<ssize_t>(sizeof(path))) {
+      __libc_fatal("readlink('/proc/self/exe') failed: %s", strerror(errno));
+    }
+    executable_path = std::string(path, path_len);
+  }
+
+  return executable_path.c_str();
+}
+
+/*
+ * This code is called after the linker has linked itself and
+ * fixed it's own GOT. It is safe to make references to externs
+ * and other non-local data at this point.
+ */
+static ElfW(Addr) __linker_init_post_relocation(KernelArgumentBlock& args, ElfW(Addr) linker_base) {
+#if TIMING
+  struct timeval t0, t1;
+  gettimeofday(&t0, 0);
+#endif
+
+  // Sanitize the environment.
+  __libc_init_AT_SECURE(args);
+
+  // Initialize system properties
+  __system_properties_init(); // may use 'environ'
+
+  // Register the debuggerd signal handler.
+  debuggerd_callbacks_t callbacks = {
+    .get_abort_message = []() {
+      return g_abort_message;
+    },
+    .post_dump = &notify_gdb_of_libraries,
+  };
+  debuggerd_init(&callbacks);
+
+  g_linker_logger.ResetState();
+
+  // Get a few environment variables.
+  const char* LD_DEBUG = getenv("LD_DEBUG");
+  if (LD_DEBUG != nullptr) {
+    g_ld_debug_verbosity = atoi(LD_DEBUG);
+  }
+
+#if defined(__LP64__)
+  INFO("[ Android dynamic linker (64-bit) ]");
+#else
+  INFO("[ Android dynamic linker (32-bit) ]");
+#endif
+
+  // These should have been sanitized by __libc_init_AT_SECURE, but the test
+  // doesn't cost us anything.
+  const char* ldpath_env = nullptr;
+  const char* ldpreload_env = nullptr;
+  if (!getauxval(AT_SECURE)) {
+    ldpath_env = getenv("LD_LIBRARY_PATH");
+    if (ldpath_env != nullptr) {
+      INFO("[ LD_LIBRARY_PATH set to \"%s\" ]", ldpath_env);
+    }
+    ldpreload_env = getenv("LD_PRELOAD");
+    if (ldpreload_env != nullptr) {
+      INFO("[ LD_PRELOAD set to \"%s\" ]", ldpreload_env);
+    }
+  }
+
+  const char* executable_path = get_executable_path();
+  struct stat file_stat;
+  if (TEMP_FAILURE_RETRY(stat(executable_path, &file_stat)) != 0) {
+    __libc_fatal("unable to stat file for the executable \"%s\": %s", executable_path, strerror(errno));
+  }
+
+  soinfo* si = soinfo_alloc(&g_default_namespace, executable_path, &file_stat, 0, RTLD_GLOBAL);
+  if (si == nullptr) {
+    __libc_fatal("Couldn't allocate soinfo: out of memory?");
+  }
+
+  /* bootstrap the link map, the main exe always needs to be first */
+  si->set_main_executable();
+  link_map* map = &(si->link_map_head);
+
+  // Register the main executable and the linker upfront to have
+  // gdb aware of them before loading the rest of the dependency
+  // tree.
+  map->l_addr = 0;
+  map->l_name = const_cast<char*>(executable_path);
+  insert_link_map_into_debug_map(map);
+  init_linker_info_for_gdb(linker_base);
+
+  // Extract information passed from the kernel.
+  si->phdr = reinterpret_cast<ElfW(Phdr)*>(args.getauxval(AT_PHDR));
+  si->phnum = args.getauxval(AT_PHNUM);
+
+  /* Compute the value of si->base. We can't rely on the fact that
+   * the first entry is the PHDR because this will not be true
+   * for certain executables (e.g. some in the NDK unit test suite)
+   */
+  si->base = 0;
+  si->size = phdr_table_get_load_size(si->phdr, si->phnum);
+  si->load_bias = 0;
+  for (size_t i = 0; i < si->phnum; ++i) {
+    if (si->phdr[i].p_type == PT_PHDR) {
+      si->load_bias = reinterpret_cast<ElfW(Addr)>(si->phdr) - si->phdr[i].p_vaddr;
+      si->base = reinterpret_cast<ElfW(Addr)>(si->phdr) - si->phdr[i].p_offset;
+      break;
+    }
+  }
+  si->dynamic = nullptr;
+
+  ElfW(Ehdr)* elf_hdr = reinterpret_cast<ElfW(Ehdr)*>(si->base);
+  if (elf_hdr->e_type != ET_DYN) {
+    __libc_fatal("\"%s\": error: only position independent executables (PIE) are supported.",
+                 g_argv[0]);
+  }
+
+  // Use LD_LIBRARY_PATH and LD_PRELOAD (but only if we aren't setuid/setgid).
+  parse_LD_LIBRARY_PATH(ldpath_env);
+  parse_LD_PRELOAD(ldpreload_env);
+
+  somain = si;
+
+  init_default_namespace();
+
+  if (!si->prelink_image()) {
+    __libc_fatal("CANNOT LINK EXECUTABLE \"%s\": %s", g_argv[0], linker_get_error_buffer());
+  }
+
+  // add somain to global group
+  si->set_dt_flags_1(si->get_dt_flags_1() | DF_1_GLOBAL);
+
+  // Load ld_preloads and dependencies.
+  StringLinkedList needed_library_name_list;
+  size_t needed_libraries_count = 0;
+  size_t ld_preloads_count = 0;
+
+  for (const auto& ld_preload_name : g_ld_preload_names) {
+    needed_library_name_list.push_back(ld_preload_name.c_str());
+    ++needed_libraries_count;
+    ++ld_preloads_count;
+  }
+
+  for_each_dt_needed(si, [&](const char* name) {
+    needed_library_name_list.push_back(name);
+    ++needed_libraries_count;
+  });
+
+  const char* needed_library_names[needed_libraries_count];
+
+  memset(needed_library_names, 0, sizeof(needed_library_names));
+  needed_library_name_list.copy_to_array(needed_library_names, needed_libraries_count);
+
+  if (needed_libraries_count > 0 &&
+      !find_libraries(&g_default_namespace, si, needed_library_names, needed_libraries_count,
+                      nullptr, &g_ld_preloads, ld_preloads_count, RTLD_GLOBAL, nullptr,
+                      /* add_as_children */ true)) {
+    __libc_fatal("CANNOT LINK EXECUTABLE \"%s\": %s", g_argv[0], linker_get_error_buffer());
+  } else if (needed_libraries_count == 0) {
+    if (!si->link_image(g_empty_list, soinfo_list_t::make_list(si), nullptr)) {
+      __libc_fatal("CANNOT LINK EXECUTABLE \"%s\": %s", g_argv[0], linker_get_error_buffer());
+    }
+    si->increment_ref_count();
+  }
+
+  add_vdso(args);
+
+  {
+    ProtectedDataGuard guard;
+
+    si->call_pre_init_constructors();
+
+    /* After the prelink_image, the si->load_bias is initialized.
+     * For so lib, the map->l_addr will be updated in notify_gdb_of_load.
+     * We need to update this value for so exe here. So Unwind_Backtrace
+     * for some arch like x86 could work correctly within so exe.
+     */
+    map->l_addr = si->load_bias;
+    si->call_constructors();
+  }
+
+#if TIMING
+  gettimeofday(&t1, nullptr);
+  PRINT("LINKER TIME: %s: %d microseconds", g_argv[0], (int) (
+           (((long long)t1.tv_sec * 1000000LL) + (long long)t1.tv_usec) -
+           (((long long)t0.tv_sec * 1000000LL) + (long long)t0.tv_usec)));
+#endif
+#if STATS
+  PRINT("RELO STATS: %s: %d abs, %d rel, %d copy, %d symbol", g_argv[0],
+         linker_stats.count[kRelocAbsolute],
+         linker_stats.count[kRelocRelative],
+         linker_stats.count[kRelocCopy],
+         linker_stats.count[kRelocSymbol]);
+#endif
+#if COUNT_PAGES
+  {
+    unsigned n;
+    unsigned i;
+    unsigned count = 0;
+    for (n = 0; n < 4096; n++) {
+      if (bitmask[n]) {
+        unsigned x = bitmask[n];
+#if defined(__LP64__)
+        for (i = 0; i < 32; i++) {
+#else
+        for (i = 0; i < 8; i++) {
+#endif
+          if (x & 1) {
+            count++;
+          }
+          x >>= 1;
+        }
+      }
+    }
+    PRINT("PAGES MODIFIED: %s: %d (%dKB)", g_argv[0], count, count * 4);
+  }
+#endif
+
+#if TIMING || STATS || COUNT_PAGES
+  fflush(stdout);
+#endif
+
+  ElfW(Addr) entry = args.getauxval(AT_ENTRY);
+  TRACE("[ Ready to execute \"%s\" @ %p ]", si->get_realpath(), reinterpret_cast<void*>(entry));
+  return entry;
+}
+
+/* Compute the load-bias of an existing executable. This shall only
+ * be used to compute the load bias of an executable or shared library
+ * that was loaded by the kernel itself.
+ *
+ * Input:
+ *    elf    -> address of ELF header, assumed to be at the start of the file.
+ * Return:
+ *    load bias, i.e. add the value of any p_vaddr in the file to get
+ *    the corresponding address in memory.
+ */
+static ElfW(Addr) get_elf_exec_load_bias(const ElfW(Ehdr)* elf) {
+  ElfW(Addr) offset = elf->e_phoff;
+  const ElfW(Phdr)* phdr_table =
+      reinterpret_cast<const ElfW(Phdr)*>(reinterpret_cast<uintptr_t>(elf) + offset);
+  const ElfW(Phdr)* phdr_end = phdr_table + elf->e_phnum;
+
+  for (const ElfW(Phdr)* phdr = phdr_table; phdr < phdr_end; phdr++) {
+    if (phdr->p_type == PT_LOAD) {
+      return reinterpret_cast<ElfW(Addr)>(elf) + phdr->p_offset - phdr->p_vaddr;
+    }
+  }
+  return 0;
+}
+
+static void __linker_cannot_link(const char* argv0) {
+  __libc_fatal("CANNOT LINK EXECUTABLE \"%s\": %s", argv0, linker_get_error_buffer());
+}
+
+/*
+ * This is the entry point for the linker, called from begin.S. This
+ * method is responsible for fixing the linker's own relocations, and
+ * then calling __linker_init_post_relocation().
+ *
+ * Because this method is called before the linker has fixed it's own
+ * relocations, any attempt to reference an extern variable, extern
+ * function, or other GOT reference will generate a segfault.
+ */
+extern "C" ElfW(Addr) __linker_init(void* raw_args) {
+  KernelArgumentBlock args(raw_args);
+
+  ElfW(Addr) linker_addr = args.getauxval(AT_BASE);
+  ElfW(Addr) entry_point = args.getauxval(AT_ENTRY);
+  ElfW(Ehdr)* elf_hdr = reinterpret_cast<ElfW(Ehdr)*>(linker_addr);
+  ElfW(Phdr)* phdr = reinterpret_cast<ElfW(Phdr)*>(linker_addr + elf_hdr->e_phoff);
+
+  soinfo linker_so(nullptr, nullptr, nullptr, 0, 0);
+
+  // If the linker is not acting as PT_INTERP entry_point is equal to
+  // _start. Which means that the linker is running as an executable and
+  // already linked by PT_INTERP.
+  //
+  // This happens when user tries to run 'adb shell /system/bin/linker'
+  // see also https://code.google.com/p/android/issues/detail?id=63174
+  if (reinterpret_cast<ElfW(Addr)>(&_start) == entry_point) {
+    __libc_format_fd(STDOUT_FILENO,
+                     "This is %s, the helper program for shared library executables.\n",
+                     args.argv[0]);
+    exit(0);
+  }
+
+  linker_so.base = linker_addr;
+  linker_so.size = phdr_table_get_load_size(phdr, elf_hdr->e_phnum);
+  linker_so.load_bias = get_elf_exec_load_bias(elf_hdr);
+  linker_so.dynamic = nullptr;
+  linker_so.phdr = phdr;
+  linker_so.phnum = elf_hdr->e_phnum;
+  linker_so.set_linker_flag();
+
+  // Prelink the linker so we can access linker globals.
+  if (!linker_so.prelink_image()) __linker_cannot_link(args.argv[0]);
+
+  // This might not be obvious... The reasons why we pass g_empty_list
+  // in place of local_group here are (1) we do not really need it, because
+  // linker is built with DT_SYMBOLIC and therefore relocates its symbols against
+  // itself without having to look into local_group and (2) allocators
+  // are not yet initialized, and therefore we cannot use linked_list.push_*
+  // functions at this point.
+  if (!linker_so.link_image(g_empty_list, g_empty_list, nullptr)) __linker_cannot_link(args.argv[0]);
+
+#if defined(__i386__)
+  // On x86, we can't make system calls before this point.
+  // We can't move this up because this needs to assign to a global.
+  // Note that until we call __libc_init_main_thread below we have
+  // no TLS, so you shouldn't make a system call that can fail, because
+  // it will SEGV when it tries to set errno.
+  __libc_init_sysinfo(args);
+#endif
+
+  // Initialize the main thread (including TLS, so system calls really work).
+  __libc_init_main_thread(args);
+
+  // We didn't protect the linker's RELRO pages in link_image because we
+  // couldn't make system calls on x86 at that point, but we can now...
+  if (!linker_so.protect_relro()) __linker_cannot_link(args.argv[0]);
+
+  // Initialize the linker's static libc's globals
+  __libc_init_globals(args);
+
+  // store argc/argv/envp to use them for calling constructors
+  g_argc = args.argc;
+  g_argv = args.argv;
+  g_envp = args.envp;
+
+  // Initialize the linker's own global variables
+  linker_so.call_constructors();
+
+  // Initialize static variables. Note that in order to
+  // get correct libdl_info we need to call constructors
+  // before get_libdl_info().
+  solist = get_libdl_info();
+  sonext = get_libdl_info();
+  g_default_namespace.add_soinfo(get_libdl_info());
+
+  // We have successfully fixed our own relocations. It's safe to run
+  // the main part of the linker now.
+  args.abort_message_ptr = &g_abort_message;
+  ElfW(Addr) start_address = __linker_init_post_relocation(args, linker_addr);
+
+  INFO("[ Jumping to _start (%p)... ]", reinterpret_cast<void*>(start_address));
+
+  // Return the address that the calling assembly stub should jump to.
+  return start_address;
+}
diff --git a/linker/linker.h b/linker/linker.h
new file mode 100644
index 0000000..4787471
--- /dev/null
+++ b/linker/linker.h
@@ -0,0 +1,159 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef _LINKER_H_
+#define _LINKER_H_
+
+#include <dlfcn.h>
+#include <android/dlext.h>
+#include <elf.h>
+#include <inttypes.h>
+#include <link.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "private/bionic_page.h"
+#include "private/libc_logging.h"
+#include "linked_list.h"
+#include "linker_common_types.h"
+#include "linker_logger.h"
+#include "linker_soinfo.h"
+
+#include <string>
+#include <vector>
+
+#if defined(__LP64__)
+#define ELFW(what) ELF64_ ## what
+#else
+#define ELFW(what) ELF32_ ## what
+#endif
+
+// mips64 interprets Elf64_Rel structures' r_info field differently.
+// bionic (like other C libraries) has macros that assume regular ELF files,
+// but the dynamic linker needs to be able to load mips64 ELF files.
+#if defined(__mips__) && defined(__LP64__)
+#undef ELF64_R_SYM
+#undef ELF64_R_TYPE
+#undef ELF64_R_INFO
+#define ELF64_R_SYM(info)   (((info) >> 0) & 0xffffffff)
+#define ELF64_R_SSYM(info)  (((info) >> 32) & 0xff)
+#define ELF64_R_TYPE3(info) (((info) >> 40) & 0xff)
+#define ELF64_R_TYPE2(info) (((info) >> 48) & 0xff)
+#define ELF64_R_TYPE(info)  (((info) >> 56) & 0xff)
+#endif
+
+#define SUPPORTED_DT_FLAGS_1 (DF_1_NOW | DF_1_GLOBAL | DF_1_NODELETE | DF_1_PIE)
+
+// Class used construct version dependency graph.
+class VersionTracker {
+ public:
+  VersionTracker() = default;
+  bool init(const soinfo* si_from);
+
+  const version_info* get_version_info(ElfW(Versym) source_symver) const;
+ private:
+  bool init_verneed(const soinfo* si_from);
+  bool init_verdef(const soinfo* si_from);
+  void add_version_info(size_t source_index, ElfW(Word) elf_hash,
+      const char* ver_name, const soinfo* target_si);
+
+  std::vector<version_info> version_infos;
+
+  DISALLOW_COPY_AND_ASSIGN(VersionTracker);
+};
+
+bool soinfo_do_lookup(soinfo* si_from, const char* name, const version_info* vi,
+                      soinfo** si_found_in, const soinfo_list_t& global_group,
+                      const soinfo_list_t& local_group, const ElfW(Sym)** symbol);
+
+enum RelocationKind {
+  kRelocAbsolute = 0,
+  kRelocRelative,
+  kRelocCopy,
+  kRelocSymbol,
+  kRelocMax
+};
+
+void count_relocation(RelocationKind kind);
+
+soinfo* get_libdl_info();
+
+void do_android_get_LD_LIBRARY_PATH(char*, size_t);
+void do_android_update_LD_LIBRARY_PATH(const char* ld_library_path);
+void* do_dlopen(const char* name, int flags, const android_dlextinfo* extinfo, void* caller_addr);
+int do_dlclose(void* handle);
+
+int do_dl_iterate_phdr(int (*cb)(dl_phdr_info* info, size_t size, void* data), void* data);
+
+bool do_dlsym(void* handle, const char* sym_name, const char* sym_ver,
+              void* caller_addr, void** symbol);
+
+int do_dladdr(const void* addr, Dl_info* info);
+
+void set_application_target_sdk_version(uint32_t target);
+uint32_t get_application_target_sdk_version();
+
+enum {
+  /* A regular namespace is the namespace with a custom search path that does
+   * not impose any restrictions on the location of native libraries.
+   */
+  ANDROID_NAMESPACE_TYPE_REGULAR = 0,
+
+  /* An isolated namespace requires all the libraries to be on the search path
+   * or under permitted_when_isolated_path. The search path is the union of
+   * ld_library_path and default_library_path.
+   */
+  ANDROID_NAMESPACE_TYPE_ISOLATED = 1,
+
+  /* The shared namespace clones the list of libraries of the caller namespace upon creation
+   * which means that they are shared between namespaces - the caller namespace and the new one
+   * will use the same copy of a library if it was loaded prior to android_create_namespace call.
+   *
+   * Note that libraries loaded after the namespace is created will not be shared.
+   *
+   * Shared namespaces can be isolated or regular. Note that they do not inherit the search path nor
+   * permitted_path from the caller's namespace.
+   */
+  ANDROID_NAMESPACE_TYPE_SHARED = 2,
+  ANDROID_NAMESPACE_TYPE_SHARED_ISOLATED = ANDROID_NAMESPACE_TYPE_SHARED |
+                                           ANDROID_NAMESPACE_TYPE_ISOLATED,
+};
+
+bool init_namespaces(const char* public_ns_sonames, const char* anon_ns_library_path);
+android_namespace_t* create_namespace(const void* caller_addr,
+                                      const char* name,
+                                      const char* ld_library_path,
+                                      const char* default_library_path,
+                                      uint64_t type,
+                                      const char* permitted_when_isolated_path,
+                                      android_namespace_t* parent_namespace);
+
+constexpr unsigned kLibraryAlignmentBits = 18;
+constexpr size_t kLibraryAlignment = 1UL << kLibraryAlignmentBits;
+
+#endif
diff --git a/linker/linker_allocator.cpp b/linker/linker_allocator.cpp
new file mode 100644
index 0000000..dc6dfc1
--- /dev/null
+++ b/linker/linker_allocator.cpp
@@ -0,0 +1,345 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "linker_allocator.h"
+#include "linker_debug.h"
+#include "linker.h"
+
+#include <algorithm>
+#include <vector>
+
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include "private/bionic_prctl.h"
+
+//
+// LinkerMemeoryAllocator is general purpose allocator
+// designed to provide the same functionality as the malloc/free/realloc
+// libc functions.
+//
+// On alloc:
+// If size is >= 1k allocator proxies malloc call directly to mmap
+// If size < 1k allocator uses SmallObjectAllocator for the size
+// rounded up to the nearest power of two.
+//
+// On free:
+//
+// For a pointer allocated using proxy-to-mmap allocator unmaps
+// the memory.
+//
+// For a pointer allocated using SmallObjectAllocator it adds
+// the block to free_blocks_list_. If the number of free pages reaches 2,
+// SmallObjectAllocator munmaps one of the pages keeping the other one
+// in reserve.
+
+static const char kSignature[4] = {'L', 'M', 'A', 1};
+
+static const size_t kSmallObjectMaxSize = 1 << kSmallObjectMaxSizeLog2;
+
+// This type is used for large allocations (with size >1k)
+static const uint32_t kLargeObject = 111;
+
+bool operator<(const small_object_page_record& one, const small_object_page_record& two) {
+  return one.page_addr < two.page_addr;
+}
+
+static inline uint16_t log2(size_t number) {
+  uint16_t result = 0;
+  number--;
+
+  while (number != 0) {
+    result++;
+    number >>= 1;
+  }
+
+  return result;
+}
+
+LinkerSmallObjectAllocator::LinkerSmallObjectAllocator(uint32_t type, size_t block_size)
+    : type_(type), block_size_(block_size), free_pages_cnt_(0), free_blocks_list_(nullptr) {}
+
+void* LinkerSmallObjectAllocator::alloc() {
+  CHECK(block_size_ != 0);
+
+  if (free_blocks_list_ == nullptr) {
+    alloc_page();
+  }
+
+  small_object_block_record* block_record = free_blocks_list_;
+  if (block_record->free_blocks_cnt > 1) {
+    small_object_block_record* next_free = reinterpret_cast<small_object_block_record*>(
+        reinterpret_cast<uint8_t*>(block_record) + block_size_);
+    next_free->next = block_record->next;
+    next_free->free_blocks_cnt = block_record->free_blocks_cnt - 1;
+    free_blocks_list_ = next_free;
+  } else {
+    free_blocks_list_ = block_record->next;
+  }
+
+  // bookkeeping...
+  auto page_record = find_page_record(block_record);
+
+  if (page_record->allocated_blocks_cnt == 0) {
+    free_pages_cnt_--;
+  }
+
+  page_record->free_blocks_cnt--;
+  page_record->allocated_blocks_cnt++;
+
+  memset(block_record, 0, block_size_);
+
+  return block_record;
+}
+
+void LinkerSmallObjectAllocator::free_page(linker_vector_t::iterator page_record) {
+  void* page_start = reinterpret_cast<void*>(page_record->page_addr);
+  void* page_end = reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(page_start) + PAGE_SIZE);
+
+  while (free_blocks_list_ != nullptr &&
+      free_blocks_list_ > page_start &&
+      free_blocks_list_ < page_end) {
+    free_blocks_list_ = free_blocks_list_->next;
+  }
+
+  small_object_block_record* current = free_blocks_list_;
+
+  while (current != nullptr) {
+    while (current->next > page_start && current->next < page_end) {
+      current->next = current->next->next;
+    }
+
+    current = current->next;
+  }
+
+  munmap(page_start, PAGE_SIZE);
+  page_records_.erase(page_record);
+  free_pages_cnt_--;
+}
+
+void LinkerSmallObjectAllocator::free(void* ptr) {
+  auto page_record = find_page_record(ptr);
+
+  ssize_t offset = reinterpret_cast<uintptr_t>(ptr) - sizeof(page_info);
+
+  if (offset % block_size_ != 0) {
+    __libc_fatal("invalid pointer: %p (block_size=%zd)", ptr, block_size_);
+  }
+
+  memset(ptr, 0, block_size_);
+  small_object_block_record* block_record = reinterpret_cast<small_object_block_record*>(ptr);
+
+  block_record->next = free_blocks_list_;
+  block_record->free_blocks_cnt = 1;
+
+  free_blocks_list_ = block_record;
+
+  page_record->free_blocks_cnt++;
+  page_record->allocated_blocks_cnt--;
+
+  if (page_record->allocated_blocks_cnt == 0) {
+    if (free_pages_cnt_++ > 1) {
+      // if we already have a free page - unmap this one.
+      free_page(page_record);
+    }
+  }
+}
+
+linker_vector_t::iterator LinkerSmallObjectAllocator::find_page_record(void* ptr) {
+  void* addr = reinterpret_cast<void*>(PAGE_START(reinterpret_cast<uintptr_t>(ptr)));
+  small_object_page_record boundary;
+  boundary.page_addr = addr;
+  linker_vector_t::iterator it = std::lower_bound(
+      page_records_.begin(), page_records_.end(), boundary);
+
+  if (it == page_records_.end() || it->page_addr != addr) {
+    // not found...
+    __libc_fatal("page record for %p was not found (block_size=%zd)", ptr, block_size_);
+  }
+
+  return it;
+}
+
+void LinkerSmallObjectAllocator::create_page_record(void* page_addr, size_t free_blocks_cnt) {
+  small_object_page_record record;
+  record.page_addr = page_addr;
+  record.free_blocks_cnt = free_blocks_cnt;
+  record.allocated_blocks_cnt = 0;
+
+  linker_vector_t::iterator it = std::lower_bound(
+      page_records_.begin(), page_records_.end(), record);
+  page_records_.insert(it, record);
+}
+
+void LinkerSmallObjectAllocator::alloc_page() {
+  static_assert(sizeof(page_info) % 16 == 0,
+                "sizeof(page_info) is not multiple of 16");
+  void* map_ptr = mmap(nullptr, PAGE_SIZE,
+      PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);
+  if (map_ptr == MAP_FAILED) {
+    __libc_fatal("mmap failed");
+  }
+
+  prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, map_ptr, PAGE_SIZE, "linker_alloc_small_objects");
+
+  memset(map_ptr, 0, PAGE_SIZE);
+
+  page_info* info = reinterpret_cast<page_info*>(map_ptr);
+  memcpy(info->signature, kSignature, sizeof(kSignature));
+  info->type = type_;
+  info->allocator_addr = this;
+
+  size_t free_blocks_cnt = (PAGE_SIZE - sizeof(page_info))/block_size_;
+
+  create_page_record(map_ptr, free_blocks_cnt);
+
+  small_object_block_record* first_block = reinterpret_cast<small_object_block_record*>(info + 1);
+
+  first_block->next = free_blocks_list_;
+  first_block->free_blocks_cnt = free_blocks_cnt;
+
+  free_blocks_list_ = first_block;
+}
+
+
+void LinkerMemoryAllocator::initialize_allocators() {
+  if (allocators_ != nullptr) {
+    return;
+  }
+
+  LinkerSmallObjectAllocator* allocators =
+      reinterpret_cast<LinkerSmallObjectAllocator*>(allocators_buf_);
+
+  for (size_t i = 0; i < kSmallObjectAllocatorsCount; ++i) {
+    uint32_t type = i + kSmallObjectMinSizeLog2;
+    new (allocators + i) LinkerSmallObjectAllocator(type, 1 << type);
+  }
+
+  allocators_ = allocators;
+}
+
+void* LinkerMemoryAllocator::alloc_mmap(size_t size) {
+  size_t allocated_size = PAGE_END(size + sizeof(page_info));
+  void* map_ptr = mmap(nullptr, allocated_size,
+      PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);
+
+  if (map_ptr == MAP_FAILED) {
+    __libc_fatal("mmap failed");
+  }
+
+  prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, map_ptr, allocated_size, "linker_alloc_lob");
+
+  memset(map_ptr, 0, allocated_size);
+
+  page_info* info = reinterpret_cast<page_info*>(map_ptr);
+  memcpy(info->signature, kSignature, sizeof(kSignature));
+  info->type = kLargeObject;
+  info->allocated_size = allocated_size;
+
+  return info + 1;
+}
+
+void* LinkerMemoryAllocator::alloc(size_t size) {
+  // treat alloc(0) as alloc(1)
+  if (size == 0) {
+    size = 1;
+  }
+
+  if (size > kSmallObjectMaxSize) {
+    return alloc_mmap(size);
+  }
+
+  uint16_t log2_size = log2(size);
+
+  if (log2_size < kSmallObjectMinSizeLog2) {
+    log2_size = kSmallObjectMinSizeLog2;
+  }
+
+  return get_small_object_allocator(log2_size)->alloc();
+}
+
+page_info* LinkerMemoryAllocator::get_page_info(void* ptr) {
+  page_info* info = reinterpret_cast<page_info*>(PAGE_START(reinterpret_cast<size_t>(ptr)));
+  if (memcmp(info->signature, kSignature, sizeof(kSignature)) != 0) {
+    __libc_fatal("invalid pointer %p (page signature mismatch)", ptr);
+  }
+
+  return info;
+}
+
+void* LinkerMemoryAllocator::realloc(void* ptr, size_t size) {
+  if (ptr == nullptr) {
+    return alloc(size);
+  }
+
+  if (size == 0) {
+    free(ptr);
+    return nullptr;
+  }
+
+  page_info* info = get_page_info(ptr);
+
+  size_t old_size = 0;
+
+  if (info->type == kLargeObject) {
+    old_size = info->allocated_size - sizeof(page_info);
+  } else {
+    LinkerSmallObjectAllocator* allocator = get_small_object_allocator(info->type);
+    if (allocator != info->allocator_addr) {
+      __libc_fatal("invalid pointer %p (page signature mismatch)", ptr);
+    }
+
+    old_size = allocator->get_block_size();
+  }
+
+  if (old_size < size) {
+    void *result = alloc(size);
+    memcpy(result, ptr, old_size);
+    free(ptr);
+    return result;
+  }
+
+  return ptr;
+}
+
+void LinkerMemoryAllocator::free(void* ptr) {
+  if (ptr == nullptr) {
+    return;
+  }
+
+  page_info* info = get_page_info(ptr);
+
+  if (info->type == kLargeObject) {
+    munmap(info, info->allocated_size);
+  } else {
+    LinkerSmallObjectAllocator* allocator = get_small_object_allocator(info->type);
+    if (allocator != info->allocator_addr) {
+      __libc_fatal("invalid pointer %p (invalid allocator address for the page)", ptr);
+    }
+
+    allocator->free(ptr);
+  }
+}
+
+LinkerSmallObjectAllocator* LinkerMemoryAllocator::get_small_object_allocator(uint32_t type) {
+  if (type < kSmallObjectMinSizeLog2 || type > kSmallObjectMaxSizeLog2) {
+    __libc_fatal("invalid type: %u", type);
+  }
+
+  initialize_allocators();
+  return &allocators_[type - kSmallObjectMinSizeLog2];
+}
diff --git a/linker/linker_allocator.h b/linker/linker_allocator.h
new file mode 100644
index 0000000..8f90dbf
--- /dev/null
+++ b/linker/linker_allocator.h
@@ -0,0 +1,143 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __LINKER_ALLOCATOR_H
+#define __LINKER_ALLOCATOR_H
+
+#include <stdlib.h>
+#include <sys/cdefs.h>
+#include <sys/mman.h>
+#include <stddef.h>
+#include <unistd.h>
+
+#include <vector>
+
+#include "private/bionic_prctl.h"
+#include "private/libc_logging.h"
+
+const uint32_t kSmallObjectMaxSizeLog2 = 10;
+const uint32_t kSmallObjectMinSizeLog2 = 4;
+const uint32_t kSmallObjectAllocatorsCount = kSmallObjectMaxSizeLog2 - kSmallObjectMinSizeLog2 + 1;
+
+class LinkerSmallObjectAllocator;
+
+// This structure is placed at the beginning of each addressable page
+// and has all information we need to find the corresponding memory allocator.
+struct page_info {
+  char signature[4];
+  uint32_t type;
+  union {
+    // we use allocated_size for large objects allocator
+    size_t allocated_size;
+    // and allocator_addr for small ones.
+    LinkerSmallObjectAllocator* allocator_addr;
+  };
+} __attribute__((aligned(16)));
+
+struct small_object_page_record {
+  void* page_addr;
+  size_t free_blocks_cnt;
+  size_t allocated_blocks_cnt;
+};
+
+// for lower_bound...
+bool operator<(const small_object_page_record& one, const small_object_page_record& two);
+
+struct small_object_block_record {
+  small_object_block_record* next;
+  size_t free_blocks_cnt;
+};
+
+// This is implementation for std::vector allocator
+template <typename T>
+class linker_vector_allocator {
+ public:
+  typedef T value_type;
+  typedef T* pointer;
+  typedef const T* const_pointer;
+  typedef T& reference;
+  typedef const T& const_reference;
+  typedef size_t size_type;
+  typedef ptrdiff_t difference_type;
+
+  T* allocate(size_t n, const T* hint = nullptr) {
+    size_t size = n * sizeof(T);
+    void* ptr = mmap(const_cast<T*>(hint), size,
+        PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);
+    if (ptr == MAP_FAILED) {
+      // Spec says we need to throw std::bad_alloc here but because our
+      // code does not support exception handling anyways - we are going to abort.
+      __libc_fatal("mmap failed");
+    }
+
+    prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, ptr, size, "linker_alloc_vector");
+
+    return reinterpret_cast<T*>(ptr);
+  }
+
+  void deallocate(T* ptr, size_t n) {
+    munmap(ptr, n * sizeof(T));
+  }
+};
+
+typedef
+    std::vector<small_object_page_record, linker_vector_allocator<small_object_page_record>>
+    linker_vector_t;
+
+
+class LinkerSmallObjectAllocator {
+ public:
+  LinkerSmallObjectAllocator(uint32_t type, size_t block_size);
+  void* alloc();
+  void free(void* ptr);
+
+  size_t get_block_size() const { return block_size_; }
+ private:
+  void alloc_page();
+  void free_page(linker_vector_t::iterator page_record);
+  linker_vector_t::iterator find_page_record(void* ptr);
+  void create_page_record(void* page_addr, size_t free_blocks_cnt);
+
+  uint32_t type_;
+  size_t block_size_;
+
+  size_t free_pages_cnt_;
+  small_object_block_record* free_blocks_list_;
+
+  // sorted vector of page records
+  linker_vector_t page_records_;
+};
+
+class LinkerMemoryAllocator {
+ public:
+  constexpr LinkerMemoryAllocator() : allocators_(nullptr), allocators_buf_() {}
+  void* alloc(size_t size);
+
+  // Note that this implementation of realloc never shrinks allocation
+  void* realloc(void* ptr, size_t size);
+  void free(void* ptr);
+ private:
+  void* alloc_mmap(size_t size);
+  page_info* get_page_info(void* ptr);
+  LinkerSmallObjectAllocator* get_small_object_allocator(uint32_t type);
+  void initialize_allocators();
+
+  LinkerSmallObjectAllocator* allocators_;
+  uint8_t allocators_buf_[sizeof(LinkerSmallObjectAllocator)*kSmallObjectAllocatorsCount];
+};
+
+
+#endif  /* __LINKER_ALLOCATOR_H */
diff --git a/linker/linker_block_allocator.cpp b/linker/linker_block_allocator.cpp
new file mode 100644
index 0000000..23298a4
--- /dev/null
+++ b/linker/linker_block_allocator.cpp
@@ -0,0 +1,144 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "linker_block_allocator.h"
+#include <inttypes.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include "private/bionic_prctl.h"
+
+// the multiplier should be power of 2
+static constexpr size_t round_up(size_t size, size_t multiplier) {
+  return (size + (multiplier - 1)) & ~(multiplier-1);
+}
+
+struct LinkerBlockAllocatorPage {
+  LinkerBlockAllocatorPage* next;
+  uint8_t bytes[PAGE_SIZE - 16] __attribute__((aligned(16)));
+};
+
+struct FreeBlockInfo {
+  void* next_block;
+  size_t num_free_blocks;
+};
+
+LinkerBlockAllocator::LinkerBlockAllocator(size_t block_size)
+  : block_size_(
+      round_up(block_size < sizeof(FreeBlockInfo) ? sizeof(FreeBlockInfo) : block_size, 16)),
+    page_list_(nullptr),
+    free_block_list_(nullptr)
+{}
+
+void* LinkerBlockAllocator::alloc() {
+  if (free_block_list_ == nullptr) {
+    create_new_page();
+  }
+
+  FreeBlockInfo* block_info = reinterpret_cast<FreeBlockInfo*>(free_block_list_);
+  if (block_info->num_free_blocks > 1) {
+    FreeBlockInfo* next_block_info = reinterpret_cast<FreeBlockInfo*>(
+      reinterpret_cast<char*>(free_block_list_) + block_size_);
+    next_block_info->next_block = block_info->next_block;
+    next_block_info->num_free_blocks = block_info->num_free_blocks - 1;
+    free_block_list_ = next_block_info;
+  } else {
+    free_block_list_ = block_info->next_block;
+  }
+
+  memset(block_info, 0, block_size_);
+
+  return block_info;
+}
+
+void LinkerBlockAllocator::free(void* block) {
+  if (block == nullptr) {
+    return;
+  }
+
+  LinkerBlockAllocatorPage* page = find_page(block);
+
+  if (page == nullptr) {
+    abort();
+  }
+
+  ssize_t offset = reinterpret_cast<uint8_t*>(block) - page->bytes;
+
+  if (offset % block_size_ != 0) {
+    abort();
+  }
+
+  memset(block, 0, block_size_);
+
+  FreeBlockInfo* block_info = reinterpret_cast<FreeBlockInfo*>(block);
+
+  block_info->next_block = free_block_list_;
+  block_info->num_free_blocks = 1;
+
+  free_block_list_ = block_info;
+}
+
+void LinkerBlockAllocator::protect_all(int prot) {
+  for (LinkerBlockAllocatorPage* page = page_list_; page != nullptr; page = page->next) {
+    if (mprotect(page, PAGE_SIZE, prot) == -1) {
+      abort();
+    }
+  }
+}
+
+void LinkerBlockAllocator::create_new_page() {
+  static_assert(sizeof(LinkerBlockAllocatorPage) == PAGE_SIZE,
+                "Invalid sizeof(LinkerBlockAllocatorPage)");
+
+  LinkerBlockAllocatorPage* page = reinterpret_cast<LinkerBlockAllocatorPage*>(
+      mmap(nullptr, PAGE_SIZE, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, 0, 0));
+
+  if (page == MAP_FAILED) {
+    abort(); // oom
+  }
+
+  prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, page, PAGE_SIZE, "linker_alloc");
+
+  memset(page, 0, PAGE_SIZE);
+
+  FreeBlockInfo* first_block = reinterpret_cast<FreeBlockInfo*>(page->bytes);
+  first_block->next_block = free_block_list_;
+  first_block->num_free_blocks = (PAGE_SIZE - sizeof(LinkerBlockAllocatorPage*))/block_size_;
+
+  free_block_list_ = first_block;
+
+  page->next = page_list_;
+  page_list_ = page;
+}
+
+LinkerBlockAllocatorPage* LinkerBlockAllocator::find_page(void* block) {
+  if (block == nullptr) {
+    abort();
+  }
+
+  LinkerBlockAllocatorPage* page = page_list_;
+  while (page != nullptr) {
+    const uint8_t* page_ptr = reinterpret_cast<const uint8_t*>(page);
+    if (block >= (page_ptr + sizeof(page->next)) && block < (page_ptr + PAGE_SIZE)) {
+      return page;
+    }
+
+    page = page->next;
+  }
+
+  abort();
+}
diff --git a/linker/linker_block_allocator.h b/linker/linker_block_allocator.h
new file mode 100644
index 0000000..4b9b995
--- /dev/null
+++ b/linker/linker_block_allocator.h
@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __LINKER_BLOCK_ALLOCATOR_H
+#define __LINKER_BLOCK_ALLOCATOR_H
+
+#include <stdlib.h>
+#include <limits.h>
+#include "private/bionic_macros.h"
+
+struct LinkerBlockAllocatorPage;
+
+/*
+ * This class is a non-template version of the LinkerTypeAllocator
+ * It keeps code inside .cpp file by keeping the interface
+ * template-free.
+ *
+ * Please use LinkerTypeAllocator<type> where possible (everywhere).
+ */
+class LinkerBlockAllocator {
+ public:
+  explicit LinkerBlockAllocator(size_t block_size);
+
+  void* alloc();
+  void free(void* block);
+  void protect_all(int prot);
+
+ private:
+  void create_new_page();
+  LinkerBlockAllocatorPage* find_page(void* block);
+
+  size_t block_size_;
+  LinkerBlockAllocatorPage* page_list_;
+  void* free_block_list_;
+
+  DISALLOW_COPY_AND_ASSIGN(LinkerBlockAllocator);
+};
+
+/*
+ * A simple allocator for the dynamic linker. An allocator allocates instances
+ * of a single fixed-size type. Allocations are backed by page-sized private
+ * anonymous mmaps.
+ *
+ * The differences between this allocator and LinkerMemoryAllocator are:
+ * 1. This allocator manages space more efficiently. LinkerMemoryAllocator
+ *    operates in power-of-two sized blocks up to 1k, when this implementation
+ *    splits the page to aligned size of structure; For example for structures
+ *    with size 513 this allocator will use 516 (520 for lp64) bytes of data
+ *    where generalized implementation is going to use 1024 sized blocks.
+ *
+ * 2. This allocator does not munmap allocated memory, where LinkerMemoryAllocator does.
+ *
+ * 3. This allocator provides mprotect services to the user, where LinkerMemoryAllocator
+ *    always treats it's memory as READ|WRITE.
+ */
+template<typename T>
+class LinkerTypeAllocator {
+ public:
+  LinkerTypeAllocator() : block_allocator_(sizeof(T)) {}
+  T* alloc() { return reinterpret_cast<T*>(block_allocator_.alloc()); }
+  void free(T* t) { block_allocator_.free(t); }
+  void protect_all(int prot) { block_allocator_.protect_all(prot); }
+ private:
+  LinkerBlockAllocator block_allocator_;
+  DISALLOW_COPY_AND_ASSIGN(LinkerTypeAllocator);
+};
+
+#endif // __LINKER_BLOCK_ALLOCATOR_H
diff --git a/linker/linker_common_types.h b/linker/linker_common_types.h
new file mode 100644
index 0000000..6afd950
--- /dev/null
+++ b/linker/linker_common_types.h
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef __LINKER_COMMON_TYPES_H
+#define __LINKER_COMMON_TYPES_H
+
+#include <android/dlext.h>
+#include "linked_list.h"
+
+// TODO(dimitry): move this to linker_defines.h? Unless it is removed by
+// consequent refactoring steps.
+
+// Android uses RELA for aarch64 and x86_64. mips64 still uses REL.
+#if defined(__aarch64__) || defined(__x86_64__)
+#define USE_RELA 1
+#endif
+
+
+struct soinfo;
+
+class SoinfoListAllocator {
+ public:
+  static LinkedListEntry<soinfo>* alloc();
+  static void free(LinkedListEntry<soinfo>* entry);
+
+ private:
+  // unconstructable
+  DISALLOW_IMPLICIT_CONSTRUCTORS(SoinfoListAllocator);
+};
+
+class NamespaceListAllocator {
+ public:
+  static LinkedListEntry<android_namespace_t>* alloc();
+  static void free(LinkedListEntry<android_namespace_t>* entry);
+
+ private:
+  // unconstructable
+  DISALLOW_IMPLICIT_CONSTRUCTORS(NamespaceListAllocator);
+};
+
+typedef LinkedList<soinfo, SoinfoListAllocator> soinfo_list_t;
+typedef LinkedList<android_namespace_t, NamespaceListAllocator> android_namespace_list_t;
+
+#endif  /* __LINKER_COMMON_TYPES_H */
diff --git a/linker/linker_debug.h b/linker/linker_debug.h
new file mode 100644
index 0000000..5af9929
--- /dev/null
+++ b/linker/linker_debug.h
@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef _LINKER_DEBUG_H_
+#define _LINKER_DEBUG_H_
+
+// You can increase the verbosity of debug traces by defining the LD_DEBUG
+// environment variable to a numeric value from 0 to 2 (corresponding to
+// INFO, TRACE, and DEBUG calls in the source). This will only
+// affect new processes being launched.
+
+// By default, traces are sent to logcat, with the "linker" tag. You can
+// change this to go to stdout instead by setting the definition of
+// LINKER_DEBUG_TO_LOG to 0.
+#define LINKER_DEBUG_TO_LOG  1
+
+#define TRACE_DEBUG          1
+#define DO_TRACE_LOOKUP      1
+#define DO_TRACE_RELO        1
+#define DO_TRACE_IFUNC       1
+#define TIMING               0
+#define STATS                0
+#define COUNT_PAGES          0
+
+/*********************************************************************
+ * You shouldn't need to modify anything below unless you are adding
+ * more debugging information.
+ *
+ * To enable/disable specific debug options, change the defines above
+ *********************************************************************/
+
+#include "private/libc_logging.h"
+#include <unistd.h>
+
+__LIBC_HIDDEN__ extern int g_ld_debug_verbosity;
+
+#define CHECK(predicate) { \
+    if (!(predicate)) { \
+      __libc_fatal("%s:%d: %s CHECK '" #predicate "' failed", \
+          __FILE__, __LINE__, __FUNCTION__); \
+    } \
+  }
+
+#if LINKER_DEBUG_TO_LOG
+#define _PRINTVF(v, x...) \
+    do { \
+      if (g_ld_debug_verbosity > (v)) __libc_format_log(5-(v), "linker", x); \
+    } while (0)
+#else /* !LINKER_DEBUG_TO_LOG */
+#define _PRINTVF(v, x...) \
+    do { \
+      if (g_ld_debug_verbosity > (v)) { __libc_format_fd(1, x); write(1, "\n", 1); } \
+    } while (0)
+#endif /* !LINKER_DEBUG_TO_LOG */
+
+#define PRINT(x...)          _PRINTVF(-1, x)
+#define INFO(x...)           _PRINTVF(0, x)
+#define TRACE(x...)          _PRINTVF(1, x)
+
+#if TRACE_DEBUG
+#define DEBUG(x...)          _PRINTVF(2, "DEBUG: " x)
+#else /* !TRACE_DEBUG */
+#define DEBUG(x...)          do {} while (0)
+#endif /* TRACE_DEBUG */
+
+#define TRACE_TYPE(t, x...)   do { if (DO_TRACE_##t) { TRACE(x); } } while (0)
+
+#if COUNT_PAGES
+extern uint32_t bitmask[];
+#if defined(__LP64__)
+#define MARK(offset) \
+    do { \
+      if ((((offset) >> 12) >> 5) < 4096) \
+          bitmask[((offset) >> 12) >> 5] |= (1 << (((offset) >> 12) & 31)); \
+    } while (0)
+#else
+#define MARK(offset) \
+    do { \
+      bitmask[((offset) >> 12) >> 3] |= (1 << (((offset) >> 12) & 7)); \
+    } while (0)
+#endif
+#else
+#define MARK(x) do {} while (0)
+
+#endif
+
+#endif /* _LINKER_DEBUG_H_ */
diff --git a/linker/linker_dlwarning.cpp b/linker/linker_dlwarning.cpp
new file mode 100644
index 0000000..c53ad66
--- /dev/null
+++ b/linker/linker_dlwarning.cpp
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "linker_dlwarning.h"
+
+#include <strings.h>
+
+#include <string>
+
+static std::string current_msg;
+
+void add_dlwarning(const char* sopath, const char* message, const char* value) {
+  if (!current_msg.empty()) {
+    current_msg += '\n';
+  }
+
+  current_msg = current_msg + basename(sopath) + ": " + message;
+
+  if (value != nullptr) {
+    current_msg = current_msg + " \"" + value + "\"";
+  }
+}
+
+// Resets the current one (like dlerror but instead of
+// being thread-local it is process-local).
+void get_dlwarning(void* obj, void (*f)(void*, const char*)) {
+  if (current_msg.empty()) {
+    f(obj, nullptr);
+  } else {
+    std::string msg = current_msg;
+    current_msg.clear();
+    f(obj, msg.c_str());
+  }
+}
diff --git a/linker/linker_dlwarning.h b/linker/linker_dlwarning.h
new file mode 100644
index 0000000..0263c72
--- /dev/null
+++ b/linker/linker_dlwarning.h
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __LINKER_DLWARNING_H
+#define __LINKER_DLWARNING_H
+
+void add_dlwarning(const char* sopath, const char* message, const char* value = nullptr);
+
+// Resets the current one (like dlerror but instead of
+// being thread-local it is process-local). The user_data
+// is used to avoid forcing user into saving the message
+// to a global variable.
+void get_dlwarning(void* user_data, void (*f)(void*, const char*));
+
+#endif  /* __LINKER_DLWARNING_H */
diff --git a/linker/linker_gdb_support.cpp b/linker/linker_gdb_support.cpp
new file mode 100644
index 0000000..de74087
--- /dev/null
+++ b/linker/linker_gdb_support.cpp
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "linker_gdb_support.h"
+
+#include <pthread.h>
+
+#include "private/ScopedPthreadMutexLocker.h"
+
+// This function is an empty stub where GDB locates a breakpoint to get notified
+// about linker activity.
+extern "C"
+void __attribute__((noinline)) __attribute__((visibility("default"))) rtld_db_dlactivity();
+
+r_debug _r_debug =
+    {1, nullptr, reinterpret_cast<uintptr_t>(&rtld_db_dlactivity), r_debug::RT_CONSISTENT, 0};
+
+static pthread_mutex_t g__r_debug_mutex = PTHREAD_MUTEX_INITIALIZER;
+static link_map* r_debug_tail = nullptr;
+
+void insert_link_map_into_debug_map(link_map* map) {
+  // Stick the new library at the end of the list.
+  // gdb tends to care more about libc than it does
+  // about leaf libraries, and ordering it this way
+  // reduces the back-and-forth over the wire.
+  if (r_debug_tail != nullptr) {
+    r_debug_tail->l_next = map;
+    map->l_prev = r_debug_tail;
+    map->l_next = nullptr;
+  } else {
+    _r_debug.r_map = map;
+    map->l_prev = nullptr;
+    map->l_next = nullptr;
+  }
+  r_debug_tail = map;
+}
+
+void remove_link_map_from_debug_map(link_map* map) {
+  if (r_debug_tail == map) {
+    r_debug_tail = map->l_prev;
+  }
+
+  if (map->l_prev) {
+    map->l_prev->l_next = map->l_next;
+  }
+  if (map->l_next) {
+    map->l_next->l_prev = map->l_prev;
+  }
+}
+
+void notify_gdb_of_load(link_map* map) {
+  ScopedPthreadMutexLocker locker(&g__r_debug_mutex);
+
+  _r_debug.r_state = r_debug::RT_ADD;
+  rtld_db_dlactivity();
+
+  insert_link_map_into_debug_map(map);
+
+  _r_debug.r_state = r_debug::RT_CONSISTENT;
+  rtld_db_dlactivity();
+}
+
+void notify_gdb_of_unload(link_map* map) {
+  ScopedPthreadMutexLocker locker(&g__r_debug_mutex);
+
+  _r_debug.r_state = r_debug::RT_DELETE;
+  rtld_db_dlactivity();
+
+  remove_link_map_from_debug_map(map);
+
+  _r_debug.r_state = r_debug::RT_CONSISTENT;
+  rtld_db_dlactivity();
+}
+
+void notify_gdb_of_libraries() {
+  _r_debug.r_state = r_debug::RT_ADD;
+  rtld_db_dlactivity();
+  _r_debug.r_state = r_debug::RT_CONSISTENT;
+  rtld_db_dlactivity();
+}
+
diff --git a/linker/linker_gdb_support.h b/linker/linker_gdb_support.h
new file mode 100644
index 0000000..2a590ba
--- /dev/null
+++ b/linker/linker_gdb_support.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef __LINKER_GDB_SUPPORT_H
+#define __LINKER_GDB_SUPPORT_H
+
+#include <link.h>
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+void insert_link_map_into_debug_map(link_map* map);
+void remove_link_map_from_debug_map(link_map* map);
+void notify_gdb_of_load(link_map* map);
+void notify_gdb_of_unload(link_map* map);
+void notify_gdb_of_libraries();
+
+extern struct r_debug _r_debug;
+
+__END_DECLS
+
+#endif
diff --git a/linker/linker_globals.cpp b/linker/linker_globals.cpp
new file mode 100644
index 0000000..155ebf4
--- /dev/null
+++ b/linker/linker_globals.cpp
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+
+#include "linker_globals.h"
+#include "linker_namespaces.h"
+
+int g_argc = 0;
+char** g_argv = nullptr;
+char** g_envp = nullptr;
+
+android_namespace_t g_default_namespace;
+
+std::unordered_map<uintptr_t, soinfo*> g_soinfo_handles_map;
+
+static char __linker_dl_err_buf[768];
+
+char* linker_get_error_buffer() {
+  return &__linker_dl_err_buf[0];
+}
+
+size_t linker_get_error_buffer_size() {
+  return sizeof(__linker_dl_err_buf);
+}
+
diff --git a/linker/linker_globals.h b/linker/linker_globals.h
new file mode 100644
index 0000000..b6f8a04
--- /dev/null
+++ b/linker/linker_globals.h
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef __LINKER_GLOBALS_H
+#define __LINKER_GLOBALS_H
+
+#include <link.h>
+#include <stddef.h>
+
+#include <unordered_map>
+
+#define DL_ERR(fmt, x...) \
+    do { \
+      __libc_format_buffer(linker_get_error_buffer(), linker_get_error_buffer_size(), fmt, ##x); \
+      /* If LD_DEBUG is set high enough, log every dlerror(3) message. */ \
+      LD_LOG(kLogErrors, "%s\n", linker_get_error_buffer()); \
+    } while (false)
+
+#define DL_WARN(fmt, x...) \
+    do { \
+      __libc_format_log(ANDROID_LOG_WARN, "linker", fmt, ##x); \
+      __libc_format_fd(2, "WARNING: linker: "); \
+      __libc_format_fd(2, fmt, ##x); \
+      __libc_format_fd(2, "\n"); \
+    } while (false)
+
+#define DL_ERR_AND_LOG(fmt, x...) \
+  do { \
+    DL_ERR(fmt, x); \
+    PRINT(fmt, x); \
+  } while (false)
+
+constexpr ElfW(Versym) kVersymNotNeeded = 0;
+constexpr ElfW(Versym) kVersymGlobal = 1;
+
+// These values are used to call constructors for .init_array && .preinit_array
+extern int g_argc;
+extern char** g_argv;
+extern char** g_envp;
+
+struct soinfo;
+struct android_namespace_t;
+
+extern android_namespace_t g_default_namespace;
+
+extern std::unordered_map<uintptr_t, soinfo*> g_soinfo_handles_map;
+
+// Error buffer "variable"
+char* linker_get_error_buffer();
+size_t linker_get_error_buffer_size();
+
+#endif  /* __LINKER_GLOBALS_H */
diff --git a/linker/linker_libc_support.c b/linker/linker_libc_support.c
new file mode 100644
index 0000000..77a0252
--- /dev/null
+++ b/linker/linker_libc_support.c
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "../libc/arch-common/bionic/__dso_handle.h"
+#include "../libc/arch-common/bionic/pthread_atfork.h"
+
+int atexit(void (*function)(void) __attribute__((__unused__))) {
+  return -1;
+}
+
diff --git a/linker/linker_logger.cpp b/linker/linker_logger.cpp
new file mode 100644
index 0000000..a9d358a
--- /dev/null
+++ b/linker/linker_logger.cpp
@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <string.h>
+#include <sys/prctl.h>
+#include <sys/system_properties.h>
+#include <unistd.h>
+
+#include <string>
+#include <vector>
+
+#include "android-base/strings.h"
+#include "linker_logger.h"
+#include "private/libc_logging.h"
+
+LinkerLogger g_linker_logger;
+
+static const char* kSystemLdDebugProperty = "debug.ld.all";
+static const char* kLdDebugPropertyPrefix = "debug.ld.app.";
+
+static const char* kOptionErrors = "dlerror";
+static const char* kOptionDlopen = "dlopen";
+
+static std::string property_get(const char* name) {
+  char value[PROP_VALUE_MAX] = {};
+  __system_property_get(name, value);
+  return value;
+}
+
+static uint32_t ParseProperty(const std::string& value) {
+  if (value.empty()) {
+    return 0;
+  }
+
+  std::vector<std::string> options = android::base::Split(value, ",");
+
+  uint32_t flags = 0;
+
+  for (const auto& o : options) {
+    if (o == kOptionErrors) {
+      flags |= kLogErrors;
+    } else if (o == kOptionDlopen){
+      flags |= kLogDlopen;
+    } else {
+      __libc_format_log(ANDROID_LOG_WARN, "linker", "Unknown debug.ld option \"%s\", will ignore.", o.c_str());
+    }
+  }
+
+  return flags;
+}
+
+void LinkerLogger::ResetState() {
+  // the most likely scenario app is not debuggable and
+  // is running on user build - the logging is disabled.
+  if (prctl(PR_GET_DUMPABLE, 0, 0, 0, 0) == 0) {
+    return;
+  }
+
+  flags_ = 0;
+  // check flag applied to all processes first
+  std::string value = property_get(kSystemLdDebugProperty);
+  flags_ |= ParseProperty(value);
+
+  // get process basename
+  std::string process_name = basename(g_argv[0]);
+
+  std::string property_name = std::string(kLdDebugPropertyPrefix) + process_name;
+
+  // Property names are limited to PROP_NAME_MAX.
+
+  if (property_name.size() >= PROP_NAME_MAX) {
+    size_t count = PROP_NAME_MAX - 1;
+    // remove trailing dots...
+    while (property_name[count-1] == '.') {
+      --count;
+    }
+
+    property_name = property_name.substr(0, count);
+  }
+  value = property_get(property_name.c_str());
+  flags_ |= ParseProperty(value);
+}
+
+void LinkerLogger::Log(uint32_t type, const char* format, ...) {
+  if ((flags_ & type) == 0) {
+    return;
+  }
+
+  va_list ap;
+  va_start(ap, format);
+  __libc_format_log_va_list(ANDROID_LOG_DEBUG, "linker", format, ap);
+  va_end(ap);
+}
+
diff --git a/linker/linker_logger.h b/linker/linker_logger.h
new file mode 100644
index 0000000..0932471
--- /dev/null
+++ b/linker/linker_logger.h
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef _LINKER_LOGGER_H_
+#define _LINKER_LOGGER_H_
+
+#include <stdlib.h>
+#include <limits.h>
+#include "private/bionic_macros.h"
+
+#define LD_LOG(type, x...) \
+  { \
+    g_linker_logger.Log(type, x); \
+  }
+
+constexpr const uint32_t kLogErrors = 1 << 0;
+constexpr const uint32_t kLogDlopen = 1 << 1;
+
+class LinkerLogger {
+ public:
+  LinkerLogger() : flags_(0) { }
+
+  void ResetState();
+  void Log(uint32_t type, const char* format, ...);
+ private:
+  uint32_t flags_;
+
+  DISALLOW_COPY_AND_ASSIGN(LinkerLogger);
+};
+
+extern LinkerLogger g_linker_logger;
+extern char** g_argv;
+
+#endif /* _LINKER_LOGGER_H_ */
diff --git a/linker/linker_mapped_file_fragment.cpp b/linker/linker_mapped_file_fragment.cpp
new file mode 100644
index 0000000..27c1c69
--- /dev/null
+++ b/linker/linker_mapped_file_fragment.cpp
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "linker_mapped_file_fragment.h"
+#include "linker_debug.h"
+#include "linker_utils.h"
+
+#include <inttypes.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+MappedFileFragment::MappedFileFragment() : map_start_(nullptr), map_size_(0),
+                                           data_(nullptr), size_ (0)
+{ }
+
+MappedFileFragment::~MappedFileFragment() {
+  if (map_start_ != nullptr) {
+    munmap(map_start_, map_size_);
+  }
+}
+
+bool MappedFileFragment::Map(int fd, off64_t base_offset, size_t elf_offset, size_t size) {
+  off64_t offset;
+  CHECK(safe_add(&offset, base_offset, elf_offset));
+
+  off64_t page_min = page_start(offset);
+  off64_t end_offset;
+
+  CHECK(safe_add(&end_offset, offset, size));
+  CHECK(safe_add(&end_offset, end_offset, page_offset(offset)));
+
+  size_t map_size = static_cast<size_t>(end_offset - page_min);
+  CHECK(map_size >= size);
+
+  uint8_t* map_start = static_cast<uint8_t*>(
+                          mmap64(nullptr, map_size, PROT_READ, MAP_PRIVATE, fd, page_min));
+
+  if (map_start == MAP_FAILED) {
+    return false;
+  }
+
+  map_start_ = map_start;
+  map_size_ = map_size;
+
+  data_ = map_start + page_offset(offset);
+  size_ = size;
+
+  return true;
+}
diff --git a/linker/linker_mapped_file_fragment.h b/linker/linker_mapped_file_fragment.h
new file mode 100644
index 0000000..91bd077
--- /dev/null
+++ b/linker/linker_mapped_file_fragment.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef LINKER_MAPPED_FILE_FRAGMENT_H
+#define LINKER_MAPPED_FILE_FRAGMENT_H
+
+#include <unistd.h>
+
+#include "private/bionic_macros.h"
+
+class MappedFileFragment {
+ public:
+  MappedFileFragment();
+  ~MappedFileFragment();
+
+  bool Map(int fd, off64_t base_offset, size_t elf_offset, size_t size);
+
+  void* data() const { return data_; }
+  size_t size() const { return size_; }
+ private:
+  void* map_start_;
+  size_t map_size_;
+  void* data_;
+  size_t size_;
+
+  DISALLOW_COPY_AND_ASSIGN(MappedFileFragment);
+};
+
+#endif /* LINKER_MAPPED_FILE_FRAGMENT_H */
diff --git a/linker/linker_memory.cpp b/linker/linker_memory.cpp
new file mode 100644
index 0000000..1892d02
--- /dev/null
+++ b/linker/linker_memory.cpp
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "linker_allocator.h"
+
+#include <stdlib.h>
+
+static LinkerMemoryAllocator g_linker_allocator;
+
+void* malloc(size_t byte_count) {
+  return g_linker_allocator.alloc(byte_count);
+}
+
+void* calloc(size_t item_count, size_t item_size) {
+  return g_linker_allocator.alloc(item_count*item_size);
+}
+
+void* realloc(void* p, size_t byte_count) {
+  return g_linker_allocator.realloc(p, byte_count);
+}
+
+void free(void* ptr) {
+  g_linker_allocator.free(ptr);
+}
+
diff --git a/linker/linker_mips.cpp b/linker/linker_mips.cpp
new file mode 100644
index 0000000..cd392dc
--- /dev/null
+++ b/linker/linker_mips.cpp
@@ -0,0 +1,333 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if !defined(__LP64__) && __mips_isa_rev >= 5
+#include <sys/prctl.h>
+#endif
+
+#include "linker.h"
+#include "linker_debug.h"
+#include "linker_globals.h"
+#include "linker_phdr.h"
+#include "linker_relocs.h"
+#include "linker_reloc_iterators.h"
+#include "linker_sleb128.h"
+#include "linker_soinfo.h"
+
+template bool soinfo::relocate<plain_reloc_iterator>(const VersionTracker& version_tracker,
+                                                     plain_reloc_iterator&& rel_iterator,
+                                                     const soinfo_list_t& global_group,
+                                                     const soinfo_list_t& local_group);
+
+template bool soinfo::relocate<packed_reloc_iterator<sleb128_decoder>>(
+    const VersionTracker& version_tracker,
+    packed_reloc_iterator<sleb128_decoder>&& rel_iterator,
+    const soinfo_list_t& global_group,
+    const soinfo_list_t& local_group);
+
+template <typename ElfRelIteratorT>
+bool soinfo::relocate(const VersionTracker& version_tracker,
+                      ElfRelIteratorT&& rel_iterator,
+                      const soinfo_list_t& global_group,
+                      const soinfo_list_t& local_group) {
+  for (size_t idx = 0; rel_iterator.has_next(); ++idx) {
+    const auto rel = rel_iterator.next();
+
+    if (rel == nullptr) {
+      return false;
+    }
+
+    ElfW(Word) type = ELFW(R_TYPE)(rel->r_info);
+    ElfW(Word) sym = ELFW(R_SYM)(rel->r_info);
+
+    ElfW(Addr) reloc = static_cast<ElfW(Addr)>(rel->r_offset + load_bias);
+    ElfW(Addr) sym_addr = 0;
+    const char* sym_name = nullptr;
+
+    DEBUG("Processing \"%s\" relocation at index %zd", get_realpath(), idx);
+    if (type == R_GENERIC_NONE) {
+      continue;
+    }
+
+    const ElfW(Sym)* s = nullptr;
+    soinfo* lsi = nullptr;
+
+    if (sym != 0) {
+      sym_name = get_string(symtab_[sym].st_name);
+      const version_info* vi = nullptr;
+
+      if (!lookup_version_info(version_tracker, sym, sym_name, &vi)) {
+        return false;
+      }
+
+      if (!soinfo_do_lookup(this, sym_name, vi, &lsi, global_group, local_group, &s)) {
+        return false;
+      }
+
+      if (s == nullptr) {
+        // mips does not support relocation with weak-undefined symbols
+        DL_ERR("cannot locate symbol \"%s\" referenced by \"%s\"...",
+               sym_name, get_realpath());
+        return false;
+      } else {
+        // We got a definition.
+        sym_addr = lsi->resolve_symbol_address(s);
+      }
+      count_relocation(kRelocSymbol);
+    }
+
+    switch (type) {
+      case R_MIPS_REL32:
+#if defined(__LP64__)
+        // MIPS Elf64_Rel entries contain compound relocations
+        // We only handle the R_MIPS_NONE|R_MIPS_64|R_MIPS_REL32 case
+        if (ELF64_R_TYPE2(rel->r_info) != R_MIPS_64 ||
+            ELF64_R_TYPE3(rel->r_info) != R_MIPS_NONE) {
+          DL_ERR("Unexpected compound relocation type:%d type2:%d type3:%d @ %p (%zu)",
+                 type, static_cast<unsigned>(ELF64_R_TYPE2(rel->r_info)),
+                 static_cast<unsigned>(ELF64_R_TYPE3(rel->r_info)), rel, idx);
+          return false;
+        }
+#endif
+        count_relocation(s == nullptr ? kRelocAbsolute : kRelocRelative);
+        MARK(rel->r_offset);
+        TRACE_TYPE(RELO, "RELO REL32 %08zx <- %08zx %s", static_cast<size_t>(reloc),
+                   static_cast<size_t>(sym_addr), sym_name ? sym_name : "*SECTIONHDR*");
+        if (s != nullptr) {
+          *reinterpret_cast<ElfW(Addr)*>(reloc) += sym_addr;
+        } else {
+          *reinterpret_cast<ElfW(Addr)*>(reloc) += load_bias;
+        }
+        break;
+      default:
+        DL_ERR("unknown reloc type %d @ %p (%zu)", type, rel, idx);
+        return false;
+    }
+  }
+  return true;
+}
+
+bool soinfo::mips_relocate_got(const VersionTracker& version_tracker,
+                               const soinfo_list_t& global_group,
+                               const soinfo_list_t& local_group) {
+  ElfW(Addr)** got = plt_got_;
+  if (got == nullptr) {
+    return true;
+  }
+
+  // got[0] is the address of the lazy resolver function.
+  // got[1] may be used for a GNU extension.
+  // Set it to a recognizable address in case someone calls it (should be _rtld_bind_start).
+  // FIXME: maybe this should be in a separate routine?
+  if ((flags_ & FLAG_LINKER) == 0) {
+    size_t g = 0;
+    got[g++] = reinterpret_cast<ElfW(Addr)*>(0xdeadbeef);
+    if (reinterpret_cast<intptr_t>(got[g]) < 0) {
+      got[g++] = reinterpret_cast<ElfW(Addr)*>(0xdeadfeed);
+    }
+    // Relocate the local GOT entries.
+    for (; g < mips_local_gotno_; g++) {
+      got[g] = reinterpret_cast<ElfW(Addr)*>(reinterpret_cast<uintptr_t>(got[g]) + load_bias);
+    }
+  }
+
+  // Now for the global GOT entries...
+  got = plt_got_ + mips_local_gotno_;
+  for (ElfW(Word) sym = mips_gotsym_; sym < mips_symtabno_; sym++, got++) {
+    // This is an undefined reference... try to locate it.
+    const ElfW(Sym)* local_sym = symtab_ + sym;
+    const char* sym_name = get_string(local_sym->st_name);
+    soinfo* lsi = nullptr;
+    const ElfW(Sym)* s = nullptr;
+
+    ElfW(Word) st_visibility = (local_sym->st_other & 0x3);
+
+    if (st_visibility == STV_DEFAULT) {
+      const version_info* vi = nullptr;
+
+      if (!lookup_version_info(version_tracker, sym, sym_name, &vi)) {
+        return false;
+      }
+
+      if (!soinfo_do_lookup(this, sym_name, vi, &lsi, global_group, local_group, &s)) {
+        return false;
+      }
+    } else if (st_visibility == STV_PROTECTED) {
+      if (local_sym->st_value == 0) {
+        DL_ERR("%s: invalid symbol \"%s\" (PROTECTED/UNDEFINED) ",
+               get_realpath(), sym_name);
+        return false;
+      }
+      s = local_sym;
+      lsi = this;
+    } else {
+      DL_ERR("%s: invalid symbol \"%s\" visibility: 0x%x",
+             get_realpath(), sym_name, st_visibility);
+      return false;
+    }
+
+    if (s == nullptr) {
+      // We only allow an undefined symbol if this is a weak reference.
+      if (ELF_ST_BIND(local_sym->st_info) != STB_WEAK) {
+        DL_ERR("%s: cannot locate \"%s\"...", get_realpath(), sym_name);
+        return false;
+      }
+      *got = 0;
+    } else {
+      // FIXME: is this sufficient?
+      // For reference see NetBSD link loader
+      // http://cvsweb.netbsd.org/bsdweb.cgi/src/libexec/ld.elf_so/arch/mips/mips_reloc.c?rev=1.53&content-type=text/x-cvsweb-markup
+      *got = reinterpret_cast<ElfW(Addr)*>(lsi->resolve_symbol_address(s));
+    }
+  }
+  return true;
+}
+
+#if !defined(__LP64__)
+
+// Checks for mips32's various floating point abis.
+// (Mips64 Android has a single floating point abi and doesn't need any checks)
+
+// Linux kernel has declarations similar to the following
+//   in <linux>/arch/mips/include/asm/elf.h,
+// but that non-uapi internal header file will never be imported
+// into bionic's kernel headers.
+
+#define PT_MIPS_ABIFLAGS  0x70000003	// is .MIPS.abiflags segment
+
+struct mips_elf_abiflags_v0 {
+  uint16_t version;  // version of this structure
+  uint8_t  isa_level, isa_rev, gpr_size, cpr1_size, cpr2_size;
+  uint8_t  fp_abi;  // mips32 ABI variants for floating point
+  uint32_t isa_ext, ases, flags1, flags2;
+};
+
+// Bits of flags1:
+#define MIPS_AFL_FLAGS1_ODDSPREG 1  // Uses odd-numbered single-prec fp regs
+
+// Some values of fp_abi:        via compiler flag:
+#define MIPS_ABI_FP_DOUBLE 1  // -mdouble-float
+#define MIPS_ABI_FP_XX     5  // -mfpxx
+#define MIPS_ABI_FP_64A    7  // -mips32r* -mfp64 -mno-odd-spreg
+
+#if __mips_isa_rev >= 5
+static bool mips_fre_mode_on = false;  // have set FRE=1 mode for process
+#endif
+
+bool soinfo::mips_check_and_adjust_fp_modes() {
+  mips_elf_abiflags_v0* abiflags = nullptr;
+  int mips_fpabi;
+
+  // Find soinfo's optional .MIPS.abiflags segment
+  for (size_t i = 0; i<phnum; ++i) {
+    const ElfW(Phdr)& ph = phdr[i];
+    if (ph.p_type == PT_MIPS_ABIFLAGS) {
+      if (ph.p_filesz < sizeof (mips_elf_abiflags_v0)) {
+        DL_ERR("Corrupt PT_MIPS_ABIFLAGS header found \"%s\"", get_realpath());
+        return false;
+      }
+      abiflags = reinterpret_cast<mips_elf_abiflags_v0*>(ph.p_vaddr + load_bias);
+      break;
+    }
+  }
+
+  // FP ABI-variant compatibility checks for MIPS o32 ABI
+  if (abiflags == nullptr) {
+    // Old compilers lack the new abiflags section.
+    // These compilers used -mfp32 -mdouble-float -modd-spreg defaults,
+    //   ie FP32 aka DOUBLE, using odd-numbered single-prec regs
+    mips_fpabi = MIPS_ABI_FP_DOUBLE;
+  } else {
+    mips_fpabi = abiflags->fp_abi;
+    if ( (abiflags->flags1 & MIPS_AFL_FLAGS1_ODDSPREG)
+         && (mips_fpabi == MIPS_ABI_FP_XX ||
+             mips_fpabi == MIPS_ABI_FP_64A   ) ) {
+      // Android supports fewer cases than Linux
+      DL_ERR("Unsupported odd-single-prec FloatPt reg uses in \"%s\"",
+             get_realpath());
+      return false;
+    }
+  }
+  if (!(mips_fpabi == MIPS_ABI_FP_DOUBLE ||
+#if __mips_isa_rev >= 5
+        mips_fpabi == MIPS_ABI_FP_64A    ||
+#endif
+        mips_fpabi == MIPS_ABI_FP_XX       )) {
+    DL_ERR("Unsupported MIPS32 FloatPt ABI %d found in \"%s\"",
+           mips_fpabi, get_realpath());
+    return false;
+  }
+
+#if __mips_isa_rev >= 5
+  // Adjust process's FR Emulation mode, if needed
+  //
+  // On Mips R5 & R6, Android runs continuously in FR=1 64bit-fpreg mode.
+  // NDK mips32 apps compiled with old compilers generate FP32 code
+  //   which expects FR=0 32-bit fp registers.
+  // NDK mips32 apps compiled with newer compilers generate modeless
+  //   FPXX code which runs on both FR=0 and FR=1 modes.
+  // Android itself is compiled in FP64A which requires FR=1 mode.
+  // FP32, FPXX, and FP64A all interlink okay, without dynamic FR mode
+  //   changes during calls.  For details, see
+  //   http://dmz-portal.mips.com/wiki/MIPS_O32_ABI_-_FR0_and_FR1_Interlinking
+  // Processes containing FR32 FR=0 code are run via kernel software assist,
+  //   which maps all odd-numbered single-precision reg refs onto the
+  //   upper half of the paired even-numbered double-precision reg.
+  // FRE=1 triggers traps to the kernel's emulator on every single-precision
+  //   fp op (for both odd and even-numbered registers).
+  // Turning on FRE=1 traps is done at most once per process, simultanously
+  //   for all threads of that process, when dlopen discovers FP32 code.
+  // The kernel repacks threads' registers when FRE mode is turn on or off.
+  //   These asynchronous adjustments are wrong if any thread was executing
+  //   FPXX code using odd-numbered single-precision regs.
+  // Current Android compilers default to the -mno-oddspreg option,
+  //   and this requirement is checked by Android's dlopen.
+  //   So FRE can always be safely turned on for FP32, anytime.
+  // Deferred enhancement: Allow loading of odd-spreg FPXX modules.
+
+  if (mips_fpabi == MIPS_ABI_FP_DOUBLE && !mips_fre_mode_on) {
+    // Turn on FRE mode, which emulates mode-sensitive FR=0 code on FR=1
+    //   register files, by trapping to kernel on refs to single-precision regs
+    if (prctl(PR_SET_FP_MODE, PR_FP_MODE_FR|PR_FP_MODE_FRE)) {
+      DL_ERR("Kernel or cpu failed to set FRE mode required for running \"%s\"",
+             get_realpath());
+      return false;
+    }
+    DL_WARN("Using FRE=1 mode to run \"%s\"", get_realpath());
+    mips_fre_mode_on = true;  // Avoid future redundant mode-switch calls
+    // FRE mode is never turned back off.
+    // Deferred enhancement:
+    //   Reset FRE mode when dlclose() removes all FP32 modules
+  }
+#else
+  // Android runs continuously in FR=0 32bit-fpreg mode.
+#endif  // __mips_isa_rev
+  return true;
+}
+
+#endif  // __LP64___
diff --git a/linker/linker_namespaces.cpp b/linker/linker_namespaces.cpp
new file mode 100644
index 0000000..675f324
--- /dev/null
+++ b/linker/linker_namespaces.cpp
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "linker_namespaces.h"
+#include "linker_utils.h"
+
+#include <vector>
+
+bool android_namespace_t::is_accessible(const std::string& file) {
+  if (!is_isolated_) {
+    return true;
+  }
+
+  for (const auto& dir : ld_library_paths_) {
+    if (file_is_in_dir(file, dir)) {
+      return true;
+    }
+  }
+
+  for (const auto& dir : default_library_paths_) {
+    if (file_is_in_dir(file, dir)) {
+      return true;
+    }
+  }
+
+  for (const auto& dir : permitted_paths_) {
+    if (file_is_under_dir(file, dir)) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
diff --git a/linker/linker_namespaces.h b/linker/linker_namespaces.h
new file mode 100644
index 0000000..c1cee8e
--- /dev/null
+++ b/linker/linker_namespaces.h
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef __LINKER_NAMESPACES_H
+#define __LINKER_NAMESPACES_H
+
+#include "linker_common_types.h"
+
+#include <string>
+#include <vector>
+
+struct android_namespace_t {
+ public:
+  android_namespace_t() : name_(nullptr), is_isolated_(false) {}
+
+  const char* get_name() const { return name_; }
+  void set_name(const char* name) { name_ = name; }
+
+  bool is_isolated() const { return is_isolated_; }
+  void set_isolated(bool isolated) { is_isolated_ = isolated; }
+
+  const std::vector<std::string>& get_ld_library_paths() const {
+    return ld_library_paths_;
+  }
+  void set_ld_library_paths(std::vector<std::string>&& library_paths) {
+    ld_library_paths_ = library_paths;
+  }
+
+  const std::vector<std::string>& get_default_library_paths() const {
+    return default_library_paths_;
+  }
+  void set_default_library_paths(std::vector<std::string>&& library_paths) {
+    default_library_paths_ = library_paths;
+  }
+
+  const std::vector<std::string>& get_permitted_paths() const {
+    return permitted_paths_;
+  }
+  void set_permitted_paths(std::vector<std::string>&& permitted_paths) {
+    permitted_paths_ = permitted_paths;
+  }
+
+  void add_soinfo(soinfo* si) {
+    soinfo_list_.push_back(si);
+  }
+
+  void add_soinfos(const soinfo_list_t& soinfos) {
+    for (auto si : soinfos) {
+      add_soinfo(si);
+    }
+  }
+
+  void remove_soinfo(soinfo* si) {
+    soinfo_list_.remove_if([&](soinfo* candidate) {
+      return si == candidate;
+    });
+  }
+
+  const soinfo_list_t& soinfo_list() const { return soinfo_list_; }
+
+  // For isolated namespaces - checks if the file is on the search path;
+  // always returns true for not isolated namespace.
+  bool is_accessible(const std::string& path);
+
+ private:
+  const char* name_;
+  bool is_isolated_;
+  std::vector<std::string> ld_library_paths_;
+  std::vector<std::string> default_library_paths_;
+  std::vector<std::string> permitted_paths_;
+  soinfo_list_t soinfo_list_;
+
+  DISALLOW_COPY_AND_ASSIGN(android_namespace_t);
+};
+
+#endif  /* __LINKER_NAMESPACES_H */
diff --git a/linker/linker_phdr.cpp b/linker/linker_phdr.cpp
new file mode 100644
index 0000000..bced722
--- /dev/null
+++ b/linker/linker_phdr.cpp
@@ -0,0 +1,1068 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "linker_phdr.h"
+
+#include <errno.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "linker.h"
+#include "linker_globals.h"
+#include "linker_debug.h"
+#include "linker_utils.h"
+
+#include "private/bionic_prctl.h"
+
+static int GetTargetElfMachine() {
+#if defined(__arm__)
+  return EM_ARM;
+#elif defined(__aarch64__)
+  return EM_AARCH64;
+#elif defined(__i386__)
+  return EM_386;
+#elif defined(__mips__)
+  return EM_MIPS;
+#elif defined(__x86_64__)
+  return EM_X86_64;
+#endif
+}
+
+/**
+  TECHNICAL NOTE ON ELF LOADING.
+
+  An ELF file's program header table contains one or more PT_LOAD
+  segments, which corresponds to portions of the file that need to
+  be mapped into the process' address space.
+
+  Each loadable segment has the following important properties:
+
+    p_offset  -> segment file offset
+    p_filesz  -> segment file size
+    p_memsz   -> segment memory size (always >= p_filesz)
+    p_vaddr   -> segment's virtual address
+    p_flags   -> segment flags (e.g. readable, writable, executable)
+
+  We will ignore the p_paddr and p_align fields of ElfW(Phdr) for now.
+
+  The loadable segments can be seen as a list of [p_vaddr ... p_vaddr+p_memsz)
+  ranges of virtual addresses. A few rules apply:
+
+  - the virtual address ranges should not overlap.
+
+  - if a segment's p_filesz is smaller than its p_memsz, the extra bytes
+    between them should always be initialized to 0.
+
+  - ranges do not necessarily start or end at page boundaries. Two distinct
+    segments can have their start and end on the same page. In this case, the
+    page inherits the mapping flags of the latter segment.
+
+  Finally, the real load addrs of each segment is not p_vaddr. Instead the
+  loader decides where to load the first segment, then will load all others
+  relative to the first one to respect the initial range layout.
+
+  For example, consider the following list:
+
+    [ offset:0,      filesz:0x4000, memsz:0x4000, vaddr:0x30000 ],
+    [ offset:0x4000, filesz:0x2000, memsz:0x8000, vaddr:0x40000 ],
+
+  This corresponds to two segments that cover these virtual address ranges:
+
+       0x30000...0x34000
+       0x40000...0x48000
+
+  If the loader decides to load the first segment at address 0xa0000000
+  then the segments' load address ranges will be:
+
+       0xa0030000...0xa0034000
+       0xa0040000...0xa0048000
+
+  In other words, all segments must be loaded at an address that has the same
+  constant offset from their p_vaddr value. This offset is computed as the
+  difference between the first segment's load address, and its p_vaddr value.
+
+  However, in practice, segments do _not_ start at page boundaries. Since we
+  can only memory-map at page boundaries, this means that the bias is
+  computed as:
+
+       load_bias = phdr0_load_address - PAGE_START(phdr0->p_vaddr)
+
+  (NOTE: The value must be used as a 32-bit unsigned integer, to deal with
+          possible wrap around UINT32_MAX for possible large p_vaddr values).
+
+  And that the phdr0_load_address must start at a page boundary, with
+  the segment's real content starting at:
+
+       phdr0_load_address + PAGE_OFFSET(phdr0->p_vaddr)
+
+  Note that ELF requires the following condition to make the mmap()-ing work:
+
+      PAGE_OFFSET(phdr0->p_vaddr) == PAGE_OFFSET(phdr0->p_offset)
+
+  The load_bias must be added to any p_vaddr value read from the ELF file to
+  determine the corresponding memory address.
+
+ **/
+
+#define MAYBE_MAP_FLAG(x, from, to)  (((x) & (from)) ? (to) : 0)
+#define PFLAGS_TO_PROT(x)            (MAYBE_MAP_FLAG((x), PF_X, PROT_EXEC) | \
+                                      MAYBE_MAP_FLAG((x), PF_R, PROT_READ) | \
+                                      MAYBE_MAP_FLAG((x), PF_W, PROT_WRITE))
+
+ElfReader::ElfReader()
+    : did_read_(false), did_load_(false), fd_(-1), file_offset_(0), file_size_(0), phdr_num_(0),
+      phdr_table_(nullptr), shdr_table_(nullptr), shdr_num_(0), dynamic_(nullptr), strtab_(nullptr),
+      strtab_size_(0), load_start_(nullptr), load_size_(0), load_bias_(0), loaded_phdr_(nullptr),
+      mapped_by_caller_(false) {
+}
+
+bool ElfReader::Read(const char* name, int fd, off64_t file_offset, off64_t file_size) {
+  CHECK(!did_read_);
+  CHECK(!did_load_);
+  name_ = name;
+  fd_ = fd;
+  file_offset_ = file_offset;
+  file_size_ = file_size;
+
+  if (ReadElfHeader() &&
+      VerifyElfHeader() &&
+      ReadProgramHeaders() &&
+      ReadSectionHeaders() &&
+      ReadDynamicSection()) {
+    did_read_ = true;
+  }
+
+  return did_read_;
+}
+
+bool ElfReader::Load(const android_dlextinfo* extinfo) {
+  CHECK(did_read_);
+  CHECK(!did_load_);
+  if (ReserveAddressSpace(extinfo) &&
+      LoadSegments() &&
+      FindPhdr()) {
+    did_load_ = true;
+  }
+
+  return did_load_;
+}
+
+const char* ElfReader::get_string(ElfW(Word) index) const {
+  CHECK(strtab_ != nullptr);
+  CHECK(index < strtab_size_);
+
+  return strtab_ + index;
+}
+
+bool ElfReader::ReadElfHeader() {
+  ssize_t rc = TEMP_FAILURE_RETRY(pread64(fd_, &header_, sizeof(header_), file_offset_));
+  if (rc < 0) {
+    DL_ERR("can't read file \"%s\": %s", name_.c_str(), strerror(errno));
+    return false;
+  }
+
+  if (rc != sizeof(header_)) {
+    DL_ERR("\"%s\" is too small to be an ELF executable: only found %zd bytes", name_.c_str(),
+           static_cast<size_t>(rc));
+    return false;
+  }
+  return true;
+}
+
+bool ElfReader::VerifyElfHeader() {
+  if (memcmp(header_.e_ident, ELFMAG, SELFMAG) != 0) {
+    DL_ERR("\"%s\" has bad ELF magic", name_.c_str());
+    return false;
+  }
+
+  // Try to give a clear diagnostic for ELF class mismatches, since they're
+  // an easy mistake to make during the 32-bit/64-bit transition period.
+  int elf_class = header_.e_ident[EI_CLASS];
+#if defined(__LP64__)
+  if (elf_class != ELFCLASS64) {
+    if (elf_class == ELFCLASS32) {
+      DL_ERR("\"%s\" is 32-bit instead of 64-bit", name_.c_str());
+    } else {
+      DL_ERR("\"%s\" has unknown ELF class: %d", name_.c_str(), elf_class);
+    }
+    return false;
+  }
+#else
+  if (elf_class != ELFCLASS32) {
+    if (elf_class == ELFCLASS64) {
+      DL_ERR("\"%s\" is 64-bit instead of 32-bit", name_.c_str());
+    } else {
+      DL_ERR("\"%s\" has unknown ELF class: %d", name_.c_str(), elf_class);
+    }
+    return false;
+  }
+#endif
+
+  if (header_.e_ident[EI_DATA] != ELFDATA2LSB) {
+    DL_ERR("\"%s\" not little-endian: %d", name_.c_str(), header_.e_ident[EI_DATA]);
+    return false;
+  }
+
+  if (header_.e_type != ET_DYN) {
+    DL_ERR("\"%s\" has unexpected e_type: %d", name_.c_str(), header_.e_type);
+    return false;
+  }
+
+  if (header_.e_version != EV_CURRENT) {
+    DL_ERR("\"%s\" has unexpected e_version: %d", name_.c_str(), header_.e_version);
+    return false;
+  }
+
+  if (header_.e_machine != GetTargetElfMachine()) {
+    DL_ERR("\"%s\" has unexpected e_machine: %d", name_.c_str(), header_.e_machine);
+    return false;
+  }
+
+  if (header_.e_shentsize != sizeof(ElfW(Shdr))) {
+    DL_ERR("\"%s\" has unsupported e_shentsize: 0x%x (expected 0x%zx)",
+           name_.c_str(), header_.e_shentsize, sizeof(ElfW(Shdr)));
+    return false;
+  }
+
+  if (header_.e_shstrndx == 0) {
+    DL_ERR("\"%s\" has invalid e_shstrndx", name_.c_str());
+    return false;
+  }
+
+  return true;
+}
+
+bool ElfReader::CheckFileRange(ElfW(Addr) offset, size_t size, size_t alignment) {
+  off64_t range_start;
+  off64_t range_end;
+
+  // Only header can be located at the 0 offset... This function called to
+  // check DYNSYM and DYNAMIC sections and phdr/shdr - none of them can be
+  // at offset 0.
+
+  return offset > 0 &&
+         safe_add(&range_start, file_offset_, offset) &&
+         safe_add(&range_end, range_start, size) &&
+         (range_start < file_size_) &&
+         (range_end <= file_size_) &&
+         ((offset % alignment) == 0);
+}
+
+// Loads the program header table from an ELF file into a read-only private
+// anonymous mmap-ed block.
+bool ElfReader::ReadProgramHeaders() {
+  phdr_num_ = header_.e_phnum;
+
+  // Like the kernel, we only accept program header tables that
+  // are smaller than 64KiB.
+  if (phdr_num_ < 1 || phdr_num_ > 65536/sizeof(ElfW(Phdr))) {
+    DL_ERR("\"%s\" has invalid e_phnum: %zd", name_.c_str(), phdr_num_);
+    return false;
+  }
+
+  // Boundary checks
+  size_t size = phdr_num_ * sizeof(ElfW(Phdr));
+  if (!CheckFileRange(header_.e_phoff, size, alignof(ElfW(Phdr)))) {
+    DL_ERR_AND_LOG("\"%s\" has invalid phdr offset/size: %zu/%zu",
+                   name_.c_str(),
+                   static_cast<size_t>(header_.e_phoff),
+                   size);
+    return false;
+  }
+
+  if (!phdr_fragment_.Map(fd_, file_offset_, header_.e_phoff, size)) {
+    DL_ERR("\"%s\" phdr mmap failed: %s", name_.c_str(), strerror(errno));
+    return false;
+  }
+
+  phdr_table_ = static_cast<ElfW(Phdr)*>(phdr_fragment_.data());
+  return true;
+}
+
+bool ElfReader::ReadSectionHeaders() {
+  shdr_num_ = header_.e_shnum;
+
+  if (shdr_num_ == 0) {
+    DL_ERR_AND_LOG("\"%s\" has no section headers", name_.c_str());
+    return false;
+  }
+
+  size_t size = shdr_num_ * sizeof(ElfW(Shdr));
+  if (!CheckFileRange(header_.e_shoff, size, alignof(const ElfW(Shdr)))) {
+    DL_ERR_AND_LOG("\"%s\" has invalid shdr offset/size: %zu/%zu",
+                   name_.c_str(),
+                   static_cast<size_t>(header_.e_shoff),
+                   size);
+    return false;
+  }
+
+  if (!shdr_fragment_.Map(fd_, file_offset_, header_.e_shoff, size)) {
+    DL_ERR("\"%s\" shdr mmap failed: %s", name_.c_str(), strerror(errno));
+    return false;
+  }
+
+  shdr_table_ = static_cast<const ElfW(Shdr)*>(shdr_fragment_.data());
+  return true;
+}
+
+bool ElfReader::ReadDynamicSection() {
+  // 1. Find .dynamic section (in section headers)
+  const ElfW(Shdr)* dynamic_shdr = nullptr;
+  for (size_t i = 0; i < shdr_num_; ++i) {
+    if (shdr_table_[i].sh_type == SHT_DYNAMIC) {
+      dynamic_shdr = &shdr_table_ [i];
+      break;
+    }
+  }
+
+  if (dynamic_shdr == nullptr) {
+    DL_ERR_AND_LOG("\"%s\" .dynamic section header was not found", name_.c_str());
+    return false;
+  }
+
+  // Make sure dynamic_shdr offset and size matches PT_DYNAMIC phdr
+  size_t pt_dynamic_offset = 0;
+  size_t pt_dynamic_filesz = 0;
+  for (size_t i = 0; i < phdr_num_; ++i) {
+    const ElfW(Phdr)* phdr = &phdr_table_[i];
+    if (phdr->p_type == PT_DYNAMIC) {
+      pt_dynamic_offset = phdr->p_offset;
+      pt_dynamic_filesz = phdr->p_filesz;
+    }
+  }
+
+  if (pt_dynamic_offset != dynamic_shdr->sh_offset) {
+    DL_ERR("\"%s\" .dynamic section has invalid offset: 0x%zx, "
+           "expected to match PT_DYNAMIC offset: 0x%zx",
+           name_.c_str(),
+           static_cast<size_t>(dynamic_shdr->sh_offset),
+           pt_dynamic_offset);
+    return false;
+  }
+
+  if (pt_dynamic_filesz != dynamic_shdr->sh_size) {
+    DL_ERR("\"%s\" .dynamic section has invalid size: 0x%zx, "
+           "expected to match PT_DYNAMIC filesz: 0x%zx",
+           name_.c_str(),
+           static_cast<size_t>(dynamic_shdr->sh_size),
+           pt_dynamic_filesz);
+    return false;
+  }
+
+  if (dynamic_shdr->sh_link >= shdr_num_) {
+    DL_ERR_AND_LOG("\"%s\" .dynamic section has invalid sh_link: %d",
+                   name_.c_str(),
+                   dynamic_shdr->sh_link);
+    return false;
+  }
+
+  const ElfW(Shdr)* strtab_shdr = &shdr_table_[dynamic_shdr->sh_link];
+
+  if (strtab_shdr->sh_type != SHT_STRTAB) {
+    DL_ERR_AND_LOG("\"%s\" .dynamic section has invalid link(%d) sh_type: %d (expected SHT_STRTAB)",
+                   name_.c_str(), dynamic_shdr->sh_link, strtab_shdr->sh_type);
+    return false;
+  }
+
+  if (!CheckFileRange(dynamic_shdr->sh_offset, dynamic_shdr->sh_size, alignof(const ElfW(Dyn)))) {
+    DL_ERR_AND_LOG("\"%s\" has invalid offset/size of .dynamic section", name_.c_str());
+    return false;
+  }
+
+  if (!dynamic_fragment_.Map(fd_, file_offset_, dynamic_shdr->sh_offset, dynamic_shdr->sh_size)) {
+    DL_ERR("\"%s\" dynamic section mmap failed: %s", name_.c_str(), strerror(errno));
+    return false;
+  }
+
+  dynamic_ = static_cast<const ElfW(Dyn)*>(dynamic_fragment_.data());
+
+  if (!CheckFileRange(strtab_shdr->sh_offset, strtab_shdr->sh_size, alignof(const char))) {
+    DL_ERR_AND_LOG("\"%s\" has invalid offset/size of the .strtab section linked from .dynamic section",
+                   name_.c_str());
+    return false;
+  }
+
+  if (!strtab_fragment_.Map(fd_, file_offset_, strtab_shdr->sh_offset, strtab_shdr->sh_size)) {
+    DL_ERR("\"%s\" strtab section mmap failed: %s", name_.c_str(), strerror(errno));
+    return false;
+  }
+
+  strtab_ = static_cast<const char*>(strtab_fragment_.data());
+  strtab_size_ = strtab_fragment_.size();
+  return true;
+}
+
+/* Returns the size of the extent of all the possibly non-contiguous
+ * loadable segments in an ELF program header table. This corresponds
+ * to the page-aligned size in bytes that needs to be reserved in the
+ * process' address space. If there are no loadable segments, 0 is
+ * returned.
+ *
+ * If out_min_vaddr or out_max_vaddr are not null, they will be
+ * set to the minimum and maximum addresses of pages to be reserved,
+ * or 0 if there is nothing to load.
+ */
+size_t phdr_table_get_load_size(const ElfW(Phdr)* phdr_table, size_t phdr_count,
+                                ElfW(Addr)* out_min_vaddr,
+                                ElfW(Addr)* out_max_vaddr) {
+  ElfW(Addr) min_vaddr = UINTPTR_MAX;
+  ElfW(Addr) max_vaddr = 0;
+
+  bool found_pt_load = false;
+  for (size_t i = 0; i < phdr_count; ++i) {
+    const ElfW(Phdr)* phdr = &phdr_table[i];
+
+    if (phdr->p_type != PT_LOAD) {
+      continue;
+    }
+    found_pt_load = true;
+
+    if (phdr->p_vaddr < min_vaddr) {
+      min_vaddr = phdr->p_vaddr;
+    }
+
+    if (phdr->p_vaddr + phdr->p_memsz > max_vaddr) {
+      max_vaddr = phdr->p_vaddr + phdr->p_memsz;
+    }
+  }
+  if (!found_pt_load) {
+    min_vaddr = 0;
+  }
+
+  min_vaddr = PAGE_START(min_vaddr);
+  max_vaddr = PAGE_END(max_vaddr);
+
+  if (out_min_vaddr != nullptr) {
+    *out_min_vaddr = min_vaddr;
+  }
+  if (out_max_vaddr != nullptr) {
+    *out_max_vaddr = max_vaddr;
+  }
+  return max_vaddr - min_vaddr;
+}
+
+// Reserve a virtual address range such that if it's limits were extended to the next 2**align
+// boundary, it would not overlap with any existing mappings.
+static void* ReserveAligned(void* hint, size_t size, size_t align) {
+  int mmap_flags = MAP_PRIVATE | MAP_ANONYMOUS;
+  // Address hint is only used in Art for the image mapping, and it is pretty important. Don't mess
+  // with it.
+  // FIXME: try an aligned allocation and fall back to plain mmap() if the former does not provide a
+  // mapping at the requested address?
+  if (align == PAGE_SIZE || hint != nullptr) {
+    void* mmap_ptr = mmap(hint, size, PROT_NONE, mmap_flags, -1, 0);
+    if (mmap_ptr == MAP_FAILED) {
+      return nullptr;
+    }
+    return mmap_ptr;
+  }
+
+  // Allocate enough space so that the end of the desired region aligned up is still inside the
+  // mapping.
+  size_t mmap_size = align_up(size, align) + align - PAGE_SIZE;
+  uint8_t* mmap_ptr =
+      reinterpret_cast<uint8_t*>(mmap(nullptr, mmap_size, PROT_NONE, mmap_flags, -1, 0));
+  if (mmap_ptr == MAP_FAILED) {
+    return nullptr;
+  }
+
+  uint8_t* first = align_up(mmap_ptr, align);
+  uint8_t* last = align_down(mmap_ptr + mmap_size, align) - size;
+  size_t n = arc4random_uniform((last - first) / PAGE_SIZE + 1);
+  uint8_t* start = first + n * PAGE_SIZE;
+  munmap(mmap_ptr, start - mmap_ptr);
+  munmap(start + size, mmap_ptr + mmap_size - (start + size));
+  return start;
+}
+
+// Reserve a virtual address range big enough to hold all loadable
+// segments of a program header table. This is done by creating a
+// private anonymous mmap() with PROT_NONE.
+bool ElfReader::ReserveAddressSpace(const android_dlextinfo* extinfo) {
+  ElfW(Addr) min_vaddr;
+  load_size_ = phdr_table_get_load_size(phdr_table_, phdr_num_, &min_vaddr);
+  if (load_size_ == 0) {
+    DL_ERR("\"%s\" has no loadable segments", name_.c_str());
+    return false;
+  }
+
+  uint8_t* addr = reinterpret_cast<uint8_t*>(min_vaddr);
+  void* start;
+  size_t reserved_size = 0;
+  bool reserved_hint = true;
+  bool strict_hint = false;
+  // Assume position independent executable by default.
+  void* mmap_hint = nullptr;
+
+  if (extinfo != nullptr) {
+    if (extinfo->flags & ANDROID_DLEXT_RESERVED_ADDRESS) {
+      reserved_size = extinfo->reserved_size;
+      reserved_hint = false;
+    } else if (extinfo->flags & ANDROID_DLEXT_RESERVED_ADDRESS_HINT) {
+      reserved_size = extinfo->reserved_size;
+    }
+
+    if (addr != nullptr && (extinfo->flags & ANDROID_DLEXT_FORCE_FIXED_VADDR) != 0) {
+      mmap_hint = addr;
+    } else if ((extinfo->flags & ANDROID_DLEXT_LOAD_AT_FIXED_ADDRESS) != 0) {
+      mmap_hint = extinfo->reserved_addr;
+      strict_hint = true;
+    }
+  }
+
+  if (load_size_ > reserved_size) {
+    if (!reserved_hint) {
+      DL_ERR("reserved address space %zd smaller than %zd bytes needed for \"%s\"",
+             reserved_size - load_size_, load_size_, name_.c_str());
+      return false;
+    }
+    start = ReserveAligned(mmap_hint, load_size_, kLibraryAlignment);
+    if (start == nullptr) {
+      DL_ERR("couldn't reserve %zd bytes of address space for \"%s\"", load_size_, name_.c_str());
+      return false;
+    }
+    if (strict_hint && (start != mmap_hint)) {
+      munmap(start, load_size_);
+      DL_ERR("couldn't reserve %zd bytes of address space at %p for \"%s\"",
+             load_size_, mmap_hint, name_.c_str());
+      return false;
+    }
+  } else {
+    start = extinfo->reserved_addr;
+    mapped_by_caller_ = true;
+  }
+
+  load_start_ = start;
+  load_bias_ = reinterpret_cast<uint8_t*>(start) - addr;
+  return true;
+}
+
+bool ElfReader::LoadSegments() {
+  for (size_t i = 0; i < phdr_num_; ++i) {
+    const ElfW(Phdr)* phdr = &phdr_table_[i];
+
+    if (phdr->p_type != PT_LOAD) {
+      continue;
+    }
+
+    // Segment addresses in memory.
+    ElfW(Addr) seg_start = phdr->p_vaddr + load_bias_;
+    ElfW(Addr) seg_end   = seg_start + phdr->p_memsz;
+
+    ElfW(Addr) seg_page_start = PAGE_START(seg_start);
+    ElfW(Addr) seg_page_end   = PAGE_END(seg_end);
+
+    ElfW(Addr) seg_file_end   = seg_start + phdr->p_filesz;
+
+    // File offsets.
+    ElfW(Addr) file_start = phdr->p_offset;
+    ElfW(Addr) file_end   = file_start + phdr->p_filesz;
+
+    ElfW(Addr) file_page_start = PAGE_START(file_start);
+    ElfW(Addr) file_length = file_end - file_page_start;
+
+    if (file_size_ <= 0) {
+      DL_ERR("\"%s\" invalid file size: %" PRId64, name_.c_str(), file_size_);
+      return false;
+    }
+
+    if (file_end > static_cast<size_t>(file_size_)) {
+      DL_ERR("invalid ELF file \"%s\" load segment[%zd]:"
+          " p_offset (%p) + p_filesz (%p) ( = %p) past end of file (0x%" PRIx64 ")",
+          name_.c_str(), i, reinterpret_cast<void*>(phdr->p_offset),
+          reinterpret_cast<void*>(phdr->p_filesz),
+          reinterpret_cast<void*>(file_end), file_size_);
+      return false;
+    }
+
+    if (file_length != 0) {
+      int prot = PFLAGS_TO_PROT(phdr->p_flags);
+      // W + E PT_LOAD segments are not allowed.
+      if ((prot & (PROT_EXEC | PROT_WRITE)) == (PROT_EXEC | PROT_WRITE)) {
+        DL_ERR_AND_LOG("\"%s\": W + E load segments are not allowed", name_.c_str());
+        return false;
+      }
+
+      void* seg_addr = mmap64(reinterpret_cast<void*>(seg_page_start),
+                            file_length,
+                            prot,
+                            MAP_FIXED|MAP_PRIVATE,
+                            fd_,
+                            file_offset_ + file_page_start);
+      if (seg_addr == MAP_FAILED) {
+        DL_ERR("couldn't map \"%s\" segment %zd: %s", name_.c_str(), i, strerror(errno));
+        return false;
+      }
+    }
+
+    // if the segment is writable, and does not end on a page boundary,
+    // zero-fill it until the page limit.
+    if ((phdr->p_flags & PF_W) != 0 && PAGE_OFFSET(seg_file_end) > 0) {
+      memset(reinterpret_cast<void*>(seg_file_end), 0, PAGE_SIZE - PAGE_OFFSET(seg_file_end));
+    }
+
+    seg_file_end = PAGE_END(seg_file_end);
+
+    // seg_file_end is now the first page address after the file
+    // content. If seg_end is larger, we need to zero anything
+    // between them. This is done by using a private anonymous
+    // map for all extra pages.
+    if (seg_page_end > seg_file_end) {
+      size_t zeromap_size = seg_page_end - seg_file_end;
+      void* zeromap = mmap(reinterpret_cast<void*>(seg_file_end),
+                           zeromap_size,
+                           PFLAGS_TO_PROT(phdr->p_flags),
+                           MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE,
+                           -1,
+                           0);
+      if (zeromap == MAP_FAILED) {
+        DL_ERR("couldn't zero fill \"%s\" gap: %s", name_.c_str(), strerror(errno));
+        return false;
+      }
+
+      prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, zeromap, zeromap_size, ".bss");
+    }
+  }
+  return true;
+}
+
+/* Used internally. Used to set the protection bits of all loaded segments
+ * with optional extra flags (i.e. really PROT_WRITE). Used by
+ * phdr_table_protect_segments and phdr_table_unprotect_segments.
+ */
+static int _phdr_table_set_load_prot(const ElfW(Phdr)* phdr_table, size_t phdr_count,
+                                     ElfW(Addr) load_bias, int extra_prot_flags) {
+  const ElfW(Phdr)* phdr = phdr_table;
+  const ElfW(Phdr)* phdr_limit = phdr + phdr_count;
+
+  for (; phdr < phdr_limit; phdr++) {
+    if (phdr->p_type != PT_LOAD || (phdr->p_flags & PF_W) != 0) {
+      continue;
+    }
+
+    ElfW(Addr) seg_page_start = PAGE_START(phdr->p_vaddr) + load_bias;
+    ElfW(Addr) seg_page_end   = PAGE_END(phdr->p_vaddr + phdr->p_memsz) + load_bias;
+
+    int prot = PFLAGS_TO_PROT(phdr->p_flags);
+    if ((extra_prot_flags & PROT_WRITE) != 0) {
+      // make sure we're never simultaneously writable / executable
+      prot &= ~PROT_EXEC;
+    }
+
+    int ret = mprotect(reinterpret_cast<void*>(seg_page_start),
+                       seg_page_end - seg_page_start,
+                       prot | extra_prot_flags);
+    if (ret < 0) {
+      return -1;
+    }
+  }
+  return 0;
+}
+
+/* Restore the original protection modes for all loadable segments.
+ * You should only call this after phdr_table_unprotect_segments and
+ * applying all relocations.
+ *
+ * Input:
+ *   phdr_table  -> program header table
+ *   phdr_count  -> number of entries in tables
+ *   load_bias   -> load bias
+ * Return:
+ *   0 on error, -1 on failure (error code in errno).
+ */
+int phdr_table_protect_segments(const ElfW(Phdr)* phdr_table,
+                                size_t phdr_count, ElfW(Addr) load_bias) {
+  return _phdr_table_set_load_prot(phdr_table, phdr_count, load_bias, 0);
+}
+
+/* Change the protection of all loaded segments in memory to writable.
+ * This is useful before performing relocations. Once completed, you
+ * will have to call phdr_table_protect_segments to restore the original
+ * protection flags on all segments.
+ *
+ * Note that some writable segments can also have their content turned
+ * to read-only by calling phdr_table_protect_gnu_relro. This is no
+ * performed here.
+ *
+ * Input:
+ *   phdr_table  -> program header table
+ *   phdr_count  -> number of entries in tables
+ *   load_bias   -> load bias
+ * Return:
+ *   0 on error, -1 on failure (error code in errno).
+ */
+int phdr_table_unprotect_segments(const ElfW(Phdr)* phdr_table,
+                                  size_t phdr_count, ElfW(Addr) load_bias) {
+  return _phdr_table_set_load_prot(phdr_table, phdr_count, load_bias, PROT_WRITE);
+}
+
+/* Used internally by phdr_table_protect_gnu_relro and
+ * phdr_table_unprotect_gnu_relro.
+ */
+static int _phdr_table_set_gnu_relro_prot(const ElfW(Phdr)* phdr_table, size_t phdr_count,
+                                          ElfW(Addr) load_bias, int prot_flags) {
+  const ElfW(Phdr)* phdr = phdr_table;
+  const ElfW(Phdr)* phdr_limit = phdr + phdr_count;
+
+  for (phdr = phdr_table; phdr < phdr_limit; phdr++) {
+    if (phdr->p_type != PT_GNU_RELRO) {
+      continue;
+    }
+
+    // Tricky: what happens when the relro segment does not start
+    // or end at page boundaries? We're going to be over-protective
+    // here and put every page touched by the segment as read-only.
+
+    // This seems to match Ian Lance Taylor's description of the
+    // feature at http://www.airs.com/blog/archives/189.
+
+    //    Extract:
+    //       Note that the current dynamic linker code will only work
+    //       correctly if the PT_GNU_RELRO segment starts on a page
+    //       boundary. This is because the dynamic linker rounds the
+    //       p_vaddr field down to the previous page boundary. If
+    //       there is anything on the page which should not be read-only,
+    //       the program is likely to fail at runtime. So in effect the
+    //       linker must only emit a PT_GNU_RELRO segment if it ensures
+    //       that it starts on a page boundary.
+    ElfW(Addr) seg_page_start = PAGE_START(phdr->p_vaddr) + load_bias;
+    ElfW(Addr) seg_page_end   = PAGE_END(phdr->p_vaddr + phdr->p_memsz) + load_bias;
+
+    int ret = mprotect(reinterpret_cast<void*>(seg_page_start),
+                       seg_page_end - seg_page_start,
+                       prot_flags);
+    if (ret < 0) {
+      return -1;
+    }
+  }
+  return 0;
+}
+
+/* Apply GNU relro protection if specified by the program header. This will
+ * turn some of the pages of a writable PT_LOAD segment to read-only, as
+ * specified by one or more PT_GNU_RELRO segments. This must be always
+ * performed after relocations.
+ *
+ * The areas typically covered are .got and .data.rel.ro, these are
+ * read-only from the program's POV, but contain absolute addresses
+ * that need to be relocated before use.
+ *
+ * Input:
+ *   phdr_table  -> program header table
+ *   phdr_count  -> number of entries in tables
+ *   load_bias   -> load bias
+ * Return:
+ *   0 on error, -1 on failure (error code in errno).
+ */
+int phdr_table_protect_gnu_relro(const ElfW(Phdr)* phdr_table,
+                                 size_t phdr_count, ElfW(Addr) load_bias) {
+  return _phdr_table_set_gnu_relro_prot(phdr_table, phdr_count, load_bias, PROT_READ);
+}
+
+/* Serialize the GNU relro segments to the given file descriptor. This can be
+ * performed after relocations to allow another process to later share the
+ * relocated segment, if it was loaded at the same address.
+ *
+ * Input:
+ *   phdr_table  -> program header table
+ *   phdr_count  -> number of entries in tables
+ *   load_bias   -> load bias
+ *   fd          -> writable file descriptor to use
+ * Return:
+ *   0 on error, -1 on failure (error code in errno).
+ */
+int phdr_table_serialize_gnu_relro(const ElfW(Phdr)* phdr_table,
+                                   size_t phdr_count,
+                                   ElfW(Addr) load_bias,
+                                   int fd) {
+  const ElfW(Phdr)* phdr = phdr_table;
+  const ElfW(Phdr)* phdr_limit = phdr + phdr_count;
+  ssize_t file_offset = 0;
+
+  for (phdr = phdr_table; phdr < phdr_limit; phdr++) {
+    if (phdr->p_type != PT_GNU_RELRO) {
+      continue;
+    }
+
+    ElfW(Addr) seg_page_start = PAGE_START(phdr->p_vaddr) + load_bias;
+    ElfW(Addr) seg_page_end   = PAGE_END(phdr->p_vaddr + phdr->p_memsz) + load_bias;
+    ssize_t size = seg_page_end - seg_page_start;
+
+    ssize_t written = TEMP_FAILURE_RETRY(write(fd, reinterpret_cast<void*>(seg_page_start), size));
+    if (written != size) {
+      return -1;
+    }
+    void* map = mmap(reinterpret_cast<void*>(seg_page_start), size, PROT_READ,
+                     MAP_PRIVATE|MAP_FIXED, fd, file_offset);
+    if (map == MAP_FAILED) {
+      return -1;
+    }
+    file_offset += size;
+  }
+  return 0;
+}
+
+/* Where possible, replace the GNU relro segments with mappings of the given
+ * file descriptor. This can be performed after relocations to allow a file
+ * previously created by phdr_table_serialize_gnu_relro in another process to
+ * replace the dirty relocated pages, saving memory, if it was loaded at the
+ * same address. We have to compare the data before we map over it, since some
+ * parts of the relro segment may not be identical due to other libraries in
+ * the process being loaded at different addresses.
+ *
+ * Input:
+ *   phdr_table  -> program header table
+ *   phdr_count  -> number of entries in tables
+ *   load_bias   -> load bias
+ *   fd          -> readable file descriptor to use
+ * Return:
+ *   0 on error, -1 on failure (error code in errno).
+ */
+int phdr_table_map_gnu_relro(const ElfW(Phdr)* phdr_table,
+                             size_t phdr_count,
+                             ElfW(Addr) load_bias,
+                             int fd) {
+  // Map the file at a temporary location so we can compare its contents.
+  struct stat file_stat;
+  if (TEMP_FAILURE_RETRY(fstat(fd, &file_stat)) != 0) {
+    return -1;
+  }
+  off_t file_size = file_stat.st_size;
+  void* temp_mapping = nullptr;
+  if (file_size > 0) {
+    temp_mapping = mmap(nullptr, file_size, PROT_READ, MAP_PRIVATE, fd, 0);
+    if (temp_mapping == MAP_FAILED) {
+      return -1;
+    }
+  }
+  size_t file_offset = 0;
+
+  // Iterate over the relro segments and compare/remap the pages.
+  const ElfW(Phdr)* phdr = phdr_table;
+  const ElfW(Phdr)* phdr_limit = phdr + phdr_count;
+
+  for (phdr = phdr_table; phdr < phdr_limit; phdr++) {
+    if (phdr->p_type != PT_GNU_RELRO) {
+      continue;
+    }
+
+    ElfW(Addr) seg_page_start = PAGE_START(phdr->p_vaddr) + load_bias;
+    ElfW(Addr) seg_page_end   = PAGE_END(phdr->p_vaddr + phdr->p_memsz) + load_bias;
+
+    char* file_base = static_cast<char*>(temp_mapping) + file_offset;
+    char* mem_base = reinterpret_cast<char*>(seg_page_start);
+    size_t match_offset = 0;
+    size_t size = seg_page_end - seg_page_start;
+
+    if (file_size - file_offset < size) {
+      // File is too short to compare to this segment. The contents are likely
+      // different as well (it's probably for a different library version) so
+      // just don't bother checking.
+      break;
+    }
+
+    while (match_offset < size) {
+      // Skip over dissimilar pages.
+      while (match_offset < size &&
+             memcmp(mem_base + match_offset, file_base + match_offset, PAGE_SIZE) != 0) {
+        match_offset += PAGE_SIZE;
+      }
+
+      // Count similar pages.
+      size_t mismatch_offset = match_offset;
+      while (mismatch_offset < size &&
+             memcmp(mem_base + mismatch_offset, file_base + mismatch_offset, PAGE_SIZE) == 0) {
+        mismatch_offset += PAGE_SIZE;
+      }
+
+      // Map over similar pages.
+      if (mismatch_offset > match_offset) {
+        void* map = mmap(mem_base + match_offset, mismatch_offset - match_offset,
+                         PROT_READ, MAP_PRIVATE|MAP_FIXED, fd, match_offset);
+        if (map == MAP_FAILED) {
+          munmap(temp_mapping, file_size);
+          return -1;
+        }
+      }
+
+      match_offset = mismatch_offset;
+    }
+
+    // Add to the base file offset in case there are multiple relro segments.
+    file_offset += size;
+  }
+  munmap(temp_mapping, file_size);
+  return 0;
+}
+
+
+#if defined(__arm__)
+
+#  ifndef PT_ARM_EXIDX
+#    define PT_ARM_EXIDX    0x70000001      /* .ARM.exidx segment */
+#  endif
+
+/* Return the address and size of the .ARM.exidx section in memory,
+ * if present.
+ *
+ * Input:
+ *   phdr_table  -> program header table
+ *   phdr_count  -> number of entries in tables
+ *   load_bias   -> load bias
+ * Output:
+ *   arm_exidx       -> address of table in memory (null on failure).
+ *   arm_exidx_count -> number of items in table (0 on failure).
+ * Return:
+ *   0 on error, -1 on failure (_no_ error code in errno)
+ */
+int phdr_table_get_arm_exidx(const ElfW(Phdr)* phdr_table, size_t phdr_count,
+                             ElfW(Addr) load_bias,
+                             ElfW(Addr)** arm_exidx, size_t* arm_exidx_count) {
+  const ElfW(Phdr)* phdr = phdr_table;
+  const ElfW(Phdr)* phdr_limit = phdr + phdr_count;
+
+  for (phdr = phdr_table; phdr < phdr_limit; phdr++) {
+    if (phdr->p_type != PT_ARM_EXIDX) {
+      continue;
+    }
+
+    *arm_exidx = reinterpret_cast<ElfW(Addr)*>(load_bias + phdr->p_vaddr);
+    *arm_exidx_count = phdr->p_memsz / 8;
+    return 0;
+  }
+  *arm_exidx = nullptr;
+  *arm_exidx_count = 0;
+  return -1;
+}
+#endif
+
+/* Return the address and size of the ELF file's .dynamic section in memory,
+ * or null if missing.
+ *
+ * Input:
+ *   phdr_table  -> program header table
+ *   phdr_count  -> number of entries in tables
+ *   load_bias   -> load bias
+ * Output:
+ *   dynamic       -> address of table in memory (null on failure).
+ *   dynamic_flags -> protection flags for section (unset on failure)
+ * Return:
+ *   void
+ */
+void phdr_table_get_dynamic_section(const ElfW(Phdr)* phdr_table, size_t phdr_count,
+                                    ElfW(Addr) load_bias, ElfW(Dyn)** dynamic,
+                                    ElfW(Word)* dynamic_flags) {
+  *dynamic = nullptr;
+  for (size_t i = 0; i<phdr_count; ++i) {
+    const ElfW(Phdr)& phdr = phdr_table[i];
+    if (phdr.p_type == PT_DYNAMIC) {
+      *dynamic = reinterpret_cast<ElfW(Dyn)*>(load_bias + phdr.p_vaddr);
+      if (dynamic_flags) {
+        *dynamic_flags = phdr.p_flags;
+      }
+      return;
+    }
+  }
+}
+
+/* Return the program interpreter string, or nullptr if missing.
+ *
+ * Input:
+ *   phdr_table  -> program header table
+ *   phdr_count  -> number of entries in tables
+ *   load_bias   -> load bias
+ * Return:
+ *   pointer to the program interpreter string.
+ */
+const char* phdr_table_get_interpreter_name(const ElfW(Phdr) * phdr_table, size_t phdr_count,
+                                            ElfW(Addr) load_bias) {
+  for (size_t i = 0; i<phdr_count; ++i) {
+    const ElfW(Phdr)& phdr = phdr_table[i];
+    if (phdr.p_type == PT_INTERP) {
+      return reinterpret_cast<const char*>(load_bias + phdr.p_vaddr);
+    }
+  }
+  return nullptr;
+}
+
+// Sets loaded_phdr_ to the address of the program header table as it appears
+// in the loaded segments in memory. This is in contrast with phdr_table_,
+// which is temporary and will be released before the library is relocated.
+bool ElfReader::FindPhdr() {
+  const ElfW(Phdr)* phdr_limit = phdr_table_ + phdr_num_;
+
+  // If there is a PT_PHDR, use it directly.
+  for (const ElfW(Phdr)* phdr = phdr_table_; phdr < phdr_limit; ++phdr) {
+    if (phdr->p_type == PT_PHDR) {
+      return CheckPhdr(load_bias_ + phdr->p_vaddr);
+    }
+  }
+
+  // Otherwise, check the first loadable segment. If its file offset
+  // is 0, it starts with the ELF header, and we can trivially find the
+  // loaded program header from it.
+  for (const ElfW(Phdr)* phdr = phdr_table_; phdr < phdr_limit; ++phdr) {
+    if (phdr->p_type == PT_LOAD) {
+      if (phdr->p_offset == 0) {
+        ElfW(Addr)  elf_addr = load_bias_ + phdr->p_vaddr;
+        const ElfW(Ehdr)* ehdr = reinterpret_cast<const ElfW(Ehdr)*>(elf_addr);
+        ElfW(Addr)  offset = ehdr->e_phoff;
+        return CheckPhdr(reinterpret_cast<ElfW(Addr)>(ehdr) + offset);
+      }
+      break;
+    }
+  }
+
+  DL_ERR("can't find loaded phdr for \"%s\"", name_.c_str());
+  return false;
+}
+
+// Ensures that our program header is actually within a loadable
+// segment. This should help catch badly-formed ELF files that
+// would cause the linker to crash later when trying to access it.
+bool ElfReader::CheckPhdr(ElfW(Addr) loaded) {
+  const ElfW(Phdr)* phdr_limit = phdr_table_ + phdr_num_;
+  ElfW(Addr) loaded_end = loaded + (phdr_num_ * sizeof(ElfW(Phdr)));
+  for (const ElfW(Phdr)* phdr = phdr_table_; phdr < phdr_limit; ++phdr) {
+    if (phdr->p_type != PT_LOAD) {
+      continue;
+    }
+    ElfW(Addr) seg_start = phdr->p_vaddr + load_bias_;
+    ElfW(Addr) seg_end = phdr->p_filesz + seg_start;
+    if (seg_start <= loaded && loaded_end <= seg_end) {
+      loaded_phdr_ = reinterpret_cast<const ElfW(Phdr)*>(loaded);
+      return true;
+    }
+  }
+  DL_ERR("\"%s\" loaded phdr %p not in loadable segment",
+         name_.c_str(), reinterpret_cast<void*>(loaded));
+  return false;
+}
diff --git a/linker/linker_phdr.h b/linker/linker_phdr.h
new file mode 100644
index 0000000..d6276ed
--- /dev/null
+++ b/linker/linker_phdr.h
@@ -0,0 +1,138 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+#ifndef LINKER_PHDR_H
+#define LINKER_PHDR_H
+
+/* Declarations related to the ELF program header table and segments.
+ *
+ * The design goal is to provide an API that is as close as possible
+ * to the ELF spec, and does not depend on linker-specific data
+ * structures (e.g. the exact layout of struct soinfo).
+ */
+
+#include "linker.h"
+#include "linker_mapped_file_fragment.h"
+
+class ElfReader {
+ public:
+  ElfReader();
+
+  bool Read(const char* name, int fd, off64_t file_offset, off64_t file_size);
+  bool Load(const android_dlextinfo* extinfo);
+
+  const char* name() const { return name_.c_str(); }
+  size_t phdr_count() const { return phdr_num_; }
+  ElfW(Addr) load_start() const { return reinterpret_cast<ElfW(Addr)>(load_start_); }
+  size_t load_size() const { return load_size_; }
+  ElfW(Addr) load_bias() const { return load_bias_; }
+  const ElfW(Phdr)* loaded_phdr() const { return loaded_phdr_; }
+  const ElfW(Dyn)* dynamic() const { return dynamic_; }
+  const char* get_string(ElfW(Word) index) const;
+  bool is_mapped_by_caller() const { return mapped_by_caller_; }
+
+ private:
+  bool ReadElfHeader();
+  bool VerifyElfHeader();
+  bool ReadProgramHeaders();
+  bool ReadSectionHeaders();
+  bool ReadDynamicSection();
+  bool ReserveAddressSpace(const android_dlextinfo* extinfo);
+  bool LoadSegments();
+  bool FindPhdr();
+  bool CheckPhdr(ElfW(Addr));
+  bool CheckFileRange(ElfW(Addr) offset, size_t size, size_t alignment);
+
+  bool did_read_;
+  bool did_load_;
+  std::string name_;
+  int fd_;
+  off64_t file_offset_;
+  off64_t file_size_;
+
+  ElfW(Ehdr) header_;
+  size_t phdr_num_;
+
+  MappedFileFragment phdr_fragment_;
+  const ElfW(Phdr)* phdr_table_;
+
+  MappedFileFragment shdr_fragment_;
+  const ElfW(Shdr)* shdr_table_;
+  size_t shdr_num_;
+
+  MappedFileFragment dynamic_fragment_;
+  const ElfW(Dyn)* dynamic_;
+
+  MappedFileFragment strtab_fragment_;
+  const char* strtab_;
+  size_t strtab_size_;
+
+  // First page of reserved address space.
+  void* load_start_;
+  // Size in bytes of reserved address space.
+  size_t load_size_;
+  // Load bias.
+  ElfW(Addr) load_bias_;
+
+  // Loaded phdr.
+  const ElfW(Phdr)* loaded_phdr_;
+
+  // Is map owned by the caller
+  bool mapped_by_caller_;
+};
+
+size_t phdr_table_get_load_size(const ElfW(Phdr)* phdr_table, size_t phdr_count,
+                                ElfW(Addr)* min_vaddr = nullptr, ElfW(Addr)* max_vaddr = nullptr);
+
+int phdr_table_protect_segments(const ElfW(Phdr)* phdr_table,
+                                size_t phdr_count, ElfW(Addr) load_bias);
+
+int phdr_table_unprotect_segments(const ElfW(Phdr)* phdr_table, size_t phdr_count,
+                                  ElfW(Addr) load_bias);
+
+int phdr_table_protect_gnu_relro(const ElfW(Phdr)* phdr_table, size_t phdr_count,
+                                 ElfW(Addr) load_bias);
+
+int phdr_table_serialize_gnu_relro(const ElfW(Phdr)* phdr_table, size_t phdr_count,
+                                   ElfW(Addr) load_bias, int fd);
+
+int phdr_table_map_gnu_relro(const ElfW(Phdr)* phdr_table, size_t phdr_count,
+                             ElfW(Addr) load_bias, int fd);
+
+#if defined(__arm__)
+int phdr_table_get_arm_exidx(const ElfW(Phdr)* phdr_table, size_t phdr_count, ElfW(Addr) load_bias,
+                             ElfW(Addr)** arm_exidx, size_t* arm_exidix_count);
+#endif
+
+void phdr_table_get_dynamic_section(const ElfW(Phdr)* phdr_table, size_t phdr_count,
+                                    ElfW(Addr) load_bias, ElfW(Dyn)** dynamic,
+                                    ElfW(Word)* dynamic_flags);
+
+const char* phdr_table_get_interpreter_name(const ElfW(Phdr) * phdr_table, size_t phdr_count,
+                                            ElfW(Addr) load_bias);
+
+#endif /* LINKER_PHDR_H */
diff --git a/linker/linker_reloc_iterators.h b/linker/linker_reloc_iterators.h
new file mode 100644
index 0000000..f28c0e0
--- /dev/null
+++ b/linker/linker_reloc_iterators.h
@@ -0,0 +1,165 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __LINKER_RELOC_ITERATORS_H
+#define __LINKER_RELOC_ITERATORS_H
+
+#include "linker.h"
+
+#include <string.h>
+
+const size_t RELOCATION_GROUPED_BY_INFO_FLAG = 1;
+const size_t RELOCATION_GROUPED_BY_OFFSET_DELTA_FLAG = 2;
+const size_t RELOCATION_GROUPED_BY_ADDEND_FLAG = 4;
+const size_t RELOCATION_GROUP_HAS_ADDEND_FLAG = 8;
+
+class plain_reloc_iterator {
+#if defined(USE_RELA)
+  typedef ElfW(Rela) rel_t;
+#else
+  typedef ElfW(Rel) rel_t;
+#endif
+ public:
+  plain_reloc_iterator(rel_t* rel_array, size_t count)
+      : begin_(rel_array), end_(begin_ + count), current_(begin_) {}
+
+  bool has_next() {
+    return current_ < end_;
+  }
+
+  rel_t* next() {
+    return current_++;
+  }
+ private:
+  rel_t* const begin_;
+  rel_t* const end_;
+  rel_t* current_;
+
+  DISALLOW_COPY_AND_ASSIGN(plain_reloc_iterator);
+};
+
+template <typename decoder_t>
+class packed_reloc_iterator {
+#if defined(USE_RELA)
+  typedef ElfW(Rela) rel_t;
+#else
+  typedef ElfW(Rel) rel_t;
+#endif
+ public:
+  explicit packed_reloc_iterator(decoder_t&& decoder)
+      : decoder_(decoder) {
+    // initialize fields
+    memset(&reloc_, 0, sizeof(reloc_));
+    relocation_count_ = decoder_.pop_front();
+    reloc_.r_offset = decoder_.pop_front();
+    relocation_index_ = 0;
+    relocation_group_index_ = 0;
+    group_size_ = 0;
+  }
+
+  bool has_next() const {
+    return relocation_index_ < relocation_count_;
+  }
+
+  rel_t* next() {
+    if (relocation_group_index_ == group_size_) {
+      if (!read_group_fields()) {
+        // Iterator is inconsistent state; it should not be called again
+        // but in case it is let's make sure has_next() returns false.
+        relocation_index_ = relocation_count_ = 0;
+        return nullptr;
+      }
+    }
+
+    if (is_relocation_grouped_by_offset_delta()) {
+      reloc_.r_offset += group_r_offset_delta_;
+    } else {
+      reloc_.r_offset += decoder_.pop_front();
+    }
+
+    if (!is_relocation_grouped_by_info()) {
+      reloc_.r_info = decoder_.pop_front();
+    }
+
+#if defined(USE_RELA)
+    if (is_relocation_group_has_addend() &&
+        !is_relocation_grouped_by_addend()) {
+      reloc_.r_addend += decoder_.pop_front();
+    }
+#endif
+
+    relocation_index_++;
+    relocation_group_index_++;
+
+    return &reloc_;
+  }
+ private:
+  bool read_group_fields() {
+    group_size_ = decoder_.pop_front();
+    group_flags_ = decoder_.pop_front();
+
+    if (is_relocation_grouped_by_offset_delta()) {
+      group_r_offset_delta_ = decoder_.pop_front();
+    }
+
+    if (is_relocation_grouped_by_info()) {
+      reloc_.r_info = decoder_.pop_front();
+    }
+
+    if (is_relocation_group_has_addend() &&
+        is_relocation_grouped_by_addend()) {
+#if !defined(USE_RELA)
+      // This platform does not support rela, and yet we have it encoded in android_rel section.
+      DL_ERR("unexpected r_addend in android.rel section");
+      return false;
+#else
+      reloc_.r_addend += decoder_.pop_front();
+    } else if (!is_relocation_group_has_addend()) {
+      reloc_.r_addend = 0;
+#endif
+    }
+
+    relocation_group_index_ = 0;
+    return true;
+  }
+
+  bool is_relocation_grouped_by_info() {
+    return (group_flags_ & RELOCATION_GROUPED_BY_INFO_FLAG) != 0;
+  }
+
+  bool is_relocation_grouped_by_offset_delta() {
+    return (group_flags_ & RELOCATION_GROUPED_BY_OFFSET_DELTA_FLAG) != 0;
+  }
+
+  bool is_relocation_grouped_by_addend() {
+    return (group_flags_ & RELOCATION_GROUPED_BY_ADDEND_FLAG) != 0;
+  }
+
+  bool is_relocation_group_has_addend() {
+    return (group_flags_ & RELOCATION_GROUP_HAS_ADDEND_FLAG) != 0;
+  }
+
+  decoder_t decoder_;
+  size_t relocation_count_;
+  size_t group_size_;
+  size_t group_flags_;
+  size_t group_r_offset_delta_;
+  size_t relocation_index_;
+  size_t relocation_group_index_;
+  rel_t reloc_;
+};
+
+#endif  // __LINKER_RELOC_ITERATORS_H
diff --git a/linker/linker_relocs.h b/linker/linker_relocs.h
new file mode 100644
index 0000000..12c1497
--- /dev/null
+++ b/linker/linker_relocs.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __LINKER_RELOCS_H
+#define __LINKER_RELOCS_H
+
+#include <elf.h>
+
+#define R_GENERIC_NONE 0 // R_*_NONE is always 0
+
+#if defined (__aarch64__)
+
+#define R_GENERIC_JUMP_SLOT R_AARCH64_JUMP_SLOT
+#define R_GENERIC_GLOB_DAT  R_AARCH64_GLOB_DAT
+#define R_GENERIC_RELATIVE  R_AARCH64_RELATIVE
+#define R_GENERIC_IRELATIVE R_AARCH64_IRELATIVE
+
+#elif defined (__arm__)
+
+#define R_GENERIC_JUMP_SLOT R_ARM_JUMP_SLOT
+#define R_GENERIC_GLOB_DAT  R_ARM_GLOB_DAT
+#define R_GENERIC_RELATIVE  R_ARM_RELATIVE
+#define R_GENERIC_IRELATIVE R_ARM_IRELATIVE
+
+#elif defined (__i386__)
+
+#define R_GENERIC_JUMP_SLOT R_386_JMP_SLOT
+#define R_GENERIC_GLOB_DAT  R_386_GLOB_DAT
+#define R_GENERIC_RELATIVE  R_386_RELATIVE
+#define R_GENERIC_IRELATIVE R_386_IRELATIVE
+
+#elif defined (__x86_64__)
+
+#define R_GENERIC_JUMP_SLOT R_X86_64_JUMP_SLOT
+#define R_GENERIC_GLOB_DAT  R_X86_64_GLOB_DAT
+#define R_GENERIC_RELATIVE  R_X86_64_RELATIVE
+#define R_GENERIC_IRELATIVE R_X86_64_IRELATIVE
+
+#endif
+
+#endif // __LINKER_RELOCS_H
diff --git a/linker/linker_sdk_versions.cpp b/linker/linker_sdk_versions.cpp
new file mode 100644
index 0000000..9aebb06
--- /dev/null
+++ b/linker/linker_sdk_versions.cpp
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "linker.h"
+#include <android/api-level.h>
+#include <atomic>
+
+static std::atomic<uint32_t> g_target_sdk_version(__ANDROID_API__);
+
+void set_application_target_sdk_version(uint32_t target) {
+  // translate current sdk_version to platform sdk_version
+  if (target == 0) {
+    target = __ANDROID_API__;
+  }
+  g_target_sdk_version = target;
+}
+
+uint32_t get_application_target_sdk_version() {
+  return g_target_sdk_version;
+}
+
diff --git a/linker/linker_sleb128.h b/linker/linker_sleb128.h
new file mode 100644
index 0000000..c4df259
--- /dev/null
+++ b/linker/linker_sleb128.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _LINKER_SLEB128_H
+#define _LINKER_SLEB128_H
+
+#include <stdint.h>
+
+#include "linker_debug.h"
+
+// Helper classes for decoding LEB128, used in packed relocation data.
+// http://en.wikipedia.org/wiki/LEB128
+
+class sleb128_decoder {
+ public:
+  sleb128_decoder(const uint8_t* buffer, size_t count)
+      : current_(buffer), end_(buffer+count) { }
+
+  size_t pop_front() {
+    size_t value = 0;
+    static const size_t size = CHAR_BIT * sizeof(value);
+
+    size_t shift = 0;
+    uint8_t byte;
+
+    do {
+      if (current_ >= end_) {
+        __libc_fatal("sleb128_decoder ran out of bounds");
+      }
+      byte = *current_++;
+      value |= (static_cast<size_t>(byte & 127) << shift);
+      shift += 7;
+    } while (byte & 128);
+
+    if (shift < size && (byte & 64)) {
+      value |= -(static_cast<size_t>(1) << shift);
+    }
+
+    return value;
+  }
+
+ private:
+  const uint8_t* current_;
+  const uint8_t* const end_;
+};
+
+#endif // __LINKER_SLEB128_H
diff --git a/linker/linker_soinfo.cpp b/linker/linker_soinfo.cpp
new file mode 100644
index 0000000..59bdc4d
--- /dev/null
+++ b/linker/linker_soinfo.cpp
@@ -0,0 +1,795 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "linker_soinfo.h"
+
+#include <dlfcn.h>
+#include <elf.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "linker_debug.h"
+#include "linker_globals.h"
+#include "linker_logger.h"
+#include "linker_utils.h"
+
+// TODO(dimitry): These functions are currently located in linker.cpp - find a better place for it
+bool find_verdef_version_index(const soinfo* si, const version_info* vi, ElfW(Versym)* versym);
+ElfW(Addr) call_ifunc_resolver(ElfW(Addr) resolver_addr);
+uint32_t get_application_target_sdk_version();
+
+soinfo::soinfo(android_namespace_t* ns, const char* realpath,
+               const struct stat* file_stat, off64_t file_offset,
+               int rtld_flags) {
+  memset(this, 0, sizeof(*this));
+
+  if (realpath != nullptr) {
+    realpath_ = realpath;
+  }
+
+  flags_ = FLAG_NEW_SOINFO;
+  version_ = SOINFO_VERSION;
+
+  if (file_stat != nullptr) {
+    this->st_dev_ = file_stat->st_dev;
+    this->st_ino_ = file_stat->st_ino;
+    this->file_offset_ = file_offset;
+  }
+
+  this->rtld_flags_ = rtld_flags;
+  this->primary_namespace_ = ns;
+}
+
+soinfo::~soinfo() {
+  g_soinfo_handles_map.erase(handle_);
+}
+
+void soinfo::set_dt_runpath(const char* path) {
+  if (!has_min_version(3)) {
+    return;
+  }
+
+  std::vector<std::string> runpaths;
+
+  split_path(path, ":", &runpaths);
+
+  std::string origin = dirname(get_realpath());
+  // FIXME: add $LIB and $PLATFORM.
+  std::pair<std::string, std::string> substs[] = {{"ORIGIN", origin}};
+  for (auto&& s : runpaths) {
+    size_t pos = 0;
+    while (pos < s.size()) {
+      pos = s.find("$", pos);
+      if (pos == std::string::npos) break;
+      for (const auto& subst : substs) {
+        const std::string& token = subst.first;
+        const std::string& replacement = subst.second;
+        if (s.substr(pos + 1, token.size()) == token) {
+          s.replace(pos, token.size() + 1, replacement);
+          // -1 to compensate for the ++pos below.
+          pos += replacement.size() - 1;
+          break;
+        } else if (s.substr(pos + 1, token.size() + 2) == "{" + token + "}") {
+          s.replace(pos, token.size() + 3, replacement);
+          pos += replacement.size() - 1;
+          break;
+        }
+      }
+      // Skip $ in case it did not match any of the known substitutions.
+      ++pos;
+    }
+  }
+
+  resolve_paths(runpaths, &dt_runpath_);
+}
+
+const ElfW(Versym)* soinfo::get_versym(size_t n) const {
+  if (has_min_version(2) && versym_ != nullptr) {
+    return versym_ + n;
+  }
+
+  return nullptr;
+}
+
+ElfW(Addr) soinfo::get_verneed_ptr() const {
+  if (has_min_version(2)) {
+    return verneed_ptr_;
+  }
+
+  return 0;
+}
+
+size_t soinfo::get_verneed_cnt() const {
+  if (has_min_version(2)) {
+    return verneed_cnt_;
+  }
+
+  return 0;
+}
+
+ElfW(Addr) soinfo::get_verdef_ptr() const {
+  if (has_min_version(2)) {
+    return verdef_ptr_;
+  }
+
+  return 0;
+}
+
+size_t soinfo::get_verdef_cnt() const {
+  if (has_min_version(2)) {
+    return verdef_cnt_;
+  }
+
+  return 0;
+}
+
+bool soinfo::find_symbol_by_name(SymbolName& symbol_name,
+                                 const version_info* vi,
+                                 const ElfW(Sym)** symbol) const {
+  uint32_t symbol_index;
+  bool success =
+      is_gnu_hash() ?
+      gnu_lookup(symbol_name, vi, &symbol_index) :
+      elf_lookup(symbol_name, vi, &symbol_index);
+
+  if (success) {
+    *symbol = symbol_index == 0 ? nullptr : symtab_ + symbol_index;
+  }
+
+  return success;
+}
+
+static bool is_symbol_global_and_defined(const soinfo* si, const ElfW(Sym)* s) {
+  if (ELF_ST_BIND(s->st_info) == STB_GLOBAL ||
+      ELF_ST_BIND(s->st_info) == STB_WEAK) {
+    return s->st_shndx != SHN_UNDEF;
+  } else if (ELF_ST_BIND(s->st_info) != STB_LOCAL) {
+    DL_WARN("unexpected ST_BIND value: %d for \"%s\" in \"%s\"",
+            ELF_ST_BIND(s->st_info), si->get_string(s->st_name), si->get_realpath());
+  }
+
+  return false;
+}
+
+static const ElfW(Versym) kVersymHiddenBit = 0x8000;
+
+static inline bool is_versym_hidden(const ElfW(Versym)* versym) {
+  // the symbol is hidden if bit 15 of versym is set.
+  return versym != nullptr && (*versym & kVersymHiddenBit) != 0;
+}
+
+static inline bool check_symbol_version(const ElfW(Versym) verneed,
+                                        const ElfW(Versym)* verdef) {
+  return verneed == kVersymNotNeeded ||
+      verdef == nullptr ||
+      verneed == (*verdef & ~kVersymHiddenBit);
+}
+
+bool soinfo::gnu_lookup(SymbolName& symbol_name,
+                        const version_info* vi,
+                        uint32_t* symbol_index) const {
+  uint32_t hash = symbol_name.gnu_hash();
+  uint32_t h2 = hash >> gnu_shift2_;
+
+  uint32_t bloom_mask_bits = sizeof(ElfW(Addr))*8;
+  uint32_t word_num = (hash / bloom_mask_bits) & gnu_maskwords_;
+  ElfW(Addr) bloom_word = gnu_bloom_filter_[word_num];
+
+  *symbol_index = 0;
+
+  TRACE_TYPE(LOOKUP, "SEARCH %s in %s@%p (gnu)",
+      symbol_name.get_name(), get_realpath(), reinterpret_cast<void*>(base));
+
+  // test against bloom filter
+  if ((1 & (bloom_word >> (hash % bloom_mask_bits)) & (bloom_word >> (h2 % bloom_mask_bits))) == 0) {
+    TRACE_TYPE(LOOKUP, "NOT FOUND %s in %s@%p",
+        symbol_name.get_name(), get_realpath(), reinterpret_cast<void*>(base));
+
+    return true;
+  }
+
+  // bloom test says "probably yes"...
+  uint32_t n = gnu_bucket_[hash % gnu_nbucket_];
+
+  if (n == 0) {
+    TRACE_TYPE(LOOKUP, "NOT FOUND %s in %s@%p",
+        symbol_name.get_name(), get_realpath(), reinterpret_cast<void*>(base));
+
+    return true;
+  }
+
+  // lookup versym for the version definition in this library
+  // note the difference between "version is not requested" (vi == nullptr)
+  // and "version not found". In the first case verneed is kVersymNotNeeded
+  // which implies that the default version can be accepted; the second case results in
+  // verneed = 1 (kVersymGlobal) and implies that we should ignore versioned symbols
+  // for this library and consider only *global* ones.
+  ElfW(Versym) verneed = 0;
+  if (!find_verdef_version_index(this, vi, &verneed)) {
+    return false;
+  }
+
+  do {
+    ElfW(Sym)* s = symtab_ + n;
+    const ElfW(Versym)* verdef = get_versym(n);
+    // skip hidden versions when verneed == kVersymNotNeeded (0)
+    if (verneed == kVersymNotNeeded && is_versym_hidden(verdef)) {
+        continue;
+    }
+    if (((gnu_chain_[n] ^ hash) >> 1) == 0 &&
+        check_symbol_version(verneed, verdef) &&
+        strcmp(get_string(s->st_name), symbol_name.get_name()) == 0 &&
+        is_symbol_global_and_defined(this, s)) {
+      TRACE_TYPE(LOOKUP, "FOUND %s in %s (%p) %zd",
+          symbol_name.get_name(), get_realpath(), reinterpret_cast<void*>(s->st_value),
+          static_cast<size_t>(s->st_size));
+      *symbol_index = n;
+      return true;
+    }
+  } while ((gnu_chain_[n++] & 1) == 0);
+
+  TRACE_TYPE(LOOKUP, "NOT FOUND %s in %s@%p",
+             symbol_name.get_name(), get_realpath(), reinterpret_cast<void*>(base));
+
+  return true;
+}
+
+bool soinfo::elf_lookup(SymbolName& symbol_name,
+                        const version_info* vi,
+                        uint32_t* symbol_index) const {
+  uint32_t hash = symbol_name.elf_hash();
+
+  TRACE_TYPE(LOOKUP, "SEARCH %s in %s@%p h=%x(elf) %zd",
+             symbol_name.get_name(), get_realpath(),
+             reinterpret_cast<void*>(base), hash, hash % nbucket_);
+
+  ElfW(Versym) verneed = 0;
+  if (!find_verdef_version_index(this, vi, &verneed)) {
+    return false;
+  }
+
+  for (uint32_t n = bucket_[hash % nbucket_]; n != 0; n = chain_[n]) {
+    ElfW(Sym)* s = symtab_ + n;
+    const ElfW(Versym)* verdef = get_versym(n);
+
+    // skip hidden versions when verneed == 0
+    if (verneed == kVersymNotNeeded && is_versym_hidden(verdef)) {
+        continue;
+    }
+
+    if (check_symbol_version(verneed, verdef) &&
+        strcmp(get_string(s->st_name), symbol_name.get_name()) == 0 &&
+        is_symbol_global_and_defined(this, s)) {
+      TRACE_TYPE(LOOKUP, "FOUND %s in %s (%p) %zd",
+                 symbol_name.get_name(), get_realpath(),
+                 reinterpret_cast<void*>(s->st_value),
+                 static_cast<size_t>(s->st_size));
+      *symbol_index = n;
+      return true;
+    }
+  }
+
+  TRACE_TYPE(LOOKUP, "NOT FOUND %s in %s@%p %x %zd",
+             symbol_name.get_name(), get_realpath(),
+             reinterpret_cast<void*>(base), hash, hash % nbucket_);
+
+  *symbol_index = 0;
+  return true;
+}
+
+ElfW(Sym)* soinfo::find_symbol_by_address(const void* addr) {
+  return is_gnu_hash() ? gnu_addr_lookup(addr) : elf_addr_lookup(addr);
+}
+
+static bool symbol_matches_soaddr(const ElfW(Sym)* sym, ElfW(Addr) soaddr) {
+  return sym->st_shndx != SHN_UNDEF &&
+      soaddr >= sym->st_value &&
+      soaddr < sym->st_value + sym->st_size;
+}
+
+ElfW(Sym)* soinfo::gnu_addr_lookup(const void* addr) {
+  ElfW(Addr) soaddr = reinterpret_cast<ElfW(Addr)>(addr) - load_bias;
+
+  for (size_t i = 0; i < gnu_nbucket_; ++i) {
+    uint32_t n = gnu_bucket_[i];
+
+    if (n == 0) {
+      continue;
+    }
+
+    do {
+      ElfW(Sym)* sym = symtab_ + n;
+      if (symbol_matches_soaddr(sym, soaddr)) {
+        return sym;
+      }
+    } while ((gnu_chain_[n++] & 1) == 0);
+  }
+
+  return nullptr;
+}
+
+ElfW(Sym)* soinfo::elf_addr_lookup(const void* addr) {
+  ElfW(Addr) soaddr = reinterpret_cast<ElfW(Addr)>(addr) - load_bias;
+
+  // Search the library's symbol table for any defined symbol which
+  // contains this address.
+  for (size_t i = 0; i < nchain_; ++i) {
+    ElfW(Sym)* sym = symtab_ + i;
+    if (symbol_matches_soaddr(sym, soaddr)) {
+      return sym;
+    }
+  }
+
+  return nullptr;
+}
+
+static void call_function(const char* function_name __unused,
+                          linker_ctor_function_t function,
+                          const char* realpath __unused) {
+  if (function == nullptr || reinterpret_cast<uintptr_t>(function) == static_cast<uintptr_t>(-1)) {
+    return;
+  }
+
+  TRACE("[ Calling c-tor %s @ %p for '%s' ]", function_name, function, realpath);
+  function(g_argc, g_argv, g_envp);
+  TRACE("[ Done calling c-tor %s @ %p for '%s' ]", function_name, function, realpath);
+}
+
+static void call_function(const char* function_name __unused,
+                          linker_dtor_function_t function,
+                          const char* realpath __unused) {
+  if (function == nullptr || reinterpret_cast<uintptr_t>(function) == static_cast<uintptr_t>(-1)) {
+    return;
+  }
+
+  TRACE("[ Calling d-tor %s @ %p for '%s' ]", function_name, function, realpath);
+  function();
+  TRACE("[ Done calling d-tor %s @ %p for '%s' ]", function_name, function, realpath);
+}
+
+template <typename F>
+static void call_array(const char* array_name __unused,
+                       F* functions,
+                       size_t count,
+                       bool reverse,
+                       const char* realpath) {
+  if (functions == nullptr) {
+    return;
+  }
+
+  TRACE("[ Calling %s (size %zd) @ %p for '%s' ]", array_name, count, functions, realpath);
+
+  int begin = reverse ? (count - 1) : 0;
+  int end = reverse ? -1 : count;
+  int step = reverse ? -1 : 1;
+
+  for (int i = begin; i != end; i += step) {
+    TRACE("[ %s[%d] == %p ]", array_name, i, functions[i]);
+    call_function("function", functions[i], realpath);
+  }
+
+  TRACE("[ Done calling %s for '%s' ]", array_name, realpath);
+}
+
+void soinfo::call_pre_init_constructors() {
+  // DT_PREINIT_ARRAY functions are called before any other constructors for executables,
+  // but ignored in a shared library.
+  call_array("DT_PREINIT_ARRAY", preinit_array_, preinit_array_count_, false, get_realpath());
+}
+
+void soinfo::call_constructors() {
+  if (constructors_called) {
+    return;
+  }
+
+  // We set constructors_called before actually calling the constructors, otherwise it doesn't
+  // protect against recursive constructor calls. One simple example of constructor recursion
+  // is the libc debug malloc, which is implemented in libc_malloc_debug_leak.so:
+  // 1. The program depends on libc, so libc's constructor is called here.
+  // 2. The libc constructor calls dlopen() to load libc_malloc_debug_leak.so.
+  // 3. dlopen() calls the constructors on the newly created
+  //    soinfo for libc_malloc_debug_leak.so.
+  // 4. The debug .so depends on libc, so CallConstructors is
+  //    called again with the libc soinfo. If it doesn't trigger the early-
+  //    out above, the libc constructor will be called again (recursively!).
+  constructors_called = true;
+
+  if (!is_main_executable() && preinit_array_ != nullptr) {
+    // The GNU dynamic linker silently ignores these, but we warn the developer.
+    PRINT("\"%s\": ignoring DT_PREINIT_ARRAY in shared library!", get_realpath());
+  }
+
+  get_children().for_each([] (soinfo* si) {
+    si->call_constructors();
+  });
+
+  TRACE("\"%s\": calling constructors", get_realpath());
+
+  // DT_INIT should be called before DT_INIT_ARRAY if both are present.
+  call_function("DT_INIT", init_func_, get_realpath());
+  call_array("DT_INIT_ARRAY", init_array_, init_array_count_, false, get_realpath());
+}
+
+void soinfo::call_destructors() {
+  if (!constructors_called) {
+    return;
+  }
+  TRACE("\"%s\": calling destructors", get_realpath());
+
+  // DT_FINI_ARRAY must be parsed in reverse order.
+  call_array("DT_FINI_ARRAY", fini_array_, fini_array_count_, true, get_realpath());
+
+  // DT_FINI should be called after DT_FINI_ARRAY if both are present.
+  call_function("DT_FINI", fini_func_, get_realpath());
+}
+
+void soinfo::add_child(soinfo* child) {
+  if (has_min_version(0)) {
+    child->parents_.push_back(this);
+    this->children_.push_back(child);
+  }
+}
+
+void soinfo::remove_all_links() {
+  if (!has_min_version(0)) {
+    return;
+  }
+
+  // 1. Untie connected soinfos from 'this'.
+  children_.for_each([&] (soinfo* child) {
+    child->parents_.remove_if([&] (const soinfo* parent) {
+      return parent == this;
+    });
+  });
+
+  parents_.for_each([&] (soinfo* parent) {
+    parent->children_.remove_if([&] (const soinfo* child) {
+      return child == this;
+    });
+  });
+
+  // 2. Remove from the primary namespace
+  primary_namespace_->remove_soinfo(this);
+  primary_namespace_ = nullptr;
+
+  // 3. Remove from secondary namespaces
+  secondary_namespaces_.for_each([&](android_namespace_t* ns) {
+    ns->remove_soinfo(this);
+  });
+
+
+  // 4. Once everything untied - clear local lists.
+  parents_.clear();
+  children_.clear();
+  secondary_namespaces_.clear();
+}
+
+dev_t soinfo::get_st_dev() const {
+  if (has_min_version(0)) {
+    return st_dev_;
+  }
+
+  return 0;
+};
+
+ino_t soinfo::get_st_ino() const {
+  if (has_min_version(0)) {
+    return st_ino_;
+  }
+
+  return 0;
+}
+
+off64_t soinfo::get_file_offset() const {
+  if (has_min_version(1)) {
+    return file_offset_;
+  }
+
+  return 0;
+}
+
+uint32_t soinfo::get_rtld_flags() const {
+  if (has_min_version(1)) {
+    return rtld_flags_;
+  }
+
+  return 0;
+}
+
+uint32_t soinfo::get_dt_flags_1() const {
+  if (has_min_version(1)) {
+    return dt_flags_1_;
+  }
+
+  return 0;
+}
+
+void soinfo::set_dt_flags_1(uint32_t dt_flags_1) {
+  if (has_min_version(1)) {
+    if ((dt_flags_1 & DF_1_GLOBAL) != 0) {
+      rtld_flags_ |= RTLD_GLOBAL;
+    }
+
+    if ((dt_flags_1 & DF_1_NODELETE) != 0) {
+      rtld_flags_ |= RTLD_NODELETE;
+    }
+
+    dt_flags_1_ = dt_flags_1;
+  }
+}
+
+void soinfo::set_nodelete() {
+  rtld_flags_ |= RTLD_NODELETE;
+}
+
+const char* soinfo::get_realpath() const {
+#if defined(__work_around_b_24465209__)
+  if (has_min_version(2)) {
+    return realpath_.c_str();
+  } else {
+    return old_name_;
+  }
+#else
+  return realpath_.c_str();
+#endif
+}
+
+void soinfo::set_soname(const char* soname) {
+#if defined(__work_around_b_24465209__)
+  if (has_min_version(2)) {
+    soname_ = soname;
+  }
+  strlcpy(old_name_, soname_, sizeof(old_name_));
+#else
+  soname_ = soname;
+#endif
+}
+
+const char* soinfo::get_soname() const {
+#if defined(__work_around_b_24465209__)
+  if (has_min_version(2)) {
+    return soname_;
+  } else {
+    return old_name_;
+  }
+#else
+  return soname_;
+#endif
+}
+
+// This is a return on get_children()/get_parents() if
+// 'this->flags' does not have FLAG_NEW_SOINFO set.
+static soinfo_list_t g_empty_list;
+
+soinfo_list_t& soinfo::get_children() {
+  if (has_min_version(0)) {
+    return children_;
+  }
+
+  return g_empty_list;
+}
+
+const soinfo_list_t& soinfo::get_children() const {
+  if (has_min_version(0)) {
+    return children_;
+  }
+
+  return g_empty_list;
+}
+
+soinfo_list_t& soinfo::get_parents() {
+  if (has_min_version(0)) {
+    return parents_;
+  }
+
+  return g_empty_list;
+}
+
+static std::vector<std::string> g_empty_runpath;
+
+const std::vector<std::string>& soinfo::get_dt_runpath() const {
+  if (has_min_version(3)) {
+    return dt_runpath_;
+  }
+
+  return g_empty_runpath;
+}
+
+android_namespace_t* soinfo::get_primary_namespace() {
+  if (has_min_version(3)) {
+    return primary_namespace_;
+  }
+
+  return &g_default_namespace;
+}
+
+void soinfo::add_secondary_namespace(android_namespace_t* secondary_ns) {
+  CHECK(has_min_version(3));
+  secondary_namespaces_.push_back(secondary_ns);
+}
+
+ElfW(Addr) soinfo::resolve_symbol_address(const ElfW(Sym)* s) const {
+  if (ELF_ST_TYPE(s->st_info) == STT_GNU_IFUNC) {
+    return call_ifunc_resolver(s->st_value + load_bias);
+  }
+
+  return static_cast<ElfW(Addr)>(s->st_value + load_bias);
+}
+
+const char* soinfo::get_string(ElfW(Word) index) const {
+  if (has_min_version(1) && (index >= strtab_size_)) {
+    __libc_fatal("%s: strtab out of bounds error; STRSZ=%zd, name=%d",
+        get_realpath(), strtab_size_, index);
+  }
+
+  return strtab_ + index;
+}
+
+bool soinfo::is_gnu_hash() const {
+  return (flags_ & FLAG_GNU_HASH) != 0;
+}
+
+bool soinfo::can_unload() const {
+  return !is_linked() || ((get_rtld_flags() & (RTLD_NODELETE | RTLD_GLOBAL)) == 0);
+}
+
+bool soinfo::is_linked() const {
+  return (flags_ & FLAG_LINKED) != 0;
+}
+
+bool soinfo::is_main_executable() const {
+  return (flags_ & FLAG_EXE) != 0;
+}
+
+bool soinfo::is_linker() const {
+  return (flags_ & FLAG_LINKER) != 0;
+}
+
+void soinfo::set_linked() {
+  flags_ |= FLAG_LINKED;
+}
+
+void soinfo::set_linker_flag() {
+  flags_ |= FLAG_LINKER;
+}
+
+void soinfo::set_main_executable() {
+  flags_ |= FLAG_EXE;
+}
+
+void soinfo::increment_ref_count() {
+  local_group_root_->ref_count_++;
+}
+
+size_t soinfo::decrement_ref_count() {
+  return --local_group_root_->ref_count_;
+}
+
+soinfo* soinfo::get_local_group_root() const {
+  return local_group_root_;
+}
+
+
+void soinfo::set_mapped_by_caller(bool mapped_by_caller) {
+  if (mapped_by_caller) {
+    flags_ |= FLAG_MAPPED_BY_CALLER;
+  } else {
+    flags_ &= ~FLAG_MAPPED_BY_CALLER;
+  }
+}
+
+bool soinfo::is_mapped_by_caller() const {
+  return (flags_ & FLAG_MAPPED_BY_CALLER) != 0;
+}
+
+// This function returns api-level at the time of
+// dlopen/load. Note that libraries opened by system
+// will always have 'current' api level.
+uint32_t soinfo::get_target_sdk_version() const {
+  if (!has_min_version(2)) {
+    return __ANDROID_API__;
+  }
+
+  return local_group_root_->target_sdk_version_;
+}
+
+uintptr_t soinfo::get_handle() const {
+  CHECK(has_min_version(3));
+  CHECK(handle_ != 0);
+  return handle_;
+}
+
+void* soinfo::to_handle() {
+  if (get_application_target_sdk_version() <= 23 || !has_min_version(3)) {
+    return this;
+  }
+
+  return reinterpret_cast<void*>(get_handle());
+}
+
+void soinfo::generate_handle() {
+  CHECK(has_min_version(3));
+  CHECK(handle_ == 0); // Make sure this is the first call
+
+  // Make sure the handle is unique and does not collide
+  // with special values which are RTLD_DEFAULT and RTLD_NEXT.
+  do {
+    arc4random_buf(&handle_, sizeof(handle_));
+    // the least significant bit for the handle is always 1
+    // making it easy to test the type of handle passed to
+    // dl* functions.
+    handle_ = handle_ | 1;
+  } while (handle_ == reinterpret_cast<uintptr_t>(RTLD_DEFAULT) ||
+           handle_ == reinterpret_cast<uintptr_t>(RTLD_NEXT) ||
+           g_soinfo_handles_map.find(handle_) != g_soinfo_handles_map.end());
+
+  g_soinfo_handles_map[handle_] = this;
+}
+
+// TODO(dimitry): Move SymbolName methods to a separate file.
+
+uint32_t calculate_elf_hash(const char* name) {
+  const uint8_t* name_bytes = reinterpret_cast<const uint8_t*>(name);
+  uint32_t h = 0, g;
+
+  while (*name_bytes) {
+    h = (h << 4) + *name_bytes++;
+    g = h & 0xf0000000;
+    h ^= g;
+    h ^= g >> 24;
+  }
+
+  return h;
+}
+
+uint32_t SymbolName::elf_hash() {
+  if (!has_elf_hash_) {
+    elf_hash_ = calculate_elf_hash(name_);
+    has_elf_hash_ = true;
+  }
+
+  return elf_hash_;
+}
+
+uint32_t SymbolName::gnu_hash() {
+  if (!has_gnu_hash_) {
+    uint32_t h = 5381;
+    const uint8_t* name = reinterpret_cast<const uint8_t*>(name_);
+    while (*name != 0) {
+      h += (h << 5) + *name++; // h*33 + c = h + h * 32 + c = h + h << 5 + c
+    }
+
+    gnu_hash_ =  h;
+    has_gnu_hash_ = true;
+  }
+
+  return gnu_hash_;
+}
+
+
diff --git a/linker/linker_soinfo.h b/linker/linker_soinfo.h
new file mode 100644
index 0000000..d7b584e
--- /dev/null
+++ b/linker/linker_soinfo.h
@@ -0,0 +1,345 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef __LINKER_SOINFO_H
+#define __LINKER_SOINFO_H
+
+#include <link.h>
+
+#include <string>
+
+#include "linker_namespaces.h"
+
+#define FLAG_LINKED           0x00000001
+#define FLAG_EXE              0x00000004 // The main executable
+#define FLAG_LINKER           0x00000010 // The linker itself
+#define FLAG_GNU_HASH         0x00000040 // uses gnu hash
+#define FLAG_MAPPED_BY_CALLER 0x00000080 // the map is reserved by the caller
+                                         // and should not be unmapped
+#define FLAG_NEW_SOINFO       0x40000000 // new soinfo format
+
+#define SOINFO_VERSION 3
+
+typedef void (*linker_dtor_function_t)();
+typedef void (*linker_ctor_function_t)(int, char**, char**);
+
+class SymbolName {
+ public:
+  explicit SymbolName(const char* name)
+      : name_(name), has_elf_hash_(false), has_gnu_hash_(false),
+        elf_hash_(0), gnu_hash_(0) { }
+
+  const char* get_name() {
+    return name_;
+  }
+
+  uint32_t elf_hash();
+  uint32_t gnu_hash();
+
+ private:
+  const char* name_;
+  bool has_elf_hash_;
+  bool has_gnu_hash_;
+  uint32_t elf_hash_;
+  uint32_t gnu_hash_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(SymbolName);
+};
+
+struct version_info {
+  constexpr version_info() : elf_hash(0), name(nullptr), target_si(nullptr) {}
+
+  uint32_t elf_hash;
+  const char* name;
+  const soinfo* target_si;
+};
+
+// TODO(dimitry): remove reference from soinfo member functions to this class.
+class VersionTracker;
+
+#if defined(__work_around_b_24465209__)
+#define SOINFO_NAME_LEN 128
+#endif
+
+struct soinfo {
+#if defined(__work_around_b_24465209__)
+ private:
+  char old_name_[SOINFO_NAME_LEN];
+#endif
+ public:
+  const ElfW(Phdr)* phdr;
+  size_t phnum;
+#if defined(__work_around_b_24465209__)
+  ElfW(Addr) unused0; // DO NOT USE, maintained for compatibility.
+#endif
+  ElfW(Addr) base;
+  size_t size;
+
+#if defined(__work_around_b_24465209__)
+  uint32_t unused1;  // DO NOT USE, maintained for compatibility.
+#endif
+
+  ElfW(Dyn)* dynamic;
+
+#if defined(__work_around_b_24465209__)
+  uint32_t unused2; // DO NOT USE, maintained for compatibility
+  uint32_t unused3; // DO NOT USE, maintained for compatibility
+#endif
+
+  soinfo* next;
+ private:
+  uint32_t flags_;
+
+  const char* strtab_;
+  ElfW(Sym)* symtab_;
+
+  size_t nbucket_;
+  size_t nchain_;
+  uint32_t* bucket_;
+  uint32_t* chain_;
+
+#if defined(__mips__) || !defined(__LP64__)
+  // This is only used by mips and mips64, but needs to be here for
+  // all 32-bit architectures to preserve binary compatibility.
+  ElfW(Addr)** plt_got_;
+#endif
+
+#if defined(USE_RELA)
+  ElfW(Rela)* plt_rela_;
+  size_t plt_rela_count_;
+
+  ElfW(Rela)* rela_;
+  size_t rela_count_;
+#else
+  ElfW(Rel)* plt_rel_;
+  size_t plt_rel_count_;
+
+  ElfW(Rel)* rel_;
+  size_t rel_count_;
+#endif
+
+  linker_ctor_function_t* preinit_array_;
+  size_t preinit_array_count_;
+
+  linker_ctor_function_t* init_array_;
+  size_t init_array_count_;
+  linker_dtor_function_t* fini_array_;
+  size_t fini_array_count_;
+
+  linker_ctor_function_t init_func_;
+  linker_dtor_function_t fini_func_;
+
+#if defined(__arm__)
+ public:
+  // ARM EABI section used for stack unwinding.
+  uint32_t* ARM_exidx;
+  size_t ARM_exidx_count;
+ private:
+#elif defined(__mips__)
+  uint32_t mips_symtabno_;
+  uint32_t mips_local_gotno_;
+  uint32_t mips_gotsym_;
+  bool mips_relocate_got(const VersionTracker& version_tracker,
+                         const soinfo_list_t& global_group,
+                         const soinfo_list_t& local_group);
+#if !defined(__LP64__)
+  bool mips_check_and_adjust_fp_modes();
+#endif
+#endif
+  size_t ref_count_;
+ public:
+  link_map link_map_head;
+
+  bool constructors_called;
+
+  // When you read a virtual address from the ELF file, add this
+  // value to get the corresponding address in the process' address space.
+  ElfW(Addr) load_bias;
+
+#if !defined(__LP64__)
+  bool has_text_relocations;
+#endif
+  bool has_DT_SYMBOLIC;
+
+ public:
+  soinfo(android_namespace_t* ns, const char* name, const struct stat* file_stat,
+         off64_t file_offset, int rtld_flags);
+  ~soinfo();
+
+  void call_constructors();
+  void call_destructors();
+  void call_pre_init_constructors();
+  bool prelink_image();
+  bool link_image(const soinfo_list_t& global_group, const soinfo_list_t& local_group,
+                  const android_dlextinfo* extinfo);
+  bool protect_relro();
+
+  void add_child(soinfo* child);
+  void remove_all_links();
+
+  ino_t get_st_ino() const;
+  dev_t get_st_dev() const;
+  off64_t get_file_offset() const;
+
+  uint32_t get_rtld_flags() const;
+  uint32_t get_dt_flags_1() const;
+  void set_dt_flags_1(uint32_t dt_flags_1);
+
+  soinfo_list_t& get_children();
+  const soinfo_list_t& get_children() const;
+
+  soinfo_list_t& get_parents();
+
+  bool find_symbol_by_name(SymbolName& symbol_name,
+                           const version_info* vi,
+                           const ElfW(Sym)** symbol) const;
+
+  ElfW(Sym)* find_symbol_by_address(const void* addr);
+  ElfW(Addr) resolve_symbol_address(const ElfW(Sym)* s) const;
+
+  const char* get_string(ElfW(Word) index) const;
+  bool can_unload() const;
+  bool is_gnu_hash() const;
+
+  bool inline has_min_version(uint32_t min_version __unused) const {
+#if defined(__work_around_b_24465209__)
+    return (flags_ & FLAG_NEW_SOINFO) != 0 && version_ >= min_version;
+#else
+    return true;
+#endif
+  }
+
+  bool is_linked() const;
+  bool is_linker() const;
+  bool is_main_executable() const;
+
+  void set_linked();
+  void set_linker_flag();
+  void set_main_executable();
+  void set_nodelete();
+
+  void increment_ref_count();
+  size_t decrement_ref_count();
+
+  soinfo* get_local_group_root() const;
+
+  void set_soname(const char* soname);
+  const char* get_soname() const;
+  const char* get_realpath() const;
+  const ElfW(Versym)* get_versym(size_t n) const;
+  ElfW(Addr) get_verneed_ptr() const;
+  size_t get_verneed_cnt() const;
+  ElfW(Addr) get_verdef_ptr() const;
+  size_t get_verdef_cnt() const;
+
+  uint32_t get_target_sdk_version() const;
+
+  void set_dt_runpath(const char *);
+  const std::vector<std::string>& get_dt_runpath() const;
+  android_namespace_t* get_primary_namespace();
+  void add_secondary_namespace(android_namespace_t* secondary_ns);
+
+  void set_mapped_by_caller(bool reserved_map);
+  bool is_mapped_by_caller() const;
+
+  uintptr_t get_handle() const;
+  void generate_handle();
+  void* to_handle();
+
+ private:
+  bool elf_lookup(SymbolName& symbol_name, const version_info* vi, uint32_t* symbol_index) const;
+  ElfW(Sym)* elf_addr_lookup(const void* addr);
+  bool gnu_lookup(SymbolName& symbol_name, const version_info* vi, uint32_t* symbol_index) const;
+  ElfW(Sym)* gnu_addr_lookup(const void* addr);
+
+  bool lookup_version_info(const VersionTracker& version_tracker, ElfW(Word) sym,
+                           const char* sym_name, const version_info** vi);
+
+  template<typename ElfRelIteratorT>
+  bool relocate(const VersionTracker& version_tracker, ElfRelIteratorT&& rel_iterator,
+                const soinfo_list_t& global_group, const soinfo_list_t& local_group);
+
+ private:
+  // This part of the structure is only available
+  // when FLAG_NEW_SOINFO is set in this->flags.
+  uint32_t version_;
+
+  // version >= 0
+  dev_t st_dev_;
+  ino_t st_ino_;
+
+  // dependency graph
+  soinfo_list_t children_;
+  soinfo_list_t parents_;
+
+  // version >= 1
+  off64_t file_offset_;
+  uint32_t rtld_flags_;
+  uint32_t dt_flags_1_;
+  size_t strtab_size_;
+
+  // version >= 2
+
+  size_t gnu_nbucket_;
+  uint32_t* gnu_bucket_;
+  uint32_t* gnu_chain_;
+  uint32_t gnu_maskwords_;
+  uint32_t gnu_shift2_;
+  ElfW(Addr)* gnu_bloom_filter_;
+
+  soinfo* local_group_root_;
+
+  uint8_t* android_relocs_;
+  size_t android_relocs_size_;
+
+  const char* soname_;
+  std::string realpath_;
+
+  const ElfW(Versym)* versym_;
+
+  ElfW(Addr) verdef_ptr_;
+  size_t verdef_cnt_;
+
+  ElfW(Addr) verneed_ptr_;
+  size_t verneed_cnt_;
+
+  uint32_t target_sdk_version_;
+
+  // version >= 3
+  std::vector<std::string> dt_runpath_;
+  android_namespace_t* primary_namespace_;
+  android_namespace_list_t secondary_namespaces_;
+  uintptr_t handle_;
+
+  friend soinfo* get_libdl_info();
+};
+
+// This function is used by dlvsym() to calculate hash of sym_ver
+uint32_t calculate_elf_hash(const char* name);
+
+#endif  /* __LINKER_SOINFO_H */
diff --git a/linker/linker_utils.cpp b/linker/linker_utils.cpp
new file mode 100644
index 0000000..e7447e4
--- /dev/null
+++ b/linker/linker_utils.cpp
@@ -0,0 +1,204 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "linker_utils.h"
+
+#include "linker_debug.h"
+#include "linker_globals.h"
+
+#include "android-base/strings.h"
+
+#include <sys/stat.h>
+#include <unistd.h>
+
+std::string dirname(const char* path) {
+  const char* last_slash = strrchr(path, '/');
+
+  if (last_slash == path) {
+    return "/";
+  } else if (last_slash == nullptr) {
+    return ".";
+  } else {
+    return std::string(path, last_slash - path);
+  }
+}
+
+bool normalize_path(const char* path, std::string* normalized_path) {
+  // Input should be an absolute path
+  if (path[0] != '/') {
+    PRINT("normalize_path - invalid input: \"%s\", the input path should be absolute", path);
+    return false;
+  }
+
+  const size_t len = strlen(path) + 1;
+  char buf[len];
+
+  const char* in_ptr = path;
+  char* out_ptr = buf;
+
+  while (*in_ptr != 0) {
+    if (*in_ptr == '/') {
+      char c1 = in_ptr[1];
+      if (c1 == '.') {
+        char c2 = in_ptr[2];
+        if (c2 == '/') {
+          in_ptr += 2;
+          continue;
+        } else if (c2 == '.' && (in_ptr[3] == '/' || in_ptr[3] == 0)) {
+          in_ptr += 3;
+          while (out_ptr > buf && *--out_ptr != '/') {
+          }
+          if (in_ptr[0] == 0) {
+            // retain '/'
+            out_ptr++;
+          }
+          continue;
+        }
+      } else if (c1 == '/') {
+        ++in_ptr;
+        continue;
+      }
+    }
+    *out_ptr++ = *in_ptr++;
+  }
+
+  *out_ptr = 0;
+  *normalized_path = buf;
+  return true;
+}
+
+bool file_is_in_dir(const std::string& file, const std::string& dir) {
+  const char* needle = dir.c_str();
+  const char* haystack = file.c_str();
+  size_t needle_len = strlen(needle);
+
+  return strncmp(haystack, needle, needle_len) == 0 &&
+         haystack[needle_len] == '/' &&
+         strchr(haystack + needle_len + 1, '/') == nullptr;
+}
+
+bool file_is_under_dir(const std::string& file, const std::string& dir) {
+  const char* needle = dir.c_str();
+  const char* haystack = file.c_str();
+  size_t needle_len = strlen(needle);
+
+  return strncmp(haystack, needle, needle_len) == 0 &&
+         haystack[needle_len] == '/';
+}
+
+const char* const kZipFileSeparator = "!/";
+
+bool parse_zip_path(const char* input_path, std::string* zip_path, std::string* entry_path) {
+  std::string normalized_path;
+  if (!normalize_path(input_path, &normalized_path)) {
+    return false;
+  }
+
+  const char* const path = normalized_path.c_str();
+  TRACE("Trying zip file open from path \"%s\" -> normalized \"%s\"", input_path, path);
+
+  // Treat an '!/' separator inside a path as the separator between the name
+  // of the zip file on disk and the subdirectory to search within it.
+  // For example, if path is "foo.zip!/bar/bas/x.so", then we search for
+  // "bar/bas/x.so" within "foo.zip".
+  const char* const separator = strstr(path, kZipFileSeparator);
+  if (separator == nullptr) {
+    return false;
+  }
+
+  char buf[512];
+  if (strlcpy(buf, path, sizeof(buf)) >= sizeof(buf)) {
+    PRINT("Warning: ignoring very long library path: %s", path);
+    return false;
+  }
+
+  buf[separator - path] = '\0';
+
+  *zip_path = buf;
+  *entry_path = &buf[separator - path + 2];
+
+  return true;
+}
+
+constexpr off64_t kPageMask = ~static_cast<off64_t>(PAGE_SIZE-1);
+
+off64_t page_start(off64_t offset) {
+  return offset & kPageMask;
+}
+
+bool safe_add(off64_t* out, off64_t a, size_t b) {
+  CHECK(a >= 0);
+  if (static_cast<uint64_t>(INT64_MAX - a) < b) {
+    return false;
+  }
+
+  *out = a + b;
+  return true;
+}
+
+size_t page_offset(off64_t offset) {
+  return static_cast<size_t>(offset & (PAGE_SIZE-1));
+}
+
+void split_path(const char* path, const char* delimiters,
+                std::vector<std::string>* paths) {
+  if (path != nullptr && path[0] != 0) {
+    *paths = android::base::Split(path, delimiters);
+  }
+}
+
+void resolve_paths(std::vector<std::string>& paths,
+                   std::vector<std::string>* resolved_paths) {
+  resolved_paths->clear();
+  for (const auto& path : paths) {
+    char resolved_path[PATH_MAX];
+    const char* original_path = path.c_str();
+    if (realpath(original_path, resolved_path) != nullptr) {
+      struct stat s;
+      if (stat(resolved_path, &s) == 0) {
+        if (S_ISDIR(s.st_mode)) {
+          resolved_paths->push_back(resolved_path);
+        } else {
+          DL_WARN("Warning: \"%s\" is not a directory (excluding from path)", resolved_path);
+          continue;
+        }
+      } else {
+        DL_WARN("Warning: cannot stat file \"%s\": %s", resolved_path, strerror(errno));
+        continue;
+      }
+    } else {
+      std::string zip_path;
+      std::string entry_path;
+
+      std::string normalized_path;
+
+      if (!normalize_path(original_path, &normalized_path)) {
+        DL_WARN("Warning: unable to normalize \"%s\"", original_path);
+        continue;
+      }
+
+      if (parse_zip_path(normalized_path.c_str(), &zip_path, &entry_path)) {
+        if (realpath(zip_path.c_str(), resolved_path) == nullptr) {
+          DL_WARN("Warning: unable to resolve \"%s\": %s", zip_path.c_str(), strerror(errno));
+          continue;
+        }
+
+        resolved_paths->push_back(std::string(resolved_path) + kZipFileSeparator + entry_path);
+      }
+    }
+  }
+}
+
diff --git a/linker/linker_utils.h b/linker/linker_utils.h
new file mode 100644
index 0000000..2e015a5
--- /dev/null
+++ b/linker/linker_utils.h
@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef __LINKER_UTILS_H
+#define __LINKER_UTILS_H
+
+#include <string>
+#include <vector>
+
+extern const char* const kZipFileSeparator;
+
+bool file_is_in_dir(const std::string& file, const std::string& dir);
+bool file_is_under_dir(const std::string& file, const std::string& dir);
+bool normalize_path(const char* path, std::string* normalized_path);
+bool parse_zip_path(const char* input_path, std::string* zip_path, std::string* entry_path);
+
+// For every path element this function checks of it exists, and is a directory,
+// and normalizes it:
+// 1. For regular path it converts it to realpath()
+// 2. For path in a zip file it uses realpath on the zipfile
+//    normalizes entry name by calling normalize_path function.
+void resolve_paths(std::vector<std::string>& paths, std::vector<std::string>* resolved_paths);
+void split_path(const char* path, const char* delimiters, std::vector<std::string>* paths);
+
+std::string dirname(const char* path);
+
+off64_t page_start(off64_t offset);
+size_t page_offset(off64_t offset);
+bool safe_add(off64_t* out, off64_t a, size_t b);
+
+#endif
diff --git a/linker/rt.cpp b/linker/rt.cpp
new file mode 100644
index 0000000..710892a
--- /dev/null
+++ b/linker/rt.cpp
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * This function is an empty stub where GDB locates a breakpoint to get notified
+ * about linker activity.  It canʼt be inlined away, can't be hidden.
+ */
+extern "C" void __attribute__((noinline)) __attribute__((visibility("default"))) rtld_db_dlactivity() {
+}
+
diff --git a/linker/tests/Android.mk b/linker/tests/Android.mk
new file mode 100644
index 0000000..d5b57f1
--- /dev/null
+++ b/linker/tests/Android.mk
@@ -0,0 +1,45 @@
+#
+# Copyright (C) 2012 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+LOCAL_PATH:= $(call my-dir)
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := linker-unit-tests
+LOCAL_MODULE_STEM_32 := $(LOCAL_MODULE)32
+LOCAL_MODULE_STEM_64 := $(LOCAL_MODULE)64
+
+LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
+
+LOCAL_CFLAGS += -g -Wall -Wextra -Wunused -Werror
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/../../libc/
+
+LOCAL_SRC_FILES := \
+  linker_block_allocator_test.cpp \
+  linker_globals.cpp \
+  linked_list_test.cpp \
+  linker_memory_allocator_test.cpp \
+  linker_sleb128_test.cpp \
+  linker_utils_test.cpp \
+  ../linker_allocator.cpp \
+  ../linker_block_allocator.cpp \
+  ../linker_utils.cpp
+
+# for __libc_fatal
+LOCAL_SRC_FILES += ../../libc/bionic/libc_logging.cpp
+
+LOCAL_STATIC_LIBRARIES += libbase
+
+include $(BUILD_NATIVE_TEST)
diff --git a/linker/tests/linked_list_test.cpp b/linker/tests/linked_list_test.cpp
new file mode 100644
index 0000000..12348d9
--- /dev/null
+++ b/linker/tests/linked_list_test.cpp
@@ -0,0 +1,233 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdlib.h>
+#include <string>
+#include <sstream>
+
+#include <gtest/gtest.h>
+
+#include "../linked_list.h"
+
+namespace {
+
+bool alloc_called = false;
+bool free_called = false;
+
+class LinkedListTestAllocator {
+ public:
+  typedef LinkedListEntry<const char> entry_t;
+
+  static entry_t* alloc() {
+    alloc_called = true;
+    return reinterpret_cast<entry_t*>(::malloc(sizeof(entry_t)));
+  }
+
+  static void free(entry_t* p) {
+    free_called = true;
+    ::free(p);
+  }
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(LinkedListTestAllocator);
+};
+
+typedef LinkedList<const char, LinkedListTestAllocator> test_list_t;
+
+std::string test_list_to_string(test_list_t& list) {
+  std::stringstream ss;
+  list.for_each([&] (const char* c) {
+    ss << c;
+  });
+
+  return ss.str();
+}
+
+};
+
+TEST(linked_list, simple) {
+  alloc_called = free_called = false;
+  test_list_t list;
+  ASSERT_EQ("", test_list_to_string(list));
+  ASSERT_TRUE(!alloc_called);
+  ASSERT_TRUE(!free_called);
+  list.push_front("a");
+  ASSERT_TRUE(alloc_called);
+  ASSERT_TRUE(!free_called);
+  ASSERT_EQ("a", test_list_to_string(list));
+  list.push_front("b");
+  ASSERT_EQ("ba", test_list_to_string(list));
+  list.push_front("c");
+  list.push_front("d");
+  ASSERT_EQ("dcba", test_list_to_string(list));
+  ASSERT_TRUE(alloc_called);
+  ASSERT_TRUE(!free_called);
+  alloc_called = free_called = false;
+  list.remove_if([] (const char* c) {
+    return *c == 'c';
+  });
+
+  ASSERT_TRUE(!alloc_called);
+  ASSERT_TRUE(free_called);
+
+  ASSERT_EQ("dba", test_list_to_string(list));
+  alloc_called = free_called = false;
+  list.remove_if([] (const char* c) {
+    return *c == '2';
+  });
+  ASSERT_TRUE(!alloc_called);
+  ASSERT_TRUE(!free_called);
+  ASSERT_EQ("dba", test_list_to_string(list));
+  list.clear();
+  ASSERT_TRUE(!alloc_called);
+  ASSERT_TRUE(free_called);
+  ASSERT_EQ("", test_list_to_string(list));
+}
+
+TEST(linked_list, push_pop) {
+  test_list_t list;
+  list.push_front("b");
+  list.push_front("a");
+  ASSERT_EQ("ab", test_list_to_string(list));
+  list.push_back("c");
+  ASSERT_EQ("abc", test_list_to_string(list));
+  ASSERT_STREQ("a", list.pop_front());
+  ASSERT_EQ("bc", test_list_to_string(list));
+  ASSERT_STREQ("b", list.pop_front());
+  ASSERT_EQ("c", test_list_to_string(list));
+  ASSERT_STREQ("c", list.pop_front());
+  ASSERT_EQ("", test_list_to_string(list));
+  ASSERT_TRUE(list.pop_front() == nullptr);
+  list.push_back("r");
+  ASSERT_EQ("r", test_list_to_string(list));
+  ASSERT_STREQ("r", list.pop_front());
+  ASSERT_TRUE(list.pop_front() == nullptr);
+}
+
+TEST(linked_list, remove_if_then_pop) {
+  test_list_t list;
+  list.push_back("a");
+  list.push_back("b");
+  list.push_back("c");
+  list.push_back("d");
+  list.remove_if([](const char* c) {
+    return *c == 'b' || *c == 'c';
+  });
+
+  ASSERT_EQ("ad", test_list_to_string(list));
+  ASSERT_STREQ("a", list.pop_front());
+  ASSERT_EQ("d", test_list_to_string(list));
+  ASSERT_STREQ("d", list.pop_front());
+  ASSERT_TRUE(list.pop_front() == nullptr);
+}
+
+TEST(linked_list, remove_if_last_then_push_back) {
+  test_list_t list;
+
+  list.push_back("a");
+  list.push_back("b");
+  list.push_back("c");
+  list.push_back("d");
+
+  list.remove_if([](const char* c) {
+    return *c == 'c' || *c == 'd';
+  });
+
+  ASSERT_EQ("ab", test_list_to_string(list));
+  list.push_back("d");
+  ASSERT_EQ("abd", test_list_to_string(list));
+}
+
+TEST(linked_list, copy_to_array) {
+  test_list_t list;
+  const size_t max_size = 128;
+  const char* buf[max_size];
+  memset(buf, 0, sizeof(buf));
+
+  ASSERT_EQ(0U, list.copy_to_array(buf, max_size));
+  ASSERT_EQ(nullptr, buf[0]);
+
+  list.push_back("a");
+  list.push_back("b");
+  list.push_back("c");
+  list.push_back("d");
+
+  memset(buf, 0, sizeof(buf));
+  ASSERT_EQ(2U, list.copy_to_array(buf, 2));
+  ASSERT_STREQ("a", buf[0]);
+  ASSERT_STREQ("b", buf[1]);
+  ASSERT_EQ(nullptr, buf[2]);
+
+  ASSERT_EQ(4U, list.copy_to_array(buf, max_size));
+  ASSERT_STREQ("a", buf[0]);
+  ASSERT_STREQ("b", buf[1]);
+  ASSERT_STREQ("c", buf[2]);
+  ASSERT_STREQ("d", buf[3]);
+  ASSERT_EQ(nullptr, buf[4]);
+
+  memset(buf, 0, sizeof(buf));
+  list.remove_if([](const char* c) {
+    return *c != 'c';
+  });
+  ASSERT_EQ(1U, list.copy_to_array(buf, max_size));
+  ASSERT_STREQ("c", buf[0]);
+  ASSERT_EQ(nullptr, buf[1]);
+
+  memset(buf, 0, sizeof(buf));
+
+  list.remove_if([](const char* c) {
+    return *c == 'c';
+  });
+
+  ASSERT_EQ(0U, list.copy_to_array(buf, max_size));
+  ASSERT_EQ(nullptr, buf[0]);
+}
+
+TEST(linked_list, test_visit) {
+  test_list_t list;
+  list.push_back("a");
+  list.push_back("b");
+  list.push_back("c");
+  list.push_back("d");
+
+  int visits = 0;
+  std::stringstream ss;
+  bool result = list.visit([&](const char* c) {
+    ++visits;
+    ss << c;
+    return true;
+  });
+
+  ASSERT_TRUE(result);
+  ASSERT_EQ(4, visits);
+  ASSERT_EQ("abcd", ss.str());
+
+  visits = 0;
+  ss.str(std::string());
+
+  result = list.visit([&](const char* c) {
+    if (++visits == 3) {
+      return false;
+    }
+
+    ss << c;
+    return true;
+  });
+
+  ASSERT_TRUE(!result);
+  ASSERT_EQ(3, visits);
+  ASSERT_EQ("ab", ss.str());
+}
+
diff --git a/linker/tests/linker_block_allocator_test.cpp b/linker/tests/linker_block_allocator_test.cpp
new file mode 100644
index 0000000..5adc425
--- /dev/null
+++ b/linker/tests/linker_block_allocator_test.cpp
@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+
+#include <gtest/gtest.h>
+
+#include "../linker_block_allocator.h"
+
+#include <unistd.h>
+
+namespace {
+
+struct test_struct_nominal {
+  void* pointer;
+  ssize_t value;
+};
+
+/*
+ * this one has size below allocator cap which is 2*sizeof(void*)
+ */
+struct test_struct_small {
+  char dummy_str[5];
+};
+
+/*
+ * 1009 byte struct (1009 is prime)
+ */
+struct test_struct_larger {
+  char dummy_str[1009];
+};
+
+static size_t kPageSize = sysconf(_SC_PAGE_SIZE);
+};
+
+TEST(linker_allocator, test_nominal) {
+  LinkerTypeAllocator<test_struct_nominal> allocator;
+
+  test_struct_nominal* ptr1 = allocator.alloc();
+  ASSERT_TRUE(ptr1 != nullptr);
+  ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr1) % 16);
+  test_struct_nominal* ptr2 = allocator.alloc();
+  ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr2) % 16);
+  ASSERT_TRUE(ptr2 != nullptr);
+  // they should be next to each other.
+  ASSERT_EQ(reinterpret_cast<uint8_t*>(ptr1)+16, reinterpret_cast<uint8_t*>(ptr2));
+
+  ptr1->value = 42;
+
+  allocator.free(ptr1);
+  allocator.free(ptr2);
+}
+
+TEST(linker_allocator, test_small) {
+  LinkerTypeAllocator<test_struct_small> allocator;
+
+  char* ptr1 = reinterpret_cast<char*>(allocator.alloc());
+  char* ptr2 = reinterpret_cast<char*>(allocator.alloc());
+
+  ASSERT_TRUE(ptr1 != nullptr);
+  ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr1) % 16);
+  ASSERT_TRUE(ptr2 != nullptr);
+  ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr2) % 16);
+  ASSERT_EQ(ptr1+16, ptr2); // aligned to 16
+}
+
+TEST(linker_allocator, test_larger) {
+  LinkerTypeAllocator<test_struct_larger> allocator;
+
+  test_struct_larger* ptr1 = allocator.alloc();
+  test_struct_larger* ptr2 = allocator.alloc();
+
+  ASSERT_TRUE(ptr1 != nullptr);
+  ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr1) % 16);
+  ASSERT_TRUE(ptr2 != nullptr);
+  ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr2) % 16);
+
+  ASSERT_EQ(reinterpret_cast<uint8_t*>(ptr1) + 1024, reinterpret_cast<uint8_t*>(ptr2));
+
+  // lets allocate until we reach next page.
+  size_t n = kPageSize/sizeof(test_struct_larger) + 1 - 2;
+
+  for (size_t i=0; i<n; ++i) {
+    ASSERT_TRUE(allocator.alloc() != nullptr);
+  }
+
+  test_struct_larger* ptr_to_free = allocator.alloc();
+  ASSERT_TRUE(ptr_to_free != nullptr);
+  allocator.free(ptr1);
+}
+
+static void protect_all() {
+  LinkerTypeAllocator<test_struct_larger> allocator;
+
+  // number of allocs to reach the end of first page
+  size_t n = kPageSize/sizeof(test_struct_larger) - 1;
+  test_struct_larger* page1_ptr = allocator.alloc();
+
+  for (size_t i=0; i<n; ++i) {
+    allocator.alloc();
+  }
+
+  test_struct_larger* page2_ptr = allocator.alloc();
+  allocator.protect_all(PROT_READ);
+  allocator.protect_all(PROT_READ | PROT_WRITE);
+  // check access
+  page2_ptr->dummy_str[23] = 27;
+  page1_ptr->dummy_str[13] = 11;
+
+  allocator.protect_all(PROT_READ);
+  fprintf(stderr, "trying to access protected page");
+
+  // this should result in segmentation fault
+  page1_ptr->dummy_str[11] = 7;
+}
+
+TEST(linker_allocator, test_protect) {
+  testing::FLAGS_gtest_death_test_style = "threadsafe";
+  ASSERT_EXIT(protect_all(), testing::KilledBySignal(SIGSEGV), "trying to access protected page");
+}
+
diff --git a/linker/tests/linker_globals.cpp b/linker/tests/linker_globals.cpp
new file mode 100644
index 0000000..7762a87
--- /dev/null
+++ b/linker/tests/linker_globals.cpp
@@ -0,0 +1,19 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// To enable logging
+int g_ld_debug_verbosity = 0;
+
diff --git a/linker/tests/linker_memory_allocator_test.cpp b/linker/tests/linker_memory_allocator_test.cpp
new file mode 100644
index 0000000..5b85536
--- /dev/null
+++ b/linker/tests/linker_memory_allocator_test.cpp
@@ -0,0 +1,203 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+
+#include <gtest/gtest.h>
+
+#include "../linker_allocator.h"
+
+#include <unistd.h>
+
+namespace {
+
+/*
+ * this one has size below allocator cap which is 2*sizeof(void*)
+ */
+struct test_struct_small {
+  char dummy_str[5];
+};
+
+struct test_struct_large {
+  char dummy_str[1009];
+};
+
+struct test_struct_huge {
+  char dummy_str[73939];
+};
+
+struct test_struct_512 {
+  char dummy_str[503];
+};
+
+};
+
+static size_t kPageSize = sysconf(_SC_PAGE_SIZE);
+
+TEST(linker_memory, test_alloc_0) {
+  LinkerMemoryAllocator allocator;
+  void* ptr = allocator.alloc(0);
+  ASSERT_TRUE(ptr != nullptr);
+  allocator.free(ptr);
+}
+
+TEST(linker_memory, test_free_nullptr) {
+  LinkerMemoryAllocator allocator;
+  allocator.free(nullptr);
+}
+
+TEST(linker_memory, test_realloc) {
+  LinkerMemoryAllocator allocator;
+  uint32_t* array = reinterpret_cast<uint32_t*>(allocator.alloc(512));
+  const size_t array_size = 512 / sizeof(uint32_t);
+
+  uint32_t model[1000];
+
+  model[0] = 1;
+  model[1] = 1;
+
+  for (size_t i = 2; i < 1000; ++i) {
+    model[i] = model[i - 1] + model[i - 2];
+  }
+
+  memcpy(array, model, array_size);
+
+  uint32_t* reallocated_ptr = reinterpret_cast<uint32_t*>(allocator.realloc(array, 1024));
+
+  ASSERT_TRUE(reallocated_ptr != nullptr);
+  ASSERT_TRUE(reallocated_ptr != array);
+
+  ASSERT_TRUE(memcmp(reallocated_ptr, model, array_size) == 0);
+
+  array = reallocated_ptr;
+
+  memcpy(array, model, 2*array_size);
+
+  reallocated_ptr = reinterpret_cast<uint32_t*>(allocator.realloc(array, 62));
+
+  ASSERT_TRUE(reallocated_ptr == array);
+
+  reallocated_ptr = reinterpret_cast<uint32_t*>(allocator.realloc(array, 4000));
+
+  ASSERT_TRUE(reallocated_ptr != nullptr);
+  ASSERT_TRUE(reallocated_ptr != array);
+  ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(reallocated_ptr) % 16);
+
+  ASSERT_TRUE(memcmp(reallocated_ptr, model, array_size * 2) == 0);
+
+  array = reallocated_ptr;
+
+  memcpy(array, model, 4000);
+
+  reallocated_ptr = reinterpret_cast<uint32_t*>(allocator.realloc(array, 64000));
+
+  ASSERT_TRUE(reallocated_ptr != nullptr);
+  ASSERT_TRUE(reallocated_ptr != array);
+  ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(reallocated_ptr) % 16);
+
+  ASSERT_TRUE(memcmp(reallocated_ptr, model, 4000) == 0);
+
+  ASSERT_EQ(nullptr, allocator.realloc(reallocated_ptr, 0));
+}
+
+TEST(linker_memory, test_small_smoke) {
+  LinkerMemoryAllocator allocator;
+
+  uint8_t zeros[16];
+  memset(zeros, 0, sizeof(zeros));
+
+  test_struct_small* ptr1 =
+      reinterpret_cast<test_struct_small*>(allocator.alloc(sizeof(test_struct_small)));
+  test_struct_small* ptr2 =
+      reinterpret_cast<test_struct_small*>(allocator.alloc(sizeof(test_struct_small)));
+
+  ASSERT_TRUE(ptr1 != nullptr);
+  ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr1) % 16);
+  ASSERT_TRUE(ptr2 != nullptr);
+  ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr2) % 16);
+
+  ASSERT_EQ(reinterpret_cast<uintptr_t>(ptr1)+16, reinterpret_cast<uintptr_t>(ptr2));
+  ASSERT_TRUE(memcmp(ptr1, zeros, 16) == 0);
+
+  allocator.free(ptr1);
+  allocator.free(ptr2);
+}
+
+TEST(linker_memory, test_huge_smoke) {
+  LinkerMemoryAllocator allocator;
+
+  // this should trigger proxy-to-mmap
+  test_struct_huge* ptr1 =
+      reinterpret_cast<test_struct_huge*>(allocator.alloc(sizeof(test_struct_huge)));
+  test_struct_huge* ptr2 =
+      reinterpret_cast<test_struct_huge*>(allocator.alloc(sizeof(test_struct_huge)));
+
+  ASSERT_TRUE(ptr1 != nullptr);
+  ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr1) % 16);
+  ASSERT_TRUE(ptr2 != nullptr);
+  ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr2) % 16);
+
+  ASSERT_TRUE(
+      reinterpret_cast<uintptr_t>(ptr1)/kPageSize != reinterpret_cast<uintptr_t>(ptr2)/kPageSize);
+  allocator.free(ptr2);
+  allocator.free(ptr1);
+}
+
+TEST(linker_memory, test_large) {
+  LinkerMemoryAllocator allocator;
+
+  test_struct_large* ptr1 =
+      reinterpret_cast<test_struct_large*>(allocator.alloc(sizeof(test_struct_large)));
+  test_struct_large* ptr2 =
+      reinterpret_cast<test_struct_large*>(allocator.alloc(1024));
+
+  ASSERT_TRUE(ptr1 != nullptr);
+  ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr1) % 16);
+  ASSERT_TRUE(ptr2 != nullptr);
+  ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr2) % 16);
+
+  ASSERT_EQ(reinterpret_cast<uintptr_t>(ptr1) + 1024, reinterpret_cast<uintptr_t>(ptr2));
+
+  // let's allocate until we reach the next page.
+  size_t n = kPageSize / sizeof(test_struct_large) + 1 - 2;
+  test_struct_large* objects[n];
+
+  for (size_t i = 0; i < n; ++i) {
+    test_struct_large* obj_ptr =
+        reinterpret_cast<test_struct_large*>(allocator.alloc(sizeof(test_struct_large)));
+    ASSERT_TRUE(obj_ptr != nullptr);
+    objects[i] = obj_ptr;
+  }
+
+  test_struct_large* ptr_to_free =
+      reinterpret_cast<test_struct_large*>(allocator.alloc(sizeof(test_struct_large)));
+
+  ASSERT_TRUE(ptr_to_free != nullptr);
+  ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr_to_free) % 16);
+
+  allocator.free(ptr1);
+
+  for (size_t i=0; i<n; ++i) {
+    allocator.free(objects[i]);
+  }
+
+  allocator.free(ptr2);
+  allocator.free(ptr_to_free);
+}
+
+
diff --git a/linker/tests/linker_sleb128_test.cpp b/linker/tests/linker_sleb128_test.cpp
new file mode 100644
index 0000000..4e29bca
--- /dev/null
+++ b/linker/tests/linker_sleb128_test.cpp
@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+
+#include <gtest/gtest.h>
+
+#include "../linker_sleb128.h"
+
+TEST(linker_sleb128, smoke) {
+  std::vector<uint8_t> encoding;
+  // 624485
+  encoding.push_back(0xe5);
+  encoding.push_back(0x8e);
+  encoding.push_back(0x26);
+  // 0
+  encoding.push_back(0x00);
+  // 1
+  encoding.push_back(0x01);
+  // 63
+  encoding.push_back(0x3f);
+  // 64
+  encoding.push_back(0xc0);
+  encoding.push_back(0x00);
+  // -1
+  encoding.push_back(0x7f);
+  // -624485
+  encoding.push_back(0x9b);
+  encoding.push_back(0xf1);
+  encoding.push_back(0x59);
+  // 2147483647
+  encoding.push_back(0xff);
+  encoding.push_back(0xff);
+  encoding.push_back(0xff);
+  encoding.push_back(0xff);
+  encoding.push_back(0x07);
+  // -2147483648
+  encoding.push_back(0x80);
+  encoding.push_back(0x80);
+  encoding.push_back(0x80);
+  encoding.push_back(0x80);
+  encoding.push_back(0x78);
+#if defined(__LP64__)
+  // 9223372036854775807
+  encoding.push_back(0xff);
+  encoding.push_back(0xff);
+  encoding.push_back(0xff);
+  encoding.push_back(0xff);
+  encoding.push_back(0xff);
+  encoding.push_back(0xff);
+  encoding.push_back(0xff);
+  encoding.push_back(0xff);
+  encoding.push_back(0xff);
+  encoding.push_back(0x00);
+  // -9223372036854775808
+  encoding.push_back(0x80);
+  encoding.push_back(0x80);
+  encoding.push_back(0x80);
+  encoding.push_back(0x80);
+  encoding.push_back(0x80);
+  encoding.push_back(0x80);
+  encoding.push_back(0x80);
+  encoding.push_back(0x80);
+  encoding.push_back(0x80);
+  encoding.push_back(0x7f);
+#endif
+  sleb128_decoder decoder(&encoding[0], encoding.size());
+
+  EXPECT_EQ(624485U, decoder.pop_front());
+
+  EXPECT_EQ(0U, decoder.pop_front());
+  EXPECT_EQ(1U, decoder.pop_front());
+  EXPECT_EQ(63U, decoder.pop_front());
+  EXPECT_EQ(64U, decoder.pop_front());
+  EXPECT_EQ(static_cast<size_t>(-1), decoder.pop_front());
+  EXPECT_EQ(static_cast<size_t>(-624485), decoder.pop_front());
+  EXPECT_EQ(2147483647U, decoder.pop_front());
+  EXPECT_EQ(static_cast<size_t>(-2147483648), decoder.pop_front());
+#if defined(__LP64__)
+  EXPECT_EQ(9223372036854775807ULL, decoder.pop_front());
+  EXPECT_EQ(static_cast<uint64_t>(-9223372036854775807LL - 1), decoder.pop_front());
+#endif
+}
diff --git a/linker/tests/linker_utils_test.cpp b/linker/tests/linker_utils_test.cpp
new file mode 100644
index 0000000..fd749fa
--- /dev/null
+++ b/linker/tests/linker_utils_test.cpp
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+
+#include <gtest/gtest.h>
+
+#include "../linker_utils.h"
+
+TEST(linker_utils, normalize_path_smoke) {
+  std::string output;
+  ASSERT_TRUE(normalize_path("/../root///dir/.///dir2/somedir/../zipfile!/dir/dir9//..///afile", &output));
+  ASSERT_EQ("/root/dir/dir2/zipfile!/dir/afile", output);
+
+  ASSERT_TRUE(normalize_path("/../root///dir/.///dir2/somedir/.../zipfile!/.dir/dir9//..///afile", &output));
+  ASSERT_EQ("/root/dir/dir2/somedir/.../zipfile!/.dir/afile", output);
+
+  ASSERT_TRUE(normalize_path("/root/..", &output));
+  ASSERT_EQ("/", output);
+
+  ASSERT_TRUE(normalize_path("/root/notroot/..", &output));
+  ASSERT_EQ("/root/", output);
+
+  ASSERT_TRUE(normalize_path("/a/../../b", &output));
+  ASSERT_EQ("/b", output);
+
+  output = "unchanged";
+  ASSERT_FALSE(normalize_path("root///dir/.///dir2/somedir/../zipfile!/dir/dir9//..///afile", &output));
+  ASSERT_EQ("unchanged", output);
+}
+
+TEST(linker_utils, file_is_in_dir_smoke) {
+  ASSERT_TRUE(file_is_in_dir("/foo/bar/file", "/foo/bar"));
+  ASSERT_FALSE(file_is_in_dir("/foo/bar/file", "/foo"));
+
+  ASSERT_FALSE(file_is_in_dir("/foo/bar/file", "/bar/foo"));
+
+  ASSERT_TRUE(file_is_in_dir("/file", ""));
+  ASSERT_FALSE(file_is_in_dir("/file", "/"));
+}
+
+TEST(linker_utils, file_is_under_dir_smoke) {
+  ASSERT_TRUE(file_is_under_dir("/foo/bar/file", "/foo/bar"));
+  ASSERT_TRUE(file_is_under_dir("/foo/bar/file", "/foo"));
+
+  ASSERT_FALSE(file_is_under_dir("/foo/bar/file", "/bar/foo"));
+
+  ASSERT_TRUE(file_is_under_dir("/file", ""));
+  ASSERT_TRUE(file_is_under_dir("/foo/bar/file", ""));
+  ASSERT_FALSE(file_is_under_dir("/file", "/"));
+  ASSERT_FALSE(file_is_under_dir("/foo/bar/file", "/"));
+}
+
+TEST(linker_utils, parse_zip_path_smoke) {
+  std::string zip_path;
+  std::string entry_path;
+
+  ASSERT_FALSE(parse_zip_path("/not/a/zip/path/file.zip", &zip_path, &entry_path));
+  ASSERT_FALSE(parse_zip_path("/not/a/zip/path/file.zip!path/in/zip", &zip_path, &entry_path));
+  ASSERT_TRUE(parse_zip_path("/zip/path/file.zip!/path/in/zip", &zip_path, &entry_path));
+  ASSERT_EQ("/zip/path/file.zip", zip_path);
+  ASSERT_EQ("path/in/zip", entry_path);
+
+  ASSERT_TRUE(parse_zip_path("/zip/path/file2.zip!/", &zip_path, &entry_path));
+  ASSERT_EQ("/zip/path/file2.zip", zip_path);
+  ASSERT_EQ("", entry_path);
+}
+
+TEST(linker_utils, page_start) {
+  ASSERT_EQ(0x0001000, page_start(0x0001000));
+  ASSERT_EQ(0x3002000, page_start(0x300222f));
+  ASSERT_EQ(0x6001000, page_start(0x6001fff));
+}
+
+TEST(linker_utils, page_offset) {
+  ASSERT_EQ(0x0U, page_offset(0x0001000));
+  ASSERT_EQ(0x22fU, page_offset(0x300222f));
+  ASSERT_EQ(0xfffU, page_offset(0x6001fff));
+}
+
+TEST(linker_utils, safe_add) {
+  int64_t val = 42;
+  ASSERT_FALSE(safe_add(&val, INT64_MAX-20, 21U));
+  ASSERT_EQ(42, val);
+  ASSERT_TRUE(safe_add(&val, INT64_MAX-42, 42U));
+  ASSERT_EQ(INT64_MAX, val);
+  ASSERT_TRUE(safe_add(&val, 2000, 42U));
+  ASSERT_EQ(2042, val);
+}