| /* libunwind - a platform-independent unwind library |
| Copyright (C) 2008 Google, Inc |
| Contributed by Paul Pluzhnikov <ppluzhnikov@google.com> |
| Copyright (C) 2010 Konstantin Belousov <kib@freebsd.org> |
| |
| This file is part of libunwind. |
| |
| Permission is hereby granted, free of charge, to any person obtaining |
| a copy of this software and associated documentation files (the |
| "Software"), to deal in the Software without restriction, including |
| without limitation the rights to use, copy, modify, merge, publish, |
| distribute, sublicense, and/or sell copies of the Software, and to |
| permit persons to whom the Software is furnished to do so, subject to |
| the following conditions: |
| |
| The above copyright notice and this permission notice shall be |
| included in all copies or substantial portions of the Software. |
| |
| THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
| NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE |
| LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION |
| OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION |
| WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ |
| |
| #include "ucontext_i.h" |
| |
| /* int _Ux86_64_getcontext (ucontext_t *ucp) |
| |
| Saves the machine context in UCP necessary for libunwind. |
| Unlike the libc implementation, we don't save the signal mask |
| and hence avoid the cost of a system call per unwind. |
| |
| */ |
| |
| .global _Ux86_64_getcontext |
| .type _Ux86_64_getcontext, @function |
| _Ux86_64_getcontext: |
| .cfi_startproc |
| |
| /* Callee saved: RBX, RBP, R12-R15 */ |
| movq %r12, UC_MCONTEXT_GREGS_R12(%rdi) |
| movq %r13, UC_MCONTEXT_GREGS_R13(%rdi) |
| movq %r14, UC_MCONTEXT_GREGS_R14(%rdi) |
| movq %r15, UC_MCONTEXT_GREGS_R15(%rdi) |
| movq %rbp, UC_MCONTEXT_GREGS_RBP(%rdi) |
| movq %rbx, UC_MCONTEXT_GREGS_RBX(%rdi) |
| |
| /* Save argument registers (not strictly needed, but setcontext |
| restores them, so don't restore garbage). */ |
| movq %r8, UC_MCONTEXT_GREGS_R8(%rdi) |
| movq %r9, UC_MCONTEXT_GREGS_R9(%rdi) |
| movq %rdi, UC_MCONTEXT_GREGS_RDI(%rdi) |
| movq %rsi, UC_MCONTEXT_GREGS_RSI(%rdi) |
| movq %rdx, UC_MCONTEXT_GREGS_RDX(%rdi) |
| movq %rax, UC_MCONTEXT_GREGS_RAX(%rdi) |
| movq %rcx, UC_MCONTEXT_GREGS_RCX(%rdi) |
| |
| #if defined __linux__ |
| /* Save fp state (not needed, except for setcontext not |
| restoring garbage). */ |
| leaq UC_MCONTEXT_FPREGS_MEM(%rdi),%r8 |
| movq %r8, UC_MCONTEXT_FPREGS_PTR(%rdi) |
| fnstenv (%r8) |
| stmxcsr FPREGS_OFFSET_MXCSR(%r8) |
| #elif defined __FreeBSD__ |
| fxsave UC_MCONTEXT_FPSTATE(%rdi) |
| movq $UC_MCONTEXT_FPOWNED_FPU,UC_MCONTEXT_OWNEDFP(%rdi) |
| movq $UC_MCONTEXT_FPFMT_XMM,UC_MCONTEXT_FPFORMAT(%rdi) |
| /* Save rflags and segment registers, so that sigreturn(2) |
| does not complain. */ |
| pushfq |
| .cfi_adjust_cfa_offset 8 |
| popq UC_MCONTEXT_RFLAGS(%rdi) |
| .cfi_adjust_cfa_offset -8 |
| movl $0, UC_MCONTEXT_FLAGS(%rdi) |
| movw %cs, UC_MCONTEXT_CS(%rdi) |
| movw %ss, UC_MCONTEXT_SS(%rdi) |
| #if 0 |
| /* Setting the flags to 0 above disables restore of segment |
| registers from the context */ |
| movw %ds, UC_MCONTEXT_DS(%rdi) |
| movw %es, UC_MCONTEXT_ES(%rdi) |
| movw %fs, UC_MCONTEXT_FS(%rdi) |
| movw %gs, UC_MCONTEXT_GS(%rdi) |
| #endif |
| movq $UC_MCONTEXT_MC_LEN_VAL, UC_MCONTEXT_MC_LEN(%rdi) |
| #else |
| #error Port me |
| #endif |
| |
| leaq 8(%rsp), %rax /* exclude this call. */ |
| movq %rax, UC_MCONTEXT_GREGS_RSP(%rdi) |
| |
| movq 0(%rsp), %rax |
| movq %rax, UC_MCONTEXT_GREGS_RIP(%rdi) |
| |
| xorq %rax, %rax |
| retq |
| .cfi_endproc |
| .size _Ux86_64_getcontext, . - _Ux86_64_getcontext |
| |
| /* int _Ux86_64_getcontext_trace (ucontext_t *ucp) |
| |
| Saves limited machine context in UCP necessary for libunwind. |
| Unlike _Ux86_64_getcontext, saves only the parts needed for |
| fast trace. If fast trace fails, caller will have to get the |
| full context. |
| */ |
| |
| .global _Ux86_64_getcontext_trace |
| .hidden _Ux86_64_getcontext_trace |
| .type _Ux86_64_getcontext_trace, @function |
| _Ux86_64_getcontext_trace: |
| .cfi_startproc |
| |
| /* Save only RBP, RBX, RSP, RIP - exclude this call. */ |
| movq %rbp, UC_MCONTEXT_GREGS_RBP(%rdi) |
| movq %rbx, UC_MCONTEXT_GREGS_RBX(%rdi) |
| |
| leaq 8(%rsp), %rax |
| movq %rax, UC_MCONTEXT_GREGS_RSP(%rdi) |
| |
| movq 0(%rsp), %rax |
| movq %rax, UC_MCONTEXT_GREGS_RIP(%rdi) |
| |
| xorq %rax, %rax |
| retq |
| .cfi_endproc |
| .size _Ux86_64_getcontext_trace, . - _Ux86_64_getcontext_trace |
| |
| /* We do not need executable stack. */ |
| .section .note.GNU-stack,"",@progbits |
