| /* libunwind - a platform-independent unwind library |
| Copyright (C) 2009 Google, Inc |
| Contributed by Paul Pluzhnikov <ppluzhnikov@google.com> |
| |
| 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 "offsets.h" |
| |
| /* int _Ux86_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_getcontext |
| .type _Ux86_getcontext, @function |
| _Ux86_getcontext: |
| .cfi_startproc |
| mov 4(%esp),%eax /* ucontext_t* */ |
| |
| /* EAX is not preserved. */ |
| movl $0, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_EAX_OFF)(%eax) |
| |
| movl %ebx, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_EBX_OFF)(%eax) |
| movl %ecx, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_ECX_OFF)(%eax) |
| movl %edx, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_EDX_OFF)(%eax) |
| movl %edi, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_EDI_OFF)(%eax) |
| movl %esi, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_ESI_OFF)(%eax) |
| movl %ebp, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_EBP_OFF)(%eax) |
| |
| movl (%esp), %ecx |
| movl %ecx, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_EIP_OFF)(%eax) |
| |
| leal 4(%esp), %ecx /* Exclude the return address. */ |
| movl %ecx, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_ESP_OFF)(%eax) |
| |
| /* glibc getcontext saves FS, but not GS */ |
| xorl %ecx, %ecx |
| movw %fs, %cx |
| movl %ecx, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_FS_OFF)(%eax) |
| |
| leal LINUX_UC_FPREGS_MEM_OFF(%eax), %ecx |
| movl %ecx, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_FPSTATE_OFF)(%eax) |
| fnstenv (%ecx) |
| fldenv (%ecx) |
| |
| xor %eax, %eax |
| ret |
| .cfi_endproc |
| .size _Ux86_getcontext, . - _Ux86_getcontext |
| |
| /* We do not need executable stack. */ |
| .section .note.GNU-stack,"",@progbits |
