/* 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