Add x64 version of getcontext.

Assembly code is derived in part from code in libunwind.
Code tested on desktop linux (Android testing pending emulation
support).

BUG=346626
R=dannyb@google.com, thestig@chromium.org

Review URL: https://breakpad.appspot.com/1454002

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1311 4c0a9323-5329-0410-9bdc-e9ce6186880e
This commit is contained in:
rmcilroy@chromium.org 2014-04-11 16:09:12 +00:00
parent a2245d6744
commit 6594ac922c
5 changed files with 275 additions and 0 deletions

View file

@ -305,6 +305,87 @@ NESTED (breakpad_getcontext, FRAME_SIZE, ra)
END (breakpad_getcontext)
#elif defined(__x86_64__)
/* The x64 implementation of breakpad_getcontext was derived in part
from the implementation of libunwind which requires the following
notice. */
/* 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. */
.text
.global breakpad_getcontext
.hidden breakpad_getcontext
.align 4
.type breakpad_getcontext, @function
breakpad_getcontext:
.cfi_startproc
/* Callee saved: RBX, RBP, R12-R15 */
movq %r12, MCONTEXT_GREGS_R12(%rdi)
movq %r13, MCONTEXT_GREGS_R13(%rdi)
movq %r14, MCONTEXT_GREGS_R14(%rdi)
movq %r15, MCONTEXT_GREGS_R15(%rdi)
movq %rbp, MCONTEXT_GREGS_RBP(%rdi)
movq %rbx, MCONTEXT_GREGS_RBX(%rdi)
/* Save argument registers (not strictly needed, but setcontext
restores them, so don't restore garbage). */
movq %r8, MCONTEXT_GREGS_R8(%rdi)
movq %r9, MCONTEXT_GREGS_R9(%rdi)
movq %rdi, MCONTEXT_GREGS_RDI(%rdi)
movq %rsi, MCONTEXT_GREGS_RSI(%rdi)
movq %rdx, MCONTEXT_GREGS_RDX(%rdi)
movq %rax, MCONTEXT_GREGS_RAX(%rdi)
movq %rcx, MCONTEXT_GREGS_RCX(%rdi)
/* Save fp state (not needed, except for setcontext not
restoring garbage). */
leaq MCONTEXT_FPREGS_MEM(%rdi),%r8
movq %r8, MCONTEXT_FPREGS_PTR(%rdi)
fnstenv (%r8)
stmxcsr FPREGS_OFFSET_MXCSR(%r8)
leaq 8(%rsp), %rax /* exclude this call. */
movq %rax, MCONTEXT_GREGS_RSP(%rdi)
movq 0(%rsp), %rax
movq %rax, MCONTEXT_GREGS_RIP(%rdi)
/* Save signal mask: sigprocmask(SIGBLOCK, NULL, &uc->uc_sigmask) */
leaq UCONTEXT_SIGMASK_OFFSET(%rdi), %rdx // arg3
xorq %rsi, %rsi // arg2 NULL
xorq %rdi, %rdi // arg1 SIGBLOCK == 0
call sigprocmask@PLT
/* Always return 0 for success, even if sigprocmask failed. */
xorl %eax, %eax
ret
.cfi_endproc
.size breakpad_getcontext, . - breakpad_getcontext
#else
#error "This file has not been ported for your CPU!"