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/* BSD `setjmp' entry point to `sigsetjmp (..., 1)'. i386 version.
Copyright (C) 1994-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
/* This just does a tail-call to `__sigsetjmp (ARG, 1)'.
We cannot do it in C because it must be a tail-call, so frame-unwinding
in setjmp doesn't clobber the state restored by longjmp. */
#include <sysdep.h>
#include <jmpbuf-offsets.h>
#include <jmp_buf-ssp.h>
#include <stap-probe.h>
#define PARMS 4 /* no space for saved regs */
#define JMPBUF PARMS
#define SIGMSK JMPBUF+4
/* Don't save shadow stack register if shadow stack isn't enabled. */
#if !SHSTK_ENABLED
# undef SHADOW_STACK_POINTER_OFFSET
#endif
ENTRY (setjmp)
/* Note that we have to use a non-exported symbol in the next
jump since otherwise gas will emit it as a jump through the
PLT which is what we cannot use here. */
movl JMPBUF(%esp), %eax
/* Save registers. */
movl %ebx, (JB_BX*4)(%eax)
movl %esi, (JB_SI*4)(%eax)
movl %edi, (JB_DI*4)(%eax)
leal JMPBUF(%esp), %ecx /* Save SP as it will be after we return. */
#ifdef PTR_MANGLE
PTR_MANGLE (%ecx)
#endif
movl %ecx, (JB_SP*4)(%eax)
movl 0(%esp), %ecx /* Save PC we are returning to now. */
LIBC_PROBE (setjmp, 3, 4@%eax, -4@$1, 4@%ecx)
#ifdef PTR_MANGLE
PTR_MANGLE (%ecx)
#endif
movl %ecx, (JB_PC*4)(%eax)
movl %ebp, (JB_BP*4)(%eax) /* Save caller's frame pointer. */
#ifdef SHADOW_STACK_POINTER_OFFSET
# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
/* Check if Shadow Stack is enabled. */
testl $X86_FEATURE_1_SHSTK, %gs:FEATURE_1_OFFSET
jz L(skip_ssp)
# else
xorl %ecx, %ecx
# endif
/* Get the current Shadow-Stack-Pointer and save it. */
rdsspd %ecx
movl %ecx, SHADOW_STACK_POINTER_OFFSET(%eax)
# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
L(skip_ssp):
# endif
#endif
/* Call __sigjmp_save. */
pushl $1
cfi_adjust_cfa_offset (4)
pushl 8(%esp)
cfi_adjust_cfa_offset (4)
call __sigjmp_save
popl %ecx
cfi_adjust_cfa_offset (-4)
popl %edx
cfi_adjust_cfa_offset (-4)
ret
END (setjmp)
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