/* BSD `setjmp' entry point to `sigsetjmp (..., 1)'. i386 version. Copyright (C) 1994-2018 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 . */ /* 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 #include #include #include #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)