1 /* BSD `setjmp' entry point to `sigsetjmp (..., 1)'. i386 version.
2 Copyright (C) 1994-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
19 /* This just does a tail-call to `__sigsetjmp (ARG, 1)'.
20 We cannot do it in C because it must be a tail-call, so frame-unwinding
21 in setjmp doesn't clobber the state restored by longjmp. */
24 #include <pointer_guard.h>
25 #include <jmpbuf-offsets.h>
26 #include <jmp_buf-ssp.h>
27 #include <stap-probe.h>
29 #define PARMS 4 /* no space for saved regs */
31 #define SIGMSK JMPBUF+4
33 /* Don't save shadow stack register if shadow stack isn't enabled. */
35 # undef SHADOW_STACK_POINTER_OFFSET
39 /* Note that we have to use a non-exported symbol in the next
40 jump since otherwise gas will emit it as a jump through the
41 PLT which is what we cannot use here. */
43 movl JMPBUF(%esp), %eax
46 movl %ebx, (JB_BX*4)(%eax)
47 movl %esi, (JB_SI*4)(%eax)
48 movl %edi, (JB_DI*4)(%eax)
49 leal JMPBUF(%esp), %ecx /* Save SP as it will be after we return. */
53 movl %ecx, (JB_SP*4)(%eax)
54 movl 0(%esp), %ecx /* Save PC we are returning to now. */
55 LIBC_PROBE (setjmp, 3, 4@%eax, -4@$1, 4@%ecx)
59 movl %ecx, (JB_PC*4)(%eax)
60 movl %ebp, (JB_BP*4)(%eax) /* Save caller's frame pointer. */
61 #ifdef SHADOW_STACK_POINTER_OFFSET
62 # if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
63 /* Check if Shadow Stack is enabled. */
64 testl $X86_FEATURE_1_SHSTK, %gs:FEATURE_1_OFFSET
69 /* Get the current Shadow-Stack-Pointer and save it. */
71 movl %ecx, SHADOW_STACK_POINTER_OFFSET(%eax)
72 # if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
77 /* Call __sigjmp_save. */
79 cfi_adjust_cfa_offset (4)
81 cfi_adjust_cfa_offset (4)
84 cfi_adjust_cfa_offset (-4)
86 cfi_adjust_cfa_offset (-4)