1/* BSD `_setjmp' entry point to `sigsetjmp (..., 0)'. i386 version.
2 Copyright (C) 1994-2024 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
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.
9
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.
14
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/>. */
18
19/* This just does a tail-call to `__sigsetjmp (ARG, 0)'.
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. */
22
23#include <sysdep.h>
24#include <pointer_guard.h>
25#include <jmpbuf-offsets.h>
26#include <stap-probe.h>
27
28#define PARMS 4 /* no space for saved regs */
29#define JMPBUF PARMS
30#define SIGMSK JMPBUF+4
31
32ENTRY (_setjmp)
33
34 xorl %eax, %eax
35 movl JMPBUF(%esp), %edx
36
37 /* Save registers. */
38 movl %ebx, (JB_BX*4)(%edx)
39 movl %esi, (JB_SI*4)(%edx)
40 movl %edi, (JB_DI*4)(%edx)
41 leal JMPBUF(%esp), %ecx /* Save SP as it will be after we return. */
42#ifdef PTR_MANGLE
43 PTR_MANGLE (%ecx)
44#endif
45 movl %ecx, (JB_SP*4)(%edx)
46 movl 0(%esp), %ecx /* Save PC we are returning to now. */
47 LIBC_PROBE (setjmp, 3, 4@%edx, -4@$0, 4@%ecx)
48#ifdef PTR_MANGLE
49 PTR_MANGLE (%ecx)
50#endif
51 movl %ecx, (JB_PC*4)(%edx)
52 movl %ebp, (JB_BP*4)(%edx) /* Save caller's frame pointer. */
53
54 movl %eax, JB_SIZE(%edx) /* No signal mask set. */
55 ret
56END (_setjmp)
57libc_hidden_def (_setjmp)
58

source code of glibc/sysdeps/i386/bsd-_setjmp.S