1 | /* setjmp for i386. |
2 | Copyright (C) 1995-2022 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 | #include <sysdep.h> |
20 | #include <jmpbuf-offsets.h> |
21 | #include <jmp_buf-ssp.h> |
22 | #include <asm-syntax.h> |
23 | #include <stap-probe.h> |
24 | |
25 | #define PARMS 4 /* no space for saved regs */ |
26 | #define JMPBUF PARMS |
27 | #define SIGMSK JMPBUF+4 |
28 | |
29 | /* Don't save shadow stack register if shadow stack isn't enabled. */ |
30 | #if !SHSTK_ENABLED |
31 | # undef SHADOW_STACK_POINTER_OFFSET |
32 | #endif |
33 | |
34 | ENTRY (__sigsetjmp) |
35 | |
36 | movl JMPBUF(%esp), %eax |
37 | |
38 | /* Save registers. */ |
39 | movl %ebx, (JB_BX*4)(%eax) |
40 | movl %esi, (JB_SI*4)(%eax) |
41 | movl %edi, (JB_DI*4)(%eax) |
42 | leal JMPBUF(%esp), %ecx /* Save SP as it will be after we return. */ |
43 | #ifdef PTR_MANGLE |
44 | PTR_MANGLE (%ecx) |
45 | #endif |
46 | movl %ecx, (JB_SP*4)(%eax) |
47 | movl 0(%esp), %ecx /* Save PC we are returning to now. */ |
48 | LIBC_PROBE (setjmp, 3, 4@%eax, -4@SIGMSK(%esp), 4@%ecx) |
49 | #ifdef PTR_MANGLE |
50 | PTR_MANGLE (%ecx) |
51 | #endif |
52 | movl %ecx, (JB_PC*4)(%eax) |
53 | movl %ebp, (JB_BP*4)(%eax) /* Save caller's frame pointer. */ |
54 | |
55 | #ifdef SHADOW_STACK_POINTER_OFFSET |
56 | # if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET |
57 | /* Check if Shadow Stack is enabled. */ |
58 | testl $X86_FEATURE_1_SHSTK, %gs:FEATURE_1_OFFSET |
59 | jz L(skip_ssp) |
60 | # else |
61 | xorl %ecx, %ecx |
62 | # endif |
63 | /* Get the current Shadow-Stack-Pointer and save it. */ |
64 | rdsspd %ecx |
65 | movl %ecx, SHADOW_STACK_POINTER_OFFSET(%eax) |
66 | # if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET |
67 | L(skip_ssp): |
68 | # endif |
69 | #endif |
70 | #if IS_IN (rtld) |
71 | /* In ld.so we never save the signal mask. */ |
72 | xorl %eax, %eax |
73 | ret |
74 | #else |
75 | /* Make a tail call to __sigjmp_save; it takes the same args. */ |
76 | jmp __sigjmp_save |
77 | #endif |
78 | END (__sigsetjmp) |
79 | hidden_def (__sigsetjmp) |
80 | |