1 | /* Copyright (C) 2011-2022 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | |
4 | The GNU C Library is free software; you can redistribute it and/or |
5 | modify it under the terms of the GNU Lesser General Public |
6 | License as published by the Free Software Foundation; either |
7 | version 2.1 of the License, or (at your option) any later version. |
8 | |
9 | The GNU C Library is distributed in the hope that it will be useful, |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | Lesser General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU Lesser General Public |
15 | License along with the GNU C Library. If not, see |
16 | <https://www.gnu.org/licenses/>. */ |
17 | |
18 | #include <jmpbuf-offsets.h> |
19 | #include <sysdep.h> |
20 | #include <setjmp.h> |
21 | #include <signal.h> |
22 | #include <stdio.h> |
23 | #include <stackinfo.h> |
24 | |
25 | #ifdef _STACK_GROWS_DOWN |
26 | #define called_from(this, saved) ((this) < (saved)) |
27 | #else |
28 | #define called_from(this, saved) ((this) > (saved)) |
29 | #endif |
30 | |
31 | extern void ____longjmp_chk (__jmp_buf __env, int __val) |
32 | __attribute__ ((__noreturn__)); |
33 | |
34 | void ____longjmp_chk (__jmp_buf env, int val) |
35 | { |
36 | void *this_frame = __builtin_frame_address (0); |
37 | void *saved_frame = JB_FRAME_ADDRESS (env); |
38 | stack_t ss; |
39 | |
40 | /* If "env" is from a frame that called us, we're all set. */ |
41 | if (called_from(this_frame, saved_frame)) |
42 | __longjmp (env: env, val: val); |
43 | |
44 | /* If we can't get the current stack state, give up and do the longjmp. */ |
45 | if (INTERNAL_SYSCALL_CALL (sigaltstack, NULL, &ss) != 0) |
46 | __longjmp (env: env, val: val); |
47 | |
48 | /* If we we are executing on the alternate stack and within the |
49 | bounds, do the longjmp. */ |
50 | if (ss.ss_flags == SS_ONSTACK |
51 | && (this_frame >= ss.ss_sp && this_frame < (ss.ss_sp + ss.ss_size))) |
52 | __longjmp (env: env, val: val); |
53 | |
54 | __fortify_fail ("longjmp causes uninitialized stack frame" ); |
55 | } |
56 | |