Commit | Line | Data |
---|---|---|
c3efb965 TT |
1 | /* Temporarily install an alternate signal stack |
2 | ||
b811d2c2 | 3 | Copyright (C) 2019-2020 Free Software Foundation, Inc. |
c3efb965 TT |
4 | |
5 | This file is part of GDB. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 3 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
19 | ||
20 | #ifndef GDBSUPPORT_ALT_STACK_H | |
21 | #define GDBSUPPORT_ALT_STACK_H | |
22 | ||
23 | #include <signal.h> | |
24 | ||
25 | namespace gdb | |
26 | { | |
27 | ||
28 | /* Try to set up an alternate signal stack for SIGSEGV handlers. | |
29 | This allows us to handle SIGSEGV signals generated when the | |
30 | normal process stack is exhausted. If this stack is not set | |
31 | up (sigaltstack is unavailable or fails) and a SIGSEGV is | |
32 | generated when the normal stack is exhausted then the program | |
33 | will behave as though no SIGSEGV handler was installed. */ | |
34 | class alternate_signal_stack | |
35 | { | |
36 | public: | |
37 | alternate_signal_stack () | |
38 | { | |
39 | #ifdef HAVE_SIGALTSTACK | |
40 | m_stack.reset ((char *) xmalloc (SIGSTKSZ)); | |
41 | ||
42 | stack_t stack; | |
43 | stack.ss_sp = m_stack.get (); | |
44 | stack.ss_size = SIGSTKSZ; | |
45 | stack.ss_flags = 0; | |
46 | ||
47 | sigaltstack (&stack, &m_old_stack); | |
48 | #endif | |
49 | } | |
50 | ||
51 | ~alternate_signal_stack () | |
52 | { | |
53 | #ifdef HAVE_SIGALTSTACK | |
54 | sigaltstack (&m_old_stack, nullptr); | |
55 | #endif | |
56 | } | |
57 | ||
58 | DISABLE_COPY_AND_ASSIGN (alternate_signal_stack); | |
59 | ||
60 | private: | |
61 | ||
62 | #ifdef HAVE_SIGALTSTACK | |
63 | gdb::unique_xmalloc_ptr<char> m_stack; | |
64 | stack_t m_old_stack; | |
65 | #endif | |
66 | }; | |
67 | ||
68 | } | |
69 | ||
70 | #endif /* GDBSUPPORT_ALT_STACK_H */ |