1 | /* Test of signal delivery on an alternate stack with MINSIGSTKSZ size. |
2 | Copyright (C) 2020-2022 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 <signal.h> |
20 | #include <stdlib.h> |
21 | #include <string.h> |
22 | #include <unistd.h> |
23 | #include <support/check.h> |
24 | #include <support/support.h> |
25 | |
26 | static volatile sig_atomic_t handler_run; |
27 | |
28 | static void |
29 | handler (int signo) |
30 | { |
31 | /* Clear a bit of on-stack memory. */ |
32 | volatile char buffer[256]; |
33 | for (size_t i = 0; i < sizeof (buffer); ++i) |
34 | buffer[i] = 0; |
35 | handler_run = 1; |
36 | } |
37 | |
38 | int |
39 | do_test (void) |
40 | { |
41 | size_t stack_buffer_size = 64 * 1024 * 1024; |
42 | void *stack_buffer = xmalloc (n: stack_buffer_size); |
43 | void *stack_end = stack_buffer + stack_buffer_size; |
44 | memset (stack_buffer, 0xCC, stack_buffer_size); |
45 | |
46 | void *stack_bottom = stack_buffer + (stack_buffer_size + MINSIGSTKSZ) / 2; |
47 | void *stack_top = stack_bottom + MINSIGSTKSZ; |
48 | stack_t stack = |
49 | { |
50 | .ss_sp = stack_bottom, |
51 | .ss_size = MINSIGSTKSZ, |
52 | }; |
53 | if (sigaltstack (ss: &stack, NULL) < 0) |
54 | FAIL_RET ("sigaltstack: %m\n" ); |
55 | |
56 | struct sigaction act = |
57 | { |
58 | .sa_handler = handler, |
59 | .sa_flags = SA_ONSTACK, |
60 | }; |
61 | if (sigaction (SIGUSR1, act: &act, NULL) < 0) |
62 | FAIL_RET ("sigaction: %m\n" ); |
63 | |
64 | if (kill (pid: getpid (), SIGUSR1) < 0) |
65 | FAIL_RET ("kill: %m\n" ); |
66 | |
67 | if (handler_run != 1) |
68 | FAIL_RET ("handler did not run\n" ); |
69 | |
70 | for (void *p = stack_buffer; p < stack_bottom; ++p) |
71 | if (*(unsigned char *) p != 0xCC) |
72 | FAIL_RET ("changed byte %ld bytes below configured stack\n" , |
73 | (long) (stack_bottom - p)); |
74 | for (void *p = stack_top; p < stack_end; ++p) |
75 | if (*(unsigned char *) p != 0xCC) |
76 | FAIL_RET ("changed byte %ld bytes above configured stack\n" , |
77 | (long) (p - stack_top)); |
78 | |
79 | free (ptr: stack_buffer); |
80 | |
81 | return 0; |
82 | } |
83 | |
84 | #include <support/test-driver.c> |
85 | |