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1 | /* Make sure longjmp fortification catches bad signal stacks. | |
2 | Copyright (C) 2013-2018 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 | <http://www.gnu.org/licenses/>. */ | |
18 | ||
19 | #include <setjmp.h> | |
20 | #include <signal.h> | |
21 | #include <string.h> | |
22 | ||
23 | static int do_test (void); | |
24 | #define TEST_FUNCTION do_test () | |
25 | #include "../test-skeleton.c" | |
26 | ||
27 | static char buf[SIGSTKSZ * 4]; | |
28 | static jmp_buf jb; | |
29 | ||
30 | static void | |
31 | handler (int sig) | |
32 | { | |
33 | if (sig == SIGUSR1) | |
34 | { | |
35 | if (setjmp (jb) != 0) | |
36 | { | |
37 | puts ("setjmp should not have been called"); | |
38 | kill (getpid (), SIGTERM); | |
39 | } | |
40 | } | |
41 | else if (sig == SIGABRT) | |
42 | { | |
43 | /* Yeah it worked. */ | |
44 | _exit (0); | |
45 | } | |
46 | } | |
47 | ||
48 | static int | |
49 | do_test (void) | |
50 | { | |
51 | stack_t ss; | |
52 | ||
53 | set_fortify_handler (handler); | |
54 | ||
55 | /* Create a valid signal stack and enable it. */ | |
56 | ss.ss_sp = buf; | |
57 | ss.ss_size = sizeof (buf); | |
58 | ss.ss_flags = 0; | |
59 | if (sigaltstack (&ss, NULL) < 0) | |
60 | { | |
61 | printf ("first sigaltstack failed: %m\n"); | |
62 | return 1; | |
63 | } | |
64 | ||
65 | /* Trigger the signal handler which will create a jmpbuf that points to the | |
66 | end of the signal stack. */ | |
67 | signal (SIGUSR1, handler); | |
68 | kill (getpid (), SIGUSR1); | |
69 | ||
70 | /* Shrink the signal stack so the jmpbuf is now invalid. | |
71 | We adjust the start & end to handle stacks that grow up & down. */ | |
72 | ss.ss_sp = buf + sizeof (buf) / 2; | |
73 | ss.ss_size = sizeof (buf) / 4; | |
74 | if (sigaltstack (&ss, NULL) < 0) | |
75 | { | |
76 | printf ("second sigaltstack failed: %m\n"); | |
77 | return 1; | |
78 | } | |
79 | ||
80 | /* This should fail. */ | |
81 | longjmp (jb, 1); | |
82 | ||
83 | puts ("longjmp returned and shouldn't"); | |
84 | return 1; | |
85 | } |