1/* Test backtrace and backtrace_symbols for signal frames.
2 Copyright (C) 2011-2022 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 <execinfo.h>
20#include <search.h>
21#include <stdio.h>
22#include <stdlib.h>
23#include <string.h>
24#include <sys/types.h>
25#include <signal.h>
26#include <unistd.h>
27
28#include "tst-backtrace.h"
29
30/* The backtrace should include at least handle_signal, a signal
31 trampoline, 3 * fn, and do_test. */
32#define NUM_FUNCTIONS 6
33
34volatile int sig_handled = 0;
35
36void
37handle_signal (int signum)
38{
39 void *addresses[NUM_FUNCTIONS];
40 char **symbols;
41 int n;
42 int i;
43
44 sig_handled = 1;
45
46 /* Get the backtrace addresses. */
47 n = backtrace (array: addresses, size: sizeof (addresses) / sizeof (addresses[0]));
48 printf (format: "Obtained backtrace with %d functions (want at least %d)\n",
49 n, NUM_FUNCTIONS);
50 /* Check that there are at least NUM_FUNCTIONS functions. */
51 if (n < NUM_FUNCTIONS)
52 {
53 FAIL ();
54 /* Only return if we got no symbols at all. The partial output is
55 still useful for debugging failures. */
56 if (n <= 0)
57 return;
58 }
59 /* Convert them to symbols. */
60 symbols = backtrace_symbols (array: addresses, size: n);
61 /* Check that symbols were obtained. */
62 if (symbols == NULL)
63 {
64 FAIL ();
65 return;
66 }
67 for (i = 0; i < n; ++i)
68 printf (format: "Function %d: %s\n", i, symbols[i]);
69 /* Check that the function names obtained are accurate. */
70 if (!match (sym: symbols[0], name: "handle_signal"))
71 FAIL ();
72 /* Do not check name for signal trampoline. */
73 for (i = 2; i < n - 1; i++)
74 if (!match (sym: symbols[i], name: "fn"))
75 {
76 FAIL ();
77 return;
78 }
79 /* Symbol names are not available for static functions, so we do not
80 check do_test. */
81}
82
83NO_INLINE int
84fn (int c)
85{
86 pid_t parent_pid, child_pid;
87
88 if (c > 0)
89 {
90 fn (c: c - 1);
91 return x;
92 }
93
94 signal (SIGUSR1, handler: handle_signal);
95 parent_pid = getpid ();
96
97 child_pid = fork ();
98 if (child_pid == (pid_t) -1)
99 abort ();
100 else if (child_pid == 0)
101 {
102 sleep (seconds: 1);
103 kill (pid: parent_pid, SIGUSR1);
104 _exit (0);
105 }
106
107 /* In the parent. */
108 while (sig_handled == 0)
109 ;
110
111 return 0;
112}
113
114NO_INLINE int
115do_test (void)
116{
117 fn (c: 2);
118 return ret;
119}
120
121#include <support/test-driver.c>
122

source code of glibc/debug/tst-backtrace4.c