debug/tst-backtrace4.c

   1 /* Test backtrace and backtrace_symbols for signal frames.
   2    Copyright (C) 2011-2021 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
  34 volatile int sig_handled = 0;
  35
  36 void
  37 handle_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 (addresses, sizeof (addresses) / sizeof (addresses[0]));
  48   printf ("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 (addresses, 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 ("Function %d: %s\n", i, symbols[i]);
  69   /* Check that the function names obtained are accurate.  */
  70   if (!match (symbols[0], "handle_signal"))
  71     FAIL ();
  72   /* Do not check name for signal trampoline.  */
  73   for (i = 2; i < n - 1; i++)
  74     if (!match (symbols[i], "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
  83 NO_INLINE int
  84 fn (int c)
  85 {
  86   pid_t parent_pid, child_pid;
  87
  88   if (c > 0)
  89     {
  90       fn (c - 1);
  91       return x;
  92     }
  93
  94   signal (SIGUSR1, 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 (1);
 103       kill (parent_pid, SIGUSR1);
 104       _exit (0);
 105     }
 106
 107   /* In the parent.  */
 108   while (sig_handled == 0)
 109     ;
 110
 111   return 0;
 112 }
 113
 114 NO_INLINE int
 115 do_test (void)
 116 {
 117   fn (2);
 118   return ret;
 119 }
 120
 121 #include <support/test-driver.c>