debug/tst-backtrace4.c

   1 /* Test backtrace and backtrace_symbols for signal frames.
   2    Copyright (C) 2011-2016 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 <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 static int do_test (void);
  31 #define TEST_FUNCTION do_test ()
  32 #include "../test-skeleton.c"
  33
  34 /* The backtrace should include at least handle_signal, a signal
  35    trampoline, 3 * fn, and do_test.  */
  36 #define NUM_FUNCTIONS 6
  37
  38 volatile int sig_handled = 0;
  39
  40 void
  41 handle_signal (int signum)
  42 {
  43   void *addresses[NUM_FUNCTIONS];
  44   char **symbols;
  45   int n;
  46   int i;
  47
  48   sig_handled = 1;
  49
  50   /* Get the backtrace addresses.  */
  51   n = backtrace (addresses, sizeof (addresses) / sizeof (addresses[0]));
  52   printf ("Obtained backtrace with %d functions (want at least %d)\n",
  53           n, NUM_FUNCTIONS);
  54   /* Check that there are at least NUM_FUNCTIONS functions.  */
  55   if (n < NUM_FUNCTIONS)
  56     {
  57       FAIL ();
  58       /* Only return if we got no symbols at all.  The partial output is
  59          still useful for debugging failures.  */
  60       if (n <= 0)
  61         return;
  62     }
  63   /* Convert them to symbols.  */
  64   symbols = backtrace_symbols (addresses, n);
  65   /* Check that symbols were obtained.  */
  66   if (symbols == NULL)
  67     {
  68       FAIL ();
  69       return;
  70     }
  71   for (i = 0; i < n; ++i)
  72     printf ("Function %d: %s\n", i, symbols[i]);
  73   /* Check that the function names obtained are accurate.  */
  74   if (!match (symbols[0], "handle_signal"))
  75     FAIL ();
  76   /* Do not check name for signal trampoline.  */
  77   for (i = 2; i < n - 1; i++)
  78     if (!match (symbols[i], "fn"))
  79       {
  80         FAIL ();
  81         return;
  82       }
  83   /* Symbol names are not available for static functions, so we do not
  84      check do_test.  */
  85 }
  86
  87 NO_INLINE int
  88 fn (int c)
  89 {
  90   pid_t parent_pid, child_pid;
  91
  92   if (c > 0)
  93     {
  94       fn (c - 1);
  95       return x;
  96     }
  97
  98   signal (SIGUSR1, handle_signal);
  99   parent_pid = getpid ();
 100
 101   child_pid = fork ();
 102   if (child_pid == (pid_t) -1)
 103     abort ();
 104   else if (child_pid == 0)
 105     {
 106       sleep (1);
 107       kill (parent_pid, SIGUSR1);
 108       _exit (0);
 109     }
 110
 111   /* In the parent.  */
 112   while (sig_handled == 0)
 113     ;
 114
 115   return 0;
 116 }
 117
 118 NO_INLINE static int
 119 do_test (void)
 120 {
 121   fn (2);
 122   return ret;
 123 }