debug/tst-backtrace4.c

   1 /* Test backtrace and backtrace_symbols for signal frames.
   2    Copyright (C) 2011-2013 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 static int do_test (void);
  29 #define TEST_FUNCTION do_test ()
  30 #include "../test-skeleton.c"
  31
  32 /* Set to a non-zero value if the test fails.  */
  33 volatile int ret;
  34
  35 /* Accesses to X are used to prevent optimization.  */
  36 volatile int x;
  37
  38 /* Called if the test fails.  */
  39 #define FAIL() \
  40   do { printf ("Failure on line %d\n", __LINE__); ret = 1; } while (0)
  41
  42 /* The backtrace should include at least handle_signal, a signal
  43    trampoline, 3 * fn, and do_test.  */
  44 #define NUM_FUNCTIONS 6
  45
  46 /* Use this attribute to prevent inlining, so that all expected frames
  47    are present.  */
  48 #define NO_INLINE __attribute__ ((noinline))
  49
  50 volatile int sig_handled = 0;
  51
  52 void
  53 handle_signal (int signum)
  54 {
  55   void *addresses[NUM_FUNCTIONS];
  56   char **symbols;
  57   int n;
  58   int i;
  59
  60   sig_handled = 1;
  61
  62   /* Get the backtrace addresses.  */
  63   n = backtrace (addresses, sizeof (addresses) / sizeof (addresses[0]));
  64   printf ("Obtained backtrace with %d functions\n", n);
  65   /*  Check that there are at least six functions.  */
  66   if (n < NUM_FUNCTIONS)
  67     {
  68       FAIL ();
  69       return;
  70     }
  71   /* Convert them to symbols.  */
  72   symbols = backtrace_symbols (addresses, n);
  73   /* Check that symbols were obtained.  */
  74   if (symbols == NULL)
  75     {
  76       FAIL ();
  77       return;
  78     }
  79   for (i = 0; i < n; ++i)
  80     printf ("Function %d: %s\n", i, symbols[i]);
  81   /* Check that the function names obtained are accurate.  */
  82   if (strstr (symbols[0], "handle_signal") == NULL)
  83     {
  84       FAIL ();
  85       return;
  86     }
  87   /* Do not check name for signal trampoline.  */
  88   for (i = 2; i < n - 1; i++)
  89     if (strstr (symbols[i], "fn") == NULL)
  90       {
  91         FAIL ();
  92         return;
  93       }
  94   /* Symbol names are not available for static functions, so we do not
  95      check do_test.  */
  96 }
  97
  98 NO_INLINE int
  99 fn (int c)
 100 {
 101   pid_t parent_pid, child_pid;
 102
 103   if (c > 0)
 104     {
 105       fn (c - 1);
 106       return x;
 107     }
 108
 109   signal (SIGUSR1, handle_signal);
 110   parent_pid = getpid ();
 111
 112   child_pid = fork ();
 113   if (child_pid == (pid_t) -1)
 114     abort ();
 115   else if (child_pid == 0)
 116     {
 117       sleep (1);
 118       kill (parent_pid, SIGUSR1);
 119       _exit (0);
 120     }
 121
 122   /* In the parent.  */
 123   while (sig_handled == 0)
 124     ;
 125
 126   return 0;
 127 }
 128
 129 NO_INLINE static int
 130 do_test (void)
 131 {
 132   fn (2);
 133   return ret;
 134 }