debug/tst-backtrace5.c

   1 /* Test backtrace and backtrace_symbols for signal frames, where a
   2    system call was interrupted by a signal.
   3    Copyright (C) 2011-2015 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <execinfo.h>
  21 #include <search.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <sys/types.h>
  26 #include <signal.h>
  27 #include <unistd.h>
  28
  29 #include "tst-backtrace.h"
  30
  31 #ifndef SIGACTION_FLAGS
  32 # define SIGACTION_FLAGS 0
  33 #endif
  34
  35 static int do_test (void);
  36 #define TEST_FUNCTION do_test ()
  37 #include "../test-skeleton.c"
  38
  39 /* The backtrace should include at least handle_signal, a signal
  40    trampoline, read, 3 * fn, and do_test.  */
  41 #define NUM_FUNCTIONS 7
  42
  43 void
  44 handle_signal (int signum)
  45 {
  46   void *addresses[NUM_FUNCTIONS];
  47   char **symbols;
  48   int n;
  49   int i;
  50
  51   /* Get the backtrace addresses.  */
  52   n = backtrace (addresses, sizeof (addresses) / sizeof (addresses[0]));
  53   printf ("Obtained backtrace with %d functions\n", n);
  54   /*  Check that there are at least seven functions.  */
  55   if (n < NUM_FUNCTIONS)
  56     {
  57       FAIL ();
  58       return;
  59     }
  60   /* Convert them to symbols.  */
  61   symbols = backtrace_symbols (addresses, n);
  62   /* Check that symbols were obtained.  */
  63   if (symbols == NULL)
  64     {
  65       FAIL ();
  66       return;
  67     }
  68   for (i = 0; i < n; ++i)
  69     printf ("Function %d: %s\n", i, symbols[i]);
  70   /* Check that the function names obtained are accurate.  */
  71   if (!match (symbols[0], "handle_signal"))
  72     {
  73       FAIL ();
  74       return;
  75     }
  76   /* Do not check name for signal trampoline.  */
  77   i = 2;
  78   if (!match (symbols[i++], "read"))
  79     {
  80       /* Perhaps symbols[2] is __kernel_vsyscall?  */
  81       if (!match (symbols[i++], "read"))
  82         {
  83           FAIL ();
  84           return;
  85         }
  86     }
  87   for (; i < n - 1; i++)
  88     if (!match (symbols[i], "fn"))
  89       {
  90         FAIL ();
  91         return;
  92       }
  93   /* Symbol names are not available for static functions, so we do not
  94      check do_test.  */
  95 }
  96
  97 NO_INLINE int
  98 fn (int c, int flags)
  99 {
 100   pid_t parent_pid, child_pid;
 101   int pipefd[2];
 102   char r[1];
 103   struct sigaction act;
 104
 105   if (c > 0)
 106     {
 107       fn (c - 1, flags);
 108       return x;
 109     }
 110
 111   memset (&act, 0, sizeof (act));
 112   act.sa_handler = handle_signal;
 113   act.sa_flags = flags;
 114   sigemptyset (&act.sa_mask);
 115   sigaction (SIGUSR1, &act, NULL);
 116   parent_pid = getpid ();
 117   if (pipe (pipefd) == -1)
 118     abort ();
 119
 120   child_pid = fork ();
 121   if (child_pid == (pid_t) -1)
 122     abort ();
 123   else if (child_pid == 0)
 124     {
 125       sleep (1);
 126       kill (parent_pid, SIGUSR1);
 127       _exit (0);
 128     }
 129
 130   /* In the parent.  */
 131   read (pipefd[0], r, 1);
 132
 133   return 0;
 134 }
 135
 136 NO_INLINE static int
 137 do_test (void)
 138 {
 139   fn (2, SIGACTION_FLAGS);
 140   return ret;
 141 }