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) 2011-2017 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 /* The backtrace should include at least handle_signal, a signal
  36    trampoline, read, 3 * fn, and do_test.  */
  37 #define NUM_FUNCTIONS 7
  38
  39 void
  40 handle_signal (int signum)
  41 {
  42   void *addresses[NUM_FUNCTIONS];
  43   char **symbols;
  44   int n;
  45   int i;
  46
  47   /* Get the backtrace addresses.  */
  48   n = backtrace (addresses, sizeof (addresses) / sizeof (addresses[0]));
  49   printf ("Obtained backtrace with %d functions\n", n);
  50   /*  Check that there are at least seven functions.  */
  51   if (n < NUM_FUNCTIONS)
  52     {
  53       FAIL ();
  54       return;
  55     }
  56   /* Convert them to symbols.  */
  57   symbols = backtrace_symbols (addresses, n);
  58   /* Check that symbols were obtained.  */
  59   if (symbols == NULL)
  60     {
  61       FAIL ();
  62       return;
  63     }
  64   for (i = 0; i < n; ++i)
  65     printf ("Function %d: %s\n", i, symbols[i]);
  66   /* Check that the function names obtained are accurate.  */
  67   if (!match (symbols[0], "handle_signal"))
  68     {
  69       FAIL ();
  70       return;
  71     }
  72   /* Do not check name for signal trampoline.  */
  73   i = 2;
  74   if (!match (symbols[i++], "read"))
  75     {
  76       /* Perhaps symbols[2] is __kernel_vsyscall?  */
  77       if (!match (symbols[i++], "read"))
  78         {
  79           FAIL ();
  80           return;
  81         }
  82     }
  83   for (; i < n - 1; i++)
  84     if (!match (symbols[i], "fn"))
  85       {
  86         FAIL ();
  87         return;
  88       }
  89   /* Symbol names are not available for static functions, so we do not
  90      check do_test.  */
  91 }
  92
  93 NO_INLINE int
  94 fn (int c, int flags)
  95 {
  96   pid_t parent_pid, child_pid;
  97   int pipefd[2];
  98   char r[1];
  99   struct sigaction act;
 100
 101   if (c > 0)
 102     {
 103       fn (c - 1, flags);
 104       return x;
 105     }
 106
 107   memset (&act, 0, sizeof (act));
 108   act.sa_handler = handle_signal;
 109   act.sa_flags = flags;
 110   sigemptyset (&act.sa_mask);
 111   sigaction (SIGUSR1, &act, NULL);
 112   parent_pid = getpid ();
 113   if (pipe (pipefd) == -1)
 114     abort ();
 115
 116   child_pid = fork ();
 117   if (child_pid == (pid_t) -1)
 118     abort ();
 119   else if (child_pid == 0)
 120     {
 121       sleep (1);
 122       kill (parent_pid, SIGUSR1);
 123       _exit (0);
 124     }
 125
 126   /* In the parent.  */
 127   read (pipefd[0], r, 1);
 128
 129   return 0;
 130 }
 131
 132 NO_INLINE int
 133 do_test (void)
 134 {
 135   fn (2, SIGACTION_FLAGS);
 136   return ret;
 137 }
 138
 139 #include <support/test-driver.c>