binutils-gdb/gdb/testsuite/gdb.base/siginfo-thread.c

/* This testcase is part of GDB, the GNU debugger.

   Copyright 2004-2017 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/

#include <signal.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/mman.h>
#include <unistd.h>
#include <pthread.h>

static void *p;

static void
handler (int sig, siginfo_t *info, void *context)
{
  /* Copy to local vars, as the test wants to read them, and si_addr,
     etc. may be preprocessor defines.  */
  int ssi_errno = info->si_errno;
  int ssi_signo = info->si_signo;
  int ssi_code = info->si_code;
  void *ssi_addr = info->si_addr;

  _exit (0); /* set breakpoint here */
}

static void *
segv_thread (void *ptr)
{
  *(int *)ptr = 0;
}

int
main (void)
{
  pthread_t thr;

  /* Set up unwritable memory.  */
  {
    size_t len;
    len = sysconf(_SC_PAGESIZE);
    p = mmap (0, len, PROT_NONE, MAP_ANON|MAP_PRIVATE, -1, 0);
    if (p == MAP_FAILED)
      {
	perror ("mmap");
	return 1;
      }
  }
  /* Set up the signal handler.  */
  {
    struct sigaction action;
    memset (&action, 0, sizeof (action));
    action.sa_sigaction = handler;
    action.sa_flags |= SA_SIGINFO;
    if (sigaction (SIGSEGV, &action, NULL))
      {
	perror ("sigaction");
	return 1;
      }
  }

  /* Create a thread that will trigger SIGSEGV.  */
  pthread_create (&thr, NULL, segv_thread, p);

  pthread_join (thr, NULL);

  return 0;
}