/* Test backtrace and backtrace_symbols for signal frames, where a

   system call was interrupted by a signal.

   Copyright (C) 2011-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <execinfo.h>

#include <search.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <sys/types.h>

#include <signal.h>

#include <unistd.h>

#include "tst-backtrace.h"

#ifndef SIGACTION_FLAGS

# define SIGACTION_FLAGS 0

#endif

/* The backtrace should include at least handle_signal, a signal

   trampoline, read, 3 * fn, and do_test.  */

#define NUM_FUNCTIONS 7

void

handle_signal (int signum)

{

  void *addresses[NUM_FUNCTIONS];

  char **symbols;

  int n;

  int i;

  /* Get the backtrace addresses.  */

  n = backtrace (addresses, sizeof (addresses) / sizeof (addresses[0]));

  printf ("Obtained backtrace with %d functions\n", n);

  /*  Check that there are at least seven functions.  */

  if (n < NUM_FUNCTIONS)

    {

      FAIL ();

      return;

    }

  /* Convert them to symbols.  */

  symbols = backtrace_symbols (addresses, n);

  /* Check that symbols were obtained.  */

  if (symbols == NULL)

    {

      FAIL ();

      return;

    }

  for (i = 0; i < n; ++i)

    printf ("Function %d: %s\n", i, symbols[i]);

  /* Check that the function names obtained are accurate.  */

  if (!match (symbols[0], "handle_signal"))

    {

      FAIL ();

      return;

    }

  /* Do not check name for signal trampoline.  */

  i = 2;

  if (!match (symbols[i++], "read"))

    {

      /* Perhaps symbols[2] is __kernel_vsyscall?  */

      if (!match (symbols[i++], "read"))

	{

	  FAIL ();

	  return;

	}

    }

  for (; i < n - 1; i++)

    if (!match (symbols[i], "fn"))

      {

	FAIL ();

	return;

      }

  /* Symbol names are not available for static functions, so we do not

     check do_test.  */

}

NO_INLINE int

fn (int c, int flags)

{

  pid_t parent_pid, child_pid;

  int pipefd[2];

  char r[1];

  struct sigaction act;

  if (c > 0)

    {

      fn (c - 1, flags);

      return x;

    }

  memset (&act, 0, sizeof (act));

  act.sa_handler = handle_signal;

  act.sa_flags = flags;

  sigemptyset (&act.sa_mask);

  sigaction (SIGUSR1, &act, NULL);

  parent_pid = getpid ();

  if (pipe (pipefd) == -1)

    abort ();

  child_pid = fork ();

  if (child_pid == (pid_t) -1)

    abort ();

  else if (child_pid == 0)

    {

      sleep (1);

      kill (parent_pid, SIGUSR1);

      _exit (0);

    }

  /* In the parent.  */

  read (pipefd[0], r, 1);

  return 0;

}

NO_INLINE int

do_test (void)

{

  fn (2, SIGACTION_FLAGS);

  return ret;

}

#include <support/test-driver.c>