/* Catastrophic failure reports.  Generic POSIX.1 version.

   Copyright (C) 1993-2018 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 <atomic.h>

#include <errno.h>

#include <fcntl.h>

#include <ldsodefs.h>

#include <paths.h>

#include <stdarg.h>

#include <stdbool.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <sysdep.h>

#include <unistd.h>

#include <sys/mman.h>

#include <sys/uio.h>

#include <not-cancel.h>

#ifdef FATAL_PREPARE_INCLUDE

#include FATAL_PREPARE_INCLUDE

#endif

#ifndef WRITEV_FOR_FATAL

# define WRITEV_FOR_FATAL	writev_for_fatal

static bool

writev_for_fatal (int fd, const struct iovec *iov, size_t niov, size_t total)

{

  return TEMP_FAILURE_RETRY (__writev (fd, iov, niov)) == total;

}

#endif

#ifndef BEFORE_ABORT

# define BEFORE_ABORT		before_abort

static void

before_abort (int do_abort __attribute__ ((unused)),

              bool written __attribute__ ((unused)),

              int fd __attribute__ ((unused)))

{

}

#endif

struct str_list

{

  const char *str;

  size_t len;

  struct str_list *next;

};

/* Abort with an error message.  */

void

__libc_message (enum __libc_message_action action, const char *fmt, ...)

{

  va_list ap;

  int fd = -1;

  va_start (ap, fmt);

#ifdef FATAL_PREPARE

  FATAL_PREPARE;

#endif

  /* Don't call __libc_secure_getenv if we aren't doing backtrace, which

     may access the corrupted stack.  */

  if ((action & do_backtrace))

    {

      /* Open a descriptor for /dev/tty unless the user explicitly

	 requests errors on standard error.  */

      const char *on_2 = __libc_secure_getenv ("LIBC_FATAL_STDERR_");

      if (on_2 == NULL || *on_2 == '\0')

	fd = __open_nocancel (_PATH_TTY, O_RDWR | O_NOCTTY | O_NDELAY);

    }

  if (fd == -1)

    fd = STDERR_FILENO;

  struct str_list *list = NULL;

  int nlist = 0;

  const char *cp = fmt;

  while (*cp != '\0')

    {

      /* Find the next "%s" or the end of the string.  */

      const char *next = cp;

      while (next[0] != '%' || next[1] != 's')

	{

	  next = __strchrnul (next + 1, '%');

	  if (next[0] == '\0')

	    break;

	}

      /* Determine what to print.  */

      const char *str;

      size_t len;

      if (cp[0] == '%' && cp[1] == 's')

	{

	  str = va_arg (ap, const char *);

	  len = strlen (str);

	  cp += 2;

	}

      else

	{

	  str = cp;

	  len = next - cp;

	  cp = next;

	}

      struct str_list *newp = alloca (sizeof (struct str_list));

      newp->str = str;

      newp->len = len;

      newp->next = list;

      list = newp;

      ++nlist;

    }

  bool written = false;

  if (nlist > 0)

    {

      struct iovec *iov = alloca (nlist * sizeof (struct iovec));

      ssize_t total = 0;

      for (int cnt = nlist - 1; cnt >= 0; --cnt)

	{

	  iov[cnt].iov_base = (char *) list->str;

	  iov[cnt].iov_len = list->len;

	  total += list->len;

	  list = list->next;

	}

      written = WRITEV_FOR_FATAL (fd, iov, nlist, total);

      if ((action & do_abort))

	{

	  total = ((total + 1 + GLRO(dl_pagesize) - 1)

		   & ~(GLRO(dl_pagesize) - 1));

	  struct abort_msg_s *buf = __mmap (NULL, total,

					    PROT_READ | PROT_WRITE,

					    MAP_ANON | MAP_PRIVATE, -1, 0);

	  if (__glibc_likely (buf != MAP_FAILED))

	    {

	      buf->size = total;

	      char *wp = buf->msg;

	      for (int cnt = 0; cnt < nlist; ++cnt)

		wp = mempcpy (wp, iov[cnt].iov_base, iov[cnt].iov_len);

	      *wp = '\0';

	      /* We have to free the old buffer since the application might

		 catch the SIGABRT signal.  */

	      struct abort_msg_s *old = atomic_exchange_acq (&__abort_msg,

							     buf);

	      if (old != NULL)

		__munmap (old, old->size);

	    }

	}

    }

  va_end (ap);

  if ((action & do_abort))

    {

      if ((action & do_backtrace))

	BEFORE_ABORT (do_abort, written, fd);

      /* Kill the application.  */

      abort ();

    }

}

void

__libc_fatal (const char *message)

{

  /* The loop is added only to keep gcc happy.  */

  while (1)

    __libc_message (do_abort | do_backtrace, "%s", message);

}

libc_hidden_def (__libc_fatal)