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/* Catastrophic failure reports. Generic POSIX.1 version.
Copyright (C) 1993-2019 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)
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