glibc/sysdeps/posix/libc_fatal.c
Joe Simmons-Talbott 5f798d38e9 stdio: Remove __libc_message alloca usage
Use a fixed size array instead.  The maximum number of arguments
is set by macro tricks.

Co-authored-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-09-11 16:16:49 +00:00

141 lines
3.3 KiB
C

/* Catastrophic failure reports. Generic POSIX.1 version.
Copyright (C) 1993-2023 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
<https://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
/* Abort with an error message. */
void
__libc_message_impl (const char *fmt, ...)
{
va_list ap;
int fd = -1;
#ifdef FATAL_PREPARE
FATAL_PREPARE;
#endif
if (fd == -1)
fd = STDERR_FILENO;
struct iovec iov[LIBC_MESSAGE_MAX_ARGS * 2 - 1];
int iovcnt = 0;
ssize_t total = 0;
va_start (ap, fmt);
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;
}
iov[iovcnt].iov_base = (char *) str;
iov[iovcnt].iov_len = len;
total += len;
iovcnt++;
}
va_end (ap);
if (iovcnt > 0)
{
WRITEV_FOR_FATAL (fd, iov, iovcnt, total);
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 < iovcnt; ++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_acquire (&__abort_msg,
buf);
if (old != NULL)
__munmap (old, old->size);
}
}
/* Kill the application. */
abort ();
}
void
__libc_fatal (const char *message)
{
/* The loop is added only to keep gcc happy. */
while (1)
__libc_message ("%s", message);
}
libc_hidden_def (__libc_fatal)