glibc/malloc/tst-malloc-backtrace.c
Martin Sebor c094c232eb Avoid -Wuse-after-free in tests [BZ #26779].
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-01-26 10:38:23 -07:00

63 lines
1.8 KiB
C

/* Verify that backtrace does not deadlock on itself on memory corruption.
Copyright (C) 2015-2022 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 <signal.h>
#include <stdlib.h>
#include <support/support.h>
#include <libc-diag.h>
#define SIZE 4096
/* Wrap free with a function to prevent gcc from optimizing it out. */
static void
__attribute__((noinline))
call_free (void *ptr)
{
free (ptr);
#if __GNUC_PREREQ (12, 0)
/* Ignore a valid warning about using a pointer made indeterminate
by a prior call to free(). */
DIAG_IGNORE_NEEDS_COMMENT (12, "-Wuse-after-free");
#endif
*(size_t *)(ptr - sizeof (size_t)) = 1;
#if __GNUC_PREREQ (12, 0)
DIAG_POP_NEEDS_COMMENT;
#endif
}
int
do_test (void)
{
void *ptr1 = malloc (SIZE);
void *ptr2 = malloc (SIZE);
/* Avoid unwanted output to TTY after an expected memory corruption. */
ignore_stderr();
call_free (ptr1);
ptr1 = malloc (SIZE);
/* Not reached. The return statement is to put ptr2 into use so that gcc
doesn't optimize out that malloc call. */
return (ptr1 == ptr2);
}
#define EXPECTED_SIGNAL SIGABRT
#include <support/test-driver.c>