1/* Verify that backtrace does not deadlock on itself on memory corruption.
2 Copyright (C) 2015-2024 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <signal.h>
20#include <stdlib.h>
21
22#include <support/support.h>
23#include <libc-diag.h>
24
25#include "tst-malloc-aux.h"
26
27#define SIZE 4096
28
29/* Wrap free with a function to prevent gcc from optimizing it out. */
30static void
31__attribute__((noinline))
32call_free (void *ptr)
33{
34 free (ptr: ptr);
35#if __GNUC_PREREQ (12, 0)
36 /* Ignore a valid warning about using a pointer made indeterminate
37 by a prior call to free(). */
38 DIAG_IGNORE_NEEDS_COMMENT (12, "-Wuse-after-free");
39#endif
40 *(size_t *)(ptr - sizeof (size_t)) = 1;
41#if __GNUC_PREREQ (12, 0)
42 DIAG_POP_NEEDS_COMMENT;
43#endif
44}
45
46int
47do_test (void)
48{
49 void *ptr1 = malloc (SIZE);
50 void *ptr2 = malloc (SIZE);
51
52 /* Avoid unwanted output to TTY after an expected memory corruption. */
53 ignore_stderr();
54
55 call_free (ptr: ptr1);
56 ptr1 = malloc (SIZE);
57
58 /* Not reached. The return statement is to put ptr2 into use so that gcc
59 doesn't optimize out that malloc call. */
60 return (ptr1 == ptr2);
61}
62
63#define EXPECTED_SIGNAL SIGABRT
64#include <support/test-driver.c>
65

source code of glibc/malloc/tst-malloc-backtrace.c