1 /* Verify that backtrace does not deadlock on itself on memory corruption.
2    Copyright (C) 2015-2021 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 
24 #define SIZE 4096
25 
26 /* Wrap free with a function to prevent gcc from optimizing it out.  */
27 static void
28 __attribute__((noinline))
call_free(void * ptr)29 call_free (void *ptr)
30 {
31   free (ptr);
32   *(size_t *)(ptr - sizeof (size_t)) = 1;
33 }
34 
35 int
do_test(void)36 do_test (void)
37 {
38   void *ptr1 = malloc (SIZE);
39   void *ptr2 = malloc (SIZE);
40 
41   /* Avoid unwanted output to TTY after an expected memory corruption.  */
42   ignore_stderr();
43 
44   call_free (ptr1);
45   ptr1 = malloc (SIZE);
46 
47   /* Not reached.  The return statement is to put ptr2 into use so that gcc
48      doesn't optimize out that malloc call.  */
49   return (ptr1 == ptr2);
50 }
51 
52 #define EXPECTED_SIGNAL SIGABRT
53 #include <support/test-driver.c>
54