malloc/tst-malloc-backtrace.c

   1 /* Verify that backtrace does not deadlock on itself on memory corruption.
   2    Copyright (C) 2015-2023 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 #define SIZE 4096
  26
  27 /* Wrap free with a function to prevent gcc from optimizing it out.  */
  28 static void
  29 __attribute__((noinline))
  30 call_free (void *ptr)
  31 {
  32   free (ptr);
  33 #if __GNUC_PREREQ (12, 0)
  34   /* Ignore a valid warning about using a pointer made indeterminate
  35      by a prior call to free().  */
  36   DIAG_IGNORE_NEEDS_COMMENT (12, "-Wuse-after-free");
  37 #endif
  38   *(size_t *)(ptr - sizeof (size_t)) = 1;
  39 #if __GNUC_PREREQ (12, 0)
  40   DIAG_POP_NEEDS_COMMENT;
  41 #endif
  42 }
  43
  44 int
  45 do_test (void)
  46 {
  47   void *ptr1 = malloc (SIZE);
  48   void *ptr2 = malloc (SIZE);
  49
  50   /* Avoid unwanted output to TTY after an expected memory corruption.  */
  51   ignore_stderr();
  52
  53   call_free (ptr1);
  54   ptr1 = malloc (SIZE);
  55
  56   /* Not reached.  The return statement is to put ptr2 into use so that gcc
  57      doesn't optimize out that malloc call.  */
  58   return (ptr1 == ptr2);
  59 }
  60
  61 #define EXPECTED_SIGNAL SIGABRT
  62 #include <support/test-driver.c>