malloc/tst-pvalloc-fortify.c

   1 /* Test fortify-source allocation size handling in pvalloc (bug 25401).
   2    Copyright (C) 2020-2021 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 License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    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; see the file COPYING.LIB.  If
  17    not, see <https://www.gnu.org/licenses/>.  */
  18
  19 #undef _FORTIFY_SOURCE
  20 #define _FORTIFY_SOURCE 2
  21 #include <malloc.h>
  22 #include <string.h>
  23 #include <support/check.h>
  24 #include <support/xunistd.h>
  25 #include <unistd.h>
  26
  27 static int
  28 do_test (void)
  29 {
  30   /* The test below assumes that pvalloc rounds up the allocation size
  31      to at least 8.  */
  32   TEST_VERIFY (xsysconf (_SC_PAGESIZE) >= 8);
  33
  34   void *p = pvalloc (5);
  35   TEST_VERIFY_EXIT (p != NULL);
  36
  37   /* This is valid assuming the page size is at least 8 because
  38      pvalloc rounds up the allocation size to a multiple of the page
  39      size.  Due to bug 25041, this used to trigger a compiler
  40      warning.  */
  41   strcpy (p, "abcdefg");
  42
  43   asm ("" : : "g" (p) : "memory"); /* Optimization barrier.  */
  44   TEST_VERIFY (malloc_usable_size (p) >= xsysconf (_SC_PAGESIZE));
  45   return 0;
  46 }
  47
  48 #include <support/test-driver.c>