malloc/tst-reallocarray.c

   1 /* Test for reallocarray.
   2    Copyright (C) 2017-2023 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 <errno.h>
  20 #include <malloc.h>
  21 #include <string.h>
  22 #include <support/check.h>
  23 #include <libc-diag.h>
  24
  25 static void *
  26 reallocarray_nowarn (void *ptr, size_t nmemb, size_t size)
  27 {
  28 #if __GNUC_PREREQ (7, 0)
  29   /* GCC 7 warns about too-large allocations; here we want to test
  30      that they fail.  */
  31   DIAG_IGNORE_NEEDS_COMMENT (7, "-Walloc-size-larger-than=");
  32 #endif
  33   void *ret = reallocarray (ptr, nmemb, size);
  34 #if __GNUC_PREREQ (7, 0)
  35   DIAG_POP_NEEDS_COMMENT;
  36 #endif
  37   return ret;
  38 }
  39
  40
  41 static int
  42 do_test (void)
  43 {
  44   void *ptr = NULL;
  45   void *ptr2 = NULL;
  46   unsigned char *c;
  47   size_t i;
  48   int ok;
  49   const size_t max = ~(size_t)0;
  50   size_t a, b;
  51
  52   /* Test overflow detection.  */
  53   errno = 0;
  54   ptr = reallocarray_nowarn (NULL, max, 2);
  55   TEST_VERIFY (!ptr);
  56   TEST_VERIFY (errno == ENOMEM);
  57
  58   errno = 0;
  59   ptr = reallocarray_nowarn (NULL, 2, max);
  60   TEST_VERIFY (!ptr);
  61   TEST_VERIFY (errno == ENOMEM);
  62
  63   a = 65537;
  64   b = max/65537 + 1;
  65   errno = 0;
  66   ptr = reallocarray_nowarn (NULL, a, b);
  67   TEST_VERIFY (!ptr);
  68   TEST_VERIFY (errno == ENOMEM);
  69
  70   errno = 0;
  71   ptr = reallocarray_nowarn (NULL, b, a);
  72   TEST_VERIFY (!ptr);
  73   TEST_VERIFY (errno == ENOMEM);
  74
  75   /* Test realloc-like behavior.  */
  76   /* Allocate memory like malloc.  */
  77   ptr = reallocarray (NULL, 10, 2);
  78   TEST_VERIFY_EXIT (ptr);
  79   TEST_VERIFY_EXIT (malloc_usable_size (ptr) >= 10*2);
  80
  81   memset (ptr, 0xAF, 10*2);
  82
  83   /* Enlarge buffer.   */
  84   ptr2 = reallocarray (ptr, 20, 2);
  85   TEST_VERIFY (ptr2);
  86   if (ptr2)
  87     ptr = ptr2;
  88   TEST_VERIFY (malloc_usable_size (ptr) >= 20*2);
  89
  90   c = ptr;
  91   ok = 1;
  92   for (i = 0; i < 10*2; ++i)
  93     {
  94       if (c[i] != 0xAF)
  95         ok = 0;
  96     }
  97   TEST_VERIFY (ok);
  98
  99   /* Decrease buffer size.  */
 100   ptr2 = reallocarray (ptr, 5, 3);
 101   TEST_VERIFY (ptr2);
 102   if (ptr2)
 103     ptr = ptr2;
 104   TEST_VERIFY_EXIT (malloc_usable_size (ptr) >= 5*3);
 105
 106   c = ptr;
 107   ok = 1;
 108   for (i = 0; i < 5*3; ++i)
 109     {
 110       if (c[i] != 0xAF)
 111         ok = 0;
 112     }
 113   TEST_VERIFY (ok);
 114
 115   /* Overflow should leave buffer untouched.  */
 116   errno = 0;
 117   ptr2 = reallocarray_nowarn (ptr, 2, ~(size_t)0);
 118   TEST_VERIFY (!ptr2);
 119   TEST_VERIFY (errno == ENOMEM);
 120
 121   c = ptr;
 122   ok = 1;
 123   for (i = 0; i < 5*3; ++i)
 124     {
 125       if (c[i] != 0xAF)
 126         ok = 0;
 127     }
 128   TEST_VERIFY (ok);
 129
 130   free (ptr);
 131
 132   return 0;
 133 }
 134
 135 #include <support/test-driver.c>