1  /*
       2   * Copyright (C) 2010-2023 Free Software Foundation, Inc.
       3   * Written by Eric Blake
       4   *
       5   * This program is free software: you can redistribute it and/or modify
       6   * it under the terms of the GNU General Public License as published by
       7   * the Free Software Foundation, either version 3 of the License, or
       8   * (at your option) any later version.
       9   *
      10   * This program 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
      13   * GNU General Public License for more details.
      14   *
      15   * You should have received a copy of the GNU General Public License
      16   * along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <config.h>
      19  
      20  #include <string.h>
      21  
      22  #include "signature.h"
      23  SIGNATURE_CHECK (strnlen, size_t, (char const *, size_t));
      24  
      25  #include <stdlib.h>
      26  
      27  #include "zerosize-ptr.h"
      28  #include "macros.h"
      29  
      30  int
      31  main (void)
      32  {
      33    size_t i;
      34    char *page_boundary = (char *) zerosize_ptr ();
      35    if (!page_boundary)
      36      {
      37        page_boundary = malloc (0x1000);
      38        ASSERT (page_boundary);
      39        page_boundary += 0x1000;
      40      }
      41  
      42    /* Basic behavior tests.  */
      43    ASSERT (strnlen ("a", 0) == 0);
      44    ASSERT (strnlen ("a", 1) == 1);
      45    ASSERT (strnlen ("a", 2) == 1);
      46    ASSERT (strnlen ("", 0x100000) == 0);
      47  
      48    /* Memory fence and alignment testing.  */
      49    for (i = 0; i < 512; i++)
      50      {
      51        char *start = page_boundary - i;
      52        size_t j = i;
      53        memset (start, 'x', i);
      54        do
      55          {
      56            if (i != j)
      57              {
      58                start[j] = 0;
      59                ASSERT (strnlen (start, i + j) == j);
      60              }
      61            ASSERT (strnlen (start, i) == j);
      62            ASSERT (strnlen (start, j) == j);
      63          }
      64        while (j--);
      65      }
      66  
      67    return 0;
      68  }