sysdeps/unix/sysv/linux/tst-ofdlocks.c

   1 /* Check non representable OFD locks regions in non-LFS mode (BZ #20251)
   2    Copyright (C) 2018 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU General Public License
   6    as published by the Free Software Foundation; either version 2
   7    of the License, or (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, see <http://www.gnu.org/licenses/>.
  16 */
  17
  18 #include <unistd.h>
  19 #include <fcntl.h>
  20 #include <stdint.h>
  21 #include <errno.h>
  22
  23 #include <support/temp_file.h>
  24 #include <support/check.h>
  25
  26 static char *temp_filename;
  27 static int temp_fd;
  28
  29 static void
  30 do_prepare (int argc, char **argv)
  31 {
  32   temp_fd = create_temp_file ("tst-ofdlocks.", &temp_filename);
  33   TEST_VERIFY_EXIT (temp_fd != -1);
  34 }
  35
  36 #define PREPARE do_prepare
  37
  38 static int
  39 do_test (void)
  40 {
  41   /* It first allocates a open file description lock range which can not
  42      be represented in a 32 bit struct flock.   */
  43   struct flock64 lck64 = {
  44     .l_type   = F_WRLCK,
  45     .l_whence = SEEK_SET,
  46     .l_start  = (off64_t)INT32_MAX + 1024,
  47     .l_len    = 1024,
  48   };
  49   TEST_VERIFY_EXIT (fcntl64 (temp_fd, F_OFD_SETLKW, &lck64) == 0);
  50
  51   /* Open file description locks placed through the same open file description
  52      (either by same file descriptor or a duplicated one created by fork,
  53      dup, fcntl F_DUPFD, etc.) overwrites then old lock.  To force a
  54      conflicting lock combination, it creates a new file descriptor.  */
  55   int fd = open64 (temp_filename, O_RDWR, 0666);
  56   TEST_VERIFY_EXIT (fd != -1);
  57
  58   /* It tries then to allocate another open file descriptior with a valid
  59      non-LFS bits struct flock but which will result in a conflicted region
  60      which can not be represented in a non-LFS struct flock.  */
  61   struct flock lck = {
  62     .l_type   = F_WRLCK,
  63     .l_whence = SEEK_SET,
  64     .l_start  = INT32_MAX - 1024,
  65     .l_len    = 4 * 1024,
  66   };
  67   int r = fcntl (fd, F_OFD_GETLK, &lck);
  68   if (sizeof (off_t) != sizeof (off64_t))
  69     TEST_VERIFY (r == -1 && errno == EOVERFLOW);
  70   else
  71     TEST_VERIFY (r == 0);
  72
  73   return 0;
  74 }
  75
  76 #include <support/test-driver.c>