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

   1 /* Check non representable OFD locks regions in non-LFS mode (BZ #20251)
   2    Copyright (C) 2018-2020 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 <https://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   int ret = fcntl64 (temp_fd, F_OFD_SETLKW, &lck64);
  50   if (ret == -1 && errno == EINVAL)
  51     /* OFD locks are only available on Linux 3.15.  */
  52     FAIL_UNSUPPORTED ("fcntl (F_OFD_SETLKW) not supported");
  53
  54   TEST_VERIFY_EXIT (ret == 0);
  55
  56   /* Open file description locks placed through the same open file description
  57      (either by same file descriptor or a duplicated one created by fork,
  58      dup, fcntl F_DUPFD, etc.) overwrites then old lock.  To force a
  59      conflicting lock combination, it creates a new file descriptor.  */
  60   int fd = open64 (temp_filename, O_RDWR, 0666);
  61   TEST_VERIFY_EXIT (fd != -1);
  62
  63   /* It tries then to allocate another open file descriptior with a valid
  64      non-LFS bits struct flock but which will result in a conflicted region
  65      which can not be represented in a non-LFS struct flock.  */
  66   struct flock lck = {
  67     .l_type   = F_WRLCK,
  68     .l_whence = SEEK_SET,
  69     .l_start  = INT32_MAX - 1024,
  70     .l_len    = 4 * 1024,
  71   };
  72   int r = fcntl (fd, F_OFD_GETLK, &lck);
  73   if (sizeof (off_t) != sizeof (off64_t))
  74     TEST_VERIFY (r == -1 && errno == EOVERFLOW);
  75   else
  76     TEST_VERIFY (r == 0);
  77
  78   return 0;
  79 }
  80
  81 #include <support/test-driver.c>