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

   1 /* Check non representable OFD locks regions in non-LFS mode for compat
   2    mode (BZ #20251)
   3    Copyright (C) 2018-2021 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU General Public License
   7    as published by the Free Software Foundation; either version 2
   8    of the License, or (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
  19 #include <unistd.h>
  20 #include <fcntl.h>
  21 #include <stdint.h>
  22 #include <errno.h>
  23
  24 #include <support/temp_file.h>
  25 #include <support/check.h>
  26
  27 #include <shlib-compat.h>
  28 #if TEST_COMPAT (libc, GLIBC_2_0, GLIBC_2_28)
  29 compat_symbol_reference (libc, fcntl, fcntl, GLIBC_2_0);
  30
  31 static char *temp_filename;
  32 static int temp_fd;
  33
  34 static void
  35 do_prepare (int argc, char **argv)
  36 {
  37   temp_fd = create_temp_file ("tst-ofdlocks-compat.", &temp_filename);
  38   TEST_VERIFY_EXIT (temp_fd != -1);
  39 }
  40
  41 #define PREPARE do_prepare
  42
  43 /* Linux between 4.13 and 4.15 return EOVERFLOW for LFS OFD locks usage
  44    in compat mode (non-LFS ABI running on a LFS default kernel, such as
  45    i386 on a x86_64 kernel or s390-32 on a s390-64 kernel) [1].  This is
  46    a kernel issue because __NR_fcntl64 is the expected way to use OFD locks
  47    (used on GLIBC for both fcntl and fcntl64).
  48
  49    [1] https://sourceware.org/ml/libc-alpha/2018-07/msg00243.html  */
  50
  51 static int
  52 do_test (void)
  53 {
  54   /* The compat fcntl version for architectures which support non-LFS
  55      operations does not wrap the flock OFD argument, so the struct is passed
  56      unmodified to kernel.  It means no EOVERFLOW is returned, so operations
  57      with LFS should not incur in failure.  */
  58
  59   struct flock64 lck64 = {
  60     .l_type   = F_WRLCK,
  61     .l_whence = SEEK_SET,
  62     .l_start  = (off64_t)INT32_MAX + 1024,
  63     .l_len    = 1024,
  64   };
  65   int ret = fcntl (temp_fd, F_OFD_SETLKW, &lck64);
  66   if (ret == -1 && errno == EINVAL)
  67     /* OFD locks are only available on Linux 3.15.  */
  68     FAIL_UNSUPPORTED ("fcntl (F_OFD_SETLKW) not supported");
  69
  70   TEST_VERIFY_EXIT (ret == 0);
  71
  72   /* Open file description locks placed through the same open file description
  73      (either by same file descriptor or a duplicated one created by fork,
  74      dup, fcntl F_DUPFD, etc.) overwrites then old lock.  To force a
  75      conflicting lock combination, it creates a new file descriptor.  */
  76   int fd = open64 (temp_filename, O_RDWR, 0666);
  77   TEST_VERIFY_EXIT (fd != -1);
  78
  79   struct flock64 lck = {
  80     .l_type   = F_WRLCK,
  81     .l_whence = SEEK_SET,
  82     .l_start  = INT32_MAX - 1024,
  83     .l_len    = 4 * 1024,
  84   };
  85   TEST_VERIFY (fcntl (fd, F_OFD_GETLK, &lck) == 0);
  86
  87   return 0;
  88 }
  89 #else
  90 static int
  91 do_test (void)
  92 {
  93   return 77;
  94 }
  95 #endif
  96
  97 #include <support/test-driver.c>