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

82 lines
2.6 KiB
C

/* Check non representable OFD locks regions in non-LFS mode (BZ #20251)
Copyright (C) 2018-2020 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, see <https://www.gnu.org/licenses/>.
*/
#include <unistd.h>
#include <fcntl.h>
#include <stdint.h>
#include <errno.h>
#include <support/temp_file.h>
#include <support/check.h>
static char *temp_filename;
static int temp_fd;
static void
do_prepare (int argc, char **argv)
{
temp_fd = create_temp_file ("tst-ofdlocks.", &temp_filename);
TEST_VERIFY_EXIT (temp_fd != -1);
}
#define PREPARE do_prepare
static int
do_test (void)
{
/* It first allocates a open file description lock range which can not
be represented in a 32 bit struct flock. */
struct flock64 lck64 = {
.l_type = F_WRLCK,
.l_whence = SEEK_SET,
.l_start = (off64_t)INT32_MAX + 1024,
.l_len = 1024,
};
int ret = fcntl64 (temp_fd, F_OFD_SETLKW, &lck64);
if (ret == -1 && errno == EINVAL)
/* OFD locks are only available on Linux 3.15. */
FAIL_UNSUPPORTED ("fcntl (F_OFD_SETLKW) not supported");
TEST_VERIFY_EXIT (ret == 0);
/* Open file description locks placed through the same open file description
(either by same file descriptor or a duplicated one created by fork,
dup, fcntl F_DUPFD, etc.) overwrites then old lock. To force a
conflicting lock combination, it creates a new file descriptor. */
int fd = open64 (temp_filename, O_RDWR, 0666);
TEST_VERIFY_EXIT (fd != -1);
/* It tries then to allocate another open file descriptior with a valid
non-LFS bits struct flock but which will result in a conflicted region
which can not be represented in a non-LFS struct flock. */
struct flock lck = {
.l_type = F_WRLCK,
.l_whence = SEEK_SET,
.l_start = INT32_MAX - 1024,
.l_len = 4 * 1024,
};
int r = fcntl (fd, F_OFD_GETLK, &lck);
if (sizeof (off_t) != sizeof (off64_t))
TEST_VERIFY (r == -1 && errno == EOVERFLOW);
else
TEST_VERIFY (r == 0);
return 0;
}
#include <support/test-driver.c>