glibc/io/tst-close_range.c

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/* Test for the close_range system call.
Copyright (C) 2021-2024 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <getopt.h>
#include <signal.h>
#include <stdbool.h>
#include <stdlib.h>
#include <stdint.h>
#include <array_length.h>
#include <support/capture_subprocess.h>
#include <support/check.h>
#include <support/descriptors.h>
#include <support/support.h>
#include <support/xsched.h>
#include <support/xunistd.h>
#define NFDS 100
static void
close_range_test_max_upper_limit (void)
{
struct support_descriptors *descrs = support_descriptors_list ();
int lowfd = support_open_dev_null_range (NFDS, O_RDONLY, 0600);
{
int r = close_range (lowfd, ~0U, 0);
if (r == -1 && errno == ENOSYS)
FAIL_UNSUPPORTED ("close_range not supported");
TEST_COMPARE (r, 0);
}
support_descriptors_check (descrs);
support_descriptors_free (descrs);
}
static void
close_range_test_common (int lowfd, unsigned int flags)
{
const int maximum_fd = lowfd + NFDS - 1;
const int half_fd = lowfd + NFDS / 2;
const int gap_1 = maximum_fd - 8;
/* Close half of the descriptors and check result. */
TEST_COMPARE (close_range (lowfd, half_fd, flags), 0);
for (int i = lowfd; i <= half_fd; i++)
{
TEST_COMPARE (fcntl (i, F_GETFL), -1);
TEST_COMPARE (errno, EBADF);
}
for (int i = half_fd + 1; i < maximum_fd; i++)
TEST_VERIFY (fcntl (i, F_GETFL) > -1);
/* Create some gaps, close up to a threshold, and check result. */
xclose (lowfd + 57);
xclose (lowfd + 78);
xclose (lowfd + 81);
xclose (lowfd + 82);
xclose (lowfd + 84);
xclose (lowfd + 90);
TEST_COMPARE (close_range (half_fd + 1, gap_1, flags), 0);
for (int i = half_fd + 1; i < gap_1; i++)
{
TEST_COMPARE (fcntl (i, F_GETFL), -1);
TEST_COMPARE (errno, EBADF);
}
for (int i = gap_1 + 1; i < maximum_fd; i++)
TEST_VERIFY (fcntl (i, F_GETFL) > -1);
/* Close the remaining but the last one. */
TEST_COMPARE (close_range (gap_1 + 1, maximum_fd - 1, flags), 0);
for (int i = gap_1 + 1; i < maximum_fd - 1; i++)
{
TEST_COMPARE (fcntl (i, F_GETFL), -1);
TEST_COMPARE (errno, EBADF);
}
TEST_VERIFY (fcntl (maximum_fd, F_GETFL) > -1);
/* Close the last one. */
TEST_COMPARE (close_range (maximum_fd, maximum_fd, flags), 0);
TEST_COMPARE (fcntl (maximum_fd, F_GETFL), -1);
TEST_COMPARE (errno, EBADF);
}
/* Basic tests: check if the syscall close ranges with and without gaps. */
static void
close_range_test (void)
{
struct support_descriptors *descrs = support_descriptors_list ();
/* Check if the temporary file descriptor has no no gaps. */
int lowfd = support_open_dev_null_range (NFDS, O_RDONLY, 0600);
close_range_test_common (lowfd, 0);
/* Double check by check the /proc. */
support_descriptors_check (descrs);
support_descriptors_free (descrs);
}
#ifdef __linux__
_Noreturn static int
close_range_test_fn (void *arg)
{
int lowfd = (int) ((uintptr_t) arg);
close_range_test_common (lowfd, 0);
exit (EXIT_SUCCESS);
}
/* Check if a clone_range on a subprocess created with CLONE_FILES close
the shared file descriptor table entries in the parent. */
static void
close_range_test_subprocess (void)
{
struct support_descriptors *descrs = support_descriptors_list ();
/* Check if the temporary file descriptor has no no gaps. */
int lowfd = support_open_dev_null_range (NFDS, O_RDONLY, 0600);
struct support_stack stack = support_stack_alloc (4096);
pid_t pid = xclone (close_range_test_fn, (void*) (uintptr_t) lowfd,
stack.stack, stack.size, CLONE_FILES | SIGCHLD);
TEST_VERIFY_EXIT (pid > 0);
int status;
xwaitpid (pid, &status, 0);
TEST_VERIFY (WIFEXITED (status));
TEST_COMPARE (WEXITSTATUS (status), 0);
support_stack_free (&stack);
for (int i = lowfd; i < NFDS; i++)
TEST_VERIFY (fcntl (i, F_GETFL) < 0);
support_descriptors_check (descrs);
support_descriptors_free (descrs);
}
#endif
#ifdef CLOSE_RANGE_UNSHARE
_Noreturn static int
close_range_unshare_test_fn (void *arg)
{
int lowfd = (int) ((uintptr_t) arg);
close_range_test_common (lowfd, CLOSE_RANGE_UNSHARE);
exit (EXIT_SUCCESS);
}
/* Check if a close_range with CLOSE_RANGE_UNSHARE issued from a subprocess
created with CLONE_FILES does not close the parent file descriptor list. */
static void
close_range_unshare_test (void)
{
struct support_descriptors *descrs1 = support_descriptors_list ();
/* Check if the temporary file descriptor has no no gaps. */
int lowfd = support_open_dev_null_range (NFDS, O_RDONLY, 0600);
struct support_descriptors *descrs2 = support_descriptors_list ();
struct support_stack stack = support_stack_alloc (4096);
pid_t pid = xclone (close_range_unshare_test_fn, (void*) (uintptr_t) lowfd,
stack.stack, stack.size, CLONE_FILES | SIGCHLD);
TEST_VERIFY_EXIT (pid > 0);
int status;
xwaitpid (pid, &status, 0);
TEST_VERIFY (WIFEXITED (status));
TEST_COMPARE (WEXITSTATUS (status), 0);
support_stack_free (&stack);
for (int i = lowfd; i < lowfd + NFDS; i++)
TEST_VERIFY (fcntl (i, F_GETFL) > -1);
support_descriptors_check (descrs2);
support_descriptors_free (descrs2);
TEST_COMPARE (close_range (lowfd, lowfd + NFDS, 0), 0);
support_descriptors_check (descrs1);
support_descriptors_free (descrs1);
}
#endif
static bool
is_in_array (int *arr, size_t len, int fd)
{
bool r = false;
for (int i = 0; i < len; i++)
if (arr[i] == fd)
return true;
return r;
}
static void
close_range_cloexec_test (void)
{
/* Check if the temporary file descriptor has no no gaps. */
int lowfd = support_open_dev_null_range (NFDS, O_RDONLY, 0600);
const int maximum_fd = lowfd + NFDS - 1;
const int half_fd = lowfd + NFDS / 2;
const int gap_1 = maximum_fd - 8;
/* Close half of the descriptors and check result. */
int r = close_range (lowfd, half_fd, CLOSE_RANGE_CLOEXEC);
if (r == -1 && errno == EINVAL)
{
printf ("%s: CLOSE_RANGE_CLOEXEC not supported\n", __func__);
return;
}
for (int i = lowfd; i <= half_fd; i++)
{
int flags = fcntl (i, F_GETFD);
TEST_VERIFY (flags > -1);
TEST_COMPARE (flags & FD_CLOEXEC, FD_CLOEXEC);
}
for (int i = half_fd + 1; i < maximum_fd; i++)
TEST_VERIFY (fcntl (i, F_GETFL) > -1);
/* Create some gaps, close up to a threshold, and check result. */
static int gap_close[] = { 57, 78, 81, 82, 84, 90 };
for (int i = 0; i < array_length (gap_close); i++)
xclose (lowfd + gap_close[i]);
TEST_COMPARE (close_range (half_fd + 1, gap_1, CLOSE_RANGE_CLOEXEC), 0);
for (int i = half_fd + 1; i < gap_1; i++)
{
int flags = fcntl (i, F_GETFD);
if (is_in_array (gap_close, array_length (gap_close), i - lowfd))
TEST_COMPARE (flags, -1);
else
{
TEST_VERIFY (flags > -1);
TEST_COMPARE (flags & FD_CLOEXEC, FD_CLOEXEC);
}
}
for (int i = gap_1 + 1; i < maximum_fd; i++)
TEST_VERIFY (fcntl (i, F_GETFL) > -1);
/* Close the remaining but the last one. */
TEST_COMPARE (close_range (gap_1 + 1, maximum_fd - 1, CLOSE_RANGE_CLOEXEC),
0);
for (int i = gap_1 + 1; i < maximum_fd - 1; i++)
{
int flags = fcntl (i, F_GETFD);
TEST_VERIFY (flags > -1);
TEST_COMPARE (flags & FD_CLOEXEC, FD_CLOEXEC);
}
TEST_VERIFY (fcntl (maximum_fd, F_GETFL) > -1);
/* Close the last one. */
TEST_COMPARE (close_range (maximum_fd, maximum_fd, CLOSE_RANGE_CLOEXEC), 0);
{
int flags = fcntl (maximum_fd, F_GETFD);
TEST_VERIFY (flags > -1);
TEST_COMPARE (flags & FD_CLOEXEC, FD_CLOEXEC);
}
}
static int
do_test (void)
{
close_range_test_max_upper_limit ();
close_range_test ();
#ifdef __linux__
close_range_test_subprocess ();
#endif
#ifdef CLOSE_RANGE_UNSHARE
close_range_unshare_test ();
#endif
close_range_cloexec_test ();
return 0;
}
#include <support/test-driver.c>