* [COMMITTED 2.34 1/2] support: Add support_open_dev_null_range
@ 2021-09-21 10:25 Michael Hudson-Doyle
2021-09-21 10:25 ` [COMMITTED 2.34 2/2] Use support_open_dev_null_range io/tst-closefrom, misc/tst-close_range, and posix/tst-spawn5 (BZ #28260) Michael Hudson-Doyle
0 siblings, 1 reply; 2+ messages in thread
From: Michael Hudson-Doyle @ 2021-09-21 10:25 UTC (permalink / raw)
To: libc-stable
From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
It returns a range of file descriptor referring to the '/dev/null'
pathname. The function takes care of restarting the open range
if a file descriptor is found within the specified range and
also increases RLIMIT_NOFILE if required.
Checked on x86_64-linux-gnu.
(cherry picked from commit e814f4b04ee413a7bb3dfa43e74c8fb4abf58359)
---
support/Makefile | 2 +
support/support-open-dev-null-range.c | 134 +++++++++++++++++++
support/support.h | 8 ++
support/tst-support-open-dev-null-range.c | 155 ++++++++++++++++++++++
4 files changed, 299 insertions(+)
create mode 100644 support/support-open-dev-null-range.c
create mode 100644 support/tst-support-open-dev-null-range.c
diff --git a/support/Makefile b/support/Makefile
index ef2b1a980a..2a0731796f 100644
--- a/support/Makefile
+++ b/support/Makefile
@@ -66,6 +66,7 @@ libsupport-routines = \
support_path_support_time64 \
support_process_state \
support_ptrace \
+ support-open-dev-null-range \
support_openpty \
support_paths \
support_quote_blob \
@@ -265,6 +266,7 @@ tests = \
tst-support_capture_subprocess \
tst-support_descriptors \
tst-support_format_dns_packet \
+ tst-support-open-dev-null-range \
tst-support-process_state \
tst-support_quote_blob \
tst-support_quote_string \
diff --git a/support/support-open-dev-null-range.c b/support/support-open-dev-null-range.c
new file mode 100644
index 0000000000..80d9dba504
--- /dev/null
+++ b/support/support-open-dev-null-range.c
@@ -0,0 +1,134 @@
+/* Return a range of open file descriptors.
+ Copyright (C) 2021 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 <errno.h>
+#include <fcntl.h>
+#include <support/support.h>
+#include <support/check.h>
+#include <support/xunistd.h>
+#include <stdlib.h>
+#include <sys/resource.h>
+
+static void
+increase_nofile (void)
+{
+ struct rlimit rl;
+ if (getrlimit (RLIMIT_NOFILE, &rl) == -1)
+ FAIL_EXIT1 ("getrlimit (RLIMIT_NOFILE): %m");
+
+ rl.rlim_cur += 128;
+
+ if (setrlimit (RLIMIT_NOFILE, &rl) == 1)
+ FAIL_EXIT1 ("setrlimit (RLIMIT_NOFILE): %m");
+}
+
+static int
+open_dev_null (int flags, mode_t mode)
+{
+ int fd = open64 ("/dev/null", flags, mode);
+ if (fd > 0)
+ return fd;
+
+ if (fd < 0 && errno != EMFILE)
+ FAIL_EXIT1 ("open64 (\"/dev/null\", 0x%x, 0%o): %m", flags, mode);
+
+ increase_nofile ();
+
+ return xopen ("/dev/null", flags, mode);
+}
+
+struct range
+{
+ int lowfd;
+ size_t len;
+};
+
+struct range_list
+{
+ size_t total;
+ size_t used;
+ struct range *ranges;
+};
+
+static void
+range_init (struct range_list *r)
+{
+ r->total = 8;
+ r->used = 0;
+ r->ranges = xmalloc (r->total * sizeof (struct range));
+}
+
+static void
+range_add (struct range_list *r, int lowfd, size_t len)
+{
+ if (r->used == r->total)
+ {
+ r->total *= 2;
+ r->ranges = xrealloc (r->ranges, r->total * sizeof (struct range));
+ }
+ r->ranges[r->used].lowfd = lowfd;
+ r->ranges[r->used].len = len;
+ r->used++;
+}
+
+static void
+range_close (struct range_list *r)
+{
+ for (size_t i = 0; i < r->used; i++)
+ {
+ int minfd = r->ranges[i].lowfd;
+ int maxfd = r->ranges[i].lowfd + r->ranges[i].len;
+ for (int fd = minfd; fd < maxfd; fd++)
+ xclose (fd);
+ }
+ free (r->ranges);
+}
+
+int
+support_open_dev_null_range (int num, int flags, mode_t mode)
+{
+ /* We keep track of the ranges that hit an already opened descriptor, so
+ we close them after we get a working range. */
+ struct range_list rl;
+ range_init (&rl);
+
+ int lowfd = open_dev_null (flags, mode);
+ int prevfd = lowfd;
+ while (true)
+ {
+ int i = 1;
+ for (; i < num; i++)
+ {
+ int fd = open_dev_null (flags, mode);
+ if (fd != lowfd + i)
+ {
+ range_add (&rl, lowfd, prevfd - lowfd + 1);
+
+ prevfd = lowfd = fd;
+ break;
+ }
+ prevfd = fd;
+ }
+ if (i == num)
+ break;
+ }
+
+ range_close (&rl);
+
+ return lowfd;
+}
diff --git a/support/support.h b/support/support.h
index a5978b939a..c219e0d9d1 100644
--- a/support/support.h
+++ b/support/support.h
@@ -197,6 +197,14 @@ struct support_stack support_stack_alloc (size_t size);
/* Deallocate the STACK. */
void support_stack_free (struct support_stack *stack);
+
+/* Create a range of NUM opened '/dev/null' file descriptors using FLAGS and
+ MODE. The function takes care of restarting the open range if a file
+ descriptor is found within the specified range and also increases
+ RLIMIT_NOFILE if required.
+ The returned value is the lowest file descriptor number. */
+int support_open_dev_null_range (int num, int flags, mode_t mode);
+
__END_DECLS
#endif /* SUPPORT_H */
diff --git a/support/tst-support-open-dev-null-range.c b/support/tst-support-open-dev-null-range.c
new file mode 100644
index 0000000000..8e29def1ce
--- /dev/null
+++ b/support/tst-support-open-dev-null-range.c
@@ -0,0 +1,155 @@
+/* Tests for support_open_dev_null_range.
+ Copyright (C) 2021 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 <errno.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <support/check.h>
+#include <support/support.h>
+#include <support/xunistd.h>
+#include <sys/resource.h>
+#include <stdlib.h>
+
+#ifndef PATH_MAX
+# define PATH_MAX 1024
+#endif
+
+#include <stdio.h>
+
+static void
+check_path (int fd)
+{
+ char *proc_fd_path = xasprintf ("/proc/self/fd/%d", fd);
+ char file_path[PATH_MAX];
+ ssize_t file_path_length
+ = readlink (proc_fd_path, file_path, sizeof (file_path));
+ free (proc_fd_path);
+ if (file_path_length < 0)
+ FAIL_EXIT1 ("readlink (%s, %p, %zu)", proc_fd_path, file_path,
+ sizeof (file_path));
+ file_path[file_path_length] = '\0';
+ TEST_COMPARE_STRING (file_path, "/dev/null");
+}
+
+static int
+number_of_opened_files (void)
+{
+ DIR *fds = opendir ("/proc/self/fd");
+ if (fds == NULL)
+ FAIL_EXIT1 ("opendir (\"/proc/self/fd\"): %m");
+
+ int r = 0;
+ while (true)
+ {
+ errno = 0;
+ struct dirent64 *e = readdir64 (fds);
+ if (e == NULL)
+ {
+ if (errno != 0)
+ FAIL_EXIT1 ("readdir: %m");
+ break;
+ }
+
+ if (e->d_name[0] == '.')
+ continue;
+
+ char *endptr;
+ long int fd = strtol (e->d_name, &endptr, 10);
+ if (*endptr != '\0' || fd < 0 || fd > INT_MAX)
+ FAIL_EXIT1 ("readdir: invalid file descriptor name: /proc/self/fd/%s",
+ e->d_name);
+
+ /* Skip the descriptor which is used to enumerate the
+ descriptors. */
+ if (fd == dirfd (fds))
+ continue;
+
+ r = r + 1;
+ }
+
+ closedir (fds);
+
+ return r;
+}
+
+static int
+do_test (void)
+{
+ const int nfds1 = 8;
+ int lowfd = support_open_dev_null_range (nfds1, O_RDONLY, 0600);
+ for (int i = 0; i < nfds1; i++)
+ {
+ TEST_VERIFY (fcntl (lowfd + i, F_GETFL) > -1);
+ check_path (lowfd + i);
+ }
+
+ /* create some gaps. */
+ xclose (lowfd + 1);
+ xclose (lowfd + 5);
+ xclose (lowfd + 6);
+
+ const int nfds2 = 16;
+ int lowfd2 = support_open_dev_null_range (nfds2, O_RDONLY, 0600);
+ for (int i = 0; i < nfds2; i++)
+ {
+ TEST_VERIFY (fcntl (lowfd2 + i, F_GETFL) > -1);
+ check_path (lowfd2 + i);
+ }
+
+ /* Decrease the maximum number of files. */
+ {
+ struct rlimit rl;
+ if (getrlimit (RLIMIT_NOFILE, &rl) == -1)
+ FAIL_EXIT1 ("getrlimit (RLIMIT_NOFILE): %m");
+
+ rl.rlim_cur = number_of_opened_files ();
+
+ if (setrlimit (RLIMIT_NOFILE, &rl) == 1)
+ FAIL_EXIT1 ("setrlimit (RLIMIT_NOFILE): %m");
+ }
+
+ const int nfds3 = 16;
+ int lowfd3 = support_open_dev_null_range (nfds3, O_RDONLY, 0600);
+ for (int i = 0; i < nfds3; i++)
+ {
+ TEST_VERIFY (fcntl (lowfd3 + i, F_GETFL) > -1);
+ check_path (lowfd3 + i);
+ }
+
+ /* create a lot of gaps to trigger the range extension. */
+ xclose (lowfd3 + 1);
+ xclose (lowfd3 + 3);
+ xclose (lowfd3 + 5);
+ xclose (lowfd3 + 7);
+ xclose (lowfd3 + 9);
+ xclose (lowfd3 + 11);
+ xclose (lowfd3 + 13);
+
+ const int nfds4 = 16;
+ int lowfd4 = support_open_dev_null_range (nfds4, O_RDONLY, 0600);
+ for (int i = 0; i < nfds4; i++)
+ {
+ TEST_VERIFY (fcntl (lowfd4 + i, F_GETFL) > -1);
+ check_path (lowfd4 + i);
+ }
+
+ return 0;
+}
+
+#include <support/test-driver.c>
--
2.30.2
^ permalink raw reply [flat|nested] 2+ messages in thread
* [COMMITTED 2.34 2/2] Use support_open_dev_null_range io/tst-closefrom, misc/tst-close_range, and posix/tst-spawn5 (BZ #28260)
2021-09-21 10:25 [COMMITTED 2.34 1/2] support: Add support_open_dev_null_range Michael Hudson-Doyle
@ 2021-09-21 10:25 ` Michael Hudson-Doyle
0 siblings, 0 replies; 2+ messages in thread
From: Michael Hudson-Doyle @ 2021-09-21 10:25 UTC (permalink / raw)
To: libc-stable
From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
It ensures a continuous range of file descriptor and avoid hitting
the RLIMIT_NOFILE.
Checked on x86_64-linux-gnu.
(cherry picked from commit 6b20880b22d1d0fce7e9f506baa6fe2d5c7fcfdc)
---
io/tst-closefrom.c | 21 +++++----------
posix/tst-spawn5.c | 13 +---------
sysdeps/unix/sysv/linux/tst-close_range.c | 31 ++++++++---------------
3 files changed, 17 insertions(+), 48 deletions(-)
diff --git a/io/tst-closefrom.c b/io/tst-closefrom.c
index d4c187073c..395ec0d894 100644
--- a/io/tst-closefrom.c
+++ b/io/tst-closefrom.c
@@ -24,31 +24,22 @@
#include <support/check.h>
#include <support/descriptors.h>
#include <support/xunistd.h>
+#include <support/support.h>
#include <array_length.h>
#define NFDS 100
-static int
-open_multiple_temp_files (void)
-{
- /* Check if the temporary file descriptor has no no gaps. */
- int lowfd = xopen ("/dev/null", O_RDONLY, 0600);
- for (int i = 1; i <= NFDS; i++)
- TEST_COMPARE (xopen ("/dev/null", O_RDONLY, 0600), lowfd + i);
- return lowfd;
-}
-
static int
closefrom_test (void)
{
struct support_descriptors *descrs = support_descriptors_list ();
- int lowfd = open_multiple_temp_files ();
+ int lowfd = support_open_dev_null_range (NFDS, O_RDONLY, 0600);
- const int maximum_fd = lowfd + NFDS;
+ const int maximum_fd = lowfd + NFDS - 1;
const int half_fd = lowfd + NFDS / 2;
- const int gap = maximum_fd / 4;
+ const int gap = lowfd + NFDS / 4;
/* Close half of the descriptors and check result. */
closefrom (half_fd);
@@ -58,7 +49,7 @@ closefrom_test (void)
TEST_COMPARE (fcntl (i, F_GETFL), -1);
TEST_COMPARE (errno, EBADF);
}
- for (int i = 0; i < half_fd; i++)
+ for (int i = lowfd; i < half_fd; i++)
TEST_VERIFY (fcntl (i, F_GETFL) > -1);
/* Create some gaps, close up to a threshold, and check result. */
@@ -74,7 +65,7 @@ closefrom_test (void)
TEST_COMPARE (fcntl (i, F_GETFL), -1);
TEST_COMPARE (errno, EBADF);
}
- for (int i = 0; i < gap; i++)
+ for (int i = lowfd; i < gap; i++)
TEST_VERIFY (fcntl (i, F_GETFL) > -1);
/* Close the remmaining but the last one. */
diff --git a/posix/tst-spawn5.c b/posix/tst-spawn5.c
index ac66738004..a95199af6b 100644
--- a/posix/tst-spawn5.c
+++ b/posix/tst-spawn5.c
@@ -47,17 +47,6 @@ static int initial_argv_count;
#define NFDS 100
-static int
-open_multiple_temp_files (void)
-{
- /* Check if the temporary file descriptor has no no gaps. */
- int lowfd = xopen ("/dev/null", O_RDONLY, 0600);
- for (int i = 1; i <= NFDS; i++)
- TEST_COMPARE (xopen ("/dev/null", O_RDONLY, 0600),
- lowfd + i);
- return lowfd;
-}
-
static int
parse_fd (const char *str)
{
@@ -185,7 +174,7 @@ spawn_closefrom_test (posix_spawn_file_actions_t *fa, int lowfd, int highfd,
static void
do_test_closefrom (void)
{
- int lowfd = open_multiple_temp_files ();
+ int lowfd = support_open_dev_null_range (NFDS, O_RDONLY, 0600);
const int half_fd = lowfd + NFDS / 2;
/* Close half of the descriptors and check result. */
diff --git a/sysdeps/unix/sysv/linux/tst-close_range.c b/sysdeps/unix/sysv/linux/tst-close_range.c
index dccb6189c5..f5069d1b8a 100644
--- a/sysdeps/unix/sysv/linux/tst-close_range.c
+++ b/sysdeps/unix/sysv/linux/tst-close_range.c
@@ -36,23 +36,12 @@
#define NFDS 100
-static int
-open_multiple_temp_files (void)
-{
- /* Check if the temporary file descriptor has no no gaps. */
- int lowfd = xopen ("/dev/null", O_RDONLY, 0600);
- for (int i = 1; i <= NFDS; i++)
- TEST_COMPARE (xopen ("/dev/null", O_RDONLY, 0600),
- lowfd + i);
- return lowfd;
-}
-
static void
close_range_test_max_upper_limit (void)
{
struct support_descriptors *descrs = support_descriptors_list ();
- int lowfd = open_multiple_temp_files ();
+ int lowfd = support_open_dev_null_range (NFDS, O_RDONLY, 0600);
{
int r = close_range (lowfd, ~0U, 0);
@@ -68,7 +57,7 @@ close_range_test_max_upper_limit (void)
static void
close_range_test_common (int lowfd, unsigned int flags)
{
- const int maximum_fd = lowfd + NFDS;
+ const int maximum_fd = lowfd + NFDS - 1;
const int half_fd = lowfd + NFDS / 2;
const int gap_1 = maximum_fd - 8;
@@ -121,7 +110,7 @@ close_range_test (void)
struct support_descriptors *descrs = support_descriptors_list ();
/* Check if the temporary file descriptor has no no gaps. */
- int lowfd = open_multiple_temp_files ();
+ int lowfd = support_open_dev_null_range (NFDS, O_RDONLY, 0600);
close_range_test_common (lowfd, 0);
@@ -146,7 +135,7 @@ close_range_test_subprocess (void)
struct support_descriptors *descrs = support_descriptors_list ();
/* Check if the temporary file descriptor has no no gaps. */
- int lowfd = open_multiple_temp_files ();
+ int lowfd = support_open_dev_null_range (NFDS, O_RDONLY, 0600);
struct support_stack stack = support_stack_alloc (4096);
@@ -184,7 +173,7 @@ close_range_unshare_test (void)
struct support_descriptors *descrs1 = support_descriptors_list ();
/* Check if the temporary file descriptor has no no gaps. */
- int lowfd = open_multiple_temp_files ();
+ int lowfd = support_open_dev_null_range (NFDS, O_RDONLY, 0600);
struct support_descriptors *descrs2 = support_descriptors_list ();
@@ -200,7 +189,7 @@ close_range_unshare_test (void)
support_stack_free (&stack);
- for (int i = 0; i < NFDS; i++)
+ for (int i = lowfd; i < lowfd + NFDS; i++)
TEST_VERIFY (fcntl (i, F_GETFL) > -1);
support_descriptors_check (descrs2);
@@ -226,9 +215,9 @@ static void
close_range_cloexec_test (void)
{
/* Check if the temporary file descriptor has no no gaps. */
- const int lowfd = open_multiple_temp_files ();
+ int lowfd = support_open_dev_null_range (NFDS, O_RDONLY, 0600);
- const int maximum_fd = lowfd + NFDS;
+ const int maximum_fd = lowfd + NFDS - 1;
const int half_fd = lowfd + NFDS / 2;
const int gap_1 = maximum_fd - 8;
@@ -251,13 +240,13 @@ close_range_cloexec_test (void)
/* 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 (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))
+ if (is_in_array (gap_close, array_length (gap_close), i - lowfd))
TEST_COMPARE (flags, -1);
else
{
--
2.30.2
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2021-09-21 10:25 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-09-21 10:25 [COMMITTED 2.34 1/2] support: Add support_open_dev_null_range Michael Hudson-Doyle
2021-09-21 10:25 ` [COMMITTED 2.34 2/2] Use support_open_dev_null_range io/tst-closefrom, misc/tst-close_range, and posix/tst-spawn5 (BZ #28260) Michael Hudson-Doyle
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).