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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2021-03-10 12:26:32 -0300
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2021-07-08 14:08:14 -0300
commit607449506f197cc9514408908f41f22537a47a8c (patch)
tree9d4304b8a8a1ccdef78a305433d845bcd3e08ae6
parent286286283e9bdc7ef894306e2dbcf4c115b97ba2 (diff)
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io: Add closefrom [BZ #10353]
The function closes all open file descriptors greater than or equal to input argument. Negative values are clamped to 0, i.e, it will close all file descriptors. As indicated by the bug report, this is a common symbol provided by different systems (Solaris, OpenBSD, NetBSD, FreeBSD) and, although its has inherent issues with not taking in consideration internal libc file descriptors (such as syslog), this is also a common feature used in multiple projects [1][2][3][4][5]. The Linux fallback implementation iterates over /proc and close all file descriptors sequentially. Although it was raised the questioning whether getdents on /proc/self/fd might return disjointed entries when file descriptor are closed; it does not seems the case on my testing on multiple kernel (v4.18, v5.4, v5.9) and the same strategy is used on different projects [1][2][3][5]. Also, the interface is set a fail-safe meaning that a failure in the fallback results in a process abort. Checked on x86_64-linux-gnu and i686-linux-gnu on kernel 5.11 and 4.15. [1] https://github.com/systemd/systemd/blob/5238e9575906297608ff802a27e2ff9effa3b338/src/basic/fd-util.c#L217 [2] https://github.com/lxc/lxc/blob/ddf4b77e11a4d08f09b7b9cd13e593f8c047edc5/src/lxc/start.c#L236 [3] https://github.com/python/cpython/blob/9e4f2f3a6b8ee995c365e86d976937c141d867f8/Modules/_posixsubprocess.c#L220 [4] https://github.com/rust-lang/rust/blob/5f47c0613ed4eb46fca3633c1297364c09e5e451/src/libstd/sys/unix/process2.rs#L303-L308 [5] https://github.com/openjdk/jdk/blob/master/src/java.base/unix/native/libjava/childproc.c#L82
-rw-r--r--NEWS4
-rw-r--r--include/unistd.h1
-rw-r--r--io/Makefile4
-rw-r--r--io/Versions3
-rw-r--r--io/closefrom.c34
-rw-r--r--io/tst-closefrom.c152
-rw-r--r--manual/llio.texi10
-rw-r--r--posix/unistd.h6
-rw-r--r--sysdeps/mach/hurd/i386/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/Makefile3
-rw-r--r--sysdeps/unix/sysv/linux/aarch64/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/alpha/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/arc/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/arm/be/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/arm/le/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/closefrom.c35
-rw-r--r--sysdeps/unix/sysv/linux/closefrom_fallback.c97
-rw-r--r--sysdeps/unix/sysv/linux/csky/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/hppa/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/i386/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/ia64/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/microblaze/be/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/microblaze/le/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/nios2/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/sh/be/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/sh/le/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/x86_64/64/libc.abilist1
-rw-r--r--sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist1
44 files changed, 380 insertions, 2 deletions
diff --git a/NEWS b/NEWS
index be04b21..e01a245 100644
--- a/NEWS
+++ b/NEWS
@@ -63,6 +63,10 @@ Major new features:
* On Linux, the close_range function has been added. It allows efficiently
closing a range of file descriptors on recent kernels (version 5.9).
+* The function closefrom has been added. It closes all file descriptors
+ greater than given integer. This function is a GNU extension, although it
+ also present in other systems.
+
Deprecated and removed features, and other changes affecting compatibility:
* The function pthread_mutex_consistent_np has been deprecated; programs
diff --git a/include/unistd.h b/include/unistd.h
index 691405a..114a431 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -158,6 +158,7 @@ extern int __brk (void *__addr) attribute_hidden;
extern int __close (int __fd);
libc_hidden_proto (__close)
extern int __libc_close (int __fd);
+extern _Bool __closefrom_fallback (int __lowfd) attribute_hidden;
extern ssize_t __read (int __fd, void *__buf, size_t __nbytes);
libc_hidden_proto (__read)
extern ssize_t __write (int __fd, const void *__buf, size_t __n);
diff --git a/io/Makefile b/io/Makefile
index 1a16990..ebb7d56 100644
--- a/io/Makefile
+++ b/io/Makefile
@@ -56,7 +56,8 @@ routines := \
sendfile sendfile64 copy_file_range \
utimensat futimens file_change_detection \
fts64-time64 \
- ftw64-time64
+ ftw64-time64 \
+ closefrom
others := pwd
test-srcs := ftwtest ftwtest-time64
@@ -77,6 +78,7 @@ tests := test-utime test-stat test-stat2 test-lfs tst-getcwd \
tst-lutimes \
tst-futimens \
tst-utimensat \
+ tst-closefrom \
tests-time64 := \
tst-futimens-time64 \
diff --git a/io/Versions b/io/Versions
index 88caf76..4e19540 100644
--- a/io/Versions
+++ b/io/Versions
@@ -137,6 +137,9 @@ libc {
stat; stat64; fstat; fstat64; lstat; lstat64; fstatat; fstatat64;
mknod; mknodat;
}
+ GLIBC_2.34 {
+ closefrom;
+ }
GLIBC_PRIVATE {
__libc_fcntl64;
__fcntl_nocancel;
diff --git a/io/closefrom.c b/io/closefrom.c
new file mode 100644
index 0000000..01660a7
--- /dev/null
+++ b/io/closefrom.c
@@ -0,0 +1,34 @@
+/* Close a range of 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 <stdio.h>
+#include <unistd.h>
+#include <not-cancel.h>
+
+void
+__closefrom (int lowfd)
+{
+ int maxfd = __getdtablesize ();
+ if (maxfd == -1)
+ __fortify_fail ("closefrom failed to get the file descriptor table size");
+
+ for (int i = 0; i < maxfd; i++)
+ if (i >= lowfd)
+ __close_nocancel_nostatus (i);
+}
+weak_alias (__closefrom, closefrom)
diff --git a/io/tst-closefrom.c b/io/tst-closefrom.c
new file mode 100644
index 0000000..d4c1870
--- /dev/null
+++ b/io/tst-closefrom.c
@@ -0,0 +1,152 @@
+/* Smoke test for the closefrom.
+ 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 <sys/resource.h>
+#include <unistd.h>
+
+#include <support/check.h>
+#include <support/descriptors.h>
+#include <support/xunistd.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 ();
+
+ const int maximum_fd = lowfd + NFDS;
+ const int half_fd = lowfd + NFDS / 2;
+ const int gap = maximum_fd / 4;
+
+ /* Close half of the descriptors and check result. */
+ closefrom (half_fd);
+
+ for (int i = half_fd; i <= maximum_fd; i++)
+ {
+ TEST_COMPARE (fcntl (i, F_GETFL), -1);
+ TEST_COMPARE (errno, EBADF);
+ }
+ for (int i = 0; i < half_fd; i++)
+ TEST_VERIFY (fcntl (i, F_GETFL) > -1);
+
+ /* Create some gaps, close up to a threshold, and check result. */
+ xclose (lowfd + 35);
+ xclose (lowfd + 38);
+ xclose (lowfd + 42);
+ xclose (lowfd + 46);
+
+ /* Close half of the descriptors and check result. */
+ closefrom (gap);
+ for (int i = gap + 1; i < maximum_fd; i++)
+ {
+ TEST_COMPARE (fcntl (i, F_GETFL), -1);
+ TEST_COMPARE (errno, EBADF);
+ }
+ for (int i = 0; i < gap; i++)
+ TEST_VERIFY (fcntl (i, F_GETFL) > -1);
+
+ /* Close the remmaining but the last one. */
+ closefrom (lowfd + 1);
+ for (int i = lowfd + 1; i <= maximum_fd; i++)
+ {
+ TEST_COMPARE (fcntl (i, F_GETFL), -1);
+ TEST_COMPARE (errno, EBADF);
+ }
+ TEST_VERIFY (fcntl (lowfd, F_GETFL) > -1);
+
+ /* Close the last one. */
+ closefrom (lowfd);
+ TEST_COMPARE (fcntl (lowfd, F_GETFL), -1);
+ TEST_COMPARE (errno, EBADF);
+
+ /* Double check by check the /proc. */
+ support_descriptors_check (descrs);
+ support_descriptors_free (descrs);
+
+ return 0;
+}
+
+/* Check if closefrom works even when no new file descriptors can be
+ created. */
+static int
+closefrom_test_file_desc_limit (void)
+{
+ int max_fd = NFDS;
+ {
+ struct rlimit rl;
+ if (getrlimit (RLIMIT_NOFILE, &rl) == -1)
+ FAIL_EXIT1 ("getrlimit (RLIMIT_NOFILE): %m");
+
+ max_fd = (rl.rlim_cur < max_fd ? rl.rlim_cur : max_fd);
+ rl.rlim_cur = max_fd;
+
+ if (setrlimit (RLIMIT_NOFILE, &rl) == 1)
+ FAIL_EXIT1 ("setrlimit (RLIMIT_NOFILE): %m");
+ }
+
+ /* Exhauste the file descriptor limit. */
+ int lowfd = xopen ("/dev/null", O_RDONLY, 0600);
+ for (;;)
+ {
+ int fd = open ("/dev/null", O_RDONLY, 0600);
+ if (fd == -1)
+ {
+ if (errno != EMFILE)
+ FAIL_EXIT1 ("open: %m");
+ break;
+ }
+ TEST_VERIFY_EXIT (fd < max_fd);
+ }
+
+ closefrom (lowfd);
+ for (int i = lowfd; i < NFDS; i++)
+ {
+ TEST_COMPARE (fcntl (i, F_GETFL), -1);
+ TEST_COMPARE (errno, EBADF);
+ }
+
+ return 0;
+}
+
+static int
+do_test (void)
+{
+ closefrom_test ();
+ closefrom_test_file_desc_limit ();
+
+ return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/manual/llio.texi b/manual/llio.texi
index e21a71f..2c59f6b 100644
--- a/manual/llio.texi
+++ b/manual/llio.texi
@@ -334,6 +334,16 @@ The kernel does not implement the required functionality.
@end table
@end deftypefun
+@deftypefun void closefrom (int @var{lowfd})
+@standards{GNU, unistd.h}
+@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{@acsfd{}}}
+
+The function @code{closefrom} closes all file descriptors larger than or equal
+to @var{lowfd} then @var{lowfd}. This function is similar to calling
+@code{close} for all open file descriptors not less than @var{lowfd}.
+
+Already closed file descriptors are ignored.
+@end deftypefun
@node I/O Primitives
@section Input and Output Primitives
diff --git a/posix/unistd.h b/posix/unistd.h
index 217c6c5..3dca657 100644
--- a/posix/unistd.h
+++ b/posix/unistd.h
@@ -357,6 +357,12 @@ extern __off64_t lseek64 (int __fd, __off64_t __offset, int __whence)
__THROW. */
extern int close (int __fd);
+#ifdef __USE_MISC
+/* Close all open file descriptors greater than or equal to LOWFD.
+ Negative LOWFD is clamped to 0. */
+extern void closefrom (int __lowfd) __THROW;
+#endif
+
/* Read NBYTES into BUF from FD. Return the
number read, -1 for errors or 0 for EOF.
diff --git a/sysdeps/mach/hurd/i386/libc.abilist b/sysdeps/mach/hurd/i386/libc.abilist
index fcfe64f..475bf2d 100644
--- a/sysdeps/mach/hurd/i386/libc.abilist
+++ b/sysdeps/mach/hurd/i386/libc.abilist
@@ -2225,6 +2225,7 @@ GLIBC_2.34 _Fork F
GLIBC_2.34 __isnanf128 F
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 _hurd_libc_proc_init F
+GLIBC_2.34 closefrom F
GLIBC_2.34 dladdr F
GLIBC_2.34 dladdr1 F
GLIBC_2.34 dlclose F
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index e308711..d45a16a 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -64,7 +64,8 @@ sysdep_routines += adjtimex clone umount umount2 readahead sysctl \
pselect32 \
xstat fxstat lxstat xstat64 fxstat64 lxstat64 \
fxstatat fxstatat64 \
- xmknod xmknodat convert_scm_timestamps
+ xmknod xmknodat convert_scm_timestamps \
+ closefrom_fallback
CFLAGS-gethostid.c = -fexceptions
CFLAGS-tee.c = -fexceptions -fasynchronous-unwind-tables
diff --git a/sysdeps/unix/sysv/linux/aarch64/libc.abilist b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
index 428b23f..5d5dc5a 100644
--- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
@@ -2408,6 +2408,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist
index d5c24d0..5f863c7 100644
--- a/sysdeps/unix/sysv/linux/alpha/libc.abilist
+++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist
@@ -2507,6 +2507,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/arc/libc.abilist b/sysdeps/unix/sysv/linux/arc/libc.abilist
index 6213e42..e9349e5 100644
--- a/sysdeps/unix/sysv/linux/arc/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arc/libc.abilist
@@ -2167,6 +2167,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/arm/be/libc.abilist b/sysdeps/unix/sysv/linux/arm/be/libc.abilist
index 37c395e..cdfa582 100644
--- a/sysdeps/unix/sysv/linux/arm/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/be/libc.abilist
@@ -301,6 +301,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/arm/le/libc.abilist b/sysdeps/unix/sysv/linux/arm/le/libc.abilist
index dd850ce..83bf346 100644
--- a/sysdeps/unix/sysv/linux/arm/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/le/libc.abilist
@@ -298,6 +298,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/closefrom.c b/sysdeps/unix/sysv/linux/closefrom.c
new file mode 100644
index 0000000..f5d7342
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/closefrom.c
@@ -0,0 +1,35 @@
+/* Close a range of file descriptors. Linux version.
+ 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 <stdio.h>
+#include <sys/param.h>
+#include <unistd.h>
+
+void
+__closefrom (int lowfd)
+{
+ int l = MAX (0, lowfd);
+
+ int r = __close_range (l, ~0U, 0);
+ if (r == 0)
+ return;
+
+ if (!__closefrom_fallback (l))
+ __fortify_fail ("closefrom failed to close a file descriptor");
+}
+weak_alias (__closefrom, closefrom)
diff --git a/sysdeps/unix/sysv/linux/closefrom_fallback.c b/sysdeps/unix/sysv/linux/closefrom_fallback.c
new file mode 100644
index 0000000..61e71d3
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/closefrom_fallback.c
@@ -0,0 +1,97 @@
+/* Close a range of file descriptors. Linux version.
+ 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 <arch-fd_to_filename.h>
+#include <dirent.h>
+#include <not-cancel.h>
+#include <stdbool.h>
+
+/* Fallback code: iterates over /proc/self/fd, closing each file descriptor
+ that fall on the criteria. */
+_Bool
+__closefrom_fallback (int from)
+{
+ bool ret = false;
+
+ int dirfd = __open_nocancel (FD_TO_FILENAME_PREFIX, O_RDONLY | O_DIRECTORY,
+ 0);
+ if (dirfd == -1)
+ {
+ /* The closefrom should work even when process can't open new files. */
+ if (errno == ENOENT)
+ goto err;
+
+ for (int i = from; i < INT_MAX; i++)
+ {
+ int r = __close_nocancel (i);
+ if (r == 0 || (r == -1 && errno != EBADF))
+ break;
+ }
+
+ dirfd = __open_nocancel (FD_TO_FILENAME_PREFIX, O_RDONLY | O_DIRECTORY,
+ 0);
+ if (dirfd == -1)
+ goto err;
+ }
+
+ char buffer[1024];
+ while (true)
+ {
+ ssize_t ret = __getdents64 (dirfd, buffer, sizeof (buffer));
+ if (ret == -1)
+ goto err;
+ else if (ret == 0)
+ break;
+
+ /* If any file descriptor is closed it resets the /proc/self position
+ read again from the start (to obtain any possible kernel update). */
+ bool closed = false;
+ char *begin = buffer, *end = buffer + ret;
+ while (begin != end)
+ {
+ unsigned short int d_reclen;
+ memcpy (&d_reclen, begin + offsetof (struct dirent64, d_reclen),
+ sizeof (d_reclen));
+ const char *dname = begin + offsetof (struct dirent64, d_name);
+ begin += d_reclen;
+
+ if (dname[0] == '.')
+ continue;
+
+ int fd = 0;
+ for (const char *s = dname; (unsigned int) (*s) - '0' < 10; s++)
+ fd = 10 * fd + (*s - '0');
+
+ if (fd == dirfd || fd < from)
+ continue;
+
+ /* We ignore close errors because EBADF, EINTR, and EIO means the
+ descriptor has been released. */
+ __close_nocancel (fd);
+ closed = true;
+ }
+
+ if (closed && __lseek (dirfd, 0, SEEK_SET) < 0)
+ goto err;
+ }
+
+ ret = true;
+err:
+ __close_nocancel (dirfd);
+ return ret;
+}
diff --git a/sysdeps/unix/sysv/linux/csky/libc.abilist b/sysdeps/unix/sysv/linux/csky/libc.abilist
index 48dc96e..705b696 100644
--- a/sysdeps/unix/sysv/linux/csky/libc.abilist
+++ b/sysdeps/unix/sysv/linux/csky/libc.abilist
@@ -2433,6 +2433,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist
index 13772d4..db77e47 100644
--- a/sysdeps/unix/sysv/linux/hppa/libc.abilist
+++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist
@@ -2386,6 +2386,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/i386/libc.abilist b/sysdeps/unix/sysv/linux/i386/libc.abilist
index 6613f4c..126c8f6 100644
--- a/sysdeps/unix/sysv/linux/i386/libc.abilist
+++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
@@ -2570,6 +2570,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/ia64/libc.abilist b/sysdeps/unix/sysv/linux/ia64/libc.abilist
index 06d096d..6ca9645 100644
--- a/sysdeps/unix/sysv/linux/ia64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/ia64/libc.abilist
@@ -2345,6 +2345,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
index dc2466f..0a5d6de 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
@@ -302,6 +302,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
index d425dba..11e4f01 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
@@ -2513,6 +2513,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
index f1fc795..6efe53a 100644
--- a/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
@@ -2484,6 +2484,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
index 7cf1c86..3b1a49c 100644
--- a/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
@@ -2481,6 +2481,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
index 41b7927..6256381 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
@@ -2478,6 +2478,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
index 91f06d23..c812e5c 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
@@ -2476,6 +2476,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
index a4d3e06..43296b2 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
@@ -2484,6 +2484,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
index 3e96b69..12652d6 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
@@ -2396,6 +2396,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/nios2/libc.abilist b/sysdeps/unix/sysv/linux/nios2/libc.abilist
index 3618eaa..676dce5 100644
--- a/sysdeps/unix/sysv/linux/nios2/libc.abilist
+++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist
@@ -2523,6 +2523,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
index 3951054..959418a 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
@@ -2540,6 +2540,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
index 4c2adbd..405b9b9 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
@@ -2573,6 +2573,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
index e9d30b1..e60fe89 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
@@ -2309,6 +2309,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
index 81c1eac..0f86da7 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
@@ -2604,6 +2604,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
index 6fa30b2..e1f3be2 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
@@ -2169,6 +2169,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
index 7c20b71..bf6b44d 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
@@ -2369,6 +2369,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
index fe0c9a2..1437ff7 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
@@ -2538,6 +2538,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
index da52d75..68e49fa 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
@@ -2346,6 +2346,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/sh/be/libc.abilist b/sysdeps/unix/sysv/linux/sh/be/libc.abilist
index 6f022d1..9ec571d 100644
--- a/sysdeps/unix/sysv/linux/sh/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/be/libc.abilist
@@ -2393,6 +2393,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/sh/le/libc.abilist b/sysdeps/unix/sysv/linux/sh/le/libc.abilist
index a4934d8..f1114f1 100644
--- a/sysdeps/unix/sysv/linux/sh/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/le/libc.abilist
@@ -2390,6 +2390,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
index 684e9d7..e63a58e 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
@@ -2533,6 +2533,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
index af10195..25f1526 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
@@ -2368,6 +2368,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
index b5e2710..88a5b0b 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
@@ -2324,6 +2324,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
index ecd0b4e..ff219a8 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
@@ -2423,6 +2423,7 @@ GLIBC_2.34 aio_write F
GLIBC_2.34 aio_write64 F
GLIBC_2.34 call_once F
GLIBC_2.34 close_range F
+GLIBC_2.34 closefrom F
GLIBC_2.34 cnd_broadcast F
GLIBC_2.34 cnd_destroy F
GLIBC_2.34 cnd_init F