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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2021-11-08 10:20:23 -0300
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2021-11-24 09:09:37 -0300
commit456b3c08b6fe78938af5d12b6869dc8c704696d6 (patch)
treebea5ff2432a7f589afccc126efb5ac8ab3b2c2b9
parente186fc5a31e46f2cbf5ea1a75223b4412907f3d8 (diff)
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io: Refactor close_range and closefrom
Now that Hurd implementis both close_range and closefrom (f2c996597d), we can make close_range() a base ABI, and make the default closefrom() implementation on top of close_range(). The generic closefrom() implementation based on __getdtablesize() is moved to generic close_range(). On Linux it will be overriden by the auto-generation syscall while on Hurd it will be a system specific implementation. The closefrom() now calls close_range() and __closefrom_fallback(). Since on Hurd close_range() does not fail, __closefrom_fallback() is an empty static inline function set by__ASSUME_CLOSE_RANGE. The __ASSUME_CLOSE_RANGE also allows optimize Linux __closefrom_fallback() implementation when --enable-kernel=5.9 or higher is used. Finally the Linux specific tst-close_range.c is moved to io and enabled as default. The Linuxism and CLOSE_RANGE_UNSHARE are guarded so it can be built for Hurd (I have not actually test it). Checked on x86_64-linux-gnu, i686-linux-gnu, and with a i686-gnu build.
-rw-r--r--include/unistd.h10
-rw-r--r--io/Makefile3
-rw-r--r--io/close_range.c (renamed from sysdeps/unix/sysv/linux/closefrom.c)34
-rw-r--r--io/closefrom.c16
-rw-r--r--io/tst-close_range.c (renamed from sysdeps/unix/sysv/linux/tst-close_range.c)8
-rw-r--r--posix/unistd.h10
-rw-r--r--sysdeps/mach/hurd/Makefile2
-rw-r--r--sysdeps/mach/hurd/bits/unistd_ext.h6
-rw-r--r--sysdeps/mach/hurd/closefrom.c29
-rw-r--r--sysdeps/mach/hurd/kernel-features.h2
-rw-r--r--sysdeps/unix/sysv/linux/Makefile1
-rw-r--r--sysdeps/unix/sysv/linux/bits/unistd_ext.h9
-rw-r--r--sysdeps/unix/sysv/linux/closefrom_fallback.c4
-rw-r--r--sysdeps/unix/sysv/linux/kernel-features.h8
-rw-r--r--sysdeps/unix/sysv/linux/syscalls.list2
15 files changed, 76 insertions, 68 deletions
diff --git a/include/unistd.h b/include/unistd.h
index 7849562c42..2bcdd494e1 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -3,6 +3,9 @@
# ifndef _ISOMAC
+# include <stdbool.h>
+# include <kernel-features.h>
+
libc_hidden_proto (_exit, __noreturn__)
# ifndef NO_RTLD_HIDDEN
rtld_hidden_proto (_exit, __noreturn__)
@@ -158,7 +161,14 @@ extern int __brk (void *__addr) attribute_hidden;
extern int __close (int __fd);
libc_hidden_proto (__close)
extern int __libc_close (int __fd);
+# if __ASSUME_CLOSE_RANGE
+static inline _Bool __closefrom_fallback (int __lowfd, _Bool dirfd_fallback)
+{
+ return false;
+}
+# else
extern _Bool __closefrom_fallback (int __lowfd, _Bool) attribute_hidden;
+# endif
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 ecf65aba60..83f6ffdb76 100644
--- a/io/Makefile
+++ b/io/Makefile
@@ -57,7 +57,7 @@ routines := \
utimensat futimens file_change_detection \
fts64-time64 \
ftw64-time64 \
- closefrom
+ closefrom close_range
others := pwd
test-srcs := ftwtest ftwtest-time64
@@ -79,6 +79,7 @@ tests := test-utime test-stat test-stat2 test-lfs tst-getcwd \
tst-futimens \
tst-utimensat \
tst-closefrom \
+ tst-close_range \
tst-ftw-bz28126
tests-time64 := \
diff --git a/sysdeps/unix/sysv/linux/closefrom.c b/io/close_range.c
index 372896b775..26a615d8b9 100644
--- a/sysdeps/unix/sysv/linux/closefrom.c
+++ b/io/close_range.c
@@ -1,4 +1,4 @@
-/* Close a range of file descriptors. Linux version.
+/* Close a range of file descriptors.
Copyright (C) 2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
@@ -16,21 +16,29 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
-#include <stdbool.h>
-#include <stdio.h>
-#include <sys/param.h>
+#include <errno.h>
+#include <not-cancel.h>
#include <unistd.h>
-void
-__closefrom (int lowfd)
+/* Close the file descriptors from FIRST up to LAST, inclusive. */
+int
+__close_range (unsigned int first, unsigned int last,
+ int flags)
{
- int l = MAX (0, lowfd);
+ if (first > last || flags != 0)
+ {
+ __set_errno (EINVAL);
+ return -1;
+ }
- int r = __close_range (l, ~0U, 0);
- if (r == 0)
- return;
+ int maxfd = __getdtablesize ();
+ if (maxfd == -1)
+ return -1;
- if (!__closefrom_fallback (l, true))
- __fortify_fail ("closefrom failed to close a file descriptor");
+ for (int i = first; i <= last && i < maxfd; i++)
+ __close_nocancel_nostatus (i);
+
+ return 0;
}
-weak_alias (__closefrom, closefrom)
+libc_hidden_def (__close_range)
+weak_alias (__close_range, close_range)
diff --git a/io/closefrom.c b/io/closefrom.c
index 01660a7531..e9167687bc 100644
--- a/io/closefrom.c
+++ b/io/closefrom.c
@@ -16,19 +16,21 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
+#include <stdbool.h>
#include <stdio.h>
+#include <sys/param.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");
+ int l = MAX (0, lowfd);
- for (int i = 0; i < maxfd; i++)
- if (i >= lowfd)
- __close_nocancel_nostatus (i);
+ int r = __close_range (l, ~0U, 0);
+ if (r == 0)
+ return ;
+
+ if (!__closefrom_fallback (l, true))
+ __fortify_fail ("closefrom failed to close a file descriptor");
}
weak_alias (__closefrom, closefrom)
diff --git a/sysdeps/unix/sysv/linux/tst-close_range.c b/io/tst-close_range.c
index f5069d1b8a..f05b4ff6ae 100644
--- a/sysdeps/unix/sysv/linux/tst-close_range.c
+++ b/io/tst-close_range.c
@@ -119,6 +119,7 @@ close_range_test (void)
support_descriptors_free (descrs);
}
+#ifdef __linux__
_Noreturn static int
close_range_test_fn (void *arg)
{
@@ -155,8 +156,10 @@ close_range_test_subprocess (void)
support_descriptors_check (descrs);
support_descriptors_free (descrs);
}
+#endif
+#ifdef CLOSE_RANGE_UNSHARE
_Noreturn static int
close_range_unshare_test_fn (void *arg)
{
@@ -200,6 +203,7 @@ close_range_unshare_test (void)
support_descriptors_check (descrs1);
support_descriptors_free (descrs1);
}
+#endif
static bool
is_in_array (int *arr, size_t len, int fd)
@@ -282,8 +286,12 @@ 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;
diff --git a/posix/unistd.h b/posix/unistd.h
index 7a61ff5e86..3c8a7ced6a 100644
--- a/posix/unistd.h
+++ b/posix/unistd.h
@@ -1199,6 +1199,16 @@ int getentropy (void *__buffer, size_t __length) __wur
__attr_access ((__write_only__, 1, 2));
#endif
+#ifdef __USE_GNU
+/* Close all file descriptors in the range FD up to MAX_FD. The flag FLAGS
+ are define by the CLOSE_RANGE prefix. This function behaves like close
+ on the range and gaps where the file descriptor is invalid or errors
+ encountered while closing file descriptors are ignored. Returns 0 on
+ successor or -1 for failure (and sets errno accordingly). */
+extern int close_range (unsigned int __fd, unsigned int __max_fd,
+ int __flags) __THROW;
+#endif
+
/* Define some macros helping to catch buffer overflows. */
#if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function
# include <bits/unistd.h>
diff --git a/sysdeps/mach/hurd/Makefile b/sysdeps/mach/hurd/Makefile
index 9acbe80f26..17bb643c18 100644
--- a/sysdeps/mach/hurd/Makefile
+++ b/sysdeps/mach/hurd/Makefile
@@ -196,7 +196,7 @@ sysdep_routines += cthreads
endif
ifeq (io, $(subdir))
-sysdep_routines += f_setlk close_nocancel close_nocancel_nostatus close_range \
+sysdep_routines += f_setlk close_nocancel close_nocancel_nostatus \
fcntl_nocancel open_nocancel openat_nocancel read_nocancel \
pread64_nocancel write_nocancel pwrite64_nocancel \
wait4_nocancel \
diff --git a/sysdeps/mach/hurd/bits/unistd_ext.h b/sysdeps/mach/hurd/bits/unistd_ext.h
index 288f504a3c..14f85539d5 100644
--- a/sysdeps/mach/hurd/bits/unistd_ext.h
+++ b/sysdeps/mach/hurd/bits/unistd_ext.h
@@ -25,10 +25,4 @@
/* Set the FD_CLOEXEC bit instead of closing the file descriptor. */
#define CLOSE_RANGE_CLOEXEC (1U << 2)
-/* Close the file descriptors from FIRST up to LAST, inclusive.
- If CLOSE_RANGE_CLOEXEC is set in FLAGS, set the FD_CLOEXEC flag
- instead of closing. */
-extern int close_range (unsigned int __first, unsigned int __last,
- int __flags) __THROW;
-
#endif /* __USE_GNU */
diff --git a/sysdeps/mach/hurd/closefrom.c b/sysdeps/mach/hurd/closefrom.c
deleted file mode 100644
index 5d667cf6c4..0000000000
--- a/sysdeps/mach/hurd/closefrom.c
+++ /dev/null
@@ -1,29 +0,0 @@
-/* Close a range of file descriptors. Hurd 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 <unistd.h>
-#include <sys/param.h>
-
-void
-__closefrom (int lowfd)
-{
- int l = MAX (0, lowfd);
-
- (void) __close_range (l, ~0U, 0);
-}
-weak_alias (__closefrom, closefrom)
diff --git a/sysdeps/mach/hurd/kernel-features.h b/sysdeps/mach/hurd/kernel-features.h
index 7d4eaee0a6..5fd37a6d7b 100644
--- a/sysdeps/mach/hurd/kernel-features.h
+++ b/sysdeps/mach/hurd/kernel-features.h
@@ -19,3 +19,5 @@
/* This file can define __ASSUME_* macros checked by certain source files.
Almost none of these are used outside of sysdeps/unix/sysv/linux code.
But those referring to POSIX-level features like O_* flags can be. */
+
+#define __ASSUME_CLOSE_RANGE 1
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 76ad06361c..76042a6019 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -120,7 +120,6 @@ tests += tst-clone tst-clone2 tst-clone3 tst-fanotify tst-personality \
tst-timerfd tst-ppoll \
tst-clock_adjtime tst-adjtimex tst-ntp_adjtime tst-ntp_gettime \
tst-ntp_gettimex tst-sigtimedwait tst-misalign-clone \
- tst-close_range \
tst-prctl \
tst-scm_rights \
# tests
diff --git a/sysdeps/unix/sysv/linux/bits/unistd_ext.h b/sysdeps/unix/sysv/linux/bits/unistd_ext.h
index ae9994403c..8f422e60da 100644
--- a/sysdeps/unix/sysv/linux/bits/unistd_ext.h
+++ b/sysdeps/unix/sysv/linux/bits/unistd_ext.h
@@ -47,13 +47,4 @@ extern __pid_t gettid (void) __THROW;
# define CLOSE_RANGE_CLOEXEC (1U << 2)
#endif
-/* Close all file descriptors in the range FD up to MAX_FD. The flag FLAGS
- are define by the CLOSE_RANGE prefix. This function behaves like close
- on the range, but in a fail-safe where it will either fail and not close
- any file descriptor or close all of them. Gaps where the file descriptor
- is invalid are ignored. Returns 0 on successor or -1 for failure (and
- sets errno accordingly). */
-extern int close_range (unsigned int __fd, unsigned int __max_fd,
- int __flags) __THROW;
-
#endif /* __USE_GNU */
diff --git a/sysdeps/unix/sysv/linux/closefrom_fallback.c b/sysdeps/unix/sysv/linux/closefrom_fallback.c
index f215fd2c09..a377ebc544 100644
--- a/sysdeps/unix/sysv/linux/closefrom_fallback.c
+++ b/sysdeps/unix/sysv/linux/closefrom_fallback.c
@@ -21,6 +21,8 @@
#include <not-cancel.h>
#include <stdbool.h>
+#if !__ASSUME_CLOSE_RANGE
+
/* Fallback code: iterates over /proc/self/fd, closing each file descriptor
that fall on the criteria. If DIRFD_FALLBACK is set, a failure on
/proc/self/fd open will trigger a fallback that tries to close a file
@@ -97,3 +99,5 @@ err:
__close_nocancel (dirfd);
return ret;
}
+
+#endif
diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h
index ffb6af196b..690db275ac 100644
--- a/sysdeps/unix/sysv/linux/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/kernel-features.h
@@ -220,6 +220,14 @@
# define __ASSUME_FACCESSAT2 0
#endif
+/* The close_range system call was introduced across all architectures
+ in Linux 5.9. */
+#if __LINUX_KERNEL_VERSION >= 0x050900
+# define __ASSUME_CLOSE_RANGE 1
+#else
+# define __ASSUME_CLOSE_RANGE 0
+#endif
+
/* The FUTEX_LOCK_PI2 operation was introduced across all architectures in Linux
5.14. */
#if __LINUX_KERNEL_VERSION >= 0x050e00
diff --git a/sysdeps/unix/sysv/linux/syscalls.list b/sysdeps/unix/sysv/linux/syscalls.list
index 29899eb264..c38dbb34a1 100644
--- a/sysdeps/unix/sysv/linux/syscalls.list
+++ b/sysdeps/unix/sysv/linux/syscalls.list
@@ -99,4 +99,4 @@ pkey_alloc EXTRA pkey_alloc i:ii pkey_alloc
pkey_free EXTRA pkey_free i:i pkey_free
gettid EXTRA gettid Ei: __gettid gettid
tgkill EXTRA tgkill i:iii __tgkill tgkill
-close_range EXTRA close_range i:iii __close_range close_range
+close_range - close_range i:iii __close_range close_range