From f2c996597d7441c1b9b390216c693ecfde3a8588 Mon Sep 17 00:00:00 2001 From: Sergey Bugaev Date: Sat, 6 Nov 2021 18:35:24 +0300 Subject: hurd: Implement close_range and closefrom The close_range () function implements the same API as the Linux and FreeBSD syscalls. It operates atomically and reliably. The specified upper bound is clamped to the actual size of the file descriptor table; it is expected that the most common use case is with last = UINT_MAX. Like in the Linux syscall, it is also possible to pass the CLOSE_RANGE_CLOEXEC flag to mark the file descriptors in the range cloexec instead of acually closing them. Also, add a Hurd version of the closefrom () function. Since unlike on Linux, close_range () cannot fail due to being unuspported by the running kernel, a fallback implementation is never necessary. Signed-off-by: Sergey Bugaev Message-Id: <20211106153524.82700-1-bugaevc@gmail.com> --- sysdeps/mach/hurd/Makefile | 2 +- sysdeps/mach/hurd/Versions | 3 ++ sysdeps/mach/hurd/bits/unistd_ext.h | 34 +++++++++++++++++++ sysdeps/mach/hurd/close_range.c | 67 +++++++++++++++++++++++++++++++++++++ sysdeps/mach/hurd/closefrom.c | 29 ++++++++++++++++ sysdeps/mach/hurd/i386/libc.abilist | 1 + 6 files changed, 135 insertions(+), 1 deletion(-) create mode 100644 sysdeps/mach/hurd/bits/unistd_ext.h create mode 100644 sysdeps/mach/hurd/close_range.c create mode 100644 sysdeps/mach/hurd/closefrom.c (limited to 'sysdeps/mach/hurd') diff --git a/sysdeps/mach/hurd/Makefile b/sysdeps/mach/hurd/Makefile index 17bb643c18..9acbe80f26 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 \ +sysdep_routines += f_setlk close_nocancel close_nocancel_nostatus close_range \ fcntl_nocancel open_nocancel openat_nocancel read_nocancel \ pread64_nocancel write_nocancel pwrite64_nocancel \ wait4_nocancel \ diff --git a/sysdeps/mach/hurd/Versions b/sysdeps/mach/hurd/Versions index 89dabd0485..d75e674bb6 100644 --- a/sysdeps/mach/hurd/Versions +++ b/sysdeps/mach/hurd/Versions @@ -10,6 +10,9 @@ libc { GLIBC_2.32 { mremap; } + GLIBC_2.35 { + close_range; + } GLIBC_PRIVATE { # Functions shared with the dynamic linker __access; __access_noerrno; __libc_read; __libc_write; __libc_lseek64; diff --git a/sysdeps/mach/hurd/bits/unistd_ext.h b/sysdeps/mach/hurd/bits/unistd_ext.h new file mode 100644 index 0000000000..288f504a3c --- /dev/null +++ b/sysdeps/mach/hurd/bits/unistd_ext.h @@ -0,0 +1,34 @@ +/* System-specific extensions of , Hurd version. + Copyright (C) 2019-2021 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 + . */ + +#ifndef _UNISTD_H +# error "Never include directly; use instead." +#endif + +#ifdef __USE_GNU + +/* 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/close_range.c b/sysdeps/mach/hurd/close_range.c new file mode 100644 index 0000000000..d6a2eab086 --- /dev/null +++ b/sysdeps/mach/hurd/close_range.c @@ -0,0 +1,67 @@ +/* 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 + . */ + +#include +#include +#include + +/* 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. */ +int +__close_range (unsigned int first, unsigned int last, + int flags) +{ + int i; + + if (first > last) + return __hurd_fail (EINVAL); + if (flags & ~CLOSE_RANGE_CLOEXEC) + return __hurd_fail (EINVAL); + + HURD_CRITICAL_BEGIN; + __mutex_lock (&_hurd_dtable_lock); + + for (i = first; i <= last && i < _hurd_dtablesize; i++) + { + struct hurd_fd *fd = _hurd_dtable[i]; + + if (fd == NULL || fd->port.port == MACH_PORT_NULL) + continue; + + __spin_lock (&fd->port.lock); + + if (flags & CLOSE_RANGE_CLOEXEC) + fd->flags |= FD_CLOEXEC; + else + { + _hurd_port_set (&fd->ctty, MACH_PORT_NULL); + _hurd_port_locked_set (&fd->port, MACH_PORT_NULL); + } + + __spin_unlock (&fd->port.lock); + } + + __mutex_unlock (&_hurd_dtable_lock); + HURD_CRITICAL_END; + + return 0; +} + +libc_hidden_def (__close_range) +strong_alias (__close_range, __libc_close_range) +weak_alias (__close_range, close_range) diff --git a/sysdeps/mach/hurd/closefrom.c b/sysdeps/mach/hurd/closefrom.c new file mode 100644 index 0000000000..5d667cf6c4 --- /dev/null +++ b/sysdeps/mach/hurd/closefrom.c @@ -0,0 +1,29 @@ +/* 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 + . */ + +#include +#include + +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/i386/libc.abilist b/sysdeps/mach/hurd/i386/libc.abilist index e849d6fa35..d8375b1073 100644 --- a/sysdeps/mach/hurd/i386/libc.abilist +++ b/sysdeps/mach/hurd/i386/libc.abilist @@ -2286,6 +2286,7 @@ GLIBC_2.34 shm_open F GLIBC_2.34 shm_unlink F GLIBC_2.34 timespec_getres F GLIBC_2.35 __memcmpeq F +GLIBC_2.35 close_range F GLIBC_2.4 __confstr_chk F GLIBC_2.4 __fgets_chk F GLIBC_2.4 __fgets_unlocked_chk F -- cgit 1.4.1