glibc/io/fcntl.h
Adhemerval Zanella 06ab719d30 Fix Linux fcntl OFD locks for non-LFS architectures (BZ#20251)
This patch fixes the OFD ("file private") locks for architectures that
support non-LFS flock definition (__USE_FILE_OFFSET64 not defined). The
issue in this case is both F_OFD_{GETLK,SETLK,SETLKW} and
F_{SET,GET}L{W}K64 expects a flock64 argument and when using old
F_OFD_* flags with a non LFS flock argument the kernel might interpret
the underlying data wrongly.  Kernel idea originally was to avoid using
such flags in non-LFS syscall, but since GLIBC uses fcntl with LFS
semantic as default it is possible to provide the functionality and
avoid the bogus struct kernel passing by adjusting the struct manually
for the required flags.

The idea follows other LFS interfaces that provide two symbols:

  1. A new LFS fcntl64 is added on default ABI with the usual macros to
     select it for FILE_OFFSET_BITS=64.

  2. The Linux non-LFS fcntl use a stack allocated struct flock64 for
     F_OFD_{GETLK,SETLK,SETLKW} copy the results on the user provided
     struct.

  3. Keep a compat symbol with old broken semantic for architectures
     that do not define __OFF_T_MATCHES_OFF64_T.

So for architectures which defines __USE_FILE_OFFSET64, fcntl64 will
aliased to fcntl and no adjustment would be required.  So to actually
use F_OFD_* with LFS support the source must be built with LFS support
(_FILE_OFFSET_BITS=64).

Also F_OFD_SETLKW command is handled a cancellation point, as for
F_SETLKW{64}.

Checked on x86_64-linux-gnu and i686-linux-gnu.

	[BZ #20251]
	* NEWS: Mention fcntl64 addition.
	* csu/check_fds.c: Replace __fcntl_nocancel by __fcntl64_nocancel.
	* login/utmp_file.c: Likewise.
	* sysdeps/posix/fdopendir.c: Likewise.
	* sysdeps/posix/opendir.c: Likewise.
	* sysdeps/unix/pt-fcntl.c: Likewise.
	* include/fcntl.h (__libc_fcntl64, __fcntl64,
	__fcntl64_nocancel_adjusted): New prototype.
	(__fcntl_nocancel_adjusted): Remove prototype.
	* io/Makefile (routines): Add fcntl64.
	(CFLAGS-fcntl64.c): New rule.
	* io/Versions [GLIBC_2.28] (fcntl64): New symbol.
	[GLIBC_PRIVATE] (__libc_fcntl): Rename to __libc_fcntl64.
	* io/fcntl.h (fcntl64): Add prototype and redirect if
	__USE_FILE_OFFSET64 is defined.
	* io/fcntl64.c: New file.
	* manual/llio.text: Add a note for which commands fcntl acts a
	cancellation point.
	* nptl/Makefile (CFLAGS-fcntl64.c): New rule.
	* sysdeps/mach/hurd/fcntl.c: Alias fcntl to fcntl64 symbols.
	* sysdeps/mach/hurd/i386/libc.abilist [GLIBC_2.28] (fcntl, fcntl64):
	New symbols.
	* sysdeps/unix/sysv/linux/fcntl.c (__libc_fcntl): Fix F_GETLK64,
	F_OFD_GETLK, F_SETLK64, F_SETLKW64, F_OFD_SETLK, and F_OFD_SETLKW for
	non-LFS case.
	* sysdeps/unix/sysv/linux/fcntl64.c: New file.
	* sysdeps/unix/sysv/linux/fcntl_nocancel.c (__fcntl_nocancel): Rename
	to __fcntl64_nocancel.
	(__fcntl_nocancel_adjusted): Rename to __fcntl64_nocancel_adjusted.
	* sysdeps/unix/sysv/linux/not-cancel.h (__fcntl_nocancel): Rename
	to __fcntl64_nocancel.
	* sysdeps/unix/sysv/linux/tst-ofdlocks.c: New file.
	* sysdeps/unix/sysv/linux/tst-ofdlocks-compat.c: Likewise.
	* sysdeps/unix/sysv/linux/Makefile (tests): Add tst-ofdlocks.
	(tests-internal): Add tst-ofdlocks-compat.
	* sysdeps/unix/sysv/linux/aarch64/libc.abilist [GLIBC_2.28]
	(fcntl64): New symbol.
	* sysdeps/unix/sysv/linux/alpha/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/ia64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist: Likewise.
	* sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/arm/libc.abilist [GLIBC_2.28] (fcntl,
	fcntl64): Likewise.
	* sysdeps/unix/sysv/linux/hppa/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/i386/libc.abilis: Likewise.
	* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/microblaze/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/nios2/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sh/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist: Likewise.
2018-06-26 13:22:53 -03:00

330 lines
11 KiB
C

/* Copyright (C) 1991-2018 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
<http://www.gnu.org/licenses/>. */
/*
* POSIX Standard: 6.5 File Control Operations <fcntl.h>
*/
#ifndef _FCNTL_H
#define _FCNTL_H 1
#include <features.h>
/* This must be early so <bits/fcntl.h> can define types winningly. */
__BEGIN_DECLS
/* Get __mode_t, __dev_t and __off_t .*/
#include <bits/types.h>
/* Get the definitions of O_*, F_*, FD_*: all the
numbers and flag bits for `open', `fcntl', et al. */
#include <bits/fcntl.h>
/* Detect if open needs mode as a third argument (or for openat as a fourth
argument). */
#ifdef __O_TMPFILE
# define __OPEN_NEEDS_MODE(oflag) \
(((oflag) & O_CREAT) != 0 || ((oflag) & __O_TMPFILE) == __O_TMPFILE)
#else
# define __OPEN_NEEDS_MODE(oflag) (((oflag) & O_CREAT) != 0)
#endif
/* POSIX.1-2001 specifies that these types are defined by <fcntl.h>.
Earlier POSIX standards permitted any type ending in `_t' to be defined
by any POSIX header, so we don't conditionalize the definitions here. */
#ifndef __mode_t_defined
typedef __mode_t mode_t;
# define __mode_t_defined
#endif
#ifndef __off_t_defined
# ifndef __USE_FILE_OFFSET64
typedef __off_t off_t;
# else
typedef __off64_t off_t;
# endif
# define __off_t_defined
#endif
#if defined __USE_LARGEFILE64 && !defined __off64_t_defined
typedef __off64_t off64_t;
# define __off64_t_defined
#endif
#ifndef __pid_t_defined
typedef __pid_t pid_t;
# define __pid_t_defined
#endif
/* For XPG all symbols from <sys/stat.h> should also be available. */
#ifdef __USE_XOPEN2K8
# include <bits/types/struct_timespec.h>
#endif
#if defined __USE_XOPEN || defined __USE_XOPEN2K8
# include <bits/stat.h>
# define S_IFMT __S_IFMT
# define S_IFDIR __S_IFDIR
# define S_IFCHR __S_IFCHR
# define S_IFBLK __S_IFBLK
# define S_IFREG __S_IFREG
# ifdef __S_IFIFO
# define S_IFIFO __S_IFIFO
# endif
# ifdef __S_IFLNK
# define S_IFLNK __S_IFLNK
# endif
# if (defined __USE_UNIX98 || defined __USE_XOPEN2K8) && defined __S_IFSOCK
# define S_IFSOCK __S_IFSOCK
# endif
/* Protection bits. */
# define S_ISUID __S_ISUID /* Set user ID on execution. */
# define S_ISGID __S_ISGID /* Set group ID on execution. */
# if defined __USE_MISC || defined __USE_XOPEN
/* Save swapped text after use (sticky bit). This is pretty well obsolete. */
# define S_ISVTX __S_ISVTX
# endif
# define S_IRUSR __S_IREAD /* Read by owner. */
# define S_IWUSR __S_IWRITE /* Write by owner. */
# define S_IXUSR __S_IEXEC /* Execute by owner. */
/* Read, write, and execute by owner. */
# define S_IRWXU (__S_IREAD|__S_IWRITE|__S_IEXEC)
# define S_IRGRP (S_IRUSR >> 3) /* Read by group. */
# define S_IWGRP (S_IWUSR >> 3) /* Write by group. */
# define S_IXGRP (S_IXUSR >> 3) /* Execute by group. */
/* Read, write, and execute by group. */
# define S_IRWXG (S_IRWXU >> 3)
# define S_IROTH (S_IRGRP >> 3) /* Read by others. */
# define S_IWOTH (S_IWGRP >> 3) /* Write by others. */
# define S_IXOTH (S_IXGRP >> 3) /* Execute by others. */
/* Read, write, and execute by others. */
# define S_IRWXO (S_IRWXG >> 3)
#endif
#ifdef __USE_MISC
# ifndef R_OK /* Verbatim from <unistd.h>. Ugh. */
/* Values for the second argument to access.
These may be OR'd together. */
# define R_OK 4 /* Test for read permission. */
# define W_OK 2 /* Test for write permission. */
# define X_OK 1 /* Test for execute permission. */
# define F_OK 0 /* Test for existence. */
# endif
#endif /* Use misc. */
/* XPG wants the following symbols. <stdio.h> has the same definitions. */
#if defined __USE_XOPEN || defined __USE_XOPEN2K8
# define SEEK_SET 0 /* Seek from beginning of file. */
# define SEEK_CUR 1 /* Seek from current position. */
# define SEEK_END 2 /* Seek from end of file. */
#endif /* XPG */
/* The constants AT_REMOVEDIR and AT_EACCESS have the same value. AT_EACCESS
is meaningful only to faccessat, while AT_REMOVEDIR is meaningful only to
unlinkat. The two functions do completely different things and therefore,
the flags can be allowed to overlap. For example, passing AT_REMOVEDIR to
faccessat would be undefined behavior and thus treating it equivalent to
AT_EACCESS is valid undefined behavior. */
#ifdef __USE_ATFILE
# define AT_FDCWD -100 /* Special value used to indicate
the *at functions should use the
current working directory. */
# define AT_SYMLINK_NOFOLLOW 0x100 /* Do not follow symbolic links. */
# define AT_REMOVEDIR 0x200 /* Remove directory instead of
unlinking file. */
# define AT_SYMLINK_FOLLOW 0x400 /* Follow symbolic links. */
# ifdef __USE_GNU
# define AT_NO_AUTOMOUNT 0x800 /* Suppress terminal automount
traversal. */
# define AT_EMPTY_PATH 0x1000 /* Allow empty relative pathname. */
# endif
# define AT_EACCESS 0x200 /* Test access permitted for
effective IDs, not real IDs. */
#endif
/* Do the file control operation described by CMD on FD.
The remaining arguments are interpreted depending on CMD.
This function is a cancellation point and therefore not marked with
__THROW. */
#ifndef __USE_FILE_OFFSET64
extern int fcntl (int __fd, int __cmd, ...);
#else
# ifdef __REDIRECT
extern int __REDIRECT (fcntl, (int __fd, int __cmd, ...), fcntl64);
# else
# define fcntl fcntl64
# endif
#endif
#ifdef __USE_LARGEFILE64
extern int fcntl64 (int __fd, int __cmd, ...);
#endif
/* Open FILE and return a new file descriptor for it, or -1 on error.
OFLAG determines the type of access used. If O_CREAT or O_TMPFILE is set
in OFLAG, the third argument is taken as a `mode_t', the mode of the
created file.
This function is a cancellation point and therefore not marked with
__THROW. */
#ifndef __USE_FILE_OFFSET64
extern int open (const char *__file, int __oflag, ...) __nonnull ((1));
#else
# ifdef __REDIRECT
extern int __REDIRECT (open, (const char *__file, int __oflag, ...), open64)
__nonnull ((1));
# else
# define open open64
# endif
#endif
#ifdef __USE_LARGEFILE64
extern int open64 (const char *__file, int __oflag, ...) __nonnull ((1));
#endif
#ifdef __USE_ATFILE
/* Similar to `open' but a relative path name is interpreted relative to
the directory for which FD is a descriptor.
NOTE: some other `openat' implementation support additional functionality
through this interface, especially using the O_XATTR flag. This is not
yet supported here.
This function is a cancellation point and therefore not marked with
__THROW. */
# ifndef __USE_FILE_OFFSET64
extern int openat (int __fd, const char *__file, int __oflag, ...)
__nonnull ((2));
# else
# ifdef __REDIRECT
extern int __REDIRECT (openat, (int __fd, const char *__file, int __oflag,
...), openat64) __nonnull ((2));
# else
# define openat openat64
# endif
# endif
# ifdef __USE_LARGEFILE64
extern int openat64 (int __fd, const char *__file, int __oflag, ...)
__nonnull ((2));
# endif
#endif
/* Create and open FILE, with mode MODE. This takes an `int' MODE
argument because that is what `mode_t' will be widened to.
This function is a cancellation point and therefore not marked with
__THROW. */
#ifndef __USE_FILE_OFFSET64
extern int creat (const char *__file, mode_t __mode) __nonnull ((1));
#else
# ifdef __REDIRECT
extern int __REDIRECT (creat, (const char *__file, mode_t __mode),
creat64) __nonnull ((1));
# else
# define creat creat64
# endif
#endif
#ifdef __USE_LARGEFILE64
extern int creat64 (const char *__file, mode_t __mode) __nonnull ((1));
#endif
#if !defined F_LOCK && (defined __USE_MISC || (defined __USE_XOPEN_EXTENDED \
&& !defined __USE_POSIX))
/* NOTE: These declarations also appear in <unistd.h>; be sure to keep both
files consistent. Some systems have them there and some here, and some
software depends on the macros being defined without including both. */
/* `lockf' is a simpler interface to the locking facilities of `fcntl'.
LEN is always relative to the current file position.
The CMD argument is one of the following. */
# define F_ULOCK 0 /* Unlock a previously locked region. */
# define F_LOCK 1 /* Lock a region for exclusive use. */
# define F_TLOCK 2 /* Test and lock a region for exclusive use. */
# define F_TEST 3 /* Test a region for other processes locks. */
# ifndef __USE_FILE_OFFSET64
extern int lockf (int __fd, int __cmd, off_t __len);
# else
# ifdef __REDIRECT
extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len), lockf64);
# else
# define lockf lockf64
# endif
# endif
# ifdef __USE_LARGEFILE64
extern int lockf64 (int __fd, int __cmd, off64_t __len);
# endif
#endif
#ifdef __USE_XOPEN2K
/* Advice the system about the expected behaviour of the application with
respect to the file associated with FD. */
# ifndef __USE_FILE_OFFSET64
extern int posix_fadvise (int __fd, off_t __offset, off_t __len,
int __advise) __THROW;
# else
# ifdef __REDIRECT_NTH
extern int __REDIRECT_NTH (posix_fadvise, (int __fd, __off64_t __offset,
__off64_t __len, int __advise),
posix_fadvise64);
# else
# define posix_fadvise posix_fadvise64
# endif
# endif
# ifdef __USE_LARGEFILE64
extern int posix_fadvise64 (int __fd, off64_t __offset, off64_t __len,
int __advise) __THROW;
# endif
/* Reserve storage for the data of the file associated with FD.
This function is a possible cancellation point and therefore not
marked with __THROW. */
# ifndef __USE_FILE_OFFSET64
extern int posix_fallocate (int __fd, off_t __offset, off_t __len);
# else
# ifdef __REDIRECT
extern int __REDIRECT (posix_fallocate, (int __fd, __off64_t __offset,
__off64_t __len),
posix_fallocate64);
# else
# define posix_fallocate posix_fallocate64
# endif
# endif
# ifdef __USE_LARGEFILE64
extern int posix_fallocate64 (int __fd, off64_t __offset, off64_t __len);
# endif
#endif
/* Define some inlines helping to catch common problems. */
#if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function \
&& defined __va_arg_pack_len
# include <bits/fcntl2.h>
#endif
__END_DECLS
#endif /* fcntl.h */