bionic/libc/include/fcntl.h
Nick Kralevich a3e230d1fa FORTIFY_SOURCE: Add openat, fix bug
Add fortify_source support for openat(). This change requires that
an argument be supplied when using O_CREAT.

Fix unnecessary call to __open_2. If, at compile time, we know that
"flags" is constant and DOESN'T contain O_CREAT, the call to __open_2
is useless.

Change-Id: Ifcd29c4fb25e25656961d7552d672e161f0cfdbd
2012-07-09 12:30:40 -07:00

118 lines
3.9 KiB
C

/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef _FCNTL_H
#define _FCNTL_H
#include <sys/cdefs.h>
#include <sys/types.h>
#include <linux/fcntl.h>
#include <unistd.h> /* this is not required, but makes client code much happier */
__BEGIN_DECLS
#ifndef O_ASYNC
#define O_ASYNC FASYNC
#endif
#ifndef O_CLOEXEC
#define O_CLOEXEC 02000000
#endif
extern int open(const char* path, int mode, ...);
extern int openat(int fd, const char* path, int mode, ...);
extern int unlinkat(int dirfd, const char *pathname, int flags);
extern int fcntl(int fd, int command, ...);
extern int creat(const char* path, mode_t mode);
#if defined(__BIONIC_FORTIFY_INLINE)
# if !defined(__clang__)
/*
* Clang doesn't have support for __builtin_va_arg_pack()
* and __builtin_va_arg_pack_len()
*
* http://clang.llvm.org/docs/UsersManual.html#c_unimpl_gcc
*/
extern void __creat_error()
__attribute__((__error__ ("called with O_CREAT, but missing mode")));
extern void __too_many_args_error()
__attribute__((__error__ ("too many arguments")));
extern int __open_real(const char *pathname, int flags, ...)
__asm__(__USER_LABEL_PREFIX__ "open");
extern int __open_2(const char *, int);
__BIONIC_FORTIFY_INLINE
int open(const char *pathname, int flags, ...) {
if (__builtin_constant_p(flags)) {
if ((flags & O_CREAT) && __builtin_va_arg_pack_len() == 0) {
__creat_error(); // compile time error
}
}
if (__builtin_va_arg_pack_len() > 1) {
__too_many_args_error(); // compile time error
}
if ((__builtin_va_arg_pack_len() == 0) && !__builtin_constant_p(flags)) {
return __open_2(pathname, flags);
}
return __open_real(pathname, flags, __builtin_va_arg_pack());
}
extern int __openat_2(int, const char *, int);
extern int __openat_real(int dirfd, const char *pathname, int flags, ...)
__asm__(__USER_LABEL_PREFIX__ "openat");
__BIONIC_FORTIFY_INLINE
int openat(int dirfd, const char *pathname, int flags, ...) {
if (__builtin_constant_p(flags)) {
if ((flags & O_CREAT) && __builtin_va_arg_pack_len() == 0) {
__creat_error(); // compile time error
}
}
if (__builtin_va_arg_pack_len() > 1) {
__too_many_args_error(); // compile time error
}
if ((__builtin_va_arg_pack_len() == 0) && !__builtin_constant_p(flags)) {
return __openat_2(dirfd, pathname, flags);
}
return __openat_real(dirfd, pathname, flags, __builtin_va_arg_pack());
}
#endif /* !defined(__clang__) */
#endif /* defined(__BIONIC_FORTIFY_INLINE) */
__END_DECLS
#endif /* _FCNTL_H */