glibc/io/bits/fcntl2.h
Eric Rannaud 65f6f938cd linux: open and openat ignore 'mode' with O_TMPFILE in flags
Both open and openat load their last argument 'mode' lazily, using
va_arg() only if O_CREAT is found in oflag. This is wrong, mode is also
necessary if O_TMPFILE is in oflag.

By chance on x86_64, the problem wasn't evident when using O_TMPFILE
with open, as the 3rd argument of open, even when not loaded with
va_arg, is left untouched in RDX, where the syscall expects it.

However, openat was not so lucky, and O_TMPFILE couldn't be used: mode
is the 4th argument, in RCX, but the syscall expects its 4th argument in
a different register than the glibc wrapper, in R10.

Introduce a macro __OPEN_NEEDS_MODE (oflag) to test if either O_CREAT or
O_TMPFILE is set in oflag.

Tested on Linux x86_64.

	[BZ #17523]
	* io/fcntl.h (__OPEN_NEEDS_MODE): New macro.
	* io/bits/fcntl2.h (open): Use it.
	(openat): Likewise.
	* io/open.c (__libc_open): Likewise.
	* io/open64.c (__libc_open64): Likewise.
	* io/open64_2.c (__open64_2): Likewise.
	* io/open_2.c (__open_2): Likewise.
	* io/openat.c (__openat): Likewise.
	* io/openat64.c (__openat64): Likewise.
	* io/openat64_2.c (__openat64_2): Likewise.
	* io/openat_2.c (__openat_2): Likewise.
	* sysdeps/mach/hurd/open.c (__libc_open): Likewise.
	* sysdeps/mach/hurd/openat.c (__openat): Likewise.
	* sysdeps/posix/open64.c (__libc_open64): Likewise.
	* sysdeps/unix/sysv/linux/dl-openat64.c (openat64): Likewise.
	* sysdeps/unix/sysv/linux/generic/open.c (__libc_open): Likewise.
	(__open_nocancel): Likewise.
	* sysdeps/unix/sysv/linux/generic/open64.c (__libc_open64): Likewise.
	* sysdeps/unix/sysv/linux/open64.c (__libc_open64): Likewise.
	* sysdeps/unix/sysv/linux/openat.c (__OPENAT): Likewise.
2015-02-24 13:19:22 +05:30

173 lines
5.4 KiB
C

/* Checking macros for fcntl functions.
Copyright (C) 2007-2015 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/>. */
#ifndef _FCNTL_H
# error "Never include <bits/fcntl2.h> directly; use <fcntl.h> instead."
#endif
/* Check that calls to open and openat with O_CREAT or O_TMPFILE set have an
appropriate third/fourth parameter. */
#ifndef __USE_FILE_OFFSET64
extern int __open_2 (const char *__path, int __oflag) __nonnull ((1));
extern int __REDIRECT (__open_alias, (const char *__path, int __oflag, ...),
open) __nonnull ((1));
#else
extern int __REDIRECT (__open_2, (const char *__path, int __oflag),
__open64_2) __nonnull ((1));
extern int __REDIRECT (__open_alias, (const char *__path, int __oflag, ...),
open64) __nonnull ((1));
#endif
__errordecl (__open_too_many_args,
"open can be called either with 2 or 3 arguments, not more");
__errordecl (__open_missing_mode,
"open with O_CREAT or O_TMPFILE in second argument needs 3 arguments");
__fortify_function int
open (const char *__path, int __oflag, ...)
{
if (__va_arg_pack_len () > 1)
__open_too_many_args ();
if (__builtin_constant_p (__oflag))
{
if (__OPEN_NEEDS_MODE (__oflag) && __va_arg_pack_len () < 1)
{
__open_missing_mode ();
return __open_2 (__path, __oflag);
}
return __open_alias (__path, __oflag, __va_arg_pack ());
}
if (__va_arg_pack_len () < 1)
return __open_2 (__path, __oflag);
return __open_alias (__path, __oflag, __va_arg_pack ());
}
#ifdef __USE_LARGEFILE64
extern int __open64_2 (const char *__path, int __oflag) __nonnull ((1));
extern int __REDIRECT (__open64_alias, (const char *__path, int __oflag,
...), open64) __nonnull ((1));
__errordecl (__open64_too_many_args,
"open64 can be called either with 2 or 3 arguments, not more");
__errordecl (__open64_missing_mode,
"open64 with O_CREAT or O_TMPFILE in second argument needs 3 arguments");
__fortify_function int
open64 (const char *__path, int __oflag, ...)
{
if (__va_arg_pack_len () > 1)
__open64_too_many_args ();
if (__builtin_constant_p (__oflag))
{
if (__OPEN_NEEDS_MODE (__oflag) && __va_arg_pack_len () < 1)
{
__open64_missing_mode ();
return __open64_2 (__path, __oflag);
}
return __open64_alias (__path, __oflag, __va_arg_pack ());
}
if (__va_arg_pack_len () < 1)
return __open64_2 (__path, __oflag);
return __open64_alias (__path, __oflag, __va_arg_pack ());
}
#endif
#ifdef __USE_ATFILE
# ifndef __USE_FILE_OFFSET64
extern int __openat_2 (int __fd, const char *__path, int __oflag)
__nonnull ((2));
extern int __REDIRECT (__openat_alias, (int __fd, const char *__path,
int __oflag, ...), openat)
__nonnull ((2));
# else
extern int __REDIRECT (__openat_2, (int __fd, const char *__path,
int __oflag), __openat64_2)
__nonnull ((2));
extern int __REDIRECT (__openat_alias, (int __fd, const char *__path,
int __oflag, ...), openat64)
__nonnull ((2));
# endif
__errordecl (__openat_too_many_args,
"openat can be called either with 3 or 4 arguments, not more");
__errordecl (__openat_missing_mode,
"openat with O_CREAT or O_TMPFILE in third argument needs 4 arguments");
__fortify_function int
openat (int __fd, const char *__path, int __oflag, ...)
{
if (__va_arg_pack_len () > 1)
__openat_too_many_args ();
if (__builtin_constant_p (__oflag))
{
if (__OPEN_NEEDS_MODE (__oflag) && __va_arg_pack_len () < 1)
{
__openat_missing_mode ();
return __openat_2 (__fd, __path, __oflag);
}
return __openat_alias (__fd, __path, __oflag, __va_arg_pack ());
}
if (__va_arg_pack_len () < 1)
return __openat_2 (__fd, __path, __oflag);
return __openat_alias (__fd, __path, __oflag, __va_arg_pack ());
}
# ifdef __USE_LARGEFILE64
extern int __openat64_2 (int __fd, const char *__path, int __oflag)
__nonnull ((2));
extern int __REDIRECT (__openat64_alias, (int __fd, const char *__path,
int __oflag, ...), openat64)
__nonnull ((2));
__errordecl (__openat64_too_many_args,
"openat64 can be called either with 3 or 4 arguments, not more");
__errordecl (__openat64_missing_mode,
"openat64 with O_CREAT or O_TMPFILE in third argument needs 4 arguments");
__fortify_function int
openat64 (int __fd, const char *__path, int __oflag, ...)
{
if (__va_arg_pack_len () > 1)
__openat64_too_many_args ();
if (__builtin_constant_p (__oflag))
{
if (__OPEN_NEEDS_MODE (__oflag) && __va_arg_pack_len () < 1)
{
__openat64_missing_mode ();
return __openat64_2 (__fd, __path, __oflag);
}
return __openat64_alias (__fd, __path, __oflag, __va_arg_pack ());
}
if (__va_arg_pack_len () < 1)
return __openat64_2 (__fd, __path, __oflag);
return __openat64_alias (__fd, __path, __oflag, __va_arg_pack ());
}
# endif
#endif