glibc/sysdeps/unix/sysv/linux/not-errno.h
Adhemerval Zanella 95a7339258 tunables: Use direct syscall for access (BZ#21744)
The function maybe_enable_malloc_check, which is called by
__tunables_init, calls __access_noerrno.  It isn't problem when
symbol is is in ld.so, which has a special version of __access_noerrno
without stack protector.  But when glibc is built with stack protector,
maybe_enable_malloc_check in libc.a can't call the regular version of
__access_noerrno with stack protector.

This patch changes how Linux defines the __access_noerrno to be an
inline call instead and thus preventing defining different build
rules for ld/static and shared.

	H.J. Lu  <hongjiu.lu@intel.com>
	Adhemerval Zanella  <adhemerval.zanella@linaro.org>

	[BZ #21744]
	* elf/dl-tunables.c: Include not-errno.h header.
	* include/unistd.h (__access_noerrno): Remove definition.
	* sysdeps/unix/sysv/linux/access.c (__access_noerrno): Likewise.
	* sysdeps/generic/not-errno.h: New file.
	* sysdeps/unix/sysv/linux/not-errno.h: Likewise.
2017-07-24 11:21:07 -03:00

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1.4 KiB
C

/* Syscall wrapper that do not set errno. Linux version.
Copyright (C) 2017 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/>. */
/* This function is used on maybe_enable_malloc_check (elf/dl-tunables.c)
and to avoid having to build/use multiple versions if stack protection
in enabled it is defined as inline. */
static inline int
__access_noerrno (const char *pathname, int mode)
{
int res;
INTERNAL_SYSCALL_DECL (err);
#ifdef __NR_access
res = INTERNAL_SYSCALL_CALL (access, err, pathname, mode);
#else
res = INTERNAL_SYSCALL_CALL (faccessat, err, AT_FDCWD, pathname, mode);
#endif
if (INTERNAL_SYSCALL_ERROR_P (res, err))
return INTERNAL_SYSCALL_ERRNO (res, err);
return 0;
}