glibc/sysdeps/unix/sysv/linux/mips/kernel-features.h
Adhemerval Zanella 841a67a0ad Consolidate arm and mips posix_fadvise implementations
As noted by c1f0601389, previous posix_fadvise consolidation
broke on mips o32.  As stated in commit message, MIPS o32 only defines
__NR_fadvise64 and it is behaves like __NR_fadvise64_64.

This patches consolidates both ARM and mips o32 version by fixing
the ARM used option (__NR_fadvise64_64 withouth the alignment required
by abi) and added another option, __ASSUME_FADVISE64_AS_64_64,
which is used on mips o32.

When this option is used, posix_fadvise will use __NR_fadvise64_64
behavior (by defining or not __ASSUME_FADVISE64_64_6ARG).  For
mips, if __NR_fadvise64_64 is not defined, __NR_fadvise will be used.

I also updated the posix_fadvise comments to explain better the
different kernel abi used in the supported architectures.

I checked with a mips o32 and verified that posix_fadvise.o is
indeed using 7 argument syscall with the expected argument position.
I also checked on i686-linux-gnu and arm-gnu-eabihf.

	* sysdeps/unix/sysv/linux/arm/posix_fadvise.c: Remove file.
	* sysdeps/unix/sysv/linux/mips/mips32/posix_fadvise.c: Likewise.
	* sysdeps/unix/sysv/linux/mips/kernel-features.h
	(__ASSUME_FADVISE64_AS_64_64): Define.
	* sysdeps/unix/sysv/linux/posix_fadvise.c [__NR_fadvise64]: Add
	!defined __ASSUME_FADVISE64_AS_64_64 to use syscall issue.
	[!__NR_fadvise64 && __ASSUME_FADVISE64_64_6ARG]: Remove
	__ALIGNMENT_ARG usage.
	[!__NR_fadvise64 && !__ASSUME_FADVISE64_64_6ARG]: Define
	__NR_fadvise64_64 if it is not defined.
2017-02-06 10:21:55 -02:00

47 lines
1.7 KiB
C

/* Set flags signalling availability of kernel features based on given
kernel version number.
Copyright (C) 1999-2017 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/>. */
#include <sgidefs.h>
#include_next <kernel-features.h>
/* The MIPS kernel does not support futex_atomic_cmpxchg_inatomic if
emulating LL/SC. */
#if __mips == 1 || defined _MIPS_ARCH_R5900
# undef __ASSUME_REQUEUE_PI
# undef __ASSUME_SET_ROBUST_LIST
#endif
/* Define this if your 32-bit syscall API requires 64-bit register
pairs to start with an even-number register. */
#if _MIPS_SIM == _ABIO32
# define __ASSUME_ALIGNED_REGISTER_PAIRS 1
/* mips32 only supports ipc syscall. */
# undef __ASSUME_DIRECT_SYSVIPC_SYSCALLS
/* The o32 MIPS fadvise64 syscall behaves as fadvise64_64. */
# define __ASSUME_FADVISE64_AS_64_64 1
#endif
/* Define that mips64-n32 is a ILP32 ABI to set the correct interface to
pass 64-bits values through syscalls. */
#if _MIPS_SIM == _ABIN32
# define __ASSUME_WORDSIZE64_ILP32 1
#endif