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.
This commit is contained in:
Adhemerval Zanella 2017-01-13 15:24:53 -02:00
parent 58557c2293
commit 841a67a0ad
5 changed files with 31 additions and 42 deletions

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@ -1,3 +1,16 @@
2017-02-06 Adhemerval Zanella <adhemerval.zanella@linaro.org>
* 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.
2017-02-05 Siddhesh Poyarekar <siddhesh@sourceware.org>
* version.h (RELEASE): Set to "development"

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@ -1,30 +0,0 @@
/* Copyright (C) 2005-2017 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 <fcntl.h>
int __posix_fadvise64_l64 (int fd, off64_t offset, off64_t len, int advise);
/* Advice the system about the expected behaviour of the application with
respect to the file associated with FD. */
int
posix_fadvise (int fd, off_t offset, off_t len, int advise)
{
/* ARM only has a syscall for fadvise64_64. */
return __posix_fadvise64_l64 (fd, offset, len, advise);
}

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@ -34,6 +34,9 @@
# 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

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@ -1,4 +0,0 @@
/* The o32 MIPS fadvise64 syscall behaves as fadvise64_64. The ARM
implementation of posix_fadvise works correctly for this case; the
generic implementation mishandles it. */
#include <sysdeps/unix/sysv/linux/arm/posix_fadvise.c>

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@ -24,12 +24,16 @@
#ifndef __OFF_T_MATCHES_OFF64_T
/* Both arm and powerpc implements fadvise64_64 with last 'advise' argument
just after 'fd' to avoid the requirement of implementing 7-arg syscalls.
ARM also defines __NR_fadvise64_64 as __NR_arm_fadvise64_64.
/* Default implementation will use __NR_fadvise64 with expected argument
positions (for instance i386 and powerpc32 that uses __ALIGNMENT_ARG).
tile requires __ASSUME_ALIGNED_REGISTER_PAIRS but implements the 32-bit
fadvise64_64 without the padding 0 after fd.
Second option will be used by arm which define __NR_arm_fadvise64_64
(redefined to __NR_fadvise64_64 in kernel-features.h) that behaves as
__NR_fadvise64_64 (without the aligment argument required for the ABI).
Third option will be used by both tile 32-bits and mips o32. Tile
will set __ASSUME_FADVISE64_64_NO_ALIGN to issue a 6 argument syscall,
while mips will use a 7 argument one with __NR_fadvise64.
s390 implements fadvice64_64 using a specific struct with arguments
packed inside. This is the only implementation handled in arch-specific
@ -39,20 +43,23 @@ int
posix_fadvise (int fd, off_t offset, off_t len, int advise)
{
INTERNAL_SYSCALL_DECL (err);
# ifdef __NR_fadvise64
# if defined (__NR_fadvise64) && !defined (__ASSUME_FADVISE64_AS_64_64)
int ret = INTERNAL_SYSCALL_CALL (fadvise64, err, fd,
__ALIGNMENT_ARG SYSCALL_LL (offset),
len, advise);
# else
# ifdef __ASSUME_FADVISE64_64_6ARG
int ret = INTERNAL_SYSCALL_CALL (fadvise64_64, err, fd, advise,
__ALIGNMENT_ARG SYSCALL_LL (offset),
SYSCALL_LL (len));
SYSCALL_LL (offset), SYSCALL_LL (len));
# else
# ifdef __ASSUME_FADVISE64_64_NO_ALIGN
# undef __ALIGNMENT_ARG
# define __ALIGNMENT_ARG
# endif
# ifndef __NR_fadvise64_64
# define __NR_fadvise64_64 __NR_fadvise64
# endif
int ret = INTERNAL_SYSCALL_CALL (fadvise64_64, err, fd,