Consolidate arm and mips posix_fadvise implementations
Commit Message
As noted by c1f0601389db64d9, 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.
---
ChangeLog | 13 ++++++++++
sysdeps/unix/sysv/linux/arm/posix_fadvise.c | 30 ----------------------
sysdeps/unix/sysv/linux/mips/kernel-features.h | 3 +++
.../unix/sysv/linux/mips/mips32/posix_fadvise.c | 4 ---
sysdeps/unix/sysv/linux/posix_fadvise.c | 23 +++++++++++------
5 files changed, 31 insertions(+), 42 deletions(-)
delete mode 100644 sysdeps/unix/sysv/linux/arm/posix_fadvise.c
delete mode 100644 sysdeps/unix/sysv/linux/mips/mips32/posix_fadvise.c
Comments
OK for 2.26 (as this isn't a bug fix).
deleted file mode 100644
@@ -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);
-}
@@ -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
deleted file mode 100644
@@ -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>
@@ -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
@@ -39,15 +43,14 @@ 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
@@ -55,6 +58,10 @@ posix_fadvise (int fd, off_t offset, off_t len, int advise)
# define __ALIGNMENT_ARG
# endif
+# ifndef __NR_fadvise64_64
+# define __NR_fadvise64_64 __NR_fadvise64
+# endif
+
int ret = INTERNAL_SYSCALL_CALL (fadvise64_64, err, fd,
__ALIGNMENT_ARG SYSCALL_LL (offset),
SYSCALL_LL (len), advise);