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Consolidate arm and mips posix_fadvise implementations

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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
Download Patch File Download Diff File Expand all files Collapse all files

23
sysdeps/unix/sysv/linux/posix_fadvise.c
View File

@ -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,