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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

View File

@ -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>