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This patch consolidates mostly of the Linux posix_fadvise{64} implementations
on sysdeps/unix/sysv/linux/posix_fadvise{64}.c. It still keeps arch-specific
files for:
* S390-32: it uses a packed structure to pass all the arguments on syscall.
It is the only supported port that implements __NR_fadvise64_64 in this
way.
* ARM: it does not implement __NR_fadvise64 (as other 32-bits ports), so
posix_fadvise calls internal posix_fadvise64 symbol.
* MIPS64 n64: it requires a different version number that other ports.
The new macro SYSCALL_LL{64} is used to handle the offset argument and
INTERNAL_SYSCALL_CALL to handle passing the correct number of expect
arguments.
The default Linux adds two new defines a port can use to control how
__NR_fadvise64_64 passes the kernel arguments:
* __ASSUME_FADVISE64_64_6ARG: the 'advise' argument is moved on second
position. This is the case of powerpc32 and arm to avoid implement
7 argument syscall.
* __ASSUME_FADVISE64_64_NO_ALIGN: for ABIs that defines
__ASSUME_ALIGNED_REGISTER_PAIRS packs the offset without the leading
'0'. This is the case of tile 32 bits.
ARM also defines __NR_fadvise64_64 as __NR_arm_fadvise64_64 (which is also
handled on arch kernel-feature.h).
Tested on x86_64, x32, i686, armhf, and aarch64.
* posix/Makefile (tests): Add tst-posix_fadvise and tst-posix_fadvise64.
* posix/tst-posix_fadvise.c: New file.
* posix/tst-posix_fadvise64.c: Likewise.
* posix/tst-posix_fadvise-common.c: Likewise.
* sysdeps/unix/sysv/linux/arm/kernel-features.h
(__ASSUME_FADVISE64_64_6ARG): Define.
* sysdeps/unix/sysv/linux/powerpc/kernel-features.h
[!__powerpc64__] (__ASSUME_FADVISE64_64_6ARG): Add define.
* sysdeps/unix/sysv/linux/arm/posix_fadvise64.c: Remove file.
* sysdeps/unix/sysv/linux/generic/wordsize-32/posix_fadvise.c: Likewise.
* sysdeps/unix/sysv/linux/i386/posix_fadvise64.S: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/posix_fadvise.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/posix_fadvise64.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n32/posix_fadvise.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n32/posix_fadvise64.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/posix_fadvise.c: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/posix_fadvise.c: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/posix_fadvise64.c:
Likewise.
* sysdeps/unix/sysv/linux/wordsize-64/posix_fadvise.c: Likewise.
* sysdeps/unix/sysv/linux/wordsize-64/posix_fadvise64.c: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/posix_fadvise64.c
(SHLIB_COMPAT(libc, GLIBC_2_2, GLIBC_2_3_3) [__posix_fadvise64_l64]:
Alias to __posix_fadvise64_l32.
(SHLIB_COMPAT(libc, GLIBC_2_2, GLIBC_2_3_3) [__posix_fadvise64_l32]:
Add compat definition to posix_fadvise64.
(SHLIB_COMPAT(libc, GLIBC_2_2, GLIBC_2_3_3) [__posix_fadvise64_l64]:
Add versioned definition to posix_fadvise64.
* sysdeps/unix/sysv/linux/posix_fadvise.c (posix_fadvise): Build iff
__OFF_T_MATCHES_OFF64_T is defined, use INTERNAL_SYSCALL_CALL, add
__ASSUME_FADVISE64_64_6ARG/__ASSUME_FADVISE64_64_NO_ALIGN support.
* sysdeps/unix/sysv/linux/posix_fadvise64.c (posix_fadvise64): Add
__ASSUME_FADVISE64_64_NO_ALIGN support and use INTERNAL_SYSCALL_CALL.
This hierarchy supports Linux systems using the new asm-generic/unistd.h, which removes many familiar old syscalls. For example, to implement open(), newer Linux architectures require glibc to invoke the __NR_openat syscall with AT_FDCWD. This hierarchy provides all those implementations. It also provides support for 32-bit platforms using the 64-bit kernel syscall APIs, as the 32-bit ones are no longer provided. Note that newer ILP32 environments (x32 or AArch64:ILP32, for example) are converting to use more 64-bit types in kernel syscalls, so that aspect of this support is in more flux as of this writing.