glibc/sysdeps/unix/sysv/linux/x86_64/x32/sysdep.h
H.J. Lu d8a7d10324 x86-64: Update LO_HI_LONG for p{readv,writev}{64}v2
The kernel interface for p{readv,writev}{64}v is

(unsigned long fd, {const }struct iovec *iov, unsigned long vlen,
 unsigned long pos_l, unsigned long pos_h)

Except for targets which define __ARCH_WANT_COMPAT_SYS_PREADV64 and
__ARCH_WANT_COMPAT_SYS_PWRITEV64,

(unsigned long fd, {const }struct iovec *iov, unsigned long vlen,
 off64_t pos)

is used for p{readv,writev}{64}v.  X32 is the only such target.  The
LO_HI_LONG macro is used to pass offset to the pos_l and pos_h pair.
Since pos_h is ignored when size of offset == sizeof of pos_l, x86-64
has

 #define LO_HI_LONG(val) (val)

But the kernel interface for p{readv,writev}{64}v2 is

(unsigned long fd, {const }struct iovec *iov, unsigned long vlen,
 unsigned long pos_l, unsigned long pos_h, int flags)

Except for targets which define __ARCH_WANT_COMPAT_SYS_PREADV64V2 and
__ARCH_WANT_COMPAT_SYS_PWRITEV64V2,

(unsigned long fd, {const }struct iovec *iov, unsigned long vlen,
 off64_t pos, int flags)

is used for p{readv,writev}{64}v2.  X32 is the only such target.  Update
x86-64 LO_HI_LONG to pass 0 as the high part of the offset argument for
p{readv,writev}{64}v2 and define a different LO_HI_LONG for x32 to only
pass one argument for offset.

Tested on x32 and x86-64.

	* sysdeps/unix/sysv/linux/x86_64/sysdep.h (LO_HI_LONG): Pass
	0 as the high part of offset.
	* sysdeps/unix/sysv/linux/x86_64/x32/sysdep.h (LO_HI_LONG): New.
2017-06-05 07:21:57 -07:00

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1.1 KiB
C

/* Copyright (C) 2012-2017 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/>. */
#ifndef _LINUX_X32_SYSDEP_H
#define _LINUX_X32_SYSDEP_H 1
/* There is some commonality. */
#include <sysdeps/unix/sysv/linux/x86_64/sysdep.h>
#include <sysdeps/x86_64/x32/sysdep.h>
/* How to pass the off{64}_t argument on p{readv,writev}{64}. */
#undef LO_HI_LONG
#define LO_HI_LONG(val) (val)
#endif /* linux/x86_64/x32/sysdep.h */