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x86-64: Update LO_HI_LONG for p{readv,writev}{64}v2

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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.
This commit is contained in:
H.J. Lu
2017-06-05 07:21:44 -07:00
parent c4c96f92f7
commit d8a7d10324
3 changed files with 11 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
sysdeps/unix/sysv/linux/x86_64/sysdep.h
View File

@@ -387,6 +387,6 @@
/* How to pass the off{64}_t argument on p{readv,writev}{64}. */
#undef LO_HI_LONG
#define LO_HI_LONG(val) (val)
#define LO_HI_LONG(val) (val), 0
#endif /* linux/x86_64/sysdep.h */

4
sysdeps/unix/sysv/linux/x86_64/x32/sysdep.h
View File

@@ -22,4 +22,8 @@
#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 */