posix: Fix and simplify default p{read,write}v implementation

Currently all architectures but microblaze use wire-up syscall for
p{readv,write}v.  Microblaze still uses the syscall emulation using
sysdep/posix/p{readv,writev}.c and it was reported in some ocasions
[1] [2] that it might have some issues with some linux specific
usage (mainly with O_DIRECT and the alignment requirement).

Although it is not an issue for virtually all the system, this
patch refactors the sysdeps/posix p{read,write}v syscall to avoid
such issue (by using posix_memalign on the buffer used on
p{read,write} call) and by refactoring it common files to avoid
the need check on defines to correct set the alias and internal
symbols.

Checked on microblaze-linux-gnu check with run-built-tests=no and
by using the sysdeps/posix implementation on x86_64-linux-gnu (just
for sanity test where it shown no regression).

	* sysdeps/posix/preadv.c: Use sysdeps/posix/preadv_common.c.
	* sysdeps/posix/preadv64.c: Likewise.
	* sysdeps/unix/sysv/linux/preadv.c: Likewise.
	* sysdeps/unix/sysv/linux/preadv64.c: Likewise.
	* sysdeps/posix/pwritev.c: Use sysdeps/posix/pwritev_common.c.
	* sysdeps/posix/pwritev64.c: Likewise.
	* sysdeps/unix/sysv/linux/pwritev.c: Likewise.
	* sysdeps/unix/sysv/linux/pwritev64.c: Likewise.
	* sysdeps/posix/preadv_common.c: New file.
	* sysdeps/posix/pwritev_common.c: Likewise.

[1] http://www.mail-archive.com/qemu-devel@nongnu.org/msg25282.html
[2] https://bugzilla.redhat.com/show_bug.cgi?id=563103#c8

1 files changed, 25 insertions, 6 deletions

diff --git a/sysdeps/posix/pwritev64.c b/sysdeps/posix/pwritev64.c
index 4948d2efee..c5392f7836 100644
--- a/sysdeps/posix/pwritev64.c
+++ b/sysdeps/posix/pwritev64.c
@@ -1,9 +1,28 @@
-#include <bits/wordsize.h>
+/* Write data into multiple buffers.  Generic LFS version.
+   Copyright (C) 2009-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
 
-#if __WORDSIZE == 32
-# define PWRITEV pwritev64
-# define PWRITE __pwrite64
-# define OFF_T off64_t
+   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.
 
-# include "pwritev.c"
+   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/>.  */
+
+#define PWRITEV pwritev64
+#define PWRITE __pwrite64
+#define OFF_T off64_t
+#include <sysdeps/posix/pwritev_common.c>
+
+libc_hidden_def (pwritev64)
+#ifdef __OFF_T_MATCHES_OFF64_T
+strong_alias (pwritev64, pwritev)
+libc_hidden_def (pwritev)
 #endif