Re: [PATCH 3/4] Consolidate pread/pread64 implementations

[Adhemerval Zanella <adhemerval dot zanella at linaro dot org>]

On 07-01-2016 19:03, Adhemerval Zanella wrote:
> 
> 
> On 07-01-2016 18:54, Mike Frysinger wrote:
>> On 07 Jan 2016 18:30, Adhemerval Zanella wrote:
>>> On 07-01-2016 17:52, Mike Frysinger wrote:
>>>> On 07 Jan 2016 15:18, Adhemerval Zanella wrote:
>>>>> From: Adhemerval Zanella <adhemerval.zanella@linaro.com>
>>>>>
>>>>> This patch consolidates all the pread/pread64 implementation for Linux
>>>>> in only one (sysdeps/unix/sysv/linux/pread.c).  It also removes the
>>>>> syscall from the auto-generation using assembly macros.
>>>>>
>>>>> For pread{64} offset argument placement the new SYSCALL_LL{64} macro
>>>>> is used.  For pread ports that do not define __NR_pread will use
>>>>> __NR_pread64 and for pread64 ports that dot define __NR_pread64 will
>>>>> use __NR_pread for the syscall.
>>>>
>>>> just to make sure i'm reading this correctly, in the past 64-bit ports
>>>> would have a pread symbol and pread64 would be an alias to it.  but with
>>>> this patch, 64-bit ports now have two symbols w/identical code ?
>>>
>>> Indeed it is something I was thinking and I was not sure how to
>>> fix it while not breaking the existing ABI.  Maybe only building
>>> the p{read,write}.c if not WORDSIZE64 is define and creating an
>>> alias on p{read,write}64.c. What do you think?
>>
>> why do you need to delete the pread64.c & syscall.lists entries ?
>> if you kept those, wouldn't things remain the same ?
>>
>> otherwise you'd have to keep the pread64.c and add a new pread.c
>> that just includes the 32-bit pread.c but also adds the aliases.
>> -mike
>>
> 
> The idea is exactly to remove the auto-generation from syscalls.list
> to simplify the cancellation syscall generation (to in the future
> just get rid of the assembly hackery in sysdep-cancel.h).
> 

Ok I got a better solution to avoid code build duplication. The only
issue is for mips64 n32, sizeof(off_t) is different than sizeof(off64_t)
which leaded to continue provide a mips pread implementation (although
as for sh is uses de default one).

Same strat applies to pwrite{64}.

What do you think?

	* sysdeps/unix/sysv/linux/arm/pread.c: Remove file.
	* sysdeps/unix/sysv/linux/arm/pread64.c: Likewise.
	* sysdeps/unix/sysv/linux/generic/wordsize-32/pread.c: Likewise.
	* sysdeps/unix/sysv/linux/generic/wordsize-32/pread64.c: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/pread.c: Likewise,
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/pread64.c: Likewise.
	* sysdeps/unix/sysv/linux/wordsize-64/pread64.c: Likewise.
	* sysdeps/unix/sysv/linux/wordsize-64/syscalls.list (pread): Remove
	syscall generation.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h
	[__NR_pread64] (__NR_pread): Remove define.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h:
	[__NR_pread64] (__NR_pread): Likewise.
	* sysdeps/unix/sysv/linux/pread.c [__NR_pread64] (__NR_pread): Remove
	define.
	(__libc_pread): Use SYSCALL_LL macro on offset argument.
	* sysdeps/unix/sysv/linux/pread64.c [__NR_pread64] (__NR_pread):
	Remove define.
	(__libc_pread64): Use SYSCALL_LL64 macro on offset argument.
	* sysdeps/unix/sysv/linux/sh/pread.c: Rewrite using default
	Linux implementation as base.
	* sysdeps/unix/sysv/linux/sh/pread64.c: Likewise.
	* sysdeps/unix/sysv/linux/mips/pread.c: Likewise.
	* sysdeps/unix/sysv/linux/mips/pread64.c: Likewise.

--

diff --git a/sysdeps/unix/sysv/linux/arm/pread.c b/sysdeps/unix/sysv/linux/arm/pread.c
deleted file mode 100644
index 8c9b878..0000000
--- a/sysdeps/unix/sysv/linux/arm/pread.c
+++ /dev/null
@@ -1,36 +0,0 @@
-/* Copyright (C) 1997-2016 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
-
-   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/>.  */
-
-#include <errno.h>
-#include <endian.h>
-#include <unistd.h>
-
-#include <sysdep-cancel.h>
-#include <sys/syscall.h>
-
-ssize_t
-__libc_pread (int fd, void *buf, size_t count, off_t offset)
-{
-  /* In the ARM EABI, 64-bit values are aligned to even/odd register
-     pairs for syscalls.  */
-  return SYSCALL_CANCEL (pread64, fd, buf, count, 0,
-			 __LONG_LONG_PAIR (offset >> 31, offset));
-}
-
-strong_alias (__libc_pread, __pread)
-weak_alias (__libc_pread, pread)
diff --git a/sysdeps/unix/sysv/linux/arm/pread64.c b/sysdeps/unix/sysv/linux/arm/pread64.c
deleted file mode 100644
index 3364b6a..0000000
--- a/sysdeps/unix/sysv/linux/arm/pread64.c
+++ /dev/null
@@ -1,37 +0,0 @@
-/* Copyright (C) 1997-2016 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
-
-   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/>.  */
-
-#include <errno.h>
-#include <endian.h>
-#include <unistd.h>
-
-#include <sysdep-cancel.h>
-#include <sys/syscall.h>
-
-ssize_t
-__libc_pread64 (int fd, void *buf, size_t count, off64_t offset)
-{
-  /* In the ARM EABI, 64-bit values are aligned to even/odd register
-     pairs for syscalls.  */
-  return SYSCALL_CANCEL (pread64, fd, buf, count, 0,
-			 __LONG_LONG_PAIR ((off_t) (offset >> 32),
-					   (off_t) (offset & 0xffffffff)));
-}
-
-weak_alias (__libc_pread64, __pread64)
-weak_alias (__libc_pread64, pread64)
diff --git a/sysdeps/unix/sysv/linux/generic/wordsize-32/pread.c b/sysdeps/unix/sysv/linux/generic/wordsize-32/pread.c
deleted file mode 100644
index 0dff648..0000000
--- a/sysdeps/unix/sysv/linux/generic/wordsize-32/pread.c
+++ /dev/null
@@ -1,37 +0,0 @@
-/* Copyright (C) 2011-2016 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
-   Based on work contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
-
-   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/>.  */
-
-#include <assert.h>
-#include <errno.h>
-#include <endian.h>
-#include <unistd.h>
-
-#include <sysdep-cancel.h>
-#include <sys/syscall.h>
-
-ssize_t
-__libc_pread (int fd, void *buf, size_t count, off_t offset)
-{
-  assert (sizeof (offset) == 4);
-  return SYSCALL_CANCEL (pread64, fd,
-                         buf, count, __ALIGNMENT_ARG
-                         __LONG_LONG_PAIR (offset >> 31, offset));
-}
-strong_alias (__libc_pread, __pread)
-weak_alias (__libc_pread, pread)
diff --git a/sysdeps/unix/sysv/linux/generic/wordsize-32/pread64.c b/sysdeps/unix/sysv/linux/generic/wordsize-32/pread64.c
deleted file mode 100644
index 8931900..0000000
--- a/sysdeps/unix/sysv/linux/generic/wordsize-32/pread64.c
+++ /dev/null
@@ -1,34 +0,0 @@
-/* Copyright (C) 2011-2016 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
-   Based on work contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
-
-   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/>.  */
-
-#include <errno.h>
-#include <endian.h>
-#include <unistd.h>
-
-#include <sysdep-cancel.h>
-#include <sys/syscall.h>
-
-ssize_t
-__libc_pread64 (int fd, void *buf, size_t count, off64_t offset)
-{
-  return SYSCALL_CANCEL (pread64, fd, buf, count, __ALIGNMENT_ARG
-                         __LONG_LONG_PAIR ((off_t) (offset >> 32),
-                                           (off_t) (offset & 0xffffffff)));
-}
-weak_alias (__libc_pread64, __pread64) weak_alias (__libc_pread64, pread64)
diff --git a/sysdeps/unix/sysv/linux/mips/pread.c b/sysdeps/unix/sysv/linux/mips/pread.c
index 02755cb..3092f0b 100644
--- a/sysdeps/unix/sysv/linux/mips/pread.c
+++ b/sysdeps/unix/sysv/linux/mips/pread.c
@@ -16,39 +16,13 @@
    License along with the GNU C Library.  If not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <assert.h>
-#include <errno.h>
-#ifndef NO_SGIDEFS_H
-#include <sgidefs.h>
-#endif
-#include <unistd.h>
-#include <endian.h>
-
 #include <sysdep-cancel.h>
-#include <sys/syscall.h>
-
-#ifdef __NR_pread64             /* Newer kernels renamed but it's the same.  */
-# ifdef __NR_pread
-#  error "__NR_pread and __NR_pread64 both defined???"
-# endif
-# define __NR_pread __NR_pread64
-#endif
-
-
-ssize_t
-__libc_pread (int fd, void *buf, size_t count, off_t offset)
-{
-#if _MIPS_SIM != _ABI64
-  assert (sizeof (offset) == 4);
-#endif
 
-#if _MIPS_SIM == _ABIN32 || _MIPS_SIM == _ABI64
-  return SYSCALL_CANCEL (pread, fd, buf, count, offset);
-#else
-  return SYSCALL_CANCEL (pread, fd, buf, count, 0,
-			 __LONG_LONG_PAIR (offset >> 31, offset));
+/* The n32 have sizeof(off_t) != sizeof(off64_t) so we can't strong/weak
+   alias the pread to pread64.  We undefine the __ASSUME_WORDSIZE64_ILP32
+   so two implementation are built.  */
+#if _MIPS_SIM == _ABIN32
+# undef __ASSUME_WORDSIZE64_ILP32
 #endif
-}
 
-strong_alias (__libc_pread, __pread)
-weak_alias (__libc_pread, pread)
+#include <sysdeps/unix/sysv/linux/pread.c>
diff --git a/sysdeps/unix/sysv/linux/mips/pread64.c b/sysdeps/unix/sysv/linux/mips/pread64.c
index ed0e91c..cd3b5fd 100644
--- a/sysdeps/unix/sysv/linux/mips/pread64.c
+++ b/sysdeps/unix/sysv/linux/mips/pread64.c
@@ -16,35 +16,13 @@
    License along with the GNU C Library.  If not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <errno.h>
-#ifndef NO_SGIDEFS_H
-#include <sgidefs.h>
-#endif
-#include <unistd.h>
-#include <endian.h>
-
 #include <sysdep-cancel.h>
-#include <sys/syscall.h>
-
-#ifdef __NR_pread64             /* Newer kernels renamed but it's the same.  */
-# ifdef __NR_pread
-#  error "__NR_pread and __NR_pread64 both defined???"
-# endif
-# define __NR_pread __NR_pread64
-#endif
-
 
-ssize_t
-__libc_pread64 (int fd, void *buf, size_t count, off64_t offset)
-{
-#if _MIPS_SIM == _ABIN32 || _MIPS_SIM == _ABI64
-  return SYSCALL_CANCEL (pread, fd, buf, count, offset);
-#else
-  return SYSCALL_CANCEL (pread, fd, buf, count, 0,
-			 __LONG_LONG_PAIR ((off_t) (offset >> 32),
-					   (off_t) (offset & 0xffffffff)));
+/* The n32 have sizeof(off_t) != sizeof(off64_t) so we can't strong/weak
+   alias the pread to pread64.  We undefine the __ASSUME_WORDSIZE64_ILP32
+   so two implementation are built.  */
+#if _MIPS_SIM == _ABIN32
+# undef __ASSUME_WORDSIZE64_ILP32
 #endif
-}
 
-weak_alias (__libc_pread64, __pread64)
-weak_alias (__libc_pread64, pread64)
+#include <sysdeps/unix/sysv/linux/pread64.c>
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/pread.c b/sysdeps/unix/sysv/linux/powerpc/powerpc32/pread.c
deleted file mode 100644
index 2d67013..0000000
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/pread.c
+++ /dev/null
@@ -1,34 +0,0 @@
-/* Copyright (C) 1997-2016 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
-
-   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/>.  */
-
-#include <assert.h>
-#include <errno.h>
-#include <unistd.h>
-
-#include <sysdep-cancel.h>
-#include <sys/syscall.h>
-
-ssize_t
-__libc_pread (int fd, void *buf, size_t count, off_t offset)
-{
-  /* On PPC32 64bit values are aligned in odd/even register pairs.  */
-  return SYSCALL_CANCEL (pread, fd, buf, count, 0, offset >> 31, offset);
-}
-
-strong_alias (__libc_pread, __pread)
-weak_alias (__libc_pread, pread)
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/pread64.c b/sysdeps/unix/sysv/linux/powerpc/powerpc32/pread64.c
deleted file mode 100644
index 712ab72..0000000
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/pread64.c
+++ /dev/null
@@ -1,35 +0,0 @@
-/* Copyright (C) 1997-2016 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
-
-   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/>.  */
-
-#include <errno.h>
-#include <unistd.h>
-
-#include <sysdep-cancel.h>
-#include <sys/syscall.h>
-
-
-ssize_t
-__libc_pread64 (int fd, void *buf, size_t count, off64_t offset)
-{
-  /* On PPC32 64bit values are aligned in odd/even register pairs.  */
-  return SYSCALL_CANCEL (pread, fd, buf, count, 0, (long) (offset >> 32),
-			 (long) offset);
-}
-
-weak_alias (__libc_pread64, __pread64)
-weak_alias (__libc_pread64, pread64)
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h b/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h
index 390ce24..c12fd7f 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h
@@ -27,13 +27,6 @@
    Handle them here so they can be catched by both C and assembler stubs in
    glibc.  */
 
-#ifdef __NR_pread64
-# ifdef __NR_pread
-#  error "__NR_pread and __NR_pread64 both defined???"
-# endif
-# define __NR_pread __NR_pread64
-#endif
-
 #ifdef __NR_pwrite64
 # ifdef __NR_pwrite
 #  error "__NR_pwrite and __NR_pwrite64 both defined???"
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h b/sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h
index 761f3ea..c39a0f2 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h
@@ -34,13 +34,6 @@
    Handle them here so they can be catched by both C and assembler stubs in
    glibc.  */
 
-#ifdef __NR_pread64
-# ifdef __NR_pread
-#  error "__NR_pread and __NR_pread64 both defined???"
-# endif
-# define __NR_pread __NR_pread64
-#endif
-
 #ifdef __NR_pwrite64
 # ifdef __NR_pwrite
 #  error "__NR_pwrite and __NR_pwrite64 both defined???"
diff --git a/sysdeps/unix/sysv/linux/pread.c b/sysdeps/unix/sysv/linux/pread.c
index 4aa3c67..cc94f22 100644
--- a/sysdeps/unix/sysv/linux/pread.c
+++ b/sysdeps/unix/sysv/linux/pread.c
@@ -16,33 +16,22 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <assert.h>
-#include <errno.h>
-#include <endian.h>
 #include <unistd.h>
-
 #include <sysdep-cancel.h>
-#include <sys/syscall.h>
 
-#ifdef __NR_pread64		/* Newer kernels renamed but it's the same.  */
-# ifdef __NR_pread
-#  error "__NR_pread and __NR_pread64 both defined???"
-# endif
+#if !(__WORDSIZE == 64) && !defined(__ASSUME_WORDSIZE64_ILP32)
+
+#ifndef __NR_pread
 # define __NR_pread __NR_pread64
 #endif
 
-
 ssize_t
 __libc_pread (int fd, void *buf, size_t count, off_t offset)
 {
-  ssize_t result;
-
-  assert (sizeof (offset) == 4);
-  result = SYSCALL_CANCEL (pread, fd, buf, count,
-			   __LONG_LONG_PAIR (offset >> 31, offset));
-
-  return result;
+  return SYSCALL_CANCEL (pread, fd, buf, count,
+			 __ALIGNMENT_ARG SYSCALL_LL (offset));
 }
 
 strong_alias (__libc_pread, __pread)
 weak_alias (__libc_pread, pread)
+#endif
diff --git a/sysdeps/unix/sysv/linux/pread64.c b/sysdeps/unix/sysv/linux/pread64.c
index 7b5019a..7e20e63 100644
--- a/sysdeps/unix/sysv/linux/pread64.c
+++ b/sysdeps/unix/sysv/linux/pread64.c
@@ -16,28 +16,25 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <errno.h>
-#include <endian.h>
 #include <unistd.h>
-
 #include <sysdep-cancel.h>
-#include <sys/syscall.h>
 
-#ifdef __NR_pread64		/* Newer kernels renamed but it's the same.  */
-# ifdef __NR_pread
-#  error "__NR_pread and __NR_pread64 both defined???"
-# endif
-# define __NR_pread __NR_pread64
+#ifndef __NR_pread64
+# define __NR_pread64 __NR_pread
 #endif
 
-
 ssize_t
 __libc_pread64 (int fd, void *buf, size_t count, off64_t offset)
 {
-  return SYSCALL_CANCEL (pread, fd, buf, count,
-			 __LONG_LONG_PAIR ((off_t) (offset >> 32),
-					   (off_t) (offset & 0xffffffff)));
+  return SYSCALL_CANCEL (pread64, fd, buf, count,
+			 __ALIGNMENT_ARG SYSCALL_LL64 (offset));
 }
 
-weak_alias (__libc_pread64, __pread64)
+strong_alias (__libc_pread64, __pread64)
 weak_alias (__libc_pread64, pread64)
+
+#if __WORDSIZE == 64 || defined __ASSUME_WORDSIZE64_ILP32
+strong_alias (__libc_pread64, __libc_pread)
+weak_alias (__libc_pread64, __pread)
+weak_alias (__libc_pread64, pread)
+#endif
diff --git a/sysdeps/unix/sysv/linux/sh/pread.c b/sysdeps/unix/sysv/linux/sh/pread.c
index 8afada5..d3f99f3 100644
--- a/sysdeps/unix/sysv/linux/sh/pread.c
+++ b/sysdeps/unix/sysv/linux/sh/pread.c
@@ -16,28 +16,8 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <assert.h>
-#include <errno.h>
-#include <unistd.h>
-#include <endian.h>
-
-#include <sysdep-cancel.h>
-#include <sys/syscall.h>
-
-#ifdef __NR_pread64             /* Newer kernels renamed but it's the same.  */
-# ifdef __NR_pread
-#  error "__NR_pread and __NR_pread64 both defined???"
-# endif
-# define __NR_pread __NR_pread64
-#endif
-
-
-ssize_t
-__libc_pread (int fd, void *buf, size_t count, off_t offset)
-{
-  return SYSCALL_CANCEL (pread, fd, buf, count, 0,
-			 __LONG_LONG_PAIR (offset >> 31, offset));
-}
-
-strong_alias (__libc_pread, __pread)
-weak_alias (__libc_pread, pread)
+/* SH4 ABI does not really require argument alignment for 64-bits, but
+   the kernel interface for pread adds a dummy long argument before the
+   offset.  */
+#define __ALIGNMENT_ARG
+#include <sysdeps/unix/sysv/linux/pread.c>
diff --git a/sysdeps/unix/sysv/linux/sh/pread64.c b/sysdeps/unix/sysv/linux/sh/pread64.c
index cfc751d..b2e8a25 100644
--- a/sysdeps/unix/sysv/linux/sh/pread64.c
+++ b/sysdeps/unix/sysv/linux/sh/pread64.c
@@ -16,28 +16,8 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <errno.h>
-#include <unistd.h>
-#include <endian.h>
-
-#include <sysdep-cancel.h>
-#include <sys/syscall.h>
-
-#ifdef __NR_pread64             /* Newer kernels renamed but it's the same.  */
-# ifdef __NR_pread
-#  error "__NR_pread and __NR_pread64 both defined???"
-# endif
-# define __NR_pread __NR_pread64
-#endif
-
-
-ssize_t
-__libc_pread64 (int fd, void *buf, size_t count, off64_t offset)
-{
-  return SYSCALL_CANCEL (pread, fd, buf, count, 0,
-			 __LONG_LONG_PAIR ((off_t) (offset >> 32),
-					   (off_t) (offset & 0xffffffff)));
-}
-
-weak_alias (__libc_pread64, __pread64)
-weak_alias (__libc_pread64, pread64)
+/* SH4 ABI does not really require argument alignment for 64-bits, but
+   the kernel interface for pread adds a dummy long argument before the
+   offset.  */
+#define __ALIGNMENT_ARG
+#include <sysdeps/unix/sysv/linux/pread64.c>
diff --git a/sysdeps/unix/sysv/linux/wordsize-64/pread64.c b/sysdeps/unix/sysv/linux/wordsize-64/pread64.c
deleted file mode 100644
index b7f298d..0000000
--- a/sysdeps/unix/sysv/linux/wordsize-64/pread64.c
+++ /dev/null
@@ -1 +0,0 @@
-/* Empty since the pread syscall is equivalent.  */
diff --git a/sysdeps/unix/sysv/linux/wordsize-64/syscalls.list b/sysdeps/unix/sysv/linux/wordsize-64/syscalls.list
index 19cc6d9..7d5f6a5 100644
--- a/sysdeps/unix/sysv/linux/wordsize-64/syscalls.list
+++ b/sysdeps/unix/sysv/linux/wordsize-64/syscalls.list
@@ -3,7 +3,6 @@
 # Whee! 64-bit systems naturally implement llseek.
 llseek		EXTRA	lseek		i:iii	__libc_lseek	__lseek lseek __libc_lseek64 __llseek llseek __lseek64 lseek64
 lseek		llseek	-
-pread		-	pread		Ci:ibni	__libc_pread	__libc_pread64 __pread pread __pread64 pread64
 pwrite		-	pwrite		Ci:ibni	__libc_pwrite	__libc_pwrite64 __pwrite pwrite __pwrite64 pwrite64
 fstatfs		-	fstatfs		i:ip	__fstatfs	fstatfs fstatfs64 __fstatfs64
 statfs		-	statfs		i:sp	__statfs	statfs statfs64