glibc/sysdeps/unix/sysv/linux/sysdep.h
Adhemerval Zanella 2152cf7eda Fix Linux sh4 pread/pwrite argument passing
Although conceptually correct for p{read,write}{64} offset argument passing,
sh4 implementation does not generate the correct expected code.  The
__ALIGNMENT_ARG redefinition is incorrect for two reasons: 1. the
kernel-features.h header is included multiple times (since it contains no
guards) and 2. the value it redefines is also incorrect (should be '0, '
instead of empty definition).

This patch fixes it by adding another macro, SYSCALL_LL_PRW{64}, meant to be
used to pass the offset argument on p{read,write}64.  It is basically the
already define SYSCALL_LL{64} plus __ALIGNMENT_ARG unless __ASSUME_PRW_DUMMY_ARG
is define.  In this case an empty dummy argument is used regardless how
__ALIGNMENT_ARG is defined (sh4 case).

Checked on x86_64, i686, aarch64, armhf, and powerpc64le (basically a sanity
check).  Also, John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> and
James Clarke <jrtc27@jrtc27.com> help me check on a debian sh4 bootstrap using
2.24 plus this patch to verify it also corrected fixed the regression issue.

I also verified the generated object for a 2.24 build and master with this
patch for sh4 and both look identical.

	* sysdeps/unix/sysv/linux/pread.c (__libc_pread): Use SYSCALL_LL_PRW.
	* sysdeps/unix/sysv/linux/pwrite.c (__libc_pwrite): Likewise.
	* sysdeps/unix/sysv/linux/pread64.c (__libc_pread64): Use
	SYSCALL_LL64_PRW.
	* sysdeps/unix/sysv/linux/pwrite64.c (__libc_pwrite64): Likewise.
	* sysdeps/unix/sysv/linux/sh/kernel-features.h: Define
	__ASSUME_PRW_DUMMY_ARG.
	* sysdeps/unix/sysv/linux/sh/pread.c: Remove file.
	* sysdeps/unix/sysv/linux/sh/pread64.c: Likewise.
	* sysdeps/unix/sysv/linux/sh/pwrite.c: Likewise.
	* sysdeps/unix/sysv/linux/sh/pwrite64.c: Likewise.
	* sysdeps/unix/sysv/linux/sysdep.h: Define SYSCALL_LL_PRW and
	SYSCALL_LL_PRW64 based on __ASSUME_PRW_DUMMY_ARG.
2016-10-24 15:26:42 -02:00

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C

/* Copyright (C) 2015-2016 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/>. */
#include <bits/wordsize.h>
#include <kernel-features.h>
/* Set error number and return -1. A target may choose to return the
internal function, __syscall_error, which sets errno and returns -1.
We use -1l, instead of -1, so that it can be casted to (void *). */
#define INLINE_SYSCALL_ERROR_RETURN_VALUE(err) \
({ \
__set_errno (err); \
-1l; \
})
/* Provide a dummy argument that can be used to force register
alignment for register pairs if required by the syscall ABI. */
#ifdef __ASSUME_ALIGNED_REGISTER_PAIRS
#define __ALIGNMENT_ARG 0,
#define __ALIGNMENT_COUNT(a,b) b
#else
#define __ALIGNMENT_ARG
#define __ALIGNMENT_COUNT(a,b) a
#endif
/* Provide a common macro to pass 64-bit value on syscalls. */
#if __WORDSIZE == 64 || defined __ASSUME_WORDSIZE64_ILP32
# define SYSCALL_LL(val) (val)
# define SYSCALL_LL64(val) (val)
#else
#define SYSCALL_LL(val) \
__LONG_LONG_PAIR ((val) >> 31, (val))
#define SYSCALL_LL64(val) \
__LONG_LONG_PAIR ((long) ((val) >> 32), (long) ((val) & 0xffffffff))
#endif
/* Provide a common macro to pass 64-bit value on pread and pwrite
syscalls. */
#ifdef __ASSUME_PRW_DUMMY_ARG
# define SYSCALL_LL_PRW(val) 0, SYSCALL_LL (val)
# define SYSCALL_LL64_PRW(val) 0, SYSCALL_LL64 (val)
#else
# define SYSCALL_LL_PRW(val) __ALIGNMENT_ARG SYSCALL_LL (val)
# define SYSCALL_LL64_PRW(val) __ALIGNMENT_ARG SYSCALL_LL64 (val)
#endif
/* Provide a macro to pass the off{64}_t argument on p{readv,writev}{64}. */
#define LO_HI_LONG(val) \
(long) (val), \
(long) (((uint64_t) (val)) >> 32)