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	This patch add three new macros (SYSCALL_LL, SYSCALL_LL64, and
__ASSUME_WORDSIZE64_ILP32) to use along with off_t and off64_t argument
syscalls.  The rationale for this change is:
1. Remove multiple implementations for the same syscall for different
   architectures (for instance, pread have 6 different implementations).
2. Also remove the requirement to use syscall wrappers for cancellable
   entrypoints.
The macro usage should be used along __ALIGNMENT_ARG to follow ABI constrains
for architecture where it applies.  For instance, pread can be rewritten as:
  return SYSCALL_CANCEL (pread, fd, buf, count,
                         __ALIGNMENT_ARG SYSCALL_LL (offset));
Another macro, SYSCALL_LL64, is provided for off64_t.  The macro
__ASSUME_WORDSIZE64_ILP32 is used by the ABI to define is uses 64-bit register
even if ABI is ILP32 (for instance x32 and mips64-n32).
The changes itself are not currently used in any implementation, so no
code change is expected.
	* sysdeps/unix/sysv/linux/generic/sysdep.h (__ALIGNMENT_ARG): Move
	definition.
	(__ALIGNMENT_COUNT): Likewise.
	* sysdeps/unix/sysv/linux/sysdep.h (__ALIGNMENT_ARG): To here.
	(__ALIGNMENT_COUNT): Likewise.
	(SYSCALL_LL): New define.
	(SYSCALL_LL64): Likewise.
	* sysdeps/unix/sysv/linux/mips/kernel-features.h:
	[_MIPS_SIM == _ABIO32] (__ASSUME_WORDSIZE64_ILP32): Define.
	* sysdeps/unix/sysv/linux/x86_64/kernel-features.h:
	[ILP32] (__ASUME_WORDSIZE64_ILP32): Likewise.
		
	
		
			
				
	
	
		
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			34 lines
		
	
	
		
			1.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Copyright (C) 2011-2016 Free Software Foundation, Inc.
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|    This file is part of the GNU C Library.
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|    Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
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| 
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|    The GNU C Library is free software; you can redistribute it and/or
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|    modify it under the terms of the GNU Lesser General Public
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|    License as published by the Free Software Foundation; either
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|    version 2.1 of the License, or (at your option) any later version.
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| 
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|    The GNU C Library is distributed in the hope that it will be useful,
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|    but WITHOUT ANY WARRANTY; without even the implied warranty of
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|    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|    Lesser General Public License for more details.
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| 
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|    You should have received a copy of the GNU Lesser General Public
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|    License along with the GNU C Library.  If not, see
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|    <http://www.gnu.org/licenses/>.  */
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| 
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| #include <bits/wordsize.h>
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| #include <kernel-features.h>
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| #include <sysdeps/unix/sysdep.h>
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| #include <sysdeps/unix/sysv/linux/sysdep.h>
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| 
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| /* Provide the common name to allow more code reuse.  */
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| #define __NR__llseek __NR_llseek
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| 
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| #if __WORDSIZE == 64
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| /* By defining the older names, glibc will build syscall wrappers for
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|    both pread and pread64; sysdeps/unix/sysv/linux/wordsize-64/pread64.c
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|    will suppress generating any separate code for pread64.c.  */
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| #define __NR_pread __NR_pread64
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| #define __NR_pwrite __NR_pwrite64
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| #endif
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