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/*
* linux/arch/unicore32/lib/strncpy_from_user.S
*
* Code specific to PKUnity SoC and UniCore ISA
*
* Copyright (C) 2001-2010 GUAN Xue-tao
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/errno.h>
.text
.align 5
/*
* Copy a string from user space to kernel space.
* r0 = dst, r1 = src, r2 = byte length
* returns the number of characters copied (strlen of copied string),
* -EFAULT on exception, or "len" if we fill the whole buffer
*/
ENTRY(__strncpy_from_user)
mov ip, r1
1: sub.a r2, r2, #1
ldrusr r3, r1, 1, ns
bfs 2f
stb.w r3, [r0]+, #1
cxor.a r3, #0
bne 1b
sub r1, r1, #1 @ take NUL character out of count
2: sub r0, r1, ip
mov pc, lr
ENDPROC(__strncpy_from_user)
.pushsection .fixup,"ax"
.align 0
9001: mov r3, #0
stb r3, [r0+], #0 @ null terminate
mov r0, #-EFAULT
mov pc, lr
.popsection
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