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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
|
|
