1/*
2 *  linux/arch/arm/lib/strncpy_from_user.S
3 *
4 *  Copyright (C) 1995-2000 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10#include <linux/linkage.h>
11#include <asm/assembler.h>
12#include <asm/errno.h>
13
14	.text
15	.align	5
16
17/*
18 * Copy a string from user space to kernel space.
19 *  r0 = dst, r1 = src, r2 = byte length
20 * returns the number of characters copied (strlen of copied string),
21 *  -EFAULT on exception, or "len" if we fill the whole buffer
22 */
23ENTRY(__arch_strncpy_from_user)
24	save_lr
25	mov	ip, r1
261:	subs	r2, r2, #1
27USER(	ldrplbt	r3, [r1], #1)
28	bmi	2f
29	strb	r3, [r0], #1
30	teq	r3, #0
31	bne	1b
32	sub	r1, r1, #1	@ take NUL character out of count
332:	sub	r0, r1, ip
34	restore_pc
35
36	.section .fixup,"ax"
37	.align	0
389001:	mov	r3, #0
39	strb	r3, [r0, #0]	@ null terminate
40	mov	r0, #-EFAULT
41	restore_pc
42	.previous
43
44