Commit | Line | Data |
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77c93b2f G |
1 | /* |
2 | * linux/arch/unicore32/lib/strncpy_from_user.S | |
3 | * | |
4 | * Code specific to PKUnity SoC and UniCore ISA | |
5 | * | |
6 | * Copyright (C) 2001-2010 GUAN Xue-tao | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | */ | |
12 | #include <linux/linkage.h> | |
13 | #include <asm/assembler.h> | |
14 | #include <asm/errno.h> | |
15 | ||
16 | .text | |
17 | .align 5 | |
18 | ||
19 | /* | |
20 | * Copy a string from user space to kernel space. | |
21 | * r0 = dst, r1 = src, r2 = byte length | |
22 | * returns the number of characters copied (strlen of copied string), | |
23 | * -EFAULT on exception, or "len" if we fill the whole buffer | |
24 | */ | |
25 | ENTRY(__strncpy_from_user) | |
26 | mov ip, r1 | |
27 | 1: sub.a r2, r2, #1 | |
28 | ldrusr r3, r1, 1, ns | |
29 | bfs 2f | |
30 | stb.w r3, [r0]+, #1 | |
31 | cxor.a r3, #0 | |
32 | bne 1b | |
33 | sub r1, r1, #1 @ take NUL character out of count | |
34 | 2: sub r0, r1, ip | |
35 | mov pc, lr | |
36 | ENDPROC(__strncpy_from_user) | |
37 | ||
38 | .pushsection .fixup,"ax" | |
39 | .align 0 | |
40 | 9001: mov r3, #0 | |
41 | stb r3, [r0+], #0 @ null terminate | |
42 | mov r0, #-EFAULT | |
43 | mov pc, lr | |
44 | .popsection | |
45 |