Commit | Line | Data |
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5f97f7f9 HS |
1 | /* |
2 | * Copy to/from userspace with optional address space checking. | |
3 | * | |
4 | * Copyright 2004-2006 Atmel Corporation | |
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/errno.h> | |
11 | ||
12 | #include <asm/page.h> | |
13 | #include <asm/thread_info.h> | |
14 | #include <asm/asm.h> | |
15 | ||
16 | /* | |
17 | * long strncpy_from_user(char *dst, const char *src, long count) | |
18 | * | |
19 | * On success, returns the length of the string, not including | |
20 | * the terminating NUL. | |
21 | * | |
22 | * If the string is longer than count, returns count | |
23 | * | |
24 | * If userspace access fails, returns -EFAULT | |
25 | */ | |
26 | .text | |
27 | .align 1 | |
28 | .global strncpy_from_user | |
29 | .type strncpy_from_user, "function" | |
30 | strncpy_from_user: | |
31 | mov r9, -EFAULT | |
32 | branch_if_kernel r8, __strncpy_from_user | |
33 | ret_if_privileged r8, r11, r10, r9 | |
34 | ||
35 | .global __strncpy_from_user | |
36 | .type __strncpy_from_user, "function" | |
37 | __strncpy_from_user: | |
38 | cp.w r10, 0 | |
39 | reteq 0 | |
40 | ||
41 | mov r9, r10 | |
42 | ||
43 | 1: ld.ub r8, r11++ | |
44 | st.b r12++, r8 | |
45 | cp.w r8, 0 | |
46 | breq 2f | |
47 | sub r9, 1 | |
48 | brne 1b | |
49 | ||
50 | 2: sub r10, r9 | |
51 | retal r10 | |
52 | ||
53 | .section .fixup, "ax" | |
54 | .align 1 | |
55 | 3: mov r12, -EFAULT | |
56 | retal r12 | |
57 | ||
58 | .section __ex_table, "a" | |
59 | .align 2 | |
60 | .long 1b, 3b |