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1da177e4 LT |
1 | /* |
2 | * linux/arch/arm26/lib/getuser.S | |
3 | * | |
4 | * Copyright (C) 2001 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 | * Idea from x86 version, (C) Copyright 1998 Linus Torvalds | |
11 | * | |
12 | * These functions have a non-standard call interface to make them more | |
13 | * efficient, especially as they return an error value in addition to | |
14 | * the "real" return value. | |
15 | * | |
16 | * __get_user_X | |
17 | * | |
18 | * Inputs: r0 contains the address | |
19 | * Outputs: r0 is the error code | |
20 | * r1, r2 contains the zero-extended value | |
21 | * lr corrupted | |
22 | * | |
23 | * No other registers must be altered. (see include/asm-arm/uaccess.h | |
24 | * for specific ASM register usage). | |
25 | * | |
26 | * Note that ADDR_LIMIT is either 0 or 0xc0000000. | |
27 | * Note also that it is intended that __get_user_bad is not global. | |
28 | */ | |
47003497 | 29 | #include <asm/asm-offsets.h> |
1da177e4 LT |
30 | #include <asm/thread_info.h> |
31 | #include <asm/errno.h> | |
32 | ||
33 | .global __get_user_1 | |
34 | __get_user_1: | |
35 | bic r1, sp, #0x1f00 | |
36 | bic r1, r1, #0x00ff | |
37 | str lr, [sp, #-4]! | |
38 | ldr r1, [r1, #TI_ADDR_LIMIT] | |
39 | sub r1, r1, #1 | |
40 | cmp r0, r1 | |
41 | bge __get_user_bad | |
42 | cmp r0, #0x02000000 | |
43 | 1: ldrlsbt r1, [r0] | |
44 | ldrgeb r1, [r0] | |
45 | mov r0, #0 | |
46 | ldmfd sp!, {pc}^ | |
47 | ||
48 | .global __get_user_2 | |
49 | __get_user_2: | |
50 | bic r2, sp, #0x1f00 | |
51 | bic r2, r2, #0x00ff | |
52 | str lr, [sp, #-4]! | |
53 | ldr r2, [r2, #TI_ADDR_LIMIT] | |
54 | sub r2, r2, #2 | |
55 | cmp r0, r2 | |
56 | bge __get_user_bad | |
57 | cmp r0, #0x02000000 | |
58 | 2: ldrlsbt r1, [r0], #1 | |
59 | 3: ldrlsbt r2, [r0] | |
60 | ldrgeb r1, [r0], #1 | |
61 | ldrgeb r2, [r0] | |
62 | orr r1, r1, r2, lsl #8 | |
63 | mov r0, #0 | |
64 | ldmfd sp!, {pc}^ | |
65 | ||
66 | .global __get_user_4 | |
67 | __get_user_4: | |
68 | bic r1, sp, #0x1f00 | |
69 | bic r1, r1, #0x00ff | |
70 | str lr, [sp, #-4]! | |
71 | ldr r1, [r1, #TI_ADDR_LIMIT] | |
72 | sub r1, r1, #4 | |
73 | cmp r0, r1 | |
74 | bge __get_user_bad | |
75 | cmp r0, #0x02000000 | |
76 | 4: ldrlst r1, [r0] | |
77 | ldrge r1, [r0] | |
78 | mov r0, #0 | |
79 | ldmfd sp!, {pc}^ | |
80 | ||
81 | .global __get_user_8 | |
82 | __get_user_8: | |
83 | bic r2, sp, #0x1f00 | |
84 | bic r2, r2, #0x00ff | |
85 | str lr, [sp, #-4]! | |
86 | ldr r2, [r2, #TI_ADDR_LIMIT] | |
87 | sub r2, r2, #8 | |
88 | cmp r0, r2 | |
89 | bge __get_user_bad_8 | |
90 | cmp r0, #0x02000000 | |
91 | 5: ldrlst r1, [r0], #4 | |
92 | 6: ldrlst r2, [r0] | |
93 | ldrge r1, [r0], #4 | |
94 | ldrge r2, [r0] | |
95 | mov r0, #0 | |
96 | ldmfd sp!, {pc}^ | |
97 | ||
98 | __get_user_bad_8: | |
99 | mov r2, #0 | |
100 | __get_user_bad: | |
101 | mov r1, #0 | |
102 | mov r0, #-EFAULT | |
103 | ldmfd sp!, {pc}^ | |
104 | ||
105 | .section __ex_table, "a" | |
106 | .long 1b, __get_user_bad | |
107 | .long 2b, __get_user_bad | |
108 | .long 3b, __get_user_bad | |
109 | .long 4b, __get_user_bad | |
110 | .long 5b, __get_user_bad_8 | |
111 | .long 6b, __get_user_bad_8 | |
112 | .previous |