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1da177e4 LT |
1 | /* |
2 | * __put_user functions. | |
3 | * | |
4 | * (C) Copyright 2005 Linus Torvalds | |
5 | * | |
6 | * These functions have a non-standard call interface | |
7 | * to make them more efficient, especially as they | |
8 | * return an error value in addition to the "real" | |
9 | * return value. | |
10 | */ | |
00e065ea JB |
11 | #include <linux/linkage.h> |
12 | #include <asm/dwarf2.h> | |
1da177e4 LT |
13 | #include <asm/thread_info.h> |
14 | ||
15 | ||
16 | /* | |
17 | * __put_user_X | |
18 | * | |
19 | * Inputs: %eax[:%edx] contains the data | |
20 | * %ecx contains the address | |
21 | * | |
22 | * Outputs: %eax is error code (0 or -EFAULT) | |
23 | * | |
24 | * These functions should not modify any other registers, | |
25 | * as they get called from within inline assembly. | |
26 | */ | |
27 | ||
00e065ea | 28 | #define ENTER CFI_STARTPROC ; \ |
00e065ea | 29 | GET_THREAD_INFO(%ebx) |
268cf048 | 30 | #define EXIT ret ; \ |
00e065ea | 31 | CFI_ENDPROC |
1da177e4 LT |
32 | |
33 | .text | |
00e065ea | 34 | ENTRY(__put_user_1) |
1da177e4 | 35 | ENTER |
efea505d | 36 | cmp TI_addr_limit(%ebx),%ecx |
1da177e4 LT |
37 | jae bad_put_user |
38 | 1: movb %al,(%ecx) | |
efea505d | 39 | xor %eax,%eax |
1da177e4 | 40 | EXIT |
00e065ea | 41 | ENDPROC(__put_user_1) |
1da177e4 | 42 | |
00e065ea | 43 | ENTRY(__put_user_2) |
1da177e4 | 44 | ENTER |
efea505d GC |
45 | mov TI_addr_limit(%ebx),%ebx |
46 | sub $1,%ebx | |
47 | cmp %ebx,%ecx | |
1da177e4 LT |
48 | jae bad_put_user |
49 | 2: movw %ax,(%ecx) | |
efea505d | 50 | xor %eax,%eax |
1da177e4 | 51 | EXIT |
00e065ea | 52 | ENDPROC(__put_user_2) |
1da177e4 | 53 | |
00e065ea | 54 | ENTRY(__put_user_4) |
1da177e4 | 55 | ENTER |
efea505d GC |
56 | mov TI_addr_limit(%ebx),%ebx |
57 | sub $3,%ebx | |
58 | cmp %ebx,%ecx | |
1da177e4 LT |
59 | jae bad_put_user |
60 | 3: movl %eax,(%ecx) | |
efea505d | 61 | xor %eax,%eax |
1da177e4 | 62 | EXIT |
00e065ea | 63 | ENDPROC(__put_user_4) |
1da177e4 | 64 | |
00e065ea | 65 | ENTRY(__put_user_8) |
1da177e4 | 66 | ENTER |
efea505d GC |
67 | mov TI_addr_limit(%ebx),%ebx |
68 | sub $7,%ebx | |
69 | cmp %ebx,%ecx | |
1da177e4 LT |
70 | jae bad_put_user |
71 | 4: movl %eax,(%ecx) | |
72 | 5: movl %edx,4(%ecx) | |
efea505d | 73 | xor %eax,%eax |
1da177e4 | 74 | EXIT |
00e065ea | 75 | ENDPROC(__put_user_8) |
1da177e4 LT |
76 | |
77 | bad_put_user: | |
268cf048 | 78 | CFI_STARTPROC |
1da177e4 LT |
79 | movl $-14,%eax |
80 | EXIT | |
00e065ea | 81 | END(bad_put_user) |
1da177e4 LT |
82 | |
83 | .section __ex_table,"a" | |
84 | .long 1b,bad_put_user | |
85 | .long 2b,bad_put_user | |
86 | .long 3b,bad_put_user | |
87 | .long 4b,bad_put_user | |
88 | .long 5b,bad_put_user | |
89 | .previous |