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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 | */ | |
11 | #include <asm/thread_info.h> | |
12 | ||
13 | ||
14 | /* | |
15 | * __put_user_X | |
16 | * | |
17 | * Inputs: %eax[:%edx] contains the data | |
18 | * %ecx contains the address | |
19 | * | |
20 | * Outputs: %eax is error code (0 or -EFAULT) | |
21 | * | |
22 | * These functions should not modify any other registers, | |
23 | * as they get called from within inline assembly. | |
24 | */ | |
25 | ||
26 | #define ENTER pushl %ebx ; GET_THREAD_INFO(%ebx) | |
27 | #define EXIT popl %ebx ; ret | |
28 | ||
29 | .text | |
30 | .align 4 | |
31 | .globl __put_user_1 | |
32 | __put_user_1: | |
33 | ENTER | |
34 | cmpl TI_addr_limit(%ebx),%ecx | |
35 | jae bad_put_user | |
36 | 1: movb %al,(%ecx) | |
37 | xorl %eax,%eax | |
38 | EXIT | |
39 | ||
40 | .align 4 | |
41 | .globl __put_user_2 | |
42 | __put_user_2: | |
43 | ENTER | |
44 | movl TI_addr_limit(%ebx),%ebx | |
45 | subl $1,%ebx | |
46 | cmpl %ebx,%ecx | |
47 | jae bad_put_user | |
48 | 2: movw %ax,(%ecx) | |
49 | xorl %eax,%eax | |
50 | EXIT | |
51 | ||
52 | .align 4 | |
53 | .globl __put_user_4 | |
54 | __put_user_4: | |
55 | ENTER | |
56 | movl TI_addr_limit(%ebx),%ebx | |
57 | subl $3,%ebx | |
58 | cmpl %ebx,%ecx | |
59 | jae bad_put_user | |
60 | 3: movl %eax,(%ecx) | |
61 | xorl %eax,%eax | |
62 | EXIT | |
63 | ||
64 | .align 4 | |
65 | .globl __put_user_8 | |
66 | __put_user_8: | |
67 | ENTER | |
68 | movl TI_addr_limit(%ebx),%ebx | |
69 | subl $7,%ebx | |
70 | cmpl %ebx,%ecx | |
71 | jae bad_put_user | |
72 | 4: movl %eax,(%ecx) | |
73 | 5: movl %edx,4(%ecx) | |
74 | xorl %eax,%eax | |
75 | EXIT | |
76 | ||
77 | bad_put_user: | |
78 | movl $-14,%eax | |
79 | EXIT | |
80 | ||
81 | .section __ex_table,"a" | |
82 | .long 1b,bad_put_user | |
83 | .long 2b,bad_put_user | |
84 | .long 3b,bad_put_user | |
85 | .long 4b,bad_put_user | |
86 | .long 5b,bad_put_user | |
87 | .previous |