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Linux kernel mirror (for testing)
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linux
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
361: 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
482: 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
603: 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
724: movl %eax,(%ecx)
735: movl %edx,4(%ecx)
74 xorl %eax,%eax
75 EXIT
76
77bad_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