1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
|
/*
* __put_user functions.
*
* (C) Copyright 2005 Linus Torvalds
*
* These functions have a non-standard call interface
* to make them more efficient, especially as they
* return an error value in addition to the "real"
* return value.
*/
#include <linux/linkage.h>
#include <asm/dwarf2.h>
#include <asm/thread_info.h>
/*
* __put_user_X
*
* Inputs: %eax[:%edx] contains the data
* %ecx contains the address
*
* Outputs: %eax is error code (0 or -EFAULT)
*
* These functions should not modify any other registers,
* as they get called from within inline assembly.
*/
#define ENTER CFI_STARTPROC ; \
pushl %ebx ; \
CFI_ADJUST_CFA_OFFSET 4 ; \
CFI_REL_OFFSET ebx, 0 ; \
GET_THREAD_INFO(%ebx)
#define EXIT popl %ebx ; \
CFI_ADJUST_CFA_OFFSET -4 ; \
CFI_RESTORE ebx ; \
ret ; \
CFI_ENDPROC
.text
ENTRY(__put_user_1)
ENTER
cmpl TI_addr_limit(%ebx),%ecx
jae bad_put_user
1: movb %al,(%ecx)
xorl %eax,%eax
EXIT
ENDPROC(__put_user_1)
ENTRY(__put_user_2)
ENTER
movl TI_addr_limit(%ebx),%ebx
subl $1,%ebx
cmpl %ebx,%ecx
jae bad_put_user
2: movw %ax,(%ecx)
xorl %eax,%eax
EXIT
ENDPROC(__put_user_2)
ENTRY(__put_user_4)
ENTER
movl TI_addr_limit(%ebx),%ebx
subl $3,%ebx
cmpl %ebx,%ecx
jae bad_put_user
3: movl %eax,(%ecx)
xorl %eax,%eax
EXIT
ENDPROC(__put_user_4)
ENTRY(__put_user_8)
ENTER
movl TI_addr_limit(%ebx),%ebx
subl $7,%ebx
cmpl %ebx,%ecx
jae bad_put_user
4: movl %eax,(%ecx)
5: movl %edx,4(%ecx)
xorl %eax,%eax
EXIT
ENDPROC(__put_user_8)
bad_put_user:
CFI_STARTPROC simple
CFI_DEF_CFA esp, 2*4
CFI_OFFSET eip, -1*4
CFI_OFFSET ebx, -2*4
movl $-14,%eax
EXIT
END(bad_put_user)
.section __ex_table,"a"
.long 1b,bad_put_user
.long 2b,bad_put_user
.long 3b,bad_put_user
.long 4b,bad_put_user
.long 5b,bad_put_user
.previous
|
