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
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
|
/* SPDX-License-Identifier: GPL-2.0 */
/*
* __put_user functions.
*
* (C) Copyright 2005 Linus Torvalds
* (C) Copyright 2005 Andi Kleen
* (C) Copyright 2008 Glauber Costa
*
* 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/thread_info.h>
#include <asm/errno.h>
#include <asm/asm.h>
#include <asm/smap.h>
#include <asm/export.h>
/*
* __put_user_X
*
* Inputs: %eax[:%edx] contains the data
* %ecx contains the address
*
* Outputs: %ecx is error code (0 or -EFAULT)
*
* Clobbers: %ebx needed for task pointer
*
* These functions should not modify any other registers,
* as they get called from within inline assembly.
*/
#ifdef CONFIG_X86_5LEVEL
#define LOAD_TASK_SIZE_MINUS_N(n) \
ALTERNATIVE __stringify(mov $((1 << 47) - 4096 - (n)),%rbx), \
__stringify(mov $((1 << 56) - 4096 - (n)),%rbx), X86_FEATURE_LA57
#else
#define LOAD_TASK_SIZE_MINUS_N(n) \
mov $(TASK_SIZE_MAX - (n)),%_ASM_BX
#endif
.text
SYM_FUNC_START(__put_user_1)
LOAD_TASK_SIZE_MINUS_N(0)
cmp %_ASM_BX,%_ASM_CX
jae .Lbad_put_user
SYM_INNER_LABEL(__put_user_nocheck_1, SYM_L_GLOBAL)
ASM_STAC
1: movb %al,(%_ASM_CX)
xor %ecx,%ecx
ASM_CLAC
RET
SYM_FUNC_END(__put_user_1)
EXPORT_SYMBOL(__put_user_1)
EXPORT_SYMBOL(__put_user_nocheck_1)
SYM_FUNC_START(__put_user_2)
LOAD_TASK_SIZE_MINUS_N(1)
cmp %_ASM_BX,%_ASM_CX
jae .Lbad_put_user
SYM_INNER_LABEL(__put_user_nocheck_2, SYM_L_GLOBAL)
ASM_STAC
2: movw %ax,(%_ASM_CX)
xor %ecx,%ecx
ASM_CLAC
RET
SYM_FUNC_END(__put_user_2)
EXPORT_SYMBOL(__put_user_2)
EXPORT_SYMBOL(__put_user_nocheck_2)
SYM_FUNC_START(__put_user_4)
LOAD_TASK_SIZE_MINUS_N(3)
cmp %_ASM_BX,%_ASM_CX
jae .Lbad_put_user
SYM_INNER_LABEL(__put_user_nocheck_4, SYM_L_GLOBAL)
ASM_STAC
3: movl %eax,(%_ASM_CX)
xor %ecx,%ecx
ASM_CLAC
RET
SYM_FUNC_END(__put_user_4)
EXPORT_SYMBOL(__put_user_4)
EXPORT_SYMBOL(__put_user_nocheck_4)
SYM_FUNC_START(__put_user_8)
LOAD_TASK_SIZE_MINUS_N(7)
cmp %_ASM_BX,%_ASM_CX
jae .Lbad_put_user
SYM_INNER_LABEL(__put_user_nocheck_8, SYM_L_GLOBAL)
ASM_STAC
4: mov %_ASM_AX,(%_ASM_CX)
#ifdef CONFIG_X86_32
5: movl %edx,4(%_ASM_CX)
#endif
xor %ecx,%ecx
ASM_CLAC
RET
SYM_FUNC_END(__put_user_8)
EXPORT_SYMBOL(__put_user_8)
EXPORT_SYMBOL(__put_user_nocheck_8)
SYM_CODE_START_LOCAL(.Lbad_put_user_clac)
ASM_CLAC
.Lbad_put_user:
movl $-EFAULT,%ecx
RET
SYM_CODE_END(.Lbad_put_user_clac)
_ASM_EXTABLE_UA(1b, .Lbad_put_user_clac)
_ASM_EXTABLE_UA(2b, .Lbad_put_user_clac)
_ASM_EXTABLE_UA(3b, .Lbad_put_user_clac)
_ASM_EXTABLE_UA(4b, .Lbad_put_user_clac)
#ifdef CONFIG_X86_32
_ASM_EXTABLE_UA(5b, .Lbad_put_user_clac)
#endif
|
