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1/*
2 * __get_user functions.
3 *
4 * (C) Copyright 1998 Linus Torvalds
5 * (C) Copyright 2005 Andi Kleen
6 * (C) Copyright 2008 Glauber Costa
7 *
8 * These functions have a non-standard call interface
9 * to make them more efficient, especially as they
10 * return an error value in addition to the "real"
11 * return value.
12 */
13
14/*
15 * __get_user_X
16 *
17 * Inputs: %[r|e]ax contains the address.
18 *
19 * Outputs: %[r|e]ax is error code (0 or -EFAULT)
20 * %[r|e]dx contains zero-extended value
21 * %ecx contains the high half for 32-bit __get_user_8
22 *
23 *
24 * These functions should not modify any other registers,
25 * as they get called from within inline assembly.
26 */
27
28#include <linux/linkage.h>
29#include <asm/dwarf2.h>
30#include <asm/page_types.h>
31#include <asm/errno.h>
32#include <asm/asm-offsets.h>
33#include <asm/thread_info.h>
34#include <asm/asm.h>
35#include <asm/smap.h>
36
37 .text
38ENTRY(__get_user_1)
39 CFI_STARTPROC
40 GET_THREAD_INFO(%_ASM_DX)
41 cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
42 jae bad_get_user
43 ASM_STAC
441: movzbl (%_ASM_AX),%edx
45 xor %eax,%eax
46 ASM_CLAC
47 ret
48 CFI_ENDPROC
49ENDPROC(__get_user_1)
50
51ENTRY(__get_user_2)
52 CFI_STARTPROC
53 add $1,%_ASM_AX
54 jc bad_get_user
55 GET_THREAD_INFO(%_ASM_DX)
56 cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
57 jae bad_get_user
58 ASM_STAC
592: movzwl -1(%_ASM_AX),%edx
60 xor %eax,%eax
61 ASM_CLAC
62 ret
63 CFI_ENDPROC
64ENDPROC(__get_user_2)
65
66ENTRY(__get_user_4)
67 CFI_STARTPROC
68 add $3,%_ASM_AX
69 jc bad_get_user
70 GET_THREAD_INFO(%_ASM_DX)
71 cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
72 jae bad_get_user
73 ASM_STAC
743: movl -3(%_ASM_AX),%edx
75 xor %eax,%eax
76 ASM_CLAC
77 ret
78 CFI_ENDPROC
79ENDPROC(__get_user_4)
80
81ENTRY(__get_user_8)
82 CFI_STARTPROC
83#ifdef CONFIG_X86_64
84 add $7,%_ASM_AX
85 jc bad_get_user
86 GET_THREAD_INFO(%_ASM_DX)
87 cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
88 jae bad_get_user
89 ASM_STAC
904: movq -7(%_ASM_AX),%rdx
91 xor %eax,%eax
92 ASM_CLAC
93 ret
94#else
95 add $7,%_ASM_AX
96 jc bad_get_user_8
97 GET_THREAD_INFO(%_ASM_DX)
98 cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
99 jae bad_get_user_8
100 ASM_STAC
1014: movl -7(%_ASM_AX),%edx
1025: movl -3(%_ASM_AX),%ecx
103 xor %eax,%eax
104 ASM_CLAC
105 ret
106#endif
107 CFI_ENDPROC
108ENDPROC(__get_user_8)
109
110
111bad_get_user:
112 CFI_STARTPROC
113 xor %edx,%edx
114 mov $(-EFAULT),%_ASM_AX
115 ASM_CLAC
116 ret
117 CFI_ENDPROC
118END(bad_get_user)
119
120#ifdef CONFIG_X86_32
121bad_get_user_8:
122 CFI_STARTPROC
123 xor %edx,%edx
124 xor %ecx,%ecx
125 mov $(-EFAULT),%_ASM_AX
126 ASM_CLAC
127 ret
128 CFI_ENDPROC
129END(bad_get_user_8)
130#endif
131
132 _ASM_EXTABLE(1b,bad_get_user)
133 _ASM_EXTABLE(2b,bad_get_user)
134 _ASM_EXTABLE(3b,bad_get_user)
135#ifdef CONFIG_X86_64
136 _ASM_EXTABLE(4b,bad_get_user)
137#else
138 _ASM_EXTABLE(4b,bad_get_user_8)
139 _ASM_EXTABLE(5b,bad_get_user_8)
140#endif
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * __get_user functions.
4 *
5 * (C) Copyright 1998 Linus Torvalds
6 * (C) Copyright 2005 Andi Kleen
7 * (C) Copyright 2008 Glauber Costa
8 *
9 * These functions have a non-standard call interface
10 * to make them more efficient, especially as they
11 * return an error value in addition to the "real"
12 * return value.
13 */
14
15/*
16 * __get_user_X
17 *
18 * Inputs: %[r|e]ax contains the address.
19 *
20 * Outputs: %[r|e]ax is error code (0 or -EFAULT)
21 * %[r|e]dx contains zero-extended value
22 * %ecx contains the high half for 32-bit __get_user_8
23 *
24 *
25 * These functions should not modify any other registers,
26 * as they get called from within inline assembly.
27 */
28
29#include <linux/linkage.h>
30#include <asm/page_types.h>
31#include <asm/errno.h>
32#include <asm/asm-offsets.h>
33#include <asm/thread_info.h>
34#include <asm/asm.h>
35#include <asm/smap.h>
36#include <asm/export.h>
37
38 .text
39ENTRY(__get_user_1)
40 mov PER_CPU_VAR(current_task), %_ASM_DX
41 cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
42 jae bad_get_user
43 sbb %_ASM_DX, %_ASM_DX /* array_index_mask_nospec() */
44 and %_ASM_DX, %_ASM_AX
45 ASM_STAC
461: movzbl (%_ASM_AX),%edx
47 xor %eax,%eax
48 ASM_CLAC
49 ret
50ENDPROC(__get_user_1)
51EXPORT_SYMBOL(__get_user_1)
52
53ENTRY(__get_user_2)
54 add $1,%_ASM_AX
55 jc bad_get_user
56 mov PER_CPU_VAR(current_task), %_ASM_DX
57 cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
58 jae bad_get_user
59 sbb %_ASM_DX, %_ASM_DX /* array_index_mask_nospec() */
60 and %_ASM_DX, %_ASM_AX
61 ASM_STAC
622: movzwl -1(%_ASM_AX),%edx
63 xor %eax,%eax
64 ASM_CLAC
65 ret
66ENDPROC(__get_user_2)
67EXPORT_SYMBOL(__get_user_2)
68
69ENTRY(__get_user_4)
70 add $3,%_ASM_AX
71 jc bad_get_user
72 mov PER_CPU_VAR(current_task), %_ASM_DX
73 cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
74 jae bad_get_user
75 sbb %_ASM_DX, %_ASM_DX /* array_index_mask_nospec() */
76 and %_ASM_DX, %_ASM_AX
77 ASM_STAC
783: movl -3(%_ASM_AX),%edx
79 xor %eax,%eax
80 ASM_CLAC
81 ret
82ENDPROC(__get_user_4)
83EXPORT_SYMBOL(__get_user_4)
84
85ENTRY(__get_user_8)
86#ifdef CONFIG_X86_64
87 add $7,%_ASM_AX
88 jc bad_get_user
89 mov PER_CPU_VAR(current_task), %_ASM_DX
90 cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
91 jae bad_get_user
92 sbb %_ASM_DX, %_ASM_DX /* array_index_mask_nospec() */
93 and %_ASM_DX, %_ASM_AX
94 ASM_STAC
954: movq -7(%_ASM_AX),%rdx
96 xor %eax,%eax
97 ASM_CLAC
98 ret
99#else
100 add $7,%_ASM_AX
101 jc bad_get_user_8
102 mov PER_CPU_VAR(current_task), %_ASM_DX
103 cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
104 jae bad_get_user_8
105 sbb %_ASM_DX, %_ASM_DX /* array_index_mask_nospec() */
106 and %_ASM_DX, %_ASM_AX
107 ASM_STAC
1084: movl -7(%_ASM_AX),%edx
1095: movl -3(%_ASM_AX),%ecx
110 xor %eax,%eax
111 ASM_CLAC
112 ret
113#endif
114ENDPROC(__get_user_8)
115EXPORT_SYMBOL(__get_user_8)
116
117
118.Lbad_get_user_clac:
119 ASM_CLAC
120bad_get_user:
121 xor %edx,%edx
122 mov $(-EFAULT),%_ASM_AX
123 ret
124
125#ifdef CONFIG_X86_32
126.Lbad_get_user_8_clac:
127 ASM_CLAC
128bad_get_user_8:
129 xor %edx,%edx
130 xor %ecx,%ecx
131 mov $(-EFAULT),%_ASM_AX
132 ret
133#endif
134
135 _ASM_EXTABLE_UA(1b, .Lbad_get_user_clac)
136 _ASM_EXTABLE_UA(2b, .Lbad_get_user_clac)
137 _ASM_EXTABLE_UA(3b, .Lbad_get_user_clac)
138#ifdef CONFIG_X86_64
139 _ASM_EXTABLE_UA(4b, .Lbad_get_user_clac)
140#else
141 _ASM_EXTABLE_UA(4b, .Lbad_get_user_8_clac)
142 _ASM_EXTABLE_UA(5b, .Lbad_get_user_8_clac)
143#endif