1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * linux/arch/arm/lib/getuser.S
4 *
5 * Copyright (C) 2001 Russell King
6 *
7 * Idea from x86 version, (C) Copyright 1998
8 *
9 * These functions have a non-standard call in
10 * efficient, especially as they return an err
11 * the "real" return value.
12 *
13 * __get_user_X
14 *
15 * Inputs: r0 contains the address
16 * r1 contains the address limit,
17 * Outputs: r0 is the error code
18 * r2, r3 contains the zero-exten
19 * lr corrupted
20 *
21 * No other registers must be altered. (see <
22 * for specific ASM register usage).
23 *
24 * Note that ADDR_LIMIT is either 0 or 0xc0000
25 * Note also that it is intended that __get_us
26 */
27 #include <linux/linkage.h>
28 #include <asm/assembler.h>
29 #include <asm/errno.h>
30 #include <asm/domain.h>
31
32 ENTRY(__get_user_1)
33 check_uaccess r0, 1, r1, r2, __get_use
34 1: TUSER(ldrb) r2, [r0]
35 mov r0, #0
36 ret lr
37 ENDPROC(__get_user_1)
38 _ASM_NOKPROBE(__get_user_1)
39
40 ENTRY(__get_user_2)
41 check_uaccess r0, 2, r1, r2, __get_use
42 #if __LINUX_ARM_ARCH__ >= 6
43
44 2: TUSER(ldrh) r2, [r0]
45
46 #else
47
48 #ifdef CONFIG_CPU_USE_DOMAINS
49 rb .req ip
50 2: ldrbt r2, [r0], #1
51 3: ldrbt rb, [r0], #0
52 #else
53 rb .req r0
54 2: ldrb r2, [r0]
55 3: ldrb rb, [r0, #1]
56 #endif
57 #ifndef __ARMEB__
58 orr r2, r2, rb, lsl #8
59 #else
60 orr r2, rb, r2, lsl #8
61 #endif
62
63 #endif /* __LINUX_ARM_ARCH__ >= 6 */
64
65 mov r0, #0
66 ret lr
67 ENDPROC(__get_user_2)
68 _ASM_NOKPROBE(__get_user_2)
69
70 ENTRY(__get_user_4)
71 check_uaccess r0, 4, r1, r2, __get_use
72 4: TUSER(ldr) r2, [r0]
73 mov r0, #0
74 ret lr
75 ENDPROC(__get_user_4)
76 _ASM_NOKPROBE(__get_user_4)
77
78 ENTRY(__get_user_8)
79 check_uaccess r0, 8, r1, r2, __get_use
80 #ifdef CONFIG_THUMB2_KERNEL
81 5: TUSER(ldr) r2, [r0]
82 6: TUSER(ldr) r3, [r0, #4]
83 #else
84 5: TUSER(ldr) r2, [r0], #4
85 6: TUSER(ldr) r3, [r0]
86 #endif
87 mov r0, #0
88 ret lr
89 ENDPROC(__get_user_8)
90 _ASM_NOKPROBE(__get_user_8)
91
92 #ifdef __ARMEB__
93 ENTRY(__get_user_32t_8)
94 check_uaccess r0, 8, r1, r2, __get_use
95 #ifdef CONFIG_CPU_USE_DOMAINS
96 add r0, r0, #4
97 7: ldrt r2, [r0]
98 #else
99 7: ldr r2, [r0, #4]
100 #endif
101 mov r0, #0
102 ret lr
103 ENDPROC(__get_user_32t_8)
104 _ASM_NOKPROBE(__get_user_32t_8)
105
106 ENTRY(__get_user_64t_1)
107 check_uaccess r0, 1, r1, r2, __get_use
108 8: TUSER(ldrb) r3, [r0]
109 mov r0, #0
110 ret lr
111 ENDPROC(__get_user_64t_1)
112 _ASM_NOKPROBE(__get_user_64t_1)
113
114 ENTRY(__get_user_64t_2)
115 check_uaccess r0, 2, r1, r2, __get_use
116 #ifdef CONFIG_CPU_USE_DOMAINS
117 rb .req ip
118 9: ldrbt r3, [r0], #1
119 10: ldrbt rb, [r0], #0
120 #else
121 rb .req r0
122 9: ldrb r3, [r0]
123 10: ldrb rb, [r0, #1]
124 #endif
125 orr r3, rb, r3, lsl #8
126 mov r0, #0
127 ret lr
128 ENDPROC(__get_user_64t_2)
129 _ASM_NOKPROBE(__get_user_64t_2)
130
131 ENTRY(__get_user_64t_4)
132 check_uaccess r0, 4, r1, r2, __get_use
133 11: TUSER(ldr) r3, [r0]
134 mov r0, #0
135 ret lr
136 ENDPROC(__get_user_64t_4)
137 _ASM_NOKPROBE(__get_user_64t_4)
138 #endif
139
140 __get_user_bad8:
141 mov r3, #0
142 __get_user_bad:
143 mov r2, #0
144 mov r0, #-EFAULT
145 ret lr
146 ENDPROC(__get_user_bad)
147 ENDPROC(__get_user_bad8)
148 _ASM_NOKPROBE(__get_user_bad)
149 _ASM_NOKPROBE(__get_user_bad8)
150
151 .pushsection __ex_table, "a"
152 .long 1b, __get_user_bad
153 .long 2b, __get_user_bad
154 #if __LINUX_ARM_ARCH__ < 6
155 .long 3b, __get_user_bad
156 #endif
157 .long 4b, __get_user_bad
158 .long 5b, __get_user_bad8
159 .long 6b, __get_user_bad8
160 #ifdef __ARMEB__
161 .long 7b, __get_user_bad
162 .long 8b, __get_user_bad8
163 .long 9b, __get_user_bad8
164 .long 10b, __get_user_bad8
165 .long 11b, __get_user_bad8
166 #endif
167 .popsection
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