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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 Linus Torvalds
8 *
9 * These functions have a non-standard call interface to make them more
10 * efficient, especially as they return an error value in addition to
11 * the "real" return value.
12 *
13 * __get_user_X
14 *
15 * Inputs: r0 contains the address
16 * r1 contains the address limit, which must be preserved
17 * Outputs: r0 is the error code
18 * r2, r3 contains the zero-extended value
19 * lr corrupted
20 *
21 * No other registers must be altered. (see <asm/uaccess.h>
22 * for specific ASM register usage).
23 *
24 * Note that ADDR_LIMIT is either 0 or 0xc0000000.
25 * Note also that it is intended that __get_user_bad is not global.
26 */
27#include <linux/linkage.h>
28#include <asm/assembler.h>
29#include <asm/errno.h>
30#include <asm/domain.h>
31
32ENTRY(__get_user_1)
33 check_uaccess r0, 1, r1, r2, __get_user_bad
341: TUSER(ldrb) r2, [r0]
35 mov r0, #0
36 ret lr
37ENDPROC(__get_user_1)
38_ASM_NOKPROBE(__get_user_1)
39
40ENTRY(__get_user_2)
41 check_uaccess r0, 2, r1, r2, __get_user_bad
42#if __LINUX_ARM_ARCH__ >= 6
43
442: TUSER(ldrh) r2, [r0]
45
46#else
47
48#ifdef CONFIG_CPU_USE_DOMAINS
49rb .req ip
502: ldrbt r2, [r0], #1
513: ldrbt rb, [r0], #0
52#else
53rb .req r0
542: ldrb r2, [r0]
553: 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
67ENDPROC(__get_user_2)
68_ASM_NOKPROBE(__get_user_2)
69
70ENTRY(__get_user_4)
71 check_uaccess r0, 4, r1, r2, __get_user_bad
724: TUSER(ldr) r2, [r0]
73 mov r0, #0
74 ret lr
75ENDPROC(__get_user_4)
76_ASM_NOKPROBE(__get_user_4)
77
78ENTRY(__get_user_8)
79 check_uaccess r0, 8, r1, r2, __get_user_bad8
80#ifdef CONFIG_THUMB2_KERNEL
815: TUSER(ldr) r2, [r0]
826: TUSER(ldr) r3, [r0, #4]
83#else
845: TUSER(ldr) r2, [r0], #4
856: TUSER(ldr) r3, [r0]
86#endif
87 mov r0, #0
88 ret lr
89ENDPROC(__get_user_8)
90_ASM_NOKPROBE(__get_user_8)
91
92#ifdef __ARMEB__
93ENTRY(__get_user_32t_8)
94 check_uaccess r0, 8, r1, r2, __get_user_bad
95#ifdef CONFIG_CPU_USE_DOMAINS
96 add r0, r0, #4
977: ldrt r2, [r0]
98#else
997: ldr r2, [r0, #4]
100#endif
101 mov r0, #0
102 ret lr
103ENDPROC(__get_user_32t_8)
104_ASM_NOKPROBE(__get_user_32t_8)
105
106ENTRY(__get_user_64t_1)
107 check_uaccess r0, 1, r1, r2, __get_user_bad8
1088: TUSER(ldrb) r3, [r0]
109 mov r0, #0
110 ret lr
111ENDPROC(__get_user_64t_1)
112_ASM_NOKPROBE(__get_user_64t_1)
113
114ENTRY(__get_user_64t_2)
115 check_uaccess r0, 2, r1, r2, __get_user_bad8
116#ifdef CONFIG_CPU_USE_DOMAINS
117rb .req ip
1189: ldrbt r3, [r0], #1
11910: ldrbt rb, [r0], #0
120#else
121rb .req r0
1229: ldrb r3, [r0]
12310: ldrb rb, [r0, #1]
124#endif
125 orr r3, rb, r3, lsl #8
126 mov r0, #0
127 ret lr
128ENDPROC(__get_user_64t_2)
129_ASM_NOKPROBE(__get_user_64t_2)
130
131ENTRY(__get_user_64t_4)
132 check_uaccess r0, 4, r1, r2, __get_user_bad8
13311: TUSER(ldr) r3, [r0]
134 mov r0, #0
135 ret lr
136ENDPROC(__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
146ENDPROC(__get_user_bad)
147ENDPROC(__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