1/*
2 *  linux/arch/arm/lib/getuser.S
3 *
4 *  Copyright (C) 2001 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 *  Idea from x86 version, (C) Copyright 1998 Linus Torvalds
11 *
12 * These functions have a non-standard call interface to make them more
13 * efficient, especially as they return an error value in addition to
14 * the "real" return value.
15 *
16 * __get_user_X
17 *
18 * Inputs:	r0 contains the address
19 *		r1 contains the address limit, which must be preserved
20 * Outputs:	r0 is the error code
21 *		r2, r3 contains the zero-extended value
22 *		lr corrupted
23 *
24 * No other registers must be altered.  (see <asm/uaccess.h>
25 * for specific ASM register usage).
26 *
27 * Note that ADDR_LIMIT is either 0 or 0xc0000000.
28 * Note also that it is intended that __get_user_bad is not global.
29 */
30#include <linux/linkage.h>
31#include <asm/assembler.h>
32#include <asm/errno.h>
33#include <asm/domain.h>
34
35ENTRY(__get_user_1)
36	check_uaccess r0, 1, r1, r2, __get_user_bad
371: TUSER(ldrb)	r2, [r0]
38	mov	r0, #0
39	ret	lr
40ENDPROC(__get_user_1)
41_ASM_NOKPROBE(__get_user_1)
42
43ENTRY(__get_user_2)
44	check_uaccess r0, 2, r1, r2, __get_user_bad
45#ifdef CONFIG_CPU_USE_DOMAINS
46rb	.req	ip
472:	ldrbt	r2, [r0], #1
483:	ldrbt	rb, [r0], #0
49#else
50rb	.req	r0
512:	ldrb	r2, [r0]
523:	ldrb	rb, [r0, #1]
53#endif
54#ifndef __ARMEB__
55	orr	r2, r2, rb, lsl #8
56#else
57	orr	r2, rb, r2, lsl #8
58#endif
59	mov	r0, #0
60	ret	lr
61ENDPROC(__get_user_2)
62_ASM_NOKPROBE(__get_user_2)
63
64ENTRY(__get_user_4)
65	check_uaccess r0, 4, r1, r2, __get_user_bad
664: TUSER(ldr)	r2, [r0]
67	mov	r0, #0
68	ret	lr
69ENDPROC(__get_user_4)
70_ASM_NOKPROBE(__get_user_4)
71
72ENTRY(__get_user_8)
73	check_uaccess r0, 8, r1, r2, __get_user_bad8
74#ifdef CONFIG_THUMB2_KERNEL
755: TUSER(ldr)	r2, [r0]
766: TUSER(ldr)	r3, [r0, #4]
77#else
785: TUSER(ldr)	r2, [r0], #4
796: TUSER(ldr)	r3, [r0]
80#endif
81	mov	r0, #0
82	ret	lr
83ENDPROC(__get_user_8)
84_ASM_NOKPROBE(__get_user_8)
85
86#ifdef __ARMEB__
87ENTRY(__get_user_32t_8)
88	check_uaccess r0, 8, r1, r2, __get_user_bad
89#ifdef CONFIG_CPU_USE_DOMAINS
90	add	r0, r0, #4
917:	ldrt	r2, [r0]
92#else
937:	ldr	r2, [r0, #4]
94#endif
95	mov	r0, #0
96	ret	lr
97ENDPROC(__get_user_32t_8)
98_ASM_NOKPROBE(__get_user_32t_8)
99
100ENTRY(__get_user_64t_1)
101	check_uaccess r0, 1, r1, r2, __get_user_bad8
1028: TUSER(ldrb)	r3, [r0]
103	mov	r0, #0
104	ret	lr
105ENDPROC(__get_user_64t_1)
106_ASM_NOKPROBE(__get_user_64t_1)
107
108ENTRY(__get_user_64t_2)
109	check_uaccess r0, 2, r1, r2, __get_user_bad8
110#ifdef CONFIG_CPU_USE_DOMAINS
111rb	.req	ip
1129:	ldrbt	r3, [r0], #1
11310:	ldrbt	rb, [r0], #0
114#else
115rb	.req	r0
1169:	ldrb	r3, [r0]
11710:	ldrb	rb, [r0, #1]
118#endif
119	orr	r3, rb, r3, lsl #8
120	mov	r0, #0
121	ret	lr
122ENDPROC(__get_user_64t_2)
123_ASM_NOKPROBE(__get_user_64t_2)
124
125ENTRY(__get_user_64t_4)
126	check_uaccess r0, 4, r1, r2, __get_user_bad8
12711: TUSER(ldr)	r3, [r0]
128	mov	r0, #0
129	ret	lr
130ENDPROC(__get_user_64t_4)
131_ASM_NOKPROBE(__get_user_64t_4)
132#endif
133
134__get_user_bad8:
135	mov	r3, #0
136__get_user_bad:
137	mov	r2, #0
138	mov	r0, #-EFAULT
139	ret	lr
140ENDPROC(__get_user_bad)
141ENDPROC(__get_user_bad8)
142_ASM_NOKPROBE(__get_user_bad)
143_ASM_NOKPROBE(__get_user_bad8)
144
145.pushsection __ex_table, "a"
146	.long	1b, __get_user_bad
147	.long	2b, __get_user_bad
148	.long	3b, __get_user_bad
149	.long	4b, __get_user_bad
150	.long	5b, __get_user_bad8
151	.long	6b, __get_user_bad8
152#ifdef __ARMEB__
153	.long   7b, __get_user_bad
154	.long	8b, __get_user_bad8
155	.long	9b, __get_user_bad8
156	.long	10b, __get_user_bad8
157	.long	11b, __get_user_bad8
158#endif
159.popsection
160