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 * Outputs:	r0 is the error code
20 *		r2, r3 contains the zero-extended value
21 *		lr corrupted
22 *
23 * No other registers must be altered.  (see <asm/uaccess.h>
24 * for specific ASM register usage).
25 *
26 * Note that ADDR_LIMIT is either 0 or 0xc0000000.
27 * Note also that it is intended that __get_user_bad is not global.
28 */
29#include <linux/linkage.h>
 
30#include <asm/errno.h>
31#include <asm/domain.h>
32
33ENTRY(__get_user_1)
341:	T(ldrb)	r2, [r0]
 
35	mov	r0, #0
36	mov	pc, lr
37ENDPROC(__get_user_1)
38
39ENTRY(__get_user_2)
40#ifdef CONFIG_THUMB2_KERNEL
412:	T(ldrb)	r2, [r0]
423:	T(ldrb)	r3, [r0, #1]
 
 
43#else
442:	T(ldrb)	r2, [r0], #1
453:	T(ldrb)	r3, [r0]
 
46#endif
47#ifndef __ARMEB__
48	orr	r2, r2, r3, lsl #8
49#else
50	orr	r2, r3, r2, lsl #8
51#endif
52	mov	r0, #0
53	mov	pc, lr
54ENDPROC(__get_user_2)
55
56ENTRY(__get_user_4)
574:	T(ldr)	r2, [r0]
 
58	mov	r0, #0
59	mov	pc, lr
60ENDPROC(__get_user_4)
61
62__get_user_bad:
63	mov	r2, #0
64	mov	r0, #-EFAULT
65	mov	pc, lr
66ENDPROC(__get_user_bad)
67
68.pushsection __ex_table, "a"
69	.long	1b, __get_user_bad
70	.long	2b, __get_user_bad
71	.long	3b, __get_user_bad
72	.long	4b, __get_user_bad
73.popsection

 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 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	mov	pc, lr
40ENDPROC(__get_user_1)
41
42ENTRY(__get_user_2)
43	check_uaccess r0, 2, r1, r2, __get_user_bad
44#ifdef CONFIG_CPU_USE_DOMAINS
45rb	.req	ip
462:	ldrbt	r2, [r0], #1
473:	ldrbt	rb, [r0], #0
48#else
49rb	.req	r0
502:	ldrb	r2, [r0]
513:	ldrb	rb, [r0, #1]
52#endif
53#ifndef __ARMEB__
54	orr	r2, r2, rb, lsl #8
55#else
56	orr	r2, rb, r2, lsl #8
57#endif
58	mov	r0, #0
59	mov	pc, lr
60ENDPROC(__get_user_2)
61
62ENTRY(__get_user_4)
63	check_uaccess r0, 4, r1, r2, __get_user_bad
644: TUSER(ldr)	r2, [r0]
65	mov	r0, #0
66	mov	pc, lr
67ENDPROC(__get_user_4)
68
69__get_user_bad:
70	mov	r2, #0
71	mov	r0, #-EFAULT
72	mov	pc, lr
73ENDPROC(__get_user_bad)
74
75.pushsection __ex_table, "a"
76	.long	1b, __get_user_bad
77	.long	2b, __get_user_bad
78	.long	3b, __get_user_bad
79	.long	4b, __get_user_bad
80.popsection