2 * linux/arch/arm/lib/getuser.S
4 * Copyright (C) 2001 Russell King
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.
10 * Idea from x86 version, (C) Copyright 1998 Linus Torvalds
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.
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
24 * No other registers must be altered. (see <asm/uaccess.h>
25 * for specific ASM register usage).
27 * Note that ADDR_LIMIT is either 0 or 0xc0000000.
28 * Note also that it is intended that __get_user_bad is not global.
30 #include <linux/linkage.h>
31 #include <asm/assembler.h>
32 #include <asm/errno.h>
33 #include <asm/domain.h>
36 check_uaccess r0, 1, r1, r2, __get_user_bad
37 1: TUSER(ldrb) r2, [r0]
43 check_uaccess r0, 2, r1, r2, __get_user_bad
44 #ifdef CONFIG_CPU_USE_DOMAINS
54 orr r2, r2, rb, lsl #8
56 orr r2, rb, r2, lsl #8
63 check_uaccess r0, 4, r1, r2, __get_user_bad
64 4: TUSER(ldr) r2, [r0]
70 check_uaccess r0, 8, r1, r2, __get_user_bad
71 #ifdef CONFIG_THUMB2_KERNEL
72 5: TUSER(ldr) r2, [r0]
73 6: TUSER(ldr) r3, [r0, #4]
75 5: TUSER(ldr) r2, [r0], #4
76 6: TUSER(ldr) r3, [r0]
84 check_uaccess r0, 8, r1, r2, __get_user_bad
85 #ifdef CONFIG_CPU_USE_DOMAINS
93 ENDPROC(__get_user_lo8)
102 ENDPROC(__get_user_bad)
103 ENDPROC(__get_user_bad8)
105 .pushsection __ex_table, "a"
106 .long 1b, __get_user_bad
107 .long 2b, __get_user_bad
108 .long 3b, __get_user_bad
109 .long 4b, __get_user_bad
110 .long 5b, __get_user_bad8
111 .long 6b, __get_user_bad8
113 .long 7b, __get_user_bad