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 * Outputs: r0 is the error code
20 * r1, r2 contains the zero-extended value
23 * No other registers must be altered. (see include/asm-arm/uaccess.h
24 * for specific ASM register usage).
26 * Note that ADDR_LIMIT is either 0 or 0xc0000000.
27 * Note also that it is intended that __get_user_bad is not global.
29 #include <asm/constants.h>
35 ldr r1, [r1, #TSK_ADDR_LIMIT]
47 ldr r2, [r2, #TSK_ADDR_LIMIT]
50 2: ldrlsbt r1, [r0], #1
52 orrls r1, r1, r2, lsl #8
61 ldr r1, [r1, #TSK_ADDR_LIMIT]
73 ldr r2, [r2, #TSK_ADDR_LIMIT]
76 5: ldrlst r1, [r0], #4
90 .section __ex_table, "a"
91 .long 1b, __get_user_bad
92 .long 2b, __get_user_bad
93 .long 3b, __get_user_bad
94 .long 4b, __get_user_bad
95 .long 5b, __get_user_bad_8
96 .long 6b, __get_user_bad_8