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 include/asm-arm/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 <asm/constants.h> 30#include <asm/thread_info.h> 31#include <asm/errno.h> 32 33 .global __get_user_1 34__get_user_1: 351: ldrbt r2, [r0] 36 mov r0, #0 37 mov pc, lr 38 39 .global __get_user_2 40__get_user_2: 412: ldrbt r2, [r0], #1 423: ldrbt r3, [r0] 43#ifndef __ARMEB__ 44 orr r2, r2, r3, lsl #8 45#else 46 orr r2, r3, r2, lsl #8 47#endif 48 mov r0, #0 49 mov pc, lr 50 51 .global __get_user_4 52__get_user_4: 534: ldrt r2, [r0] 54 mov r0, #0 55 mov pc, lr 56 57 .global __get_user_8 58__get_user_8: 595: ldrt r2, [r0], #4 606: ldrt r3, [r0] 61 mov r0, #0 62 mov pc, lr 63 64__get_user_bad_8: 65 mov r3, #0 66__get_user_bad: 67 mov r2, #0 68 mov r0, #-EFAULT 69 mov pc, lr 70 71.section __ex_table, "a" 72 .long 1b, __get_user_bad 73 .long 2b, __get_user_bad 74 .long 3b, __get_user_bad 75 .long 4b, __get_user_bad 76 .long 5b, __get_user_bad_8 77 .long 6b, __get_user_bad_8 78.previous 79