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#include <asm/export.h> 35 36ENTRY(__get_user_1) 37 check_uaccess r0, 1, r1, r2, __get_user_bad 381: TUSER(ldrb) r2, [r0] 39 mov r0, #0 40 ret lr 41ENDPROC(__get_user_1) 42EXPORT_SYMBOL(__get_user_1) 43 44ENTRY(__get_user_2) 45 check_uaccess r0, 2, r1, r2, __get_user_bad 46#ifdef CONFIG_CPU_USE_DOMAINS 47rb .req ip 482: ldrbt r2, [r0], #1 493: ldrbt rb, [r0], #0 50#else 51rb .req r0 522: ldrb r2, [r0] 533: ldrb rb, [r0, #1] 54#endif 55#ifndef __ARMEB__ 56 orr r2, r2, rb, lsl #8 57#else 58 orr r2, rb, r2, lsl #8 59#endif 60 mov r0, #0 61 ret lr 62ENDPROC(__get_user_2) 63EXPORT_SYMBOL(__get_user_2) 64 65ENTRY(__get_user_4) 66 check_uaccess r0, 4, r1, r2, __get_user_bad 674: TUSER(ldr) r2, [r0] 68 mov r0, #0 69 ret lr 70ENDPROC(__get_user_4) 71EXPORT_SYMBOL(__get_user_4) 72 73ENTRY(__get_user_8) 74 check_uaccess r0, 8, r1, r2, __get_user_bad 75#ifdef CONFIG_THUMB2_KERNEL 765: TUSER(ldr) r2, [r0] 776: TUSER(ldr) r3, [r0, #4] 78#else 795: TUSER(ldr) r2, [r0], #4 806: TUSER(ldr) r3, [r0] 81#endif 82 mov r0, #0 83 ret lr 84ENDPROC(__get_user_8) 85EXPORT_SYMBOL(__get_user_8) 86 87#ifdef __ARMEB__ 88ENTRY(__get_user_32t_8) 89 check_uaccess r0, 8, r1, r2, __get_user_bad 90#ifdef CONFIG_CPU_USE_DOMAINS 91 add r0, r0, #4 927: ldrt r2, [r0] 93#else 947: ldr r2, [r0, #4] 95#endif 96 mov r0, #0 97 ret lr 98ENDPROC(__get_user_32t_8) 99EXPORT_SYMBOL(__get_user_32t_8) 100 101ENTRY(__get_user_64t_1) 102 check_uaccess r0, 1, r1, r2, __get_user_bad8 1038: TUSER(ldrb) r3, [r0] 104 mov r0, #0 105 ret lr 106ENDPROC(__get_user_64t_1) 107EXPORT_SYMBOL(__get_user_64t_1) 108 109ENTRY(__get_user_64t_2) 110 check_uaccess r0, 2, r1, r2, __get_user_bad8 111#ifdef CONFIG_CPU_USE_DOMAINS 112rb .req ip 1139: ldrbt r3, [r0], #1 11410: ldrbt rb, [r0], #0 115#else 116rb .req r0 1179: ldrb r3, [r0] 11810: ldrb rb, [r0, #1] 119#endif 120 orr r3, rb, r3, lsl #8 121 mov r0, #0 122 ret lr 123ENDPROC(__get_user_64t_2) 124EXPORT_SYMBOL(__get_user_64t_2) 125 126ENTRY(__get_user_64t_4) 127 check_uaccess r0, 4, r1, r2, __get_user_bad8 12811: TUSER(ldr) r3, [r0] 129 mov r0, #0 130 ret lr 131ENDPROC(__get_user_64t_4) 132EXPORT_SYMBOL(__get_user_64t_4) 133#endif 134 135__get_user_bad8: 136 mov r3, #0 137__get_user_bad: 138 mov r2, #0 139 mov r0, #-EFAULT 140 ret lr 141ENDPROC(__get_user_bad) 142ENDPROC(__get_user_bad8) 143 144.pushsection __ex_table, "a" 145 .long 1b, __get_user_bad 146 .long 2b, __get_user_bad 147 .long 3b, __get_user_bad 148 .long 4b, __get_user_bad 149 .long 5b, __get_user_bad8 150 .long 6b, __get_user_bad8 151#ifdef __ARMEB__ 152 .long 7b, __get_user_bad 153 .long 8b, __get_user_bad8 154 .long 9b, __get_user_bad8 155 .long 10b, __get_user_bad8 156 .long 11b, __get_user_bad8 157#endif 158.popsection 159