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 35ENTRY(__get_user_1) 36 check_uaccess r0, 1, r1, r2, __get_user_bad 371: TUSER(ldrb) r2, [r0] 38 mov r0, #0 39 ret 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 ret 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 ret lr 67ENDPROC(__get_user_4) 68 69ENTRY(__get_user_8) 70 check_uaccess r0, 8, r1, r2, __get_user_bad8 71#ifdef CONFIG_THUMB2_KERNEL 725: TUSER(ldr) r2, [r0] 736: TUSER(ldr) r3, [r0, #4] 74#else 755: TUSER(ldr) r2, [r0], #4 766: TUSER(ldr) r3, [r0] 77#endif 78 mov r0, #0 79 ret lr 80ENDPROC(__get_user_8) 81 82#ifdef __ARMEB__ 83ENTRY(__get_user_32t_8) 84 check_uaccess r0, 8, r1, r2, __get_user_bad 85#ifdef CONFIG_CPU_USE_DOMAINS 86 add r0, r0, #4 877: ldrt r2, [r0] 88#else 897: ldr r2, [r0, #4] 90#endif 91 mov r0, #0 92 ret lr 93ENDPROC(__get_user_32t_8) 94 95ENTRY(__get_user_64t_1) 96 check_uaccess r0, 1, r1, r2, __get_user_bad8 978: TUSER(ldrb) r3, [r0] 98 mov r0, #0 99 ret lr 100ENDPROC(__get_user_64t_1) 101 102ENTRY(__get_user_64t_2) 103 check_uaccess r0, 2, r1, r2, __get_user_bad8 104#ifdef CONFIG_CPU_USE_DOMAINS 105rb .req ip 1069: ldrbt r3, [r0], #1 10710: ldrbt rb, [r0], #0 108#else 109rb .req r0 1109: ldrb r3, [r0] 11110: ldrb rb, [r0, #1] 112#endif 113 orr r3, rb, r3, lsl #8 114 mov r0, #0 115 ret lr 116ENDPROC(__get_user_64t_2) 117 118ENTRY(__get_user_64t_4) 119 check_uaccess r0, 4, r1, r2, __get_user_bad8 12011: TUSER(ldr) r3, [r0] 121 mov r0, #0 122 ret lr 123ENDPROC(__get_user_64t_4) 124#endif 125 126__get_user_bad8: 127 mov r3, #0 128__get_user_bad: 129 mov r2, #0 130 mov r0, #-EFAULT 131 ret lr 132ENDPROC(__get_user_bad) 133ENDPROC(__get_user_bad8) 134 135.pushsection __ex_table, "a" 136 .long 1b, __get_user_bad 137 .long 2b, __get_user_bad 138 .long 3b, __get_user_bad 139 .long 4b, __get_user_bad 140 .long 5b, __get_user_bad8 141 .long 6b, __get_user_bad8 142#ifdef __ARMEB__ 143 .long 7b, __get_user_bad 144 .long 8b, __get_user_bad8 145 .long 9b, __get_user_bad8 146 .long 10b, __get_user_bad8 147 .long 11b, __get_user_bad8 148#endif 149.popsection 150