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_ASM_NOKPROBE(__get_user_1) 42 43ENTRY(__get_user_2) 44 check_uaccess r0, 2, r1, r2, __get_user_bad 45#ifdef CONFIG_CPU_USE_DOMAINS 46rb .req ip 472: ldrbt r2, [r0], #1 483: ldrbt rb, [r0], #0 49#else 50rb .req r0 512: ldrb r2, [r0] 523: ldrb rb, [r0, #1] 53#endif 54#ifndef __ARMEB__ 55 orr r2, r2, rb, lsl #8 56#else 57 orr r2, rb, r2, lsl #8 58#endif 59 mov r0, #0 60 ret lr 61ENDPROC(__get_user_2) 62_ASM_NOKPROBE(__get_user_2) 63 64ENTRY(__get_user_4) 65 check_uaccess r0, 4, r1, r2, __get_user_bad 664: TUSER(ldr) r2, [r0] 67 mov r0, #0 68 ret lr 69ENDPROC(__get_user_4) 70_ASM_NOKPROBE(__get_user_4) 71 72ENTRY(__get_user_8) 73 check_uaccess r0, 8, r1, r2, __get_user_bad8 74#ifdef CONFIG_THUMB2_KERNEL 755: TUSER(ldr) r2, [r0] 766: TUSER(ldr) r3, [r0, #4] 77#else 785: TUSER(ldr) r2, [r0], #4 796: TUSER(ldr) r3, [r0] 80#endif 81 mov r0, #0 82 ret lr 83ENDPROC(__get_user_8) 84_ASM_NOKPROBE(__get_user_8) 85 86#ifdef __ARMEB__ 87ENTRY(__get_user_32t_8) 88 check_uaccess r0, 8, r1, r2, __get_user_bad 89#ifdef CONFIG_CPU_USE_DOMAINS 90 add r0, r0, #4 917: ldrt r2, [r0] 92#else 937: ldr r2, [r0, #4] 94#endif 95 mov r0, #0 96 ret lr 97ENDPROC(__get_user_32t_8) 98_ASM_NOKPROBE(__get_user_32t_8) 99 100ENTRY(__get_user_64t_1) 101 check_uaccess r0, 1, r1, r2, __get_user_bad8 1028: TUSER(ldrb) r3, [r0] 103 mov r0, #0 104 ret lr 105ENDPROC(__get_user_64t_1) 106_ASM_NOKPROBE(__get_user_64t_1) 107 108ENTRY(__get_user_64t_2) 109 check_uaccess r0, 2, r1, r2, __get_user_bad8 110#ifdef CONFIG_CPU_USE_DOMAINS 111rb .req ip 1129: ldrbt r3, [r0], #1 11310: ldrbt rb, [r0], #0 114#else 115rb .req r0 1169: ldrb r3, [r0] 11710: ldrb rb, [r0, #1] 118#endif 119 orr r3, rb, r3, lsl #8 120 mov r0, #0 121 ret lr 122ENDPROC(__get_user_64t_2) 123_ASM_NOKPROBE(__get_user_64t_2) 124 125ENTRY(__get_user_64t_4) 126 check_uaccess r0, 4, r1, r2, __get_user_bad8 12711: TUSER(ldr) r3, [r0] 128 mov r0, #0 129 ret lr 130ENDPROC(__get_user_64t_4) 131_ASM_NOKPROBE(__get_user_64t_4) 132#endif 133 134__get_user_bad8: 135 mov r3, #0 136__get_user_bad: 137 mov r2, #0 138 mov r0, #-EFAULT 139 ret lr 140ENDPROC(__get_user_bad) 141ENDPROC(__get_user_bad8) 142_ASM_NOKPROBE(__get_user_bad) 143_ASM_NOKPROBE(__get_user_bad8) 144 145.pushsection __ex_table, "a" 146 .long 1b, __get_user_bad 147 .long 2b, __get_user_bad 148 .long 3b, __get_user_bad 149 .long 4b, __get_user_bad 150 .long 5b, __get_user_bad8 151 .long 6b, __get_user_bad8 152#ifdef __ARMEB__ 153 .long 7b, __get_user_bad 154 .long 8b, __get_user_bad8 155 .long 9b, __get_user_bad8 156 .long 10b, __get_user_bad8 157 .long 11b, __get_user_bad8 158#endif 159.popsection 160