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_bad 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_lo8) 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_lo8) 94#endif 95 96__get_user_bad8: 97 mov r3, #0 98__get_user_bad: 99 mov r2, #0 100 mov r0, #-EFAULT 101 ret lr 102ENDPROC(__get_user_bad) 103ENDPROC(__get_user_bad8) 104 105.pushsection __ex_table, "a" 106 .long 1b, __get_user_bad 107 .long 2b, __get_user_bad 108 .long 3b, __get_user_bad 109 .long 4b, __get_user_bad 110 .long 5b, __get_user_bad8 111 .long 6b, __get_user_bad8 112#ifdef __ARMEB__ 113 .long 7b, __get_user_bad 114#endif 115.popsection 116