| rjw | 1f88458 | 2022-01-06 17:20:42 +0800 | [diff] [blame^] | 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 | |
| 35 | ENTRY(__get_user_1) |
| 36 | check_uaccess r0, 1, r1, r2, __get_user_bad |
| 37 | 1: TUSER(ldrb) r2, [r0] |
| 38 | mov r0, #0 |
| 39 | ret lr |
| 40 | ENDPROC(__get_user_1) |
| 41 | _ASM_NOKPROBE(__get_user_1) |
| 42 | |
| 43 | ENTRY(__get_user_2) |
| 44 | check_uaccess r0, 2, r1, r2, __get_user_bad |
| 45 | #if __LINUX_ARM_ARCH__ >= 6 |
| 46 | |
| 47 | 2: TUSER(ldrh) r2, [r0] |
| 48 | |
| 49 | #else |
| 50 | |
| 51 | #ifdef CONFIG_CPU_USE_DOMAINS |
| 52 | rb .req ip |
| 53 | 2: ldrbt r2, [r0], #1 |
| 54 | 3: ldrbt rb, [r0], #0 |
| 55 | #else |
| 56 | rb .req r0 |
| 57 | 2: ldrb r2, [r0] |
| 58 | 3: ldrb rb, [r0, #1] |
| 59 | #endif |
| 60 | #ifndef __ARMEB__ |
| 61 | orr r2, r2, rb, lsl #8 |
| 62 | #else |
| 63 | orr r2, rb, r2, lsl #8 |
| 64 | #endif |
| 65 | |
| 66 | #endif /* __LINUX_ARM_ARCH__ >= 6 */ |
| 67 | |
| 68 | mov r0, #0 |
| 69 | ret lr |
| 70 | ENDPROC(__get_user_2) |
| 71 | _ASM_NOKPROBE(__get_user_2) |
| 72 | |
| 73 | ENTRY(__get_user_4) |
| 74 | check_uaccess r0, 4, r1, r2, __get_user_bad |
| 75 | 4: TUSER(ldr) r2, [r0] |
| 76 | mov r0, #0 |
| 77 | ret lr |
| 78 | ENDPROC(__get_user_4) |
| 79 | _ASM_NOKPROBE(__get_user_4) |
| 80 | |
| 81 | ENTRY(__get_user_8) |
| 82 | check_uaccess r0, 8, r1, r2, __get_user_bad8 |
| 83 | #ifdef CONFIG_THUMB2_KERNEL |
| 84 | 5: TUSER(ldr) r2, [r0] |
| 85 | 6: TUSER(ldr) r3, [r0, #4] |
| 86 | #else |
| 87 | 5: TUSER(ldr) r2, [r0], #4 |
| 88 | 6: TUSER(ldr) r3, [r0] |
| 89 | #endif |
| 90 | mov r0, #0 |
| 91 | ret lr |
| 92 | ENDPROC(__get_user_8) |
| 93 | _ASM_NOKPROBE(__get_user_8) |
| 94 | |
| 95 | #ifdef __ARMEB__ |
| 96 | ENTRY(__get_user_32t_8) |
| 97 | check_uaccess r0, 8, r1, r2, __get_user_bad |
| 98 | #ifdef CONFIG_CPU_USE_DOMAINS |
| 99 | add r0, r0, #4 |
| 100 | 7: ldrt r2, [r0] |
| 101 | #else |
| 102 | 7: ldr r2, [r0, #4] |
| 103 | #endif |
| 104 | mov r0, #0 |
| 105 | ret lr |
| 106 | ENDPROC(__get_user_32t_8) |
| 107 | _ASM_NOKPROBE(__get_user_32t_8) |
| 108 | |
| 109 | ENTRY(__get_user_64t_1) |
| 110 | check_uaccess r0, 1, r1, r2, __get_user_bad8 |
| 111 | 8: TUSER(ldrb) r3, [r0] |
| 112 | mov r0, #0 |
| 113 | ret lr |
| 114 | ENDPROC(__get_user_64t_1) |
| 115 | _ASM_NOKPROBE(__get_user_64t_1) |
| 116 | |
| 117 | ENTRY(__get_user_64t_2) |
| 118 | check_uaccess r0, 2, r1, r2, __get_user_bad8 |
| 119 | #ifdef CONFIG_CPU_USE_DOMAINS |
| 120 | rb .req ip |
| 121 | 9: ldrbt r3, [r0], #1 |
| 122 | 10: ldrbt rb, [r0], #0 |
| 123 | #else |
| 124 | rb .req r0 |
| 125 | 9: ldrb r3, [r0] |
| 126 | 10: ldrb rb, [r0, #1] |
| 127 | #endif |
| 128 | orr r3, rb, r3, lsl #8 |
| 129 | mov r0, #0 |
| 130 | ret lr |
| 131 | ENDPROC(__get_user_64t_2) |
| 132 | _ASM_NOKPROBE(__get_user_64t_2) |
| 133 | |
| 134 | ENTRY(__get_user_64t_4) |
| 135 | check_uaccess r0, 4, r1, r2, __get_user_bad8 |
| 136 | 11: TUSER(ldr) r3, [r0] |
| 137 | mov r0, #0 |
| 138 | ret lr |
| 139 | ENDPROC(__get_user_64t_4) |
| 140 | _ASM_NOKPROBE(__get_user_64t_4) |
| 141 | #endif |
| 142 | |
| 143 | __get_user_bad8: |
| 144 | mov r3, #0 |
| 145 | __get_user_bad: |
| 146 | mov r2, #0 |
| 147 | mov r0, #-EFAULT |
| 148 | ret lr |
| 149 | ENDPROC(__get_user_bad) |
| 150 | ENDPROC(__get_user_bad8) |
| 151 | _ASM_NOKPROBE(__get_user_bad) |
| 152 | _ASM_NOKPROBE(__get_user_bad8) |
| 153 | |
| 154 | .pushsection __ex_table, "a" |
| 155 | .long 1b, __get_user_bad |
| 156 | .long 2b, __get_user_bad |
| 157 | #if __LINUX_ARM_ARCH__ < 6 |
| 158 | .long 3b, __get_user_bad |
| 159 | #endif |
| 160 | .long 4b, __get_user_bad |
| 161 | .long 5b, __get_user_bad8 |
| 162 | .long 6b, __get_user_bad8 |
| 163 | #ifdef __ARMEB__ |
| 164 | .long 7b, __get_user_bad |
| 165 | .long 8b, __get_user_bad8 |
| 166 | .long 9b, __get_user_bad8 |
| 167 | .long 10b, __get_user_bad8 |
| 168 | .long 11b, __get_user_bad8 |
| 169 | #endif |
| 170 | .popsection |