.. | .. |
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| 1 | +/* SPDX-License-Identifier: GPL-2.0-only */ |
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1 | 2 | /* |
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2 | 3 | * Copyright (C) 2012 Regents of the University of California |
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3 | | - * |
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4 | | - * This program is free software; you can redistribute it and/or |
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5 | | - * modify it under the terms of the GNU General Public License |
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6 | | - * as published by the Free Software Foundation, version 2. |
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7 | | - * |
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8 | | - * This program is distributed in the hope that it will be useful, |
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9 | | - * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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10 | | - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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11 | | - * GNU General Public License for more details. |
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12 | 4 | * |
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13 | 5 | * This file was copied from include/asm-generic/uaccess.h |
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14 | 6 | */ |
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.. | .. |
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16 | 8 | #ifndef _ASM_RISCV_UACCESS_H |
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17 | 9 | #define _ASM_RISCV_UACCESS_H |
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18 | 10 | |
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| 11 | +#include <asm/pgtable.h> /* for TASK_SIZE */ |
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| 12 | + |
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19 | 13 | /* |
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20 | 14 | * User space memory access functions |
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21 | 15 | */ |
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| 16 | +#ifdef CONFIG_MMU |
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22 | 17 | #include <linux/errno.h> |
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23 | 18 | #include <linux/compiler.h> |
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24 | 19 | #include <linux/thread_info.h> |
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25 | 20 | #include <asm/byteorder.h> |
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| 21 | +#include <asm/extable.h> |
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26 | 22 | #include <asm/asm.h> |
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27 | 23 | |
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28 | 24 | #define __enable_user_access() \ |
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.. | .. |
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30 | 26 | #define __disable_user_access() \ |
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31 | 27 | __asm__ __volatile__ ("csrc sstatus, %0" : : "r" (SR_SUM) : "memory") |
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32 | 28 | |
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33 | | -/* |
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34 | | - * The fs value determines whether argument validity checking should be |
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35 | | - * performed or not. If get_fs() == USER_DS, checking is performed, with |
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36 | | - * get_fs() == KERNEL_DS, checking is bypassed. |
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37 | | - * |
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38 | | - * For historical reasons, these macros are grossly misnamed. |
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39 | | - */ |
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40 | | - |
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41 | | -#define KERNEL_DS (~0UL) |
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42 | | -#define USER_DS (TASK_SIZE) |
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43 | | - |
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44 | | -#define get_ds() (KERNEL_DS) |
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45 | | -#define get_fs() (current_thread_info()->addr_limit) |
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46 | | - |
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47 | | -static inline void set_fs(mm_segment_t fs) |
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48 | | -{ |
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49 | | - current_thread_info()->addr_limit = fs; |
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50 | | -} |
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51 | | - |
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52 | | -#define segment_eq(a, b) ((a) == (b)) |
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53 | | - |
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54 | | -#define user_addr_max() (get_fs()) |
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55 | | - |
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56 | | - |
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57 | | -#define VERIFY_READ 0 |
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58 | | -#define VERIFY_WRITE 1 |
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59 | | - |
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60 | 29 | /** |
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61 | 30 | * access_ok: - Checks if a user space pointer is valid |
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62 | | - * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that |
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63 | | - * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe |
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64 | | - * to write to a block, it is always safe to read from it. |
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65 | 31 | * @addr: User space pointer to start of block to check |
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66 | 32 | * @size: Size of block to check |
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67 | 33 | * |
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.. | .. |
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76 | 42 | * checks that the pointer is in the user space range - after calling |
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77 | 43 | * this function, memory access functions may still return -EFAULT. |
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78 | 44 | */ |
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79 | | -#define access_ok(type, addr, size) ({ \ |
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| 45 | +#define access_ok(addr, size) ({ \ |
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80 | 46 | __chk_user_ptr(addr); \ |
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81 | 47 | likely(__access_ok((unsigned long __force)(addr), (size))); \ |
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82 | 48 | }) |
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.. | .. |
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87 | 53 | */ |
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88 | 54 | static inline int __access_ok(unsigned long addr, unsigned long size) |
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89 | 55 | { |
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90 | | - const mm_segment_t fs = get_fs(); |
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91 | | - |
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92 | | - return (size <= fs) && (addr <= (fs - size)); |
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| 56 | + return size <= TASK_SIZE && addr <= TASK_SIZE - size; |
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93 | 57 | } |
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94 | 58 | |
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95 | 59 | /* |
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.. | .. |
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105 | 69 | * on our cache or tlb entries. |
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106 | 70 | */ |
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107 | 71 | |
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108 | | -struct exception_table_entry { |
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109 | | - unsigned long insn, fixup; |
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110 | | -}; |
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111 | | - |
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112 | | -extern int fixup_exception(struct pt_regs *state); |
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113 | | - |
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114 | | -#if defined(__LITTLE_ENDIAN) |
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115 | | -#define __MSW 1 |
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116 | 72 | #define __LSW 0 |
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117 | | -#elif defined(__BIG_ENDIAN) |
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118 | | -#define __MSW 0 |
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119 | | -#define __LSW 1 |
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120 | | -#else |
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121 | | -#error "Unknown endianness" |
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122 | | -#endif |
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| 73 | +#define __MSW 1 |
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123 | 74 | |
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124 | 75 | /* |
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125 | 76 | * The "__xxx" versions of the user access functions do not verify the address |
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.. | .. |
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131 | 82 | do { \ |
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132 | 83 | uintptr_t __tmp; \ |
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133 | 84 | __typeof__(x) __x; \ |
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134 | | - __enable_user_access(); \ |
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135 | 85 | __asm__ __volatile__ ( \ |
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136 | 86 | "1:\n" \ |
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137 | 87 | " " insn " %1, %3\n" \ |
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.. | .. |
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149 | 99 | " .previous" \ |
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150 | 100 | : "+r" (err), "=&r" (__x), "=r" (__tmp) \ |
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151 | 101 | : "m" (*(ptr)), "i" (-EFAULT)); \ |
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152 | | - __disable_user_access(); \ |
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153 | 102 | (x) = __x; \ |
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154 | 103 | } while (0) |
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155 | 104 | |
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.. | .. |
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162 | 111 | u32 __user *__ptr = (u32 __user *)(ptr); \ |
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163 | 112 | u32 __lo, __hi; \ |
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164 | 113 | uintptr_t __tmp; \ |
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165 | | - __enable_user_access(); \ |
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166 | 114 | __asm__ __volatile__ ( \ |
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167 | 115 | "1:\n" \ |
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168 | 116 | " lw %1, %4\n" \ |
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.. | .. |
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186 | 134 | "=r" (__tmp) \ |
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187 | 135 | : "m" (__ptr[__LSW]), "m" (__ptr[__MSW]), \ |
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188 | 136 | "i" (-EFAULT)); \ |
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189 | | - __disable_user_access(); \ |
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190 | 137 | (x) = (__typeof__(x))((__typeof__((x)-(x)))( \ |
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191 | 138 | (((u64)__hi << 32) | __lo))); \ |
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192 | 139 | } while (0) |
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193 | 140 | #endif /* CONFIG_64BIT */ |
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194 | 141 | |
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| 142 | +#define __get_user_nocheck(x, __gu_ptr, __gu_err) \ |
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| 143 | +do { \ |
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| 144 | + switch (sizeof(*__gu_ptr)) { \ |
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| 145 | + case 1: \ |
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| 146 | + __get_user_asm("lb", (x), __gu_ptr, __gu_err); \ |
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| 147 | + break; \ |
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| 148 | + case 2: \ |
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| 149 | + __get_user_asm("lh", (x), __gu_ptr, __gu_err); \ |
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| 150 | + break; \ |
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| 151 | + case 4: \ |
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| 152 | + __get_user_asm("lw", (x), __gu_ptr, __gu_err); \ |
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| 153 | + break; \ |
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| 154 | + case 8: \ |
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| 155 | + __get_user_8((x), __gu_ptr, __gu_err); \ |
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| 156 | + break; \ |
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| 157 | + default: \ |
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| 158 | + BUILD_BUG(); \ |
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| 159 | + } \ |
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| 160 | +} while (0) |
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195 | 161 | |
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196 | 162 | /** |
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197 | 163 | * __get_user: - Get a simple variable from user space, with less checking. |
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.. | .. |
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215 | 181 | */ |
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216 | 182 | #define __get_user(x, ptr) \ |
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217 | 183 | ({ \ |
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218 | | - register long __gu_err = 0; \ |
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219 | 184 | const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ |
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| 185 | + long __gu_err = 0; \ |
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| 186 | + \ |
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220 | 187 | __chk_user_ptr(__gu_ptr); \ |
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221 | | - switch (sizeof(*__gu_ptr)) { \ |
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222 | | - case 1: \ |
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223 | | - __get_user_asm("lb", (x), __gu_ptr, __gu_err); \ |
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224 | | - break; \ |
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225 | | - case 2: \ |
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226 | | - __get_user_asm("lh", (x), __gu_ptr, __gu_err); \ |
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227 | | - break; \ |
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228 | | - case 4: \ |
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229 | | - __get_user_asm("lw", (x), __gu_ptr, __gu_err); \ |
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230 | | - break; \ |
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231 | | - case 8: \ |
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232 | | - __get_user_8((x), __gu_ptr, __gu_err); \ |
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233 | | - break; \ |
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234 | | - default: \ |
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235 | | - BUILD_BUG(); \ |
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236 | | - } \ |
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| 188 | + \ |
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| 189 | + __enable_user_access(); \ |
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| 190 | + __get_user_nocheck(x, __gu_ptr, __gu_err); \ |
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| 191 | + __disable_user_access(); \ |
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| 192 | + \ |
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237 | 193 | __gu_err; \ |
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238 | 194 | }) |
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239 | 195 | |
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.. | .. |
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258 | 214 | ({ \ |
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259 | 215 | const __typeof__(*(ptr)) __user *__p = (ptr); \ |
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260 | 216 | might_fault(); \ |
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261 | | - access_ok(VERIFY_READ, __p, sizeof(*__p)) ? \ |
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| 217 | + access_ok(__p, sizeof(*__p)) ? \ |
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262 | 218 | __get_user((x), __p) : \ |
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263 | | - ((x) = 0, -EFAULT); \ |
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| 219 | + ((x) = (__force __typeof__(x))0, -EFAULT); \ |
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264 | 220 | }) |
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265 | 221 | |
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266 | 222 | #define __put_user_asm(insn, x, ptr, err) \ |
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267 | 223 | do { \ |
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268 | 224 | uintptr_t __tmp; \ |
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269 | 225 | __typeof__(*(ptr)) __x = x; \ |
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270 | | - __enable_user_access(); \ |
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271 | 226 | __asm__ __volatile__ ( \ |
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272 | 227 | "1:\n" \ |
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273 | 228 | " " insn " %z3, %2\n" \ |
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.. | .. |
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284 | 239 | " .previous" \ |
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285 | 240 | : "+r" (err), "=r" (__tmp), "=m" (*(ptr)) \ |
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286 | 241 | : "rJ" (__x), "i" (-EFAULT)); \ |
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287 | | - __disable_user_access(); \ |
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288 | 242 | } while (0) |
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289 | 243 | |
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290 | 244 | #ifdef CONFIG_64BIT |
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.. | .. |
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296 | 250 | u32 __user *__ptr = (u32 __user *)(ptr); \ |
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297 | 251 | u64 __x = (__typeof__((x)-(x)))(x); \ |
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298 | 252 | uintptr_t __tmp; \ |
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299 | | - __enable_user_access(); \ |
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300 | 253 | __asm__ __volatile__ ( \ |
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301 | 254 | "1:\n" \ |
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302 | 255 | " sw %z4, %2\n" \ |
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.. | .. |
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318 | 271 | "=m" (__ptr[__LSW]), \ |
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319 | 272 | "=m" (__ptr[__MSW]) \ |
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320 | 273 | : "rJ" (__x), "rJ" (__x >> 32), "i" (-EFAULT)); \ |
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321 | | - __disable_user_access(); \ |
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322 | 274 | } while (0) |
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323 | 275 | #endif /* CONFIG_64BIT */ |
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324 | 276 | |
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325 | | - |
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326 | | -/** |
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327 | | - * __put_user: - Write a simple value into user space, with less checking. |
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328 | | - * @x: Value to copy to user space. |
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329 | | - * @ptr: Destination address, in user space. |
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330 | | - * |
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331 | | - * Context: User context only. This function may sleep. |
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332 | | - * |
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333 | | - * This macro copies a single simple value from kernel space to user |
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334 | | - * space. It supports simple types like char and int, but not larger |
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335 | | - * data types like structures or arrays. |
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336 | | - * |
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337 | | - * @ptr must have pointer-to-simple-variable type, and @x must be assignable |
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338 | | - * to the result of dereferencing @ptr. |
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339 | | - * |
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340 | | - * Caller must check the pointer with access_ok() before calling this |
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341 | | - * function. |
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342 | | - * |
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343 | | - * Returns zero on success, or -EFAULT on error. |
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344 | | - */ |
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345 | | -#define __put_user(x, ptr) \ |
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346 | | -({ \ |
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347 | | - register long __pu_err = 0; \ |
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348 | | - __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ |
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349 | | - __chk_user_ptr(__gu_ptr); \ |
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| 277 | +#define __put_user_nocheck(x, __gu_ptr, __pu_err) \ |
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| 278 | +do { \ |
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350 | 279 | switch (sizeof(*__gu_ptr)) { \ |
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351 | 280 | case 1: \ |
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352 | 281 | __put_user_asm("sb", (x), __gu_ptr, __pu_err); \ |
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.. | .. |
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363 | 292 | default: \ |
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364 | 293 | BUILD_BUG(); \ |
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365 | 294 | } \ |
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| 295 | +} while (0) |
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| 296 | + |
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| 297 | +/** |
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| 298 | + * __put_user: - Write a simple value into user space, with less checking. |
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| 299 | + * @x: Value to copy to user space. |
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| 300 | + * @ptr: Destination address, in user space. |
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| 301 | + * |
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| 302 | + * Context: User context only. This function may sleep. |
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| 303 | + * |
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| 304 | + * This macro copies a single simple value from kernel space to user |
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| 305 | + * space. It supports simple types like char and int, but not larger |
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| 306 | + * data types like structures or arrays. |
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| 307 | + * |
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| 308 | + * @ptr must have pointer-to-simple-variable type, and @x must be assignable |
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| 309 | + * to the result of dereferencing @ptr. The value of @x is copied to avoid |
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| 310 | + * re-ordering where @x is evaluated inside the block that enables user-space |
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| 311 | + * access (thus bypassing user space protection if @x is a function). |
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| 312 | + * |
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| 313 | + * Caller must check the pointer with access_ok() before calling this |
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| 314 | + * function. |
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| 315 | + * |
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| 316 | + * Returns zero on success, or -EFAULT on error. |
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| 317 | + */ |
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| 318 | +#define __put_user(x, ptr) \ |
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| 319 | +({ \ |
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| 320 | + __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ |
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| 321 | + __typeof__(*__gu_ptr) __val = (x); \ |
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| 322 | + long __pu_err = 0; \ |
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| 323 | + \ |
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| 324 | + __chk_user_ptr(__gu_ptr); \ |
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| 325 | + \ |
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| 326 | + __enable_user_access(); \ |
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| 327 | + __put_user_nocheck(__val, __gu_ptr, __pu_err); \ |
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| 328 | + __disable_user_access(); \ |
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| 329 | + \ |
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366 | 330 | __pu_err; \ |
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367 | 331 | }) |
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368 | 332 | |
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.. | .. |
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386 | 350 | ({ \ |
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387 | 351 | __typeof__(*(ptr)) __user *__p = (ptr); \ |
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388 | 352 | might_fault(); \ |
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389 | | - access_ok(VERIFY_WRITE, __p, sizeof(*__p)) ? \ |
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| 353 | + access_ok(__p, sizeof(*__p)) ? \ |
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390 | 354 | __put_user((x), __p) : \ |
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391 | 355 | -EFAULT; \ |
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392 | 356 | }) |
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393 | 357 | |
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394 | 358 | |
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395 | | -extern unsigned long __must_check __asm_copy_to_user(void __user *to, |
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| 359 | +unsigned long __must_check __asm_copy_to_user(void __user *to, |
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396 | 360 | const void *from, unsigned long n); |
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397 | | -extern unsigned long __must_check __asm_copy_from_user(void *to, |
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| 361 | +unsigned long __must_check __asm_copy_from_user(void *to, |
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398 | 362 | const void __user *from, unsigned long n); |
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399 | 363 | |
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400 | 364 | static inline unsigned long |
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.. | .. |
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421 | 385 | unsigned long __must_check clear_user(void __user *to, unsigned long n) |
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422 | 386 | { |
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423 | 387 | might_fault(); |
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424 | | - return access_ok(VERIFY_WRITE, to, n) ? |
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| 388 | + return access_ok(to, n) ? |
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425 | 389 | __clear_user(to, n) : n; |
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426 | 390 | } |
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427 | 391 | |
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.. | .. |
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500 | 464 | __ret; \ |
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501 | 465 | }) |
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502 | 466 | |
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| 467 | +#define HAVE_GET_KERNEL_NOFAULT |
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| 468 | + |
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| 469 | +#define __get_kernel_nofault(dst, src, type, err_label) \ |
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| 470 | +do { \ |
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| 471 | + long __kr_err; \ |
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| 472 | + \ |
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| 473 | + __get_user_nocheck(*((type *)(dst)), (type *)(src), __kr_err); \ |
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| 474 | + if (unlikely(__kr_err)) \ |
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| 475 | + goto err_label; \ |
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| 476 | +} while (0) |
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| 477 | + |
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| 478 | +#define __put_kernel_nofault(dst, src, type, err_label) \ |
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| 479 | +do { \ |
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| 480 | + long __kr_err; \ |
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| 481 | + \ |
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| 482 | + __put_user_nocheck(*((type *)(src)), (type *)(dst), __kr_err); \ |
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| 483 | + if (unlikely(__kr_err)) \ |
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| 484 | + goto err_label; \ |
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| 485 | +} while (0) |
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| 486 | + |
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| 487 | +#else /* CONFIG_MMU */ |
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| 488 | +#include <asm-generic/uaccess.h> |
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| 489 | +#endif /* CONFIG_MMU */ |
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503 | 490 | #endif /* _ASM_RISCV_UACCESS_H */ |
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