| Ley Foon Tan | 5ccc6af5 | 2014-11-06 15:19:41 +0800 | [diff] [blame] | 1 | /* |
| 2 | * This file is subject to the terms and conditions of the GNU General Public |
| 3 | * License. See the file "COPYING" in the main directory of this archive |
| 4 | * for more details. |
| 5 | * |
| 6 | * Copyright (C) 2009, Wind River Systems Inc |
| 7 | * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com |
| 8 | */ |
| 9 | |
| 10 | #include <linux/export.h> |
| 11 | #include <linux/uaccess.h> |
| 12 | |
| 13 | asm(".global __copy_from_user\n" |
| 14 | " .type __copy_from_user, @function\n" |
| 15 | "__copy_from_user:\n" |
| 16 | " movi r2,7\n" |
| 17 | " mov r3,r4\n" |
| 18 | " bge r2,r6,1f\n" |
| 19 | " xor r2,r4,r5\n" |
| 20 | " andi r2,r2,3\n" |
| 21 | " movi r7,3\n" |
| 22 | " beq r2,zero,4f\n" |
| 23 | "1: addi r6,r6,-1\n" |
| 24 | " movi r2,-1\n" |
| 25 | " beq r6,r2,3f\n" |
| 26 | " mov r7,r2\n" |
| 27 | "2: ldbu r2,0(r5)\n" |
| 28 | " addi r6,r6,-1\n" |
| 29 | " addi r5,r5,1\n" |
| 30 | " stb r2,0(r3)\n" |
| 31 | " addi r3,r3,1\n" |
| 32 | " bne r6,r7,2b\n" |
| 33 | "3:\n" |
| 34 | " addi r2,r6,1\n" |
| 35 | " ret\n" |
| 36 | "13:mov r2,r6\n" |
| 37 | " ret\n" |
| 38 | "4: andi r2,r4,1\n" |
| 39 | " cmpeq r2,r2,zero\n" |
| 40 | " beq r2,zero,7f\n" |
| 41 | "5: andi r2,r3,2\n" |
| 42 | " beq r2,zero,6f\n" |
| 43 | "9: ldhu r2,0(r5)\n" |
| 44 | " addi r6,r6,-2\n" |
| 45 | " addi r5,r5,2\n" |
| 46 | " sth r2,0(r3)\n" |
| 47 | " addi r3,r3,2\n" |
| 48 | "6: bge r7,r6,1b\n" |
| 49 | "10:ldw r2,0(r5)\n" |
| 50 | " addi r6,r6,-4\n" |
| 51 | " addi r5,r5,4\n" |
| 52 | " stw r2,0(r3)\n" |
| 53 | " addi r3,r3,4\n" |
| 54 | " br 6b\n" |
| 55 | "7: ldbu r2,0(r5)\n" |
| 56 | " addi r6,r6,-1\n" |
| 57 | " addi r5,r5,1\n" |
| 58 | " addi r3,r4,1\n" |
| 59 | " stb r2,0(r4)\n" |
| 60 | " br 5b\n" |
| 61 | ".section __ex_table,\"a\"\n" |
| 62 | ".word 2b,3b\n" |
| 63 | ".word 9b,13b\n" |
| 64 | ".word 10b,13b\n" |
| 65 | ".word 7b,13b\n" |
| 66 | ".previous\n" |
| 67 | ); |
| 68 | EXPORT_SYMBOL(__copy_from_user); |
| 69 | |
| 70 | asm( |
| 71 | " .global __copy_to_user\n" |
| 72 | " .type __copy_to_user, @function\n" |
| 73 | "__copy_to_user:\n" |
| 74 | " movi r2,7\n" |
| 75 | " mov r3,r4\n" |
| 76 | " bge r2,r6,1f\n" |
| 77 | " xor r2,r4,r5\n" |
| 78 | " andi r2,r2,3\n" |
| 79 | " movi r7,3\n" |
| 80 | " beq r2,zero,4f\n" |
| 81 | /* Bail if we try to copy zero bytes */ |
| 82 | "1: addi r6,r6,-1\n" |
| 83 | " movi r2,-1\n" |
| 84 | " beq r6,r2,3f\n" |
| 85 | /* Copy byte by byte for small copies and if src^dst != 0 */ |
| 86 | " mov r7,r2\n" |
| 87 | "2: ldbu r2,0(r5)\n" |
| 88 | " addi r5,r5,1\n" |
| 89 | "9: stb r2,0(r3)\n" |
| 90 | " addi r6,r6,-1\n" |
| 91 | " addi r3,r3,1\n" |
| 92 | " bne r6,r7,2b\n" |
| 93 | "3: addi r2,r6,1\n" |
| 94 | " ret\n" |
| 95 | "13:mov r2,r6\n" |
| 96 | " ret\n" |
| 97 | /* If 'to' is an odd address byte copy */ |
| 98 | "4: andi r2,r4,1\n" |
| 99 | " cmpeq r2,r2,zero\n" |
| 100 | " beq r2,zero,7f\n" |
| 101 | /* If 'to' is not divideable by four copy halfwords */ |
| 102 | "5: andi r2,r3,2\n" |
| 103 | " beq r2,zero,6f\n" |
| 104 | " ldhu r2,0(r5)\n" |
| 105 | " addi r5,r5,2\n" |
| 106 | "10:sth r2,0(r3)\n" |
| 107 | " addi r6,r6,-2\n" |
| 108 | " addi r3,r3,2\n" |
| 109 | /* Copy words */ |
| 110 | "6: bge r7,r6,1b\n" |
| 111 | " ldw r2,0(r5)\n" |
| 112 | " addi r5,r5,4\n" |
| 113 | "11:stw r2,0(r3)\n" |
| 114 | " addi r6,r6,-4\n" |
| 115 | " addi r3,r3,4\n" |
| 116 | " br 6b\n" |
| 117 | /* Copy remaining bytes */ |
| 118 | "7: ldbu r2,0(r5)\n" |
| 119 | " addi r5,r5,1\n" |
| 120 | " addi r3,r4,1\n" |
| 121 | "12: stb r2,0(r4)\n" |
| 122 | " addi r6,r6,-1\n" |
| 123 | " br 5b\n" |
| 124 | ".section __ex_table,\"a\"\n" |
| 125 | ".word 9b,3b\n" |
| 126 | ".word 10b,13b\n" |
| 127 | ".word 11b,13b\n" |
| 128 | ".word 12b,13b\n" |
| 129 | ".previous\n"); |
| 130 | EXPORT_SYMBOL(__copy_to_user); |
| 131 | |
| 132 | long strncpy_from_user(char *__to, const char __user *__from, long __len) |
| 133 | { |
| 134 | int l = strnlen_user(__from, __len); |
| 135 | int is_zt = 1; |
| 136 | |
| 137 | if (l > __len) { |
| 138 | is_zt = 0; |
| 139 | l = __len; |
| 140 | } |
| 141 | |
| 142 | if (l == 0 || copy_from_user(__to, __from, l)) |
| 143 | return -EFAULT; |
| 144 | |
| 145 | if (is_zt) |
| 146 | l--; |
| 147 | return l; |
| 148 | } |
| 149 | |
| 150 | long strnlen_user(const char __user *s, long n) |
| 151 | { |
| 152 | long i; |
| 153 | |
| 154 | for (i = 0; i < n; i++) { |
| 155 | char c; |
| 156 | |
| 157 | if (get_user(c, s + i) == -EFAULT) |
| 158 | return 0; |
| 159 | if (c == 0) |
| 160 | return i + 1; |
| 161 | } |
| 162 | return n + 1; |
| 163 | } |