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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 | // SPDX-License-Identifier: GPL-2.0 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. #include <linux/uaccess.h> #include <linux/types.h> unsigned long raw_copy_from_user(void *to, const void *from, unsigned long n) { if (access_ok(from, n)) __copy_user_zeroing(to, from, n); else memset(to, 0, n); return n; } EXPORT_SYMBOL(raw_copy_from_user); unsigned long raw_copy_to_user(void *to, const void *from, unsigned long n) { if (access_ok(to, n)) __copy_user(to, from, n); return n; } EXPORT_SYMBOL(raw_copy_to_user); /* * copy a null terminated string from userspace. */ #define __do_strncpy_from_user(dst, src, count, res) \ do { \ int tmp; \ long faultres; \ asm volatile( \ " cmpnei %3, 0 \n" \ " bf 4f \n" \ "1: cmpnei %1, 0 \n" \ " bf 5f \n" \ "2: ldb %4, (%3, 0) \n" \ " stb %4, (%2, 0) \n" \ " cmpnei %4, 0 \n" \ " bf 3f \n" \ " addi %3, 1 \n" \ " addi %2, 1 \n" \ " subi %1, 1 \n" \ " br 1b \n" \ "3: subu %0, %1 \n" \ " br 5f \n" \ "4: mov %0, %5 \n" \ " br 5f \n" \ ".section __ex_table, \"a\" \n" \ ".align 2 \n" \ ".long 2b, 4b \n" \ ".previous \n" \ "5: \n" \ : "=r"(res), "=r"(count), "=r"(dst), \ "=r"(src), "=r"(tmp), "=r"(faultres) \ : "5"(-EFAULT), "0"(count), "1"(count), \ "2"(dst), "3"(src) \ : "memory", "cc"); \ } while (0) /* * __strncpy_from_user: - Copy a NUL terminated string from userspace, * with less checking. * @dst: Destination address, in kernel space. This buffer must be at * least @count bytes long. * @src: Source address, in user space. * @count: Maximum number of bytes to copy, including the trailing NUL. * * Copies a NUL-terminated string from userspace to kernel space. * Caller must check the specified block with access_ok() before calling * this function. * * On success, returns the length of the string (not including the trailing * NUL). * * If access to userspace fails, returns -EFAULT (some data may have been * copied). * * If @count is smaller than the length of the string, copies @count bytes * and returns @count. */ long __strncpy_from_user(char *dst, const char *src, long count) { long res; __do_strncpy_from_user(dst, src, count, res); return res; } EXPORT_SYMBOL(__strncpy_from_user); /* * strncpy_from_user: - Copy a NUL terminated string from userspace. * @dst: Destination address, in kernel space. This buffer must be at * least @count bytes long. * @src: Source address, in user space. * @count: Maximum number of bytes to copy, including the trailing NUL. * * Copies a NUL-terminated string from userspace to kernel space. * * On success, returns the length of the string (not including the trailing * NUL). * * If access to userspace fails, returns -EFAULT (some data may have been * copied). * * If @count is smaller than the length of the string, copies @count bytes * and returns @count. */ long strncpy_from_user(char *dst, const char *src, long count) { long res = -EFAULT; if (access_ok(src, 1)) __do_strncpy_from_user(dst, src, count, res); return res; } EXPORT_SYMBOL(strncpy_from_user); /* * strlen_user: - Get the size of a string in user space. * @str: The string to measure. * @n: The maximum valid length * * Get the size of a NUL-terminated string in user space. * * Returns the size of the string INCLUDING the terminating NUL. * On exception, returns 0. * If the string is too long, returns a value greater than @n. */ long strnlen_user(const char *s, long n) { unsigned long res, tmp; if (s == NULL) return 0; asm volatile( " cmpnei %1, 0 \n" " bf 3f \n" "1: cmpnei %0, 0 \n" " bf 3f \n" "2: ldb %3, (%1, 0) \n" " cmpnei %3, 0 \n" " bf 3f \n" " subi %0, 1 \n" " addi %1, 1 \n" " br 1b \n" "3: subu %2, %0 \n" " addi %2, 1 \n" " br 5f \n" "4: movi %0, 0 \n" " br 5f \n" ".section __ex_table, \"a\" \n" ".align 2 \n" ".long 2b, 4b \n" ".previous \n" "5: \n" : "=r"(n), "=r"(s), "=r"(res), "=r"(tmp) : "0"(n), "1"(s), "2"(n) : "memory", "cc"); return res; } EXPORT_SYMBOL(strnlen_user); #define __do_clear_user(addr, size) \ do { \ int __d0, zvalue, tmp; \ \ asm volatile( \ "0: cmpnei %1, 0 \n" \ " bf 7f \n" \ " mov %3, %1 \n" \ " andi %3, 3 \n" \ " cmpnei %3, 0 \n" \ " bf 1f \n" \ " br 5f \n" \ "1: cmplti %0, 32 \n" /* 4W */ \ " bt 3f \n" \ "8: stw %2, (%1, 0) \n" \ "10: stw %2, (%1, 4) \n" \ "11: stw %2, (%1, 8) \n" \ "12: stw %2, (%1, 12) \n" \ "13: stw %2, (%1, 16) \n" \ "14: stw %2, (%1, 20) \n" \ "15: stw %2, (%1, 24) \n" \ "16: stw %2, (%1, 28) \n" \ " addi %1, 32 \n" \ " subi %0, 32 \n" \ " br 1b \n" \ "3: cmplti %0, 4 \n" /* 1W */ \ " bt 5f \n" \ "4: stw %2, (%1, 0) \n" \ " addi %1, 4 \n" \ " subi %0, 4 \n" \ " br 3b \n" \ "5: cmpnei %0, 0 \n" /* 1B */ \ "9: bf 7f \n" \ "6: stb %2, (%1, 0) \n" \ " addi %1, 1 \n" \ " subi %0, 1 \n" \ " br 5b \n" \ ".section __ex_table,\"a\" \n" \ ".align 2 \n" \ ".long 8b, 9b \n" \ ".long 10b, 9b \n" \ ".long 11b, 9b \n" \ ".long 12b, 9b \n" \ ".long 13b, 9b \n" \ ".long 14b, 9b \n" \ ".long 15b, 9b \n" \ ".long 16b, 9b \n" \ ".long 4b, 9b \n" \ ".long 6b, 9b \n" \ ".previous \n" \ "7: \n" \ : "=r"(size), "=r" (__d0), \ "=r"(zvalue), "=r"(tmp) \ : "0"(size), "1"(addr), "2"(0) \ : "memory", "cc"); \ } while (0) /* * clear_user: - Zero a block of memory in user space. * @to: Destination address, in user space. * @n: Number of bytes to zero. * * Zero a block of memory in user space. * * Returns number of bytes that could not be cleared. * On success, this will be zero. */ unsigned long clear_user(void __user *to, unsigned long n) { if (access_ok(to, n)) __do_clear_user(to, n); return n; } EXPORT_SYMBOL(clear_user); /* * __clear_user: - Zero a block of memory in user space, with less checking. * @to: Destination address, in user space. * @n: Number of bytes to zero. * * Zero a block of memory in user space. Caller must check * the specified block with access_ok() before calling this function. * * Returns number of bytes that could not be cleared. * On success, this will be zero. */ unsigned long __clear_user(void __user *to, unsigned long n) { __do_clear_user(to, n); return n; } EXPORT_SYMBOL(__clear_user); |