1 /* SPDX-License-Identifier: GPL-2.0 */ 2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. 3 4 #ifndef __ASM_CSKY_UACCESS_H 5 #define __ASM_CSKY_UACCESS_H 6 7 /* 8 * User space memory access functions 9 */ 10 #include <linux/compiler.h> 11 #include <linux/errno.h> 12 #include <linux/types.h> 13 #include <linux/sched.h> 14 #include <linux/string.h> 15 #include <linux/version.h> 16 #include <asm/segment.h> 17 18 static inline int access_ok(const void *addr, unsigned long size) 19 { 20 unsigned long limit = current_thread_info()->addr_limit.seg; 21 22 return (((unsigned long)addr < limit) && 23 ((unsigned long)(addr + size) < limit)); 24 } 25 26 #define __addr_ok(addr) (access_ok(addr, 0)) 27 28 extern int __put_user_bad(void); 29 30 /* 31 * Tell gcc we read from memory instead of writing: this is because 32 * we do not write to any memory gcc knows about, so there are no 33 * aliasing issues. 34 */ 35 36 /* 37 * These are the main single-value transfer routines. They automatically 38 * use the right size if we just have the right pointer type. 39 * 40 * This gets kind of ugly. We want to return _two_ values in "get_user()" 41 * and yet we don't want to do any pointers, because that is too much 42 * of a performance impact. Thus we have a few rather ugly macros here, 43 * and hide all the ugliness from the user. 44 * 45 * The "__xxx" versions of the user access functions are versions that 46 * do not verify the address space, that must have been done previously 47 * with a separate "access_ok()" call (this is used when we do multiple 48 * accesses to the same area of user memory). 49 * 50 * As we use the same address space for kernel and user data on 51 * Ckcore, we can just do these as direct assignments. (Of course, the 52 * exception handling means that it's no longer "just"...) 53 */ 54 55 #define put_user(x, ptr) \ 56 __put_user_check((x), (ptr), sizeof(*(ptr))) 57 58 #define __put_user(x, ptr) \ 59 __put_user_nocheck((x), (ptr), sizeof(*(ptr))) 60 61 #define __ptr(x) ((unsigned long *)(x)) 62 63 #define get_user(x, ptr) \ 64 __get_user_check((x), (ptr), sizeof(*(ptr))) 65 66 #define __get_user(x, ptr) \ 67 __get_user_nocheck((x), (ptr), sizeof(*(ptr))) 68 69 #define __put_user_nocheck(x, ptr, size) \ 70 ({ \ 71 long __pu_err = 0; \ 72 typeof(*(ptr)) *__pu_addr = (ptr); \ 73 typeof(*(ptr)) __pu_val = (typeof(*(ptr)))(x); \ 74 if (__pu_addr) \ 75 __put_user_size(__pu_val, (__pu_addr), (size), \ 76 __pu_err); \ 77 __pu_err; \ 78 }) 79 80 #define __put_user_check(x, ptr, size) \ 81 ({ \ 82 long __pu_err = -EFAULT; \ 83 typeof(*(ptr)) *__pu_addr = (ptr); \ 84 typeof(*(ptr)) __pu_val = (typeof(*(ptr)))(x); \ 85 if (access_ok(__pu_addr, size) && __pu_addr) \ 86 __put_user_size(__pu_val, __pu_addr, (size), __pu_err); \ 87 __pu_err; \ 88 }) 89 90 #define __put_user_size(x, ptr, size, retval) \ 91 do { \ 92 retval = 0; \ 93 switch (size) { \ 94 case 1: \ 95 __put_user_asm_b(x, ptr, retval); \ 96 break; \ 97 case 2: \ 98 __put_user_asm_h(x, ptr, retval); \ 99 break; \ 100 case 4: \ 101 __put_user_asm_w(x, ptr, retval); \ 102 break; \ 103 case 8: \ 104 __put_user_asm_64(x, ptr, retval); \ 105 break; \ 106 default: \ 107 __put_user_bad(); \ 108 } \ 109 } while (0) 110 111 /* 112 * We don't tell gcc that we are accessing memory, but this is OK 113 * because we do not write to any memory gcc knows about, so there 114 * are no aliasing issues. 115 * 116 * Note that PC at a fault is the address *after* the faulting 117 * instruction. 118 */ 119 #define __put_user_asm_b(x, ptr, err) \ 120 do { \ 121 int errcode; \ 122 asm volatile( \ 123 "1: stb %1, (%2,0) \n" \ 124 " br 3f \n" \ 125 "2: mov %0, %3 \n" \ 126 " br 3f \n" \ 127 ".section __ex_table, \"a\" \n" \ 128 ".align 2 \n" \ 129 ".long 1b,2b \n" \ 130 ".previous \n" \ 131 "3: \n" \ 132 : "=r"(err), "=r"(x), "=r"(ptr), "=r"(errcode) \ 133 : "0"(err), "1"(x), "2"(ptr), "3"(-EFAULT) \ 134 : "memory"); \ 135 } while (0) 136 137 #define __put_user_asm_h(x, ptr, err) \ 138 do { \ 139 int errcode; \ 140 asm volatile( \ 141 "1: sth %1, (%2,0) \n" \ 142 " br 3f \n" \ 143 "2: mov %0, %3 \n" \ 144 " br 3f \n" \ 145 ".section __ex_table, \"a\" \n" \ 146 ".align 2 \n" \ 147 ".long 1b,2b \n" \ 148 ".previous \n" \ 149 "3: \n" \ 150 : "=r"(err), "=r"(x), "=r"(ptr), "=r"(errcode) \ 151 : "0"(err), "1"(x), "2"(ptr), "3"(-EFAULT) \ 152 : "memory"); \ 153 } while (0) 154 155 #define __put_user_asm_w(x, ptr, err) \ 156 do { \ 157 int errcode; \ 158 asm volatile( \ 159 "1: stw %1, (%2,0) \n" \ 160 " br 3f \n" \ 161 "2: mov %0, %3 \n" \ 162 " br 3f \n" \ 163 ".section __ex_table,\"a\" \n" \ 164 ".align 2 \n" \ 165 ".long 1b, 2b \n" \ 166 ".previous \n" \ 167 "3: \n" \ 168 : "=r"(err), "=r"(x), "=r"(ptr), "=r"(errcode) \ 169 : "0"(err), "1"(x), "2"(ptr), "3"(-EFAULT) \ 170 : "memory"); \ 171 } while (0) 172 173 #define __put_user_asm_64(x, ptr, err) \ 174 do { \ 175 int tmp; \ 176 int errcode; \ 177 typeof(*(ptr))src = (typeof(*(ptr)))x; \ 178 typeof(*(ptr))*psrc = &src; \ 179 \ 180 asm volatile( \ 181 " ldw %3, (%1, 0) \n" \ 182 "1: stw %3, (%2, 0) \n" \ 183 " ldw %3, (%1, 4) \n" \ 184 "2: stw %3, (%2, 4) \n" \ 185 " br 4f \n" \ 186 "3: mov %0, %4 \n" \ 187 " br 4f \n" \ 188 ".section __ex_table, \"a\" \n" \ 189 ".align 2 \n" \ 190 ".long 1b, 3b \n" \ 191 ".long 2b, 3b \n" \ 192 ".previous \n" \ 193 "4: \n" \ 194 : "=r"(err), "=r"(psrc), "=r"(ptr), \ 195 "=r"(tmp), "=r"(errcode) \ 196 : "0"(err), "1"(psrc), "2"(ptr), "3"(0), "4"(-EFAULT) \ 197 : "memory"); \ 198 } while (0) 199 200 #define __get_user_nocheck(x, ptr, size) \ 201 ({ \ 202 long __gu_err; \ 203 __get_user_size(x, (ptr), (size), __gu_err); \ 204 __gu_err; \ 205 }) 206 207 #define __get_user_check(x, ptr, size) \ 208 ({ \ 209 int __gu_err = -EFAULT; \ 210 const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ 211 if (access_ok(__gu_ptr, size) && __gu_ptr) \ 212 __get_user_size(x, __gu_ptr, size, __gu_err); \ 213 __gu_err; \ 214 }) 215 216 #define __get_user_size(x, ptr, size, retval) \ 217 do { \ 218 switch (size) { \ 219 case 1: \ 220 __get_user_asm_common((x), ptr, "ldb", retval); \ 221 break; \ 222 case 2: \ 223 __get_user_asm_common((x), ptr, "ldh", retval); \ 224 break; \ 225 case 4: \ 226 __get_user_asm_common((x), ptr, "ldw", retval); \ 227 break; \ 228 default: \ 229 x = 0; \ 230 (retval) = __get_user_bad(); \ 231 } \ 232 } while (0) 233 234 #define __get_user_asm_common(x, ptr, ins, err) \ 235 do { \ 236 int errcode; \ 237 asm volatile( \ 238 "1: " ins " %1, (%4,0) \n" \ 239 " br 3f \n" \ 240 /* Fix up codes */ \ 241 "2: mov %0, %2 \n" \ 242 " movi %1, 0 \n" \ 243 " br 3f \n" \ 244 ".section __ex_table,\"a\" \n" \ 245 ".align 2 \n" \ 246 ".long 1b, 2b \n" \ 247 ".previous \n" \ 248 "3: \n" \ 249 : "=r"(err), "=r"(x), "=r"(errcode) \ 250 : "0"(0), "r"(ptr), "2"(-EFAULT) \ 251 : "memory"); \ 252 } while (0) 253 254 extern int __get_user_bad(void); 255 256 #define __copy_user(to, from, n) \ 257 do { \ 258 int w0, w1, w2, w3; \ 259 asm volatile( \ 260 "0: cmpnei %1, 0 \n" \ 261 " bf 8f \n" \ 262 " mov %3, %1 \n" \ 263 " or %3, %2 \n" \ 264 " andi %3, 3 \n" \ 265 " cmpnei %3, 0 \n" \ 266 " bf 1f \n" \ 267 " br 5f \n" \ 268 "1: cmplti %0, 16 \n" /* 4W */ \ 269 " bt 3f \n" \ 270 " ldw %3, (%2, 0) \n" \ 271 " ldw %4, (%2, 4) \n" \ 272 " ldw %5, (%2, 8) \n" \ 273 " ldw %6, (%2, 12) \n" \ 274 "2: stw %3, (%1, 0) \n" \ 275 "9: stw %4, (%1, 4) \n" \ 276 "10: stw %5, (%1, 8) \n" \ 277 "11: stw %6, (%1, 12) \n" \ 278 " addi %2, 16 \n" \ 279 " addi %1, 16 \n" \ 280 " subi %0, 16 \n" \ 281 " br 1b \n" \ 282 "3: cmplti %0, 4 \n" /* 1W */ \ 283 " bt 5f \n" \ 284 " ldw %3, (%2, 0) \n" \ 285 "4: stw %3, (%1, 0) \n" \ 286 " addi %2, 4 \n" \ 287 " addi %1, 4 \n" \ 288 " subi %0, 4 \n" \ 289 " br 3b \n" \ 290 "5: cmpnei %0, 0 \n" /* 1B */ \ 291 " bf 8f \n" \ 292 " ldb %3, (%2, 0) \n" \ 293 "6: stb %3, (%1, 0) \n" \ 294 " addi %2, 1 \n" \ 295 " addi %1, 1 \n" \ 296 " subi %0, 1 \n" \ 297 " br 5b \n" \ 298 "7: br 8f \n" \ 299 ".section __ex_table, \"a\" \n" \ 300 ".align 2 \n" \ 301 ".long 2b, 7b \n" \ 302 ".long 9b, 7b \n" \ 303 ".long 10b, 7b \n" \ 304 ".long 11b, 7b \n" \ 305 ".long 4b, 7b \n" \ 306 ".long 6b, 7b \n" \ 307 ".previous \n" \ 308 "8: \n" \ 309 : "=r"(n), "=r"(to), "=r"(from), "=r"(w0), \ 310 "=r"(w1), "=r"(w2), "=r"(w3) \ 311 : "0"(n), "1"(to), "2"(from) \ 312 : "memory"); \ 313 } while (0) 314 315 #define __copy_user_zeroing(to, from, n) \ 316 do { \ 317 int tmp; \ 318 int nsave; \ 319 asm volatile( \ 320 "0: cmpnei %1, 0 \n" \ 321 " bf 7f \n" \ 322 " mov %3, %1 \n" \ 323 " or %3, %2 \n" \ 324 " andi %3, 3 \n" \ 325 " cmpnei %3, 0 \n" \ 326 " bf 1f \n" \ 327 " br 5f \n" \ 328 "1: cmplti %0, 16 \n" \ 329 " bt 3f \n" \ 330 "2: ldw %3, (%2, 0) \n" \ 331 "10: ldw %4, (%2, 4) \n" \ 332 " stw %3, (%1, 0) \n" \ 333 " stw %4, (%1, 4) \n" \ 334 "11: ldw %3, (%2, 8) \n" \ 335 "12: ldw %4, (%2, 12) \n" \ 336 " stw %3, (%1, 8) \n" \ 337 " stw %4, (%1, 12) \n" \ 338 " addi %2, 16 \n" \ 339 " addi %1, 16 \n" \ 340 " subi %0, 16 \n" \ 341 " br 1b \n" \ 342 "3: cmplti %0, 4 \n" \ 343 " bt 5f \n" \ 344 "4: ldw %3, (%2, 0) \n" \ 345 " stw %3, (%1, 0) \n" \ 346 " addi %2, 4 \n" \ 347 " addi %1, 4 \n" \ 348 " subi %0, 4 \n" \ 349 " br 3b \n" \ 350 "5: cmpnei %0, 0 \n" \ 351 " bf 7f \n" \ 352 "6: ldb %3, (%2, 0) \n" \ 353 " stb %3, (%1, 0) \n" \ 354 " addi %2, 1 \n" \ 355 " addi %1, 1 \n" \ 356 " subi %0, 1 \n" \ 357 " br 5b \n" \ 358 "8: mov %3, %0 \n" \ 359 " movi %4, 0 \n" \ 360 "9: stb %4, (%1, 0) \n" \ 361 " addi %1, 1 \n" \ 362 " subi %3, 1 \n" \ 363 " cmpnei %3, 0 \n" \ 364 " bt 9b \n" \ 365 " br 7f \n" \ 366 ".section __ex_table, \"a\" \n" \ 367 ".align 2 \n" \ 368 ".long 2b, 8b \n" \ 369 ".long 10b, 8b \n" \ 370 ".long 11b, 8b \n" \ 371 ".long 12b, 8b \n" \ 372 ".long 4b, 8b \n" \ 373 ".long 6b, 8b \n" \ 374 ".previous \n" \ 375 "7: \n" \ 376 : "=r"(n), "=r"(to), "=r"(from), "=r"(nsave), \ 377 "=r"(tmp) \ 378 : "0"(n), "1"(to), "2"(from) \ 379 : "memory"); \ 380 } while (0) 381 382 unsigned long raw_copy_from_user(void *to, const void *from, unsigned long n); 383 unsigned long raw_copy_to_user(void *to, const void *from, unsigned long n); 384 385 unsigned long clear_user(void *to, unsigned long n); 386 unsigned long __clear_user(void __user *to, unsigned long n); 387 388 long strncpy_from_user(char *dst, const char *src, long count); 389 long __strncpy_from_user(char *dst, const char *src, long count); 390 391 /* 392 * Return the size of a string (including the ending 0) 393 * 394 * Return 0 on exception, a value greater than N if too long 395 */ 396 long strnlen_user(const char *src, long n); 397 398 #define strlen_user(str) strnlen_user(str, 32767) 399 400 struct exception_table_entry { 401 unsigned long insn; 402 unsigned long nextinsn; 403 }; 404 405 extern int fixup_exception(struct pt_regs *regs); 406 407 #endif /* __ASM_CSKY_UACCESS_H */ 408