include/asm-mips64/uaccess.h

   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) 1996, 1997, 1998, 1999, 2000 by Ralf Baechle
   7  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
   8  */
   9 #ifndef _ASM_UACCESS_H
  10 #define _ASM_UACCESS_H
  11
  12 #include <linux/errno.h>
  13 #include <linux/sched.h>
  14
  15 #define STR(x)  __STR(x)
  16 #define __STR(x)  #x
  17
  18 /*
  19  * The fs value determines whether argument validity checking should be
  20  * performed or not.  If get_fs() == USER_DS, checking is performed, with
  21  * get_fs() == KERNEL_DS, checking is bypassed.
  22  *
  23  * For historical reasons, these macros are grossly misnamed.
  24  */
  25 #define KERNEL_DS       ((mm_segment_t) { (unsigned long) 0L })
  26 #define USER_DS         ((mm_segment_t) { (unsigned long) -1L })
  27
  28 #define VERIFY_READ    0
  29 #define VERIFY_WRITE   1
  30
  31 #define get_fs()        (current->thread.current_ds)
  32 #define get_ds()        (KERNEL_DS)
  33 #define set_fs(x)       (current->thread.current_ds=(x))
  34
  35 #define segment_eq(a,b) ((a).seg == (b).seg)
  36
  37
  38 /*
  39  * Is a address valid? This does a straighforward calculation rather
  40  * than tests.
  41  *
  42  * Address valid if:
  43  *  - "addr" doesn't have any high-bits set
  44  *  - AND "size" doesn't have any high-bits set
  45  *  - AND "addr+size" doesn't have any high-bits set
  46  *  - OR we are in kernel mode.
  47  */
  48 #define __ua_size(size)                                                 \
  49         (__builtin_constant_p(size) && (signed long) (size) > 0 ? 0 : (size))
  50
  51 #define __access_ok(addr,size,mask)                                     \
  52         (((signed long)((mask)&(addr | (addr + size) | __ua_size(size)))) >= 0)
  53
  54 #define __access_mask ((long)(get_fs().seg))
  55
  56 #define access_ok(type,addr,size) \
  57         __access_ok(((unsigned long)(addr)),(size),__access_mask)
  58
  59 static inline int verify_area(int type, const void * addr, unsigned long size)
  60 {
  61         return access_ok(type,addr,size) ? 0 : -EFAULT;
  62 }
  63
  64 /*
  65  * Uh, these should become the main single-value transfer routines ...
  66  * They automatically use the right size if we just have the right
  67  * pointer type ...
  68  *
  69  * As MIPS uses the same address space for kernel and user data, we
  70  * can just do these as direct assignments.
  71  *
  72  * Careful to not
  73  * (a) re-use the arguments for side effects (sizeof is ok)
  74  * (b) require any knowledge of processes at this stage
  75  */
  76 #define put_user(x,ptr) \
  77         __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
  78 #define get_user(x,ptr) \
  79         __get_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
  80
  81 /*
  82  * The "__xxx" versions do not do address space checking, useful when
  83  * doing multiple accesses to the same area (the user has to do the
  84  * checks by hand with "access_ok()")
  85  */
  86 #define __put_user(x,ptr) \
  87         __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
  88 #define __get_user(x,ptr) \
  89         __get_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
  90
  91 struct __large_struct { unsigned long buf[100]; };
  92 #define __m(x) (*(struct __large_struct *)(x))
  93
  94 #define __get_user_nocheck(x,ptr,size)                          \
  95 ({                                                              \
  96         long __gu_err;                                          \
  97         __typeof(*(ptr)) __gu_val;                              \
  98         long __gu_addr;                                         \
  99         __asm__("":"=r" (__gu_val));                            \
 100         __gu_addr = (long) (ptr);                               \
 101         __asm__("":"=r" (__gu_err));                            \
 102         switch (size) {                                         \
 103         case 1: __get_user_asm("lb"); break;                    \
 104         case 2: __get_user_asm("lh"); break;                    \
 105         case 4: __get_user_asm("lw"); break;                    \
 106         case 8: __get_user_asm("ld"); break;                    \
 107         default: __get_user_unknown(); break;                   \
 108         } x = (__typeof__(*(ptr))) __gu_val; __gu_err;          \
 109 })
 110
 111 #define __get_user_check(x,ptr,size)                            \
 112 ({                                                              \
 113         long __gu_err;                                          \
 114         __typeof__(*(ptr)) __gu_val;                            \
 115         long __gu_addr;                                         \
 116         __asm__("":"=r" (__gu_val));                            \
 117         __gu_addr = (long) (ptr);                               \
 118         __asm__("":"=r" (__gu_err));                            \
 119         if (__access_ok(__gu_addr,size,__access_mask)) {        \
 120                 switch (size) {                                 \
 121                 case 1: __get_user_asm("lb"); break;            \
 122                 case 2: __get_user_asm("lh"); break;            \
 123                 case 4: __get_user_asm("lw"); break;            \
 124                 case 8: __get_user_asm("ld"); break;            \
 125                 default: __get_user_unknown(); break;           \
 126                 }                                               \
 127         } x = (__typeof__(*(ptr))) __gu_val; __gu_err;          \
 128 })
 129
 130 #define __get_user_asm(insn)                                    \
 131 ({                                                              \
 132         __asm__ __volatile__(                                   \
 133         "1:\t" insn "\t%1,%2\n\t"                               \
 134         "move\t%0,$0\n"                                         \
 135         "2:\n\t"                                                \
 136         ".section\t.fixup,\"ax\"\n"                             \
 137         "3:\tli\t%0,%3\n\t"                                     \
 138         "move\t%1,$0\n\t"                                       \
 139         "j\t2b\n\t"                                             \
 140         ".previous\n\t"                                         \
 141         ".section\t__ex_table,\"a\"\n\t"                        \
 142         ".dword\t1b,3b\n\t"                                     \
 143         ".previous"                                             \
 144         :"=r" (__gu_err), "=r" (__gu_val)                       \
 145         :"o" (__m(__gu_addr)), "i" (-EFAULT));                  \
 146 })
 147
 148 extern void __get_user_unknown(void);
 149
 150 #define __put_user_nocheck(x,ptr,size)                          \
 151 ({                                                              \
 152         long __pu_err;                                          \
 153         __typeof__(*(ptr)) __pu_val;                            \
 154         long __pu_addr;                                         \
 155         __pu_val = (x);                                         \
 156         __pu_addr = (long) (ptr);                               \
 157         __asm__("":"=r" (__pu_err));                            \
 158         switch (size) {                                         \
 159         case 1: __put_user_asm("sb"); break;                    \
 160         case 2: __put_user_asm("sh"); break;                    \
 161         case 4: __put_user_asm("sw"); break;                    \
 162         case 8: __put_user_asm("sd"); break;                    \
 163         default: __put_user_unknown(); break;                   \
 164         } __pu_err;                                             \
 165 })
 166
 167 #define __put_user_check(x,ptr,size)                            \
 168 ({                                                              \
 169         long __pu_err;                                          \
 170         __typeof__(*(ptr)) __pu_val;                            \
 171         long __pu_addr;                                         \
 172         __pu_val = (x);                                         \
 173         __pu_addr = (long) (ptr);                               \
 174         __asm__("":"=r" (__pu_err));                            \
 175         if (__access_ok(__pu_addr,size,__access_mask)) {        \
 176                 switch (size) {                                 \
 177                 case 1: __put_user_asm("sb"); break;            \
 178                 case 2: __put_user_asm("sh"); break;            \
 179                 case 4: __put_user_asm("sw"); break;            \
 180                 case 8: __put_user_asm("sd"); break;            \
 181                 default: __put_user_unknown(); break;           \
 182                 }                                               \
 183         } __pu_err;                                             \
 184 })
 185
 186 #define __put_user_asm(insn)                                    \
 187 ({                                                              \
 188         __asm__ __volatile__(                                   \
 189         "1:\t" insn "\t%z1, %2\t\t\t# __put_user_asm\n\t"       \
 190         "move\t%0,$0\n"                                         \
 191         "2:\n\t"                                                \
 192         ".section\t.fixup,\"ax\"\n"                             \
 193         "3:\tli\t%0,%3\n\t"                                     \
 194         "j\t2b\n\t"                                             \
 195         ".previous\n\t"                                         \
 196         ".section\t__ex_table,\"a\"\n\t"                        \
 197         ".dword\t1b,3b\n\t"                                     \
 198         ".previous"                                             \
 199         :"=r" (__pu_err)                                        \
 200         :"Jr" (__pu_val), "o" (__m(__pu_addr)), "i" (-EFAULT)); \
 201 })
 202
 203 extern void __put_user_unknown(void);
 204
 205 /*
 206  * We're generating jump to subroutines which will be outside the range of
 207  * jump instructions
 208  */
 209 #ifdef MODULE
 210 #define __MODULE_JAL(destination)       \
 211         ".set\tnoat\n\t"                \
 212         "dla\t$1, " #destination "\n\t" \
 213         "jalr\t$1\n\t"                  \
 214         ".set\tat\n\t"
 215 #else
 216 #define __MODULE_JAL(destination)       \
 217         "jal\t" #destination "\n\t"
 218 #endif
 219
 220 extern size_t __copy_user(void *__to, const void *__from, size_t __n);
 221
 222 #define __invoke_copy_to_user(to,from,n)                                \
 223 ({                                                                      \
 224         register void *__cu_to_r __asm__ ("$4");                        \
 225         register const void *__cu_from_r __asm__ ("$5");                \
 226         register long __cu_len_r __asm__ ("$6");                        \
 227                                                                         \
 228         __cu_to_r = (to);                                               \
 229         __cu_from_r = (from);                                           \
 230         __cu_len_r = (n);                                               \
 231         __asm__ __volatile__(                                           \
 232         __MODULE_JAL(__copy_user)                                       \
 233         : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)       \
 234         :                                                               \
 235         : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31",         \
 236           "memory");                                                    \
 237         __cu_len_r;                                                     \
 238 })
 239
 240 #define __copy_to_user(to,from,n)                                       \
 241 ({                                                                      \
 242         void *__cu_to;                                                  \
 243         const void *__cu_from;                                          \
 244         long __cu_len;                                                  \
 245                                                                         \
 246         __cu_to = (to);                                                 \
 247         __cu_from = (from);                                             \
 248         __cu_len = (n);                                                 \
 249         __cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len); \
 250         __cu_len;                                                       \
 251 })
 252
 253 #define copy_to_user(to,from,n)                                         \
 254 ({                                                                      \
 255         void *__cu_to;                                                  \
 256         const void *__cu_from;                                          \
 257         long __cu_len;                                                  \
 258                                                                         \
 259         __cu_to = (to);                                                 \
 260         __cu_from = (from);                                             \
 261         __cu_len = (n);                                                 \
 262         if (access_ok(VERIFY_WRITE, __cu_to, __cu_len))                 \
 263                 __cu_len = __invoke_copy_to_user(__cu_to, __cu_from,    \
 264                                                 __cu_len);              \
 265         __cu_len;                                                       \
 266 })
 267
 268 #define __invoke_copy_from_user(to,from,n)                              \
 269 ({                                                                      \
 270         register void *__cu_to_r __asm__ ("$4");                        \
 271         register const void *__cu_from_r __asm__ ("$5");                \
 272         register long __cu_len_r __asm__ ("$6");                        \
 273                                                                         \
 274         __cu_to_r = (to);                                               \
 275         __cu_from_r = (from);                                           \
 276         __cu_len_r = (n);                                               \
 277         __asm__ __volatile__(                                           \
 278         ".set\tnoreorder\n\t"                                           \
 279         __MODULE_JAL(__copy_user)                                       \
 280         ".set\tnoat\n\t"                                                \
 281         "daddu\t$1, %1, %2\n\t"                                         \
 282         ".set\tat\n\t"                                                  \
 283         ".set\treorder\n\t"                                             \
 284         "move\t%0, $6"                                                  \
 285         : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)       \
 286         :                                                               \
 287         : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31",         \
 288           "memory");                                                    \
 289         __cu_len_r;                                                     \
 290 })
 291
 292 #define __copy_from_user(to,from,n)                                     \
 293 ({                                                                      \
 294         void *__cu_to;                                                  \
 295         const void *__cu_from;                                          \
 296         long __cu_len;                                                  \
 297                                                                         \
 298         __cu_to = (to);                                                 \
 299         __cu_from = (from);                                             \
 300         __cu_len = (n);                                                 \
 301         __cu_len = __invoke_copy_from_user(__cu_to, __cu_from,          \
 302                                            __cu_len);                   \
 303         __cu_len;                                                       \
 304 })
 305
 306 #define copy_from_user(to,from,n)                                       \
 307 ({                                                                      \
 308         void *__cu_to;                                                  \
 309         const void *__cu_from;                                          \
 310         long __cu_len;                                                  \
 311                                                                         \
 312         __cu_to = (to);                                                 \
 313         __cu_from = (from);                                             \
 314         __cu_len = (n);                                                 \
 315         if (access_ok(VERIFY_READ, __cu_from, __cu_len))                \
 316                 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from,  \
 317                                                    __cu_len);           \
 318         __cu_len;                                                       \
 319 })
 320
 321 static inline __kernel_size_t
 322 __clear_user(void *addr, __kernel_size_t size)
 323 {
 324         __kernel_size_t res;
 325
 326         __asm__ __volatile__(
 327                 "move\t$4, %1\n\t"
 328                 "move\t$5, $0\n\t"
 329                 "move\t$6, %2\n\t"
 330                 __MODULE_JAL(__bzero)
 331                 "move\t%0, $6"
 332                 : "=r" (res)
 333                 : "r" (addr), "r" (size)
 334                 : "$4", "$5", "$6", "$8", "$9", "$31");
 335
 336         return res;
 337 }
 338
 339 #define clear_user(addr,n)                                      \
 340 ({                                                              \
 341         void * __cl_addr = (addr);                              \
 342         unsigned long __cl_size = (n);                          \
 343         if (__cl_size && __access_ok(VERIFY_WRITE,              \
 344                ((unsigned long)(__cl_addr)), __cl_size))        \
 345                 __cl_size = __clear_user(__cl_addr, __cl_size); \
 346         __cl_size;                                              \
 347 })
 348
 349 /*
 350  * Returns: -EFAULT if exception before terminator, N if the entire
 351  * buffer filled, else strlen.
 352  */
 353 static inline long
 354 __strncpy_from_user(char *__to, const char *__from, long __len)
 355 {
 356         long res;
 357
 358         __asm__ __volatile__(
 359                 "move\t$4, %1\n\t"
 360                 "move\t$5, %2\n\t"
 361                 "move\t$6, %3\n\t"
 362                 __MODULE_JAL(__strncpy_from_user_nocheck_asm)
 363                 "move\t%0, $2"
 364                 : "=r" (res)
 365                 : "r" (__to), "r" (__from), "r" (__len)
 366                 : "$2", "$3", "$4", "$5", "$6", "$8", "$31", "memory");
 367
 368         return res;
 369 }
 370
 371 static inline long
 372 strncpy_from_user(char *__to, const char *__from, long __len)
 373 {
 374         long res;
 375
 376         __asm__ __volatile__(
 377                 "move\t$4, %1\n\t"
 378                 "move\t$5, %2\n\t"
 379                 "move\t$6, %3\n\t"
 380                 __MODULE_JAL(__strncpy_from_user_asm)
 381                 "move\t%0, $2"
 382                 : "=r" (res)
 383                 : "r" (__to), "r" (__from), "r" (__len)
 384                 : "$2", "$3", "$4", "$5", "$6", "$8", "$31", "memory");
 385
 386         return res;
 387 }
 388
 389 /* Returns: 0 if bad, string length+1 (memory size) of string if ok */
 390 static inline long __strlen_user(const char *s)
 391 {
 392         long res;
 393
 394         __asm__ __volatile__(
 395                 "move\t$4, %1\n\t"
 396                 __MODULE_JAL(__strlen_user_nocheck_asm)
 397                 "move\t%0, $2"
 398                 : "=r" (res)
 399                 : "r" (s)
 400                 : "$2", "$4", "$8", "$31");
 401
 402         return res;
 403 }
 404
 405 static inline long strlen_user(const char *s)
 406 {
 407         long res;
 408
 409         __asm__ __volatile__(
 410                 "move\t$4, %1\n\t"
 411                 __MODULE_JAL(__strlen_user_asm)
 412                 "move\t%0, $2"
 413                 : "=r" (res)
 414                 : "r" (s)
 415                 : "$2", "$4", "$8", "$31");
 416
 417         return res;
 418 }
 419
 420 /* Returns: 0 if bad, string length+1 (memory size) of string if ok */
 421 static inline long __strnlen_user(const char *s, long n)
 422 {
 423         long res;
 424
 425         __asm__ __volatile__(
 426                 "move\t$4, %1\n\t"
 427                 "move\t$5, %2\n\t"
 428                 __MODULE_JAL(__strnlen_user_nocheck_asm)
 429                 "move\t%0, $2"
 430                 : "=r" (res)
 431                 : "r" (s), "r" (n)
 432                 : "$2", "$4", "$5", "$8", "$31");
 433
 434         return res;
 435 }
 436
 437 static inline long strnlen_user(const char *s, long n)
 438 {
 439         long res;
 440
 441         __asm__ __volatile__(
 442                 "move\t$4, %1\n\t"
 443                 "move\t$5, %2\n\t"
 444                 __MODULE_JAL(__strnlen_user_asm)
 445                 "move\t%0, $2"
 446                 : "=r" (res)
 447                 : "r" (s), "r" (n)
 448                 : "$2", "$4", "$5", "$8", "$31");
 449
 450         return res;
 451 }
 452
 453 struct exception_table_entry
 454 {
 455         unsigned long insn;
 456         unsigned long nextinsn;
 457 };
 458
 459 /* Returns 0 if exception not found and fixup.unit otherwise.  */
 460 extern unsigned long search_exception_table(unsigned long addr);
 461
 462 /* Returns the new pc */
 463 #define fixup_exception(map_reg, fixup_unit, pc)                \
 464 ({                                                              \
 465         fixup_unit;                                             \
 466 })
 467
 468 #endif /* _ASM_UACCESS_H */