include/asm-mips/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, 03, 04 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/config.h>
  13 #include <linux/kernel.h>
  14 #include <linux/errno.h>
  15 #include <linux/thread_info.h>
  16 #include <asm-generic/uaccess.h>
  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 #ifdef CONFIG_MIPS32
  26
  27 #define __UA_LIMIT      0x80000000UL
  28
  29 #define __UA_ADDR       ".word"
  30 #define __UA_LA         "la"
  31 #define __UA_ADDU       "addu"
  32 #define __UA_t0         "$8"
  33 #define __UA_t1         "$9"
  34
  35 #endif /* CONFIG_MIPS32 */
  36
  37 #ifdef CONFIG_MIPS64
  38
  39 #define __UA_LIMIT      (- TASK_SIZE)
  40
  41 #define __UA_ADDR       ".dword"
  42 #define __UA_LA         "dla"
  43 #define __UA_ADDU       "daddu"
  44 #define __UA_t0         "$12"
  45 #define __UA_t1         "$13"
  46
  47 #endif /* CONFIG_MIPS64 */
  48
  49 /*
  50  * USER_DS is a bitmask that has the bits set that may not be set in a valid
  51  * userspace address.  Note that we limit 32-bit userspace to 0x7fff8000 but
  52  * the arithmetic we're doing only works if the limit is a power of two, so
  53  * we use 0x80000000 here on 32-bit kernels.  If a process passes an invalid
  54  * address in this range it's the process's problem, not ours :-)
  55  */
  56
  57 #define KERNEL_DS       ((mm_segment_t) { 0UL })
  58 #define USER_DS         ((mm_segment_t) { __UA_LIMIT })
  59
  60 #define VERIFY_READ    0
  61 #define VERIFY_WRITE   1
  62
  63 #define get_ds()        (KERNEL_DS)
  64 #define get_fs()        (current_thread_info()->addr_limit)
  65 #define set_fs(x)       (current_thread_info()->addr_limit = (x))
  66
  67 #define segment_eq(a,b) ((a).seg == (b).seg)
  68
  69
  70 /*
  71  * Is a address valid? This does a straighforward calculation rather
  72  * than tests.
  73  *
  74  * Address valid if:
  75  *  - "addr" doesn't have any high-bits set
  76  *  - AND "size" doesn't have any high-bits set
  77  *  - AND "addr+size" doesn't have any high-bits set
  78  *  - OR we are in kernel mode.
  79  *
  80  * __ua_size() is a trick to avoid runtime checking of positive constant
  81  * sizes; for those we already know at compile time that the size is ok.
  82  */
  83 #define __ua_size(size)                                                 \
  84         ((__builtin_constant_p(size) && (signed long) (size) > 0) ? 0 : (size))
  85
  86 /*
  87  * access_ok: - Checks if a user space pointer is valid
  88  * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE.  Note that
  89  *        %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
  90  *        to write to a block, it is always safe to read from it.
  91  * @addr: User space pointer to start of block to check
  92  * @size: Size of block to check
  93  *
  94  * Context: User context only.  This function may sleep.
  95  *
  96  * Checks if a pointer to a block of memory in user space is valid.
  97  *
  98  * Returns true (nonzero) if the memory block may be valid, false (zero)
  99  * if it is definitely invalid.
 100  *
 101  * Note that, depending on architecture, this function probably just
 102  * checks that the pointer is in the user space range - after calling
 103  * this function, memory access functions may still return -EFAULT.
 104  */
 105
 106 #define __access_mask get_fs().seg
 107
 108 #define __access_ok(addr, size, mask)                                   \
 109         (((signed long)((mask) & ((addr) | ((addr) + (size)) | __ua_size(size)))) == 0)
 110
 111 #define access_ok(type, addr, size)                                     \
 112         likely(__access_ok((unsigned long)(addr), (size),__access_mask))
 113
 114 /*
 115  * verify_area: - Obsolete, use access_ok()
 116  * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE
 117  * @addr: User space pointer to start of block to check
 118  * @size: Size of block to check
 119  *
 120  * Context: User context only.  This function may sleep.
 121  *
 122  * This function has been replaced by access_ok().
 123  *
 124  * Checks if a pointer to a block of memory in user space is valid.
 125  *
 126  * Returns zero if the memory block may be valid, -EFAULT
 127  * if it is definitely invalid.
 128  *
 129  * See access_ok() for more details.
 130  */
 131 static inline int verify_area(int type, const void * addr, unsigned long size)
 132 {
 133         return access_ok(type, addr, size) ? 0 : -EFAULT;
 134 }
 135
 136 /*
 137  * put_user: - Write a simple value into user space.
 138  * @x:   Value to copy to user space.
 139  * @ptr: Destination address, in user space.
 140  *
 141  * Context: User context only.  This function may sleep.
 142  *
 143  * This macro copies a single simple value from kernel space to user
 144  * space.  It supports simple types like char and int, but not larger
 145  * data types like structures or arrays.
 146  *
 147  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 148  * to the result of dereferencing @ptr.
 149  *
 150  * Returns zero on success, or -EFAULT on error.
 151  */
 152 #define put_user(x,ptr) \
 153         __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
 154
 155 /*
 156  * get_user: - Get a simple variable from user space.
 157  * @x:   Variable to store result.
 158  * @ptr: Source address, in user space.
 159  *
 160  * Context: User context only.  This function may sleep.
 161  *
 162  * This macro copies a single simple variable from user space to kernel
 163  * space.  It supports simple types like char and int, but not larger
 164  * data types like structures or arrays.
 165  *
 166  * @ptr must have pointer-to-simple-variable type, and the result of
 167  * dereferencing @ptr must be assignable to @x without a cast.
 168  *
 169  * Returns zero on success, or -EFAULT on error.
 170  * On error, the variable @x is set to zero.
 171  */
 172 #define get_user(x,ptr) \
 173         __get_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
 174
 175 /*
 176  * __put_user: - Write a simple value into user space, with less checking.
 177  * @x:   Value to copy to user space.
 178  * @ptr: Destination address, in user space.
 179  *
 180  * Context: User context only.  This function may sleep.
 181  *
 182  * This macro copies a single simple value from kernel space to user
 183  * space.  It supports simple types like char and int, but not larger
 184  * data types like structures or arrays.
 185  *
 186  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 187  * to the result of dereferencing @ptr.
 188  *
 189  * Caller must check the pointer with access_ok() before calling this
 190  * function.
 191  *
 192  * Returns zero on success, or -EFAULT on error.
 193  */
 194 #define __put_user(x,ptr) \
 195         __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
 196
 197 /*
 198  * __get_user: - Get a simple variable from user space, with less checking.
 199  * @x:   Variable to store result.
 200  * @ptr: Source address, in user space.
 201  *
 202  * Context: User context only.  This function may sleep.
 203  *
 204  * This macro copies a single simple variable from user space to kernel
 205  * space.  It supports simple types like char and int, but not larger
 206  * data types like structures or arrays.
 207  *
 208  * @ptr must have pointer-to-simple-variable type, and the result of
 209  * dereferencing @ptr must be assignable to @x without a cast.
 210  *
 211  * Caller must check the pointer with access_ok() before calling this
 212  * function.
 213  *
 214  * Returns zero on success, or -EFAULT on error.
 215  * On error, the variable @x is set to zero.
 216  */
 217 #define __get_user(x,ptr) \
 218         __get_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
 219
 220 struct __large_struct { unsigned long buf[100]; };
 221 #define __m(x) (*(struct __large_struct *)(x))
 222
 223 /*
 224  * Yuck.  We need two variants, one for 64bit operation and one
 225  * for 32 bit mode and old iron.
 226  */
 227 #ifdef __mips64
 228 #define __GET_USER_DW(__gu_err) __get_user_asm("ld", __gu_err)
 229 #else
 230 #define __GET_USER_DW(__gu_err) __get_user_asm_ll32(__gu_err)
 231 #endif
 232
 233 #define __get_user_nocheck(x,ptr,size)                                  \
 234 ({                                                                      \
 235         long __gu_err = 0;                                              \
 236         __typeof(*(ptr)) __gu_val = 0;                                  \
 237         long __gu_addr;                                                 \
 238         might_sleep();                                                  \
 239         __gu_addr = (long) (ptr);                                       \
 240         switch (size) {                                                 \
 241         case 1: __get_user_asm("lb", __gu_err); break;                  \
 242         case 2: __get_user_asm("lh", __gu_err); break;                  \
 243         case 4: __get_user_asm("lw", __gu_err); break;                  \
 244         case 8: __GET_USER_DW(__gu_err); break;                         \
 245         default: __get_user_unknown(); break;                           \
 246         }                                                               \
 247          x = (__typeof__(*(ptr))) __gu_val;                             \
 248         __gu_err;                                                       \
 249 })
 250
 251 #define __get_user_check(x,ptr,size)                                    \
 252 ({                                                                      \
 253         __typeof__(*(ptr)) __gu_val = 0;                                \
 254         long __gu_addr = (long) (ptr);                                  \
 255         long __gu_err;                                                  \
 256                                                                         \
 257         might_sleep();                                                  \
 258         __gu_err = verify_area(VERIFY_READ, (void *) __gu_addr, size);  \
 259                                                                         \
 260         if (likely(!__gu_err)) {                                        \
 261                 switch (size) {                                         \
 262                 case 1: __get_user_asm("lb", __gu_err); break;          \
 263                 case 2: __get_user_asm("lh", __gu_err); break;          \
 264                 case 4: __get_user_asm("lw", __gu_err); break;          \
 265                 case 8: __GET_USER_DW(__gu_err); break;                 \
 266                 default: __get_user_unknown(); break;                   \
 267                 }                                                       \
 268         }                                                               \
 269         x = (__typeof__(*(ptr))) __gu_val;                              \
 270          __gu_err;                                                      \
 271 })
 272
 273 #define __get_user_asm(insn,__gu_err)                                   \
 274 ({                                                                      \
 275         __asm__ __volatile__(                                           \
 276         "1:     " insn "        %1, %3                          \n"     \
 277         "2:                                                     \n"     \
 278         "       .section .fixup,\"ax\"                          \n"     \
 279         "3:     li      %0, %4                                  \n"     \
 280         "       j       2b                                      \n"     \
 281         "       .previous                                       \n"     \
 282         "       .section __ex_table,\"a\"                       \n"     \
 283         "       "__UA_ADDR "\t1b, 3b                            \n"     \
 284         "       .previous                                       \n"     \
 285         : "=r" (__gu_err), "=r" (__gu_val)                              \
 286         : "0" (__gu_err), "o" (__m(__gu_addr)), "i" (-EFAULT));         \
 287 })
 288
 289 /*
 290  * Get a long long 64 using 32 bit registers.
 291  */
 292 #define __get_user_asm_ll32(__gu_err)                                   \
 293 ({                                                                      \
 294         __asm__ __volatile__(                                           \
 295         "1:     lw      %1, %3                                  \n"     \
 296         "2:     lw      %D1, %4                                 \n"     \
 297         "       move    %0, $0                                  \n"     \
 298         "3:     .section        .fixup,\"ax\"                   \n"     \
 299         "4:     li      %0, %5                                  \n"     \
 300         "       move    %1, $0                                  \n"     \
 301         "       move    %D1, $0                                 \n"     \
 302         "       j       3b                                      \n"     \
 303         "       .previous                                       \n"     \
 304         "       .section        __ex_table,\"a\"                \n"     \
 305         "       " __UA_ADDR "   1b, 4b                          \n"     \
 306         "       " __UA_ADDR "   2b, 4b                          \n"     \
 307         "       .previous                                       \n"     \
 308         : "=r" (__gu_err), "=&r" (__gu_val)                             \
 309         : "0" (__gu_err), "o" (__m(__gu_addr)),                         \
 310           "o" (__m(__gu_addr + 4)), "i" (-EFAULT));                     \
 311 })
 312
 313 extern void __get_user_unknown(void);
 314
 315 /*
 316  * Yuck.  We need two variants, one for 64bit operation and one
 317  * for 32 bit mode and old iron.
 318  */
 319 #ifdef __mips64
 320 #define __PUT_USER_DW(__pu_val) __put_user_asm("sd", __pu_val)
 321 #else
 322 #define __PUT_USER_DW(__pu_val) __put_user_asm_ll32(__pu_val)
 323 #endif
 324
 325 #define __put_user_nocheck(x,ptr,size)                                  \
 326 ({                                                                      \
 327         long __pu_err = 0;                                              \
 328         __typeof__(*(ptr)) __pu_val;                                    \
 329         long __pu_addr;                                                 \
 330         might_sleep();                                                  \
 331         __pu_val = (x);                                                 \
 332         __pu_addr = (long) (ptr);                                       \
 333         switch (size) {                                                 \
 334         case 1: __put_user_asm("sb", __pu_val); break;                  \
 335         case 2: __put_user_asm("sh", __pu_val); break;                  \
 336         case 4: __put_user_asm("sw", __pu_val); break;                  \
 337         case 8: __PUT_USER_DW(__pu_val); break;                         \
 338         default: __put_user_unknown(); break;                           \
 339         }                                                               \
 340         __pu_err;                                                       \
 341 })
 342
 343 #define __put_user_check(x,ptr,size)                                    \
 344 ({                                                                      \
 345         __typeof__(*(ptr)) __pu_val = (x);                              \
 346         long __pu_addr = (long) (ptr);                                  \
 347         long __pu_err;                                                  \
 348                                                                         \
 349         might_sleep();                                                  \
 350         __pu_err = verify_area(VERIFY_WRITE, (void *) __pu_addr, size); \
 351                                                                         \
 352         if (likely(!__pu_err)) {                                        \
 353                 switch (size) {                                         \
 354                 case 1: __put_user_asm("sb", __pu_val); break;          \
 355                 case 2: __put_user_asm("sh", __pu_val); break;          \
 356                 case 4: __put_user_asm("sw", __pu_val); break;          \
 357                 case 8: __PUT_USER_DW(__pu_val); break;                 \
 358                 default: __put_user_unknown(); break;                   \
 359                 }                                                       \
 360         }                                                               \
 361         __pu_err;                                                       \
 362 })
 363
 364 #define __put_user_asm(insn, __pu_val)                                  \
 365 ({                                                                      \
 366         __asm__ __volatile__(                                           \
 367         "1:     " insn "        %z2, %3         # __put_user_asm\n"     \
 368         "2:                                                     \n"     \
 369         "       .section        .fixup,\"ax\"                   \n"     \
 370         "3:     li      %0, %4                                  \n"     \
 371         "       j       2b                                      \n"     \
 372         "       .previous                                       \n"     \
 373         "       .section        __ex_table,\"a\"                \n"     \
 374         "       " __UA_ADDR "   1b, 3b                          \n"     \
 375         "       .previous                                       \n"     \
 376         : "=r" (__pu_err)                                               \
 377         : "0" (__pu_err), "Jr" (__pu_val), "o" (__m(__pu_addr)),        \
 378           "i" (-EFAULT));                                               \
 379 })
 380
 381 #define __put_user_asm_ll32(__pu_val)                                   \
 382 ({                                                                      \
 383         __asm__ __volatile__(                                           \
 384         "1:     sw      %2, %3          # __put_user_asm_ll32   \n"     \
 385         "2:     sw      %D2, %4                                 \n"     \
 386         "3:                                                     \n"     \
 387         "       .section        .fixup,\"ax\"                   \n"     \
 388         "4:     li      %0, %5                                  \n"     \
 389         "       j       3b                                      \n"     \
 390         "       .previous                                       \n"     \
 391         "       .section        __ex_table,\"a\"                \n"     \
 392         "       " __UA_ADDR "   1b, 4b                          \n"     \
 393         "       " __UA_ADDR "   2b, 4b                          \n"     \
 394         "       .previous"                                              \
 395         : "=r" (__pu_err)                                               \
 396         : "0" (__pu_err), "r" (__pu_val), "o" (__m(__pu_addr)),         \
 397           "o" (__m(__pu_addr + 4)), "i" (-EFAULT));                     \
 398 })
 399
 400 extern void __put_user_unknown(void);
 401
 402 /*
 403  * We're generating jump to subroutines which will be outside the range of
 404  * jump instructions
 405  */
 406 #ifdef MODULE
 407 #define __MODULE_JAL(destination)                                       \
 408         ".set\tnoat\n\t"                                                \
 409         __UA_LA "\t$1, " #destination "\n\t"                            \
 410         "jalr\t$1\n\t"                                                  \
 411         ".set\tat\n\t"
 412 #else
 413 #define __MODULE_JAL(destination)                                       \
 414         "jal\t" #destination "\n\t"
 415 #endif
 416
 417 extern size_t __copy_user(void *__to, const void *__from, size_t __n);
 418
 419 #define __invoke_copy_to_user(to,from,n)                                \
 420 ({                                                                      \
 421         register void *__cu_to_r __asm__ ("$4");                        \
 422         register const void *__cu_from_r __asm__ ("$5");                \
 423         register long __cu_len_r __asm__ ("$6");                        \
 424                                                                         \
 425         __cu_to_r = (to);                                               \
 426         __cu_from_r = (from);                                           \
 427         __cu_len_r = (n);                                               \
 428         __asm__ __volatile__(                                           \
 429         __MODULE_JAL(__copy_user)                                       \
 430         : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)       \
 431         :                                                               \
 432         : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31",         \
 433           "memory");                                                    \
 434         __cu_len_r;                                                     \
 435 })
 436
 437 /*
 438  * __copy_to_user: - Copy a block of data into user space, with less checking.
 439  * @to:   Destination address, in user space.
 440  * @from: Source address, in kernel space.
 441  * @n:    Number of bytes to copy.
 442  *
 443  * Context: User context only.  This function may sleep.
 444  *
 445  * Copy data from kernel space to user space.  Caller must check
 446  * the specified block with access_ok() before calling this function.
 447  *
 448  * Returns number of bytes that could not be copied.
 449  * On success, this will be zero.
 450  */
 451 #define __copy_to_user(to,from,n)                                       \
 452 ({                                                                      \
 453         void *__cu_to;                                                  \
 454         const void *__cu_from;                                          \
 455         long __cu_len;                                                  \
 456                                                                         \
 457         might_sleep();                                                  \
 458         __cu_to = (to);                                                 \
 459         __cu_from = (from);                                             \
 460         __cu_len = (n);                                                 \
 461         __cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len); \
 462         __cu_len;                                                       \
 463 })
 464
 465 #define __copy_to_user_inatomic __copy_to_user
 466 #define __copy_from_user_inatomic __copy_from_user
 467
 468 /*
 469  * copy_to_user: - Copy a block of data into user space.
 470  * @to:   Destination address, in user space.
 471  * @from: Source address, in kernel space.
 472  * @n:    Number of bytes to copy.
 473  *
 474  * Context: User context only.  This function may sleep.
 475  *
 476  * Copy data from kernel space to user space.
 477  *
 478  * Returns number of bytes that could not be copied.
 479  * On success, this will be zero.
 480  */
 481 #define copy_to_user(to,from,n)                                         \
 482 ({                                                                      \
 483         void *__cu_to;                                                  \
 484         const void *__cu_from;                                          \
 485         long __cu_len;                                                  \
 486                                                                         \
 487         might_sleep();                                                  \
 488         __cu_to = (to);                                                 \
 489         __cu_from = (from);                                             \
 490         __cu_len = (n);                                                 \
 491         if (access_ok(VERIFY_WRITE, __cu_to, __cu_len))                 \
 492                 __cu_len = __invoke_copy_to_user(__cu_to, __cu_from,    \
 493                                                  __cu_len);             \
 494         __cu_len;                                                       \
 495 })
 496
 497 #define __invoke_copy_from_user(to,from,n)                              \
 498 ({                                                                      \
 499         register void *__cu_to_r __asm__ ("$4");                        \
 500         register const void *__cu_from_r __asm__ ("$5");                \
 501         register long __cu_len_r __asm__ ("$6");                        \
 502                                                                         \
 503         __cu_to_r = (to);                                               \
 504         __cu_from_r = (from);                                           \
 505         __cu_len_r = (n);                                               \
 506         __asm__ __volatile__(                                           \
 507         ".set\tnoreorder\n\t"                                           \
 508         __MODULE_JAL(__copy_user)                                       \
 509         ".set\tnoat\n\t"                                                \
 510         __UA_ADDU "\t$1, %1, %2\n\t"                                    \
 511         ".set\tat\n\t"                                                  \
 512         ".set\treorder"                                                 \
 513         : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)       \
 514         :                                                               \
 515         : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31",         \
 516           "memory");                                                    \
 517         __cu_len_r;                                                     \
 518 })
 519
 520 /*
 521  * __copy_from_user: - Copy a block of data from user space, with less checking. * @to:   Destination address, in kernel space.
 522  * @from: Source address, in user space.
 523  * @n:    Number of bytes to copy.
 524  *
 525  * Context: User context only.  This function may sleep.
 526  *
 527  * Copy data from user space to kernel space.  Caller must check
 528  * the specified block with access_ok() before calling this function.
 529  *
 530  * Returns number of bytes that could not be copied.
 531  * On success, this will be zero.
 532  *
 533  * If some data could not be copied, this function will pad the copied
 534  * data to the requested size using zero bytes.
 535  */
 536 #define __copy_from_user(to,from,n)                                     \
 537 ({                                                                      \
 538         void *__cu_to;                                                  \
 539         const void *__cu_from;                                          \
 540         long __cu_len;                                                  \
 541                                                                         \
 542         might_sleep();                                                  \
 543         __cu_to = (to);                                                 \
 544         __cu_from = (from);                                             \
 545         __cu_len = (n);                                                 \
 546         __cu_len = __invoke_copy_from_user(__cu_to, __cu_from,          \
 547                                            __cu_len);                   \
 548         __cu_len;                                                       \
 549 })
 550
 551 /*
 552  * copy_from_user: - Copy a block of data from user space.
 553  * @to:   Destination address, in kernel space.
 554  * @from: Source address, in user space.
 555  * @n:    Number of bytes to copy.
 556  *
 557  * Context: User context only.  This function may sleep.
 558  *
 559  * Copy data from user space to kernel space.
 560  *
 561  * Returns number of bytes that could not be copied.
 562  * On success, this will be zero.
 563  *
 564  * If some data could not be copied, this function will pad the copied
 565  * data to the requested size using zero bytes.
 566  */
 567 #define copy_from_user(to,from,n)                                       \
 568 ({                                                                      \
 569         void *__cu_to;                                                  \
 570         const void *__cu_from;                                          \
 571         long __cu_len;                                                  \
 572                                                                         \
 573         might_sleep();                                                  \
 574         __cu_to = (to);                                                 \
 575         __cu_from = (from);                                             \
 576         __cu_len = (n);                                                 \
 577         if (access_ok(VERIFY_READ, __cu_from, __cu_len))                \
 578                 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from,  \
 579                                                    __cu_len);           \
 580         __cu_len;                                                       \
 581 })
 582
 583 #define __copy_in_user(to, from, n)     __copy_from_user(to, from, n)
 584
 585 #define copy_in_user(to,from,n)                                         \
 586 ({                                                                      \
 587         void *__cu_to;                                                  \
 588         const void *__cu_from;                                          \
 589         long __cu_len;                                                  \
 590                                                                         \
 591         might_sleep();                                                  \
 592         __cu_to = (to);                                                 \
 593         __cu_from = (from);                                             \
 594         __cu_len = (n);                                                 \
 595         if (likely(access_ok(VERIFY_READ, __cu_from, __cu_len) &&       \
 596                    access_ok(VERIFY_WRITE, __cu_to, __cu_len)))         \
 597                 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from,  \
 598                                                    __cu_len);           \
 599         __cu_len;                                                       \
 600 })
 601
 602 /*
 603  * __clear_user: - Zero a block of memory in user space, with less checking.
 604  * @to:   Destination address, in user space.
 605  * @n:    Number of bytes to zero.
 606  *
 607  * Zero a block of memory in user space.  Caller must check
 608  * the specified block with access_ok() before calling this function.
 609  *
 610  * Returns number of bytes that could not be cleared.
 611  * On success, this will be zero.
 612  */
 613 static inline __kernel_size_t
 614 __clear_user(void *addr, __kernel_size_t size)
 615 {
 616         __kernel_size_t res;
 617
 618         might_sleep();
 619         __asm__ __volatile__(
 620                 "move\t$4, %1\n\t"
 621                 "move\t$5, $0\n\t"
 622                 "move\t$6, %2\n\t"
 623                 __MODULE_JAL(__bzero)
 624                 "move\t%0, $6"
 625                 : "=r" (res)
 626                 : "r" (addr), "r" (size)
 627                 : "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
 628
 629         return res;
 630 }
 631
 632 #define clear_user(addr,n)                                              \
 633 ({                                                                      \
 634         void * __cl_addr = (addr);                                      \
 635         unsigned long __cl_size = (n);                                  \
 636         if (__cl_size && access_ok(VERIFY_WRITE,                        \
 637                 ((unsigned long)(__cl_addr)), __cl_size))               \
 638                 __cl_size = __clear_user(__cl_addr, __cl_size);         \
 639         __cl_size;                                                      \
 640 })
 641
 642 /*
 643  * __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
 644  * @dst:   Destination address, in kernel space.  This buffer must be at
 645  *         least @count bytes long.
 646  * @src:   Source address, in user space.
 647  * @count: Maximum number of bytes to copy, including the trailing NUL.
 648  *
 649  * Copies a NUL-terminated string from userspace to kernel space.
 650  * Caller must check the specified block with access_ok() before calling
 651  * this function.
 652  *
 653  * On success, returns the length of the string (not including the trailing
 654  * NUL).
 655  *
 656  * If access to userspace fails, returns -EFAULT (some data may have been
 657  * copied).
 658  *
 659  * If @count is smaller than the length of the string, copies @count bytes
 660  * and returns @count.
 661  */
 662 static inline long
 663 __strncpy_from_user(char *__to, const char *__from, long __len)
 664 {
 665         long res;
 666
 667         might_sleep();
 668         __asm__ __volatile__(
 669                 "move\t$4, %1\n\t"
 670                 "move\t$5, %2\n\t"
 671                 "move\t$6, %3\n\t"
 672                 __MODULE_JAL(__strncpy_from_user_nocheck_asm)
 673                 "move\t%0, $2"
 674                 : "=r" (res)
 675                 : "r" (__to), "r" (__from), "r" (__len)
 676                 : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
 677
 678         return res;
 679 }
 680
 681 /*
 682  * strncpy_from_user: - Copy a NUL terminated string from userspace.
 683  * @dst:   Destination address, in kernel space.  This buffer must be at
 684  *         least @count bytes long.
 685  * @src:   Source address, in user space.
 686  * @count: Maximum number of bytes to copy, including the trailing NUL.
 687  *
 688  * Copies a NUL-terminated string from userspace to kernel space.
 689  *
 690  * On success, returns the length of the string (not including the trailing
 691  * NUL).
 692  *
 693  * If access to userspace fails, returns -EFAULT (some data may have been
 694  * copied).
 695  *
 696  * If @count is smaller than the length of the string, copies @count bytes
 697  * and returns @count.
 698  */
 699 static inline long
 700 strncpy_from_user(char *__to, const char *__from, long __len)
 701 {
 702         long res;
 703
 704         might_sleep();
 705         __asm__ __volatile__(
 706                 "move\t$4, %1\n\t"
 707                 "move\t$5, %2\n\t"
 708                 "move\t$6, %3\n\t"
 709                 __MODULE_JAL(__strncpy_from_user_asm)
 710                 "move\t%0, $2"
 711                 : "=r" (res)
 712                 : "r" (__to), "r" (__from), "r" (__len)
 713                 : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
 714
 715         return res;
 716 }
 717
 718 /* Returns: 0 if bad, string length+1 (memory size) of string if ok */
 719 static inline long __strlen_user(const char *s)
 720 {
 721         long res;
 722
 723         might_sleep();
 724         __asm__ __volatile__(
 725                 "move\t$4, %1\n\t"
 726                 __MODULE_JAL(__strlen_user_nocheck_asm)
 727                 "move\t%0, $2"
 728                 : "=r" (res)
 729                 : "r" (s)
 730                 : "$2", "$4", __UA_t0, "$31");
 731
 732         return res;
 733 }
 734
 735 /*
 736  * strlen_user: - Get the size of a string in user space.
 737  * @str: The string to measure.
 738  *
 739  * Context: User context only.  This function may sleep.
 740  *
 741  * Get the size of a NUL-terminated string in user space.
 742  *
 743  * Returns the size of the string INCLUDING the terminating NUL.
 744  * On exception, returns 0.
 745  *
 746  * If there is a limit on the length of a valid string, you may wish to
 747  * consider using strnlen_user() instead.
 748  */
 749 static inline long strlen_user(const char *s)
 750 {
 751         long res;
 752
 753         might_sleep();
 754         __asm__ __volatile__(
 755                 "move\t$4, %1\n\t"
 756                 __MODULE_JAL(__strlen_user_asm)
 757                 "move\t%0, $2"
 758                 : "=r" (res)
 759                 : "r" (s)
 760                 : "$2", "$4", __UA_t0, "$31");
 761
 762         return res;
 763 }
 764
 765 /* Returns: 0 if bad, string length+1 (memory size) of string if ok */
 766 static inline long __strnlen_user(const char *s, long n)
 767 {
 768         long res;
 769
 770         might_sleep();
 771         __asm__ __volatile__(
 772                 "move\t$4, %1\n\t"
 773                 "move\t$5, %2\n\t"
 774                 __MODULE_JAL(__strnlen_user_nocheck_asm)
 775                 "move\t%0, $2"
 776                 : "=r" (res)
 777                 : "r" (s), "r" (n)
 778                 : "$2", "$4", "$5", __UA_t0, "$31");
 779
 780         return res;
 781 }
 782
 783 /*
 784  * strlen_user: - Get the size of a string in user space.
 785  * @str: The string to measure.
 786  *
 787  * Context: User context only.  This function may sleep.
 788  *
 789  * Get the size of a NUL-terminated string in user space.
 790  *
 791  * Returns the size of the string INCLUDING the terminating NUL.
 792  * On exception, returns 0.
 793  *
 794  * If there is a limit on the length of a valid string, you may wish to
 795  * consider using strnlen_user() instead.
 796  */
 797 static inline long strnlen_user(const char *s, long n)
 798 {
 799         long res;
 800
 801         might_sleep();
 802         __asm__ __volatile__(
 803                 "move\t$4, %1\n\t"
 804                 "move\t$5, %2\n\t"
 805                 __MODULE_JAL(__strnlen_user_asm)
 806                 "move\t%0, $2"
 807                 : "=r" (res)
 808                 : "r" (s), "r" (n)
 809                 : "$2", "$4", "$5", __UA_t0, "$31");
 810
 811         return res;
 812 }
 813
 814 struct exception_table_entry
 815 {
 816         unsigned long insn;
 817         unsigned long nextinsn;
 818 };
 819
 820 extern int fixup_exception(struct pt_regs *regs);
 821
 822 #endif /* _ASM_UACCESS_H */