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/deprecated and will go away soon,
 116  * use access_ok() instead.
 117  * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE
 118  * @addr: User space pointer to start of block to check
 119  * @size: Size of block to check
 120  *
 121  * Context: User context only.  This function may sleep.
 122  *
 123  * This function has been replaced by access_ok().
 124  *
 125  * Checks if a pointer to a block of memory in user space is valid.
 126  *
 127  * Returns zero if the memory block may be valid, -EFAULT
 128  * if it is definitely invalid.
 129  *
 130  * See access_ok() for more details.
 131  */
 132 static inline int __deprecated verify_area(int type, const void * addr, unsigned long size)
 133 {
 134         return access_ok(type, addr, size) ? 0 : -EFAULT;
 135 }
 136
 137 /*
 138  * put_user: - Write a simple value into user space.
 139  * @x:   Value to copy to user space.
 140  * @ptr: Destination address, in user space.
 141  *
 142  * Context: User context only.  This function may sleep.
 143  *
 144  * This macro copies a single simple value from kernel space to user
 145  * space.  It supports simple types like char and int, but not larger
 146  * data types like structures or arrays.
 147  *
 148  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 149  * to the result of dereferencing @ptr.
 150  *
 151  * Returns zero on success, or -EFAULT on error.
 152  */
 153 #define put_user(x,ptr) \
 154         __put_user_check((x),(ptr),sizeof(*(ptr)))
 155
 156 /*
 157  * get_user: - Get a simple variable from user space.
 158  * @x:   Variable to store result.
 159  * @ptr: Source address, in user space.
 160  *
 161  * Context: User context only.  This function may sleep.
 162  *
 163  * This macro copies a single simple variable from user space to kernel
 164  * space.  It supports simple types like char and int, but not larger
 165  * data types like structures or arrays.
 166  *
 167  * @ptr must have pointer-to-simple-variable type, and the result of
 168  * dereferencing @ptr must be assignable to @x without a cast.
 169  *
 170  * Returns zero on success, or -EFAULT on error.
 171  * On error, the variable @x is set to zero.
 172  */
 173 #define get_user(x,ptr) \
 174         __get_user_check((x),(ptr),sizeof(*(ptr)))
 175
 176 /*
 177  * __put_user: - Write a simple value into user space, with less checking.
 178  * @x:   Value to copy to user space.
 179  * @ptr: Destination address, in user space.
 180  *
 181  * Context: User context only.  This function may sleep.
 182  *
 183  * This macro copies a single simple value from kernel space to user
 184  * space.  It supports simple types like char and int, but not larger
 185  * data types like structures or arrays.
 186  *
 187  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 188  * to the result of dereferencing @ptr.
 189  *
 190  * Caller must check the pointer with access_ok() before calling this
 191  * function.
 192  *
 193  * Returns zero on success, or -EFAULT on error.
 194  */
 195 #define __put_user(x,ptr) \
 196         __put_user_nocheck((x),(ptr),sizeof(*(ptr)))
 197
 198 /*
 199  * __get_user: - Get a simple variable from user space, with less checking.
 200  * @x:   Variable to store result.
 201  * @ptr: Source address, in user space.
 202  *
 203  * Context: User context only.  This function may sleep.
 204  *
 205  * This macro copies a single simple variable from user space to kernel
 206  * space.  It supports simple types like char and int, but not larger
 207  * data types like structures or arrays.
 208  *
 209  * @ptr must have pointer-to-simple-variable type, and the result of
 210  * dereferencing @ptr must be assignable to @x without a cast.
 211  *
 212  * Caller must check the pointer with access_ok() before calling this
 213  * function.
 214  *
 215  * Returns zero on success, or -EFAULT on error.
 216  * On error, the variable @x is set to zero.
 217  */
 218 #define __get_user(x,ptr) \
 219         __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
 220
 221 struct __large_struct { unsigned long buf[100]; };
 222 #define __m(x) (*(struct __large_struct *)(x))
 223
 224 /*
 225  * Yuck.  We need two variants, one for 64bit operation and one
 226  * for 32 bit mode and old iron.
 227  */
 228 #ifdef __mips64
 229 #define __GET_USER_DW(__gu_err) __get_user_asm("ld", __gu_err)
 230 #else
 231 #define __GET_USER_DW(__gu_err) __get_user_asm_ll32(__gu_err)
 232 #endif
 233
 234 #define __get_user_nocheck(x,ptr,size)                                  \
 235 ({                                                                      \
 236         __typeof(*(ptr)) __gu_val = 0;                                  \
 237         long __gu_addr;                                                 \
 238         long __gu_err = 0;                                              \
 239                                                                         \
 240         might_sleep();                                                  \
 241         __gu_addr = (long) (ptr);                                       \
 242         switch (size) {                                                 \
 243         case 1: __get_user_asm("lb", __gu_err); break;                  \
 244         case 2: __get_user_asm("lh", __gu_err); break;                  \
 245         case 4: __get_user_asm("lw", __gu_err); break;                  \
 246         case 8: __GET_USER_DW(__gu_err); break;                         \
 247         default: __get_user_unknown(); break;                           \
 248         }                                                               \
 249         x = (__typeof__(*(ptr))) __gu_val;                              \
 250         __gu_err;                                                       \
 251 })
 252
 253 #define __get_user_check(x,ptr,size)                                    \
 254 ({                                                                      \
 255         __typeof__(*(ptr)) __gu_val = 0;                                \
 256         long __gu_addr;                                                 \
 257         long __gu_err;                                                  \
 258                                                                         \
 259         might_sleep();                                                  \
 260         __gu_addr = (long) (ptr);                                       \
 261         __gu_err = access_ok(VERIFY_READ, (void *) __gu_addr, size)     \
 262                                 ? 0 : -EFAULT;                          \
 263                                                                         \
 264         if (likely(!__gu_err)) {                                        \
 265                 switch (size) {                                         \
 266                 case 1: __get_user_asm("lb", __gu_err); break;          \
 267                 case 2: __get_user_asm("lh", __gu_err); break;          \
 268                 case 4: __get_user_asm("lw", __gu_err); break;          \
 269                 case 8: __GET_USER_DW(__gu_err); break;                 \
 270                 default: __get_user_unknown(); break;                   \
 271                 }                                                       \
 272         }                                                               \
 273         x = (__typeof__(*(ptr))) __gu_val;                              \
 274         __gu_err;                                                       \
 275 })
 276
 277 #define __get_user_asm(insn,__gu_err)                                   \
 278 ({                                                                      \
 279         __asm__ __volatile__(                                           \
 280         "1:     " insn "        %1, %3                          \n"     \
 281         "2:                                                     \n"     \
 282         "       .section .fixup,\"ax\"                          \n"     \
 283         "3:     li      %0, %4                                  \n"     \
 284         "       j       2b                                      \n"     \
 285         "       .previous                                       \n"     \
 286         "       .section __ex_table,\"a\"                       \n"     \
 287         "       "__UA_ADDR "\t1b, 3b                            \n"     \
 288         "       .previous                                       \n"     \
 289         : "=r" (__gu_err), "=r" (__gu_val)                              \
 290         : "0" (__gu_err), "o" (__m(__gu_addr)), "i" (-EFAULT));         \
 291 })
 292
 293 /*
 294  * Get a long long 64 using 32 bit registers.
 295  */
 296 #define __get_user_asm_ll32(__gu_err)                                   \
 297 ({                                                                      \
 298         __asm__ __volatile__(                                           \
 299         "1:     lw      %1, %3                                  \n"     \
 300         "2:     lw      %D1, %4                                 \n"     \
 301         "       move    %0, $0                                  \n"     \
 302         "3:     .section        .fixup,\"ax\"                   \n"     \
 303         "4:     li      %0, %5                                  \n"     \
 304         "       move    %1, $0                                  \n"     \
 305         "       move    %D1, $0                                 \n"     \
 306         "       j       3b                                      \n"     \
 307         "       .previous                                       \n"     \
 308         "       .section        __ex_table,\"a\"                \n"     \
 309         "       " __UA_ADDR "   1b, 4b                          \n"     \
 310         "       " __UA_ADDR "   2b, 4b                          \n"     \
 311         "       .previous                                       \n"     \
 312         : "=r" (__gu_err), "=&r" (__gu_val)                             \
 313         : "0" (__gu_err), "o" (__m(__gu_addr)),                         \
 314           "o" (__m(__gu_addr + 4)), "i" (-EFAULT));                     \
 315 })
 316
 317 extern void __get_user_unknown(void);
 318
 319 /*
 320  * Yuck.  We need two variants, one for 64bit operation and one
 321  * for 32 bit mode and old iron.
 322  */
 323 #ifdef __mips64
 324 #define __PUT_USER_DW(__pu_val) __put_user_asm("sd", __pu_val)
 325 #else
 326 #define __PUT_USER_DW(__pu_val) __put_user_asm_ll32(__pu_val)
 327 #endif
 328
 329 #define __put_user_nocheck(x,ptr,size)                                  \
 330 ({                                                                      \
 331         __typeof__(*(ptr)) __pu_val;                                    \
 332         long __pu_addr;                                                 \
 333         long __pu_err = 0;                                              \
 334                                                                         \
 335         might_sleep();                                                  \
 336         __pu_val = (x);                                                 \
 337         __pu_addr = (long) (ptr);                                       \
 338         switch (size) {                                                 \
 339         case 1: __put_user_asm("sb", __pu_val); break;                  \
 340         case 2: __put_user_asm("sh", __pu_val); break;                  \
 341         case 4: __put_user_asm("sw", __pu_val); break;                  \
 342         case 8: __PUT_USER_DW(__pu_val); break;                         \
 343         default: __put_user_unknown(); break;                           \
 344         }                                                               \
 345         __pu_err;                                                       \
 346 })
 347
 348 #define __put_user_check(x,ptr,size)                                    \
 349 ({                                                                      \
 350         __typeof__(*(ptr)) __pu_val;                                    \
 351         long __pu_addr;                                                 \
 352         long __pu_err;                                                  \
 353                                                                         \
 354         might_sleep();                                                  \
 355         __pu_val = (x);                                                 \
 356         __pu_addr = (long) (ptr);                                       \
 357         __pu_err = access_ok(VERIFY_WRITE, (void *) __pu_addr, size)    \
 358                                 ? 0 : -EFAULT;                          \
 359                                                                         \
 360         if (likely(!__pu_err)) {                                        \
 361                 switch (size) {                                         \
 362                 case 1: __put_user_asm("sb", __pu_val); break;          \
 363                 case 2: __put_user_asm("sh", __pu_val); break;          \
 364                 case 4: __put_user_asm("sw", __pu_val); break;          \
 365                 case 8: __PUT_USER_DW(__pu_val); break;                 \
 366                 default: __put_user_unknown(); break;                   \
 367                 }                                                       \
 368         }                                                               \
 369         __pu_err;                                                       \
 370 })
 371
 372 #define __put_user_asm(insn, __pu_val)                                  \
 373 ({                                                                      \
 374         __asm__ __volatile__(                                           \
 375         "1:     " insn "        %z2, %3         # __put_user_asm\n"     \
 376         "2:                                                     \n"     \
 377         "       .section        .fixup,\"ax\"                   \n"     \
 378         "3:     li      %0, %4                                  \n"     \
 379         "       j       2b                                      \n"     \
 380         "       .previous                                       \n"     \
 381         "       .section        __ex_table,\"a\"                \n"     \
 382         "       " __UA_ADDR "   1b, 3b                          \n"     \
 383         "       .previous                                       \n"     \
 384         : "=r" (__pu_err)                                               \
 385         : "0" (__pu_err), "Jr" (__pu_val), "o" (__m(__pu_addr)),        \
 386           "i" (-EFAULT));                                               \
 387 })
 388
 389 #define __put_user_asm_ll32(__pu_val)                                   \
 390 ({                                                                      \
 391         __asm__ __volatile__(                                           \
 392         "1:     sw      %2, %3          # __put_user_asm_ll32   \n"     \
 393         "2:     sw      %D2, %4                                 \n"     \
 394         "3:                                                     \n"     \
 395         "       .section        .fixup,\"ax\"                   \n"     \
 396         "4:     li      %0, %5                                  \n"     \
 397         "       j       3b                                      \n"     \
 398         "       .previous                                       \n"     \
 399         "       .section        __ex_table,\"a\"                \n"     \
 400         "       " __UA_ADDR "   1b, 4b                          \n"     \
 401         "       " __UA_ADDR "   2b, 4b                          \n"     \
 402         "       .previous"                                              \
 403         : "=r" (__pu_err)                                               \
 404         : "0" (__pu_err), "r" (__pu_val), "o" (__m(__pu_addr)),         \
 405           "o" (__m(__pu_addr + 4)), "i" (-EFAULT));                     \
 406 })
 407
 408 extern void __put_user_unknown(void);
 409
 410 /*
 411  * We're generating jump to subroutines which will be outside the range of
 412  * jump instructions
 413  */
 414 #ifdef MODULE
 415 #define __MODULE_JAL(destination)                                       \
 416         ".set\tnoat\n\t"                                                \
 417         __UA_LA "\t$1, " #destination "\n\t"                            \
 418         "jalr\t$1\n\t"                                                  \
 419         ".set\tat\n\t"
 420 #else
 421 #define __MODULE_JAL(destination)                                       \
 422         "jal\t" #destination "\n\t"
 423 #endif
 424
 425 extern size_t __copy_user(void *__to, const void *__from, size_t __n);
 426
 427 #define __invoke_copy_to_user(to,from,n)                                \
 428 ({                                                                      \
 429         register void *__cu_to_r __asm__ ("$4");                        \
 430         register const void *__cu_from_r __asm__ ("$5");                \
 431         register long __cu_len_r __asm__ ("$6");                        \
 432                                                                         \
 433         __cu_to_r = (to);                                               \
 434         __cu_from_r = (from);                                           \
 435         __cu_len_r = (n);                                               \
 436         __asm__ __volatile__(                                           \
 437         __MODULE_JAL(__copy_user)                                       \
 438         : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)       \
 439         :                                                               \
 440         : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31",         \
 441           "memory");                                                    \
 442         __cu_len_r;                                                     \
 443 })
 444
 445 /*
 446  * __copy_to_user: - Copy a block of data into user space, with less checking.
 447  * @to:   Destination address, in user space.
 448  * @from: Source address, in kernel space.
 449  * @n:    Number of bytes to copy.
 450  *
 451  * Context: User context only.  This function may sleep.
 452  *
 453  * Copy data from kernel space to user space.  Caller must check
 454  * the specified block with access_ok() before calling this function.
 455  *
 456  * Returns number of bytes that could not be copied.
 457  * On success, this will be zero.
 458  */
 459 #define __copy_to_user(to,from,n)                                       \
 460 ({                                                                      \
 461         void *__cu_to;                                                  \
 462         const void *__cu_from;                                          \
 463         long __cu_len;                                                  \
 464                                                                         \
 465         might_sleep();                                                  \
 466         __cu_to = (to);                                                 \
 467         __cu_from = (from);                                             \
 468         __cu_len = (n);                                                 \
 469         __cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len); \
 470         __cu_len;                                                       \
 471 })
 472
 473 #define __copy_to_user_inatomic __copy_to_user
 474 #define __copy_from_user_inatomic __copy_from_user
 475
 476 /*
 477  * copy_to_user: - Copy a block of data into user space.
 478  * @to:   Destination address, in user space.
 479  * @from: Source address, in kernel space.
 480  * @n:    Number of bytes to copy.
 481  *
 482  * Context: User context only.  This function may sleep.
 483  *
 484  * Copy data from kernel space to user space.
 485  *
 486  * Returns number of bytes that could not be copied.
 487  * On success, this will be zero.
 488  */
 489 #define copy_to_user(to,from,n)                                         \
 490 ({                                                                      \
 491         void *__cu_to;                                                  \
 492         const void *__cu_from;                                          \
 493         long __cu_len;                                                  \
 494                                                                         \
 495         might_sleep();                                                  \
 496         __cu_to = (to);                                                 \
 497         __cu_from = (from);                                             \
 498         __cu_len = (n);                                                 \
 499         if (access_ok(VERIFY_WRITE, __cu_to, __cu_len))                 \
 500                 __cu_len = __invoke_copy_to_user(__cu_to, __cu_from,    \
 501                                                  __cu_len);             \
 502         __cu_len;                                                       \
 503 })
 504
 505 #define __invoke_copy_from_user(to,from,n)                              \
 506 ({                                                                      \
 507         register void *__cu_to_r __asm__ ("$4");                        \
 508         register const void *__cu_from_r __asm__ ("$5");                \
 509         register long __cu_len_r __asm__ ("$6");                        \
 510                                                                         \
 511         __cu_to_r = (to);                                               \
 512         __cu_from_r = (from);                                           \
 513         __cu_len_r = (n);                                               \
 514         __asm__ __volatile__(                                           \
 515         ".set\tnoreorder\n\t"                                           \
 516         __MODULE_JAL(__copy_user)                                       \
 517         ".set\tnoat\n\t"                                                \
 518         __UA_ADDU "\t$1, %1, %2\n\t"                                    \
 519         ".set\tat\n\t"                                                  \
 520         ".set\treorder"                                                 \
 521         : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)       \
 522         :                                                               \
 523         : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31",         \
 524           "memory");                                                    \
 525         __cu_len_r;                                                     \
 526 })
 527
 528 /*
 529  * __copy_from_user: - Copy a block of data from user space, with less checking. * @to:   Destination address, in kernel space.
 530  * @from: Source address, in user space.
 531  * @n:    Number of bytes to copy.
 532  *
 533  * Context: User context only.  This function may sleep.
 534  *
 535  * Copy data from user space to kernel space.  Caller must check
 536  * the specified block with access_ok() before calling this function.
 537  *
 538  * Returns number of bytes that could not be copied.
 539  * On success, this will be zero.
 540  *
 541  * If some data could not be copied, this function will pad the copied
 542  * data to the requested size using zero bytes.
 543  */
 544 #define __copy_from_user(to,from,n)                                     \
 545 ({                                                                      \
 546         void *__cu_to;                                                  \
 547         const void *__cu_from;                                          \
 548         long __cu_len;                                                  \
 549                                                                         \
 550         might_sleep();                                                  \
 551         __cu_to = (to);                                                 \
 552         __cu_from = (from);                                             \
 553         __cu_len = (n);                                                 \
 554         __cu_len = __invoke_copy_from_user(__cu_to, __cu_from,          \
 555                                            __cu_len);                   \
 556         __cu_len;                                                       \
 557 })
 558
 559 /*
 560  * copy_from_user: - Copy a block of data from user space.
 561  * @to:   Destination address, in kernel space.
 562  * @from: Source address, in user space.
 563  * @n:    Number of bytes to copy.
 564  *
 565  * Context: User context only.  This function may sleep.
 566  *
 567  * Copy data from user space to kernel space.
 568  *
 569  * Returns number of bytes that could not be copied.
 570  * On success, this will be zero.
 571  *
 572  * If some data could not be copied, this function will pad the copied
 573  * data to the requested size using zero bytes.
 574  */
 575 #define copy_from_user(to,from,n)                                       \
 576 ({                                                                      \
 577         void *__cu_to;                                                  \
 578         const void *__cu_from;                                          \
 579         long __cu_len;                                                  \
 580                                                                         \
 581         might_sleep();                                                  \
 582         __cu_to = (to);                                                 \
 583         __cu_from = (from);                                             \
 584         __cu_len = (n);                                                 \
 585         if (access_ok(VERIFY_READ, __cu_from, __cu_len))                \
 586                 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from,  \
 587                                                    __cu_len);           \
 588         __cu_len;                                                       \
 589 })
 590
 591 #define __copy_in_user(to, from, n)     __copy_from_user(to, from, n)
 592
 593 #define copy_in_user(to,from,n)                                         \
 594 ({                                                                      \
 595         void *__cu_to;                                                  \
 596         const void *__cu_from;                                          \
 597         long __cu_len;                                                  \
 598                                                                         \
 599         might_sleep();                                                  \
 600         __cu_to = (to);                                                 \
 601         __cu_from = (from);                                             \
 602         __cu_len = (n);                                                 \
 603         if (likely(access_ok(VERIFY_READ, __cu_from, __cu_len) &&       \
 604                    access_ok(VERIFY_WRITE, __cu_to, __cu_len)))         \
 605                 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from,  \
 606                                                    __cu_len);           \
 607         __cu_len;                                                       \
 608 })
 609
 610 /*
 611  * __clear_user: - Zero a block of memory in user space, with less checking.
 612  * @to:   Destination address, in user space.
 613  * @n:    Number of bytes to zero.
 614  *
 615  * Zero a block of memory in user space.  Caller must check
 616  * the specified block with access_ok() before calling this function.
 617  *
 618  * Returns number of bytes that could not be cleared.
 619  * On success, this will be zero.
 620  */
 621 static inline __kernel_size_t
 622 __clear_user(void *addr, __kernel_size_t size)
 623 {
 624         __kernel_size_t res;
 625
 626         might_sleep();
 627         __asm__ __volatile__(
 628                 "move\t$4, %1\n\t"
 629                 "move\t$5, $0\n\t"
 630                 "move\t$6, %2\n\t"
 631                 __MODULE_JAL(__bzero)
 632                 "move\t%0, $6"
 633                 : "=r" (res)
 634                 : "r" (addr), "r" (size)
 635                 : "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
 636
 637         return res;
 638 }
 639
 640 #define clear_user(addr,n)                                              \
 641 ({                                                                      \
 642         void * __cl_addr = (addr);                                      \
 643         unsigned long __cl_size = (n);                                  \
 644         if (__cl_size && access_ok(VERIFY_WRITE,                        \
 645                 ((unsigned long)(__cl_addr)), __cl_size))               \
 646                 __cl_size = __clear_user(__cl_addr, __cl_size);         \
 647         __cl_size;                                                      \
 648 })
 649
 650 /*
 651  * __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
 652  * @dst:   Destination address, in kernel space.  This buffer must be at
 653  *         least @count bytes long.
 654  * @src:   Source address, in user space.
 655  * @count: Maximum number of bytes to copy, including the trailing NUL.
 656  *
 657  * Copies a NUL-terminated string from userspace to kernel space.
 658  * Caller must check the specified block with access_ok() before calling
 659  * this function.
 660  *
 661  * On success, returns the length of the string (not including the trailing
 662  * NUL).
 663  *
 664  * If access to userspace fails, returns -EFAULT (some data may have been
 665  * copied).
 666  *
 667  * If @count is smaller than the length of the string, copies @count bytes
 668  * and returns @count.
 669  */
 670 static inline long
 671 __strncpy_from_user(char *__to, const char *__from, long __len)
 672 {
 673         long res;
 674
 675         might_sleep();
 676         __asm__ __volatile__(
 677                 "move\t$4, %1\n\t"
 678                 "move\t$5, %2\n\t"
 679                 "move\t$6, %3\n\t"
 680                 __MODULE_JAL(__strncpy_from_user_nocheck_asm)
 681                 "move\t%0, $2"
 682                 : "=r" (res)
 683                 : "r" (__to), "r" (__from), "r" (__len)
 684                 : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
 685
 686         return res;
 687 }
 688
 689 /*
 690  * strncpy_from_user: - Copy a NUL terminated string from userspace.
 691  * @dst:   Destination address, in kernel space.  This buffer must be at
 692  *         least @count bytes long.
 693  * @src:   Source address, in user space.
 694  * @count: Maximum number of bytes to copy, including the trailing NUL.
 695  *
 696  * Copies a NUL-terminated string from userspace to kernel space.
 697  *
 698  * On success, returns the length of the string (not including the trailing
 699  * NUL).
 700  *
 701  * If access to userspace fails, returns -EFAULT (some data may have been
 702  * copied).
 703  *
 704  * If @count is smaller than the length of the string, copies @count bytes
 705  * and returns @count.
 706  */
 707 static inline long
 708 strncpy_from_user(char *__to, const char *__from, long __len)
 709 {
 710         long res;
 711
 712         might_sleep();
 713         __asm__ __volatile__(
 714                 "move\t$4, %1\n\t"
 715                 "move\t$5, %2\n\t"
 716                 "move\t$6, %3\n\t"
 717                 __MODULE_JAL(__strncpy_from_user_asm)
 718                 "move\t%0, $2"
 719                 : "=r" (res)
 720                 : "r" (__to), "r" (__from), "r" (__len)
 721                 : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
 722
 723         return res;
 724 }
 725
 726 /* Returns: 0 if bad, string length+1 (memory size) of string if ok */
 727 static inline long __strlen_user(const char *s)
 728 {
 729         long res;
 730
 731         might_sleep();
 732         __asm__ __volatile__(
 733                 "move\t$4, %1\n\t"
 734                 __MODULE_JAL(__strlen_user_nocheck_asm)
 735                 "move\t%0, $2"
 736                 : "=r" (res)
 737                 : "r" (s)
 738                 : "$2", "$4", __UA_t0, "$31");
 739
 740         return res;
 741 }
 742
 743 /*
 744  * strlen_user: - Get the size of a string in user space.
 745  * @str: The string to measure.
 746  *
 747  * Context: User context only.  This function may sleep.
 748  *
 749  * Get the size of a NUL-terminated string in user space.
 750  *
 751  * Returns the size of the string INCLUDING the terminating NUL.
 752  * On exception, returns 0.
 753  *
 754  * If there is a limit on the length of a valid string, you may wish to
 755  * consider using strnlen_user() instead.
 756  */
 757 static inline long strlen_user(const char *s)
 758 {
 759         long res;
 760
 761         might_sleep();
 762         __asm__ __volatile__(
 763                 "move\t$4, %1\n\t"
 764                 __MODULE_JAL(__strlen_user_asm)
 765                 "move\t%0, $2"
 766                 : "=r" (res)
 767                 : "r" (s)
 768                 : "$2", "$4", __UA_t0, "$31");
 769
 770         return res;
 771 }
 772
 773 /* Returns: 0 if bad, string length+1 (memory size) of string if ok */
 774 static inline long __strnlen_user(const char *s, long n)
 775 {
 776         long res;
 777
 778         might_sleep();
 779         __asm__ __volatile__(
 780                 "move\t$4, %1\n\t"
 781                 "move\t$5, %2\n\t"
 782                 __MODULE_JAL(__strnlen_user_nocheck_asm)
 783                 "move\t%0, $2"
 784                 : "=r" (res)
 785                 : "r" (s), "r" (n)
 786                 : "$2", "$4", "$5", __UA_t0, "$31");
 787
 788         return res;
 789 }
 790
 791 /*
 792  * strlen_user: - Get the size of a string in user space.
 793  * @str: The string to measure.
 794  *
 795  * Context: User context only.  This function may sleep.
 796  *
 797  * Get the size of a NUL-terminated string in user space.
 798  *
 799  * Returns the size of the string INCLUDING the terminating NUL.
 800  * On exception, returns 0.
 801  *
 802  * If there is a limit on the length of a valid string, you may wish to
 803  * consider using strnlen_user() instead.
 804  */
 805 static inline long strnlen_user(const char *s, long n)
 806 {
 807         long res;
 808
 809         might_sleep();
 810         __asm__ __volatile__(
 811                 "move\t$4, %1\n\t"
 812                 "move\t$5, %2\n\t"
 813                 __MODULE_JAL(__strnlen_user_asm)
 814                 "move\t%0, $2"
 815                 : "=r" (res)
 816                 : "r" (s), "r" (n)
 817                 : "$2", "$4", "$5", __UA_t0, "$31");
 818
 819         return res;
 820 }
 821
 822 struct exception_table_entry
 823 {
 824         unsigned long insn;
 825         unsigned long nextinsn;
 826 };
 827
 828 extern int fixup_exception(struct pt_regs *regs);
 829
 830 #endif /* _ASM_UACCESS_H */