arch/mips/include/asm/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  * Copyright (C) 2007  Maciej W. Rozycki
   9  */
  10 #ifndef _ASM_UACCESS_H
  11 #define _ASM_UACCESS_H
  12
  13 #include <linux/kernel.h>
  14 #include <linux/errno.h>
  15 #include <linux/thread_info.h>
  16
  17 /*
  18  * The fs value determines whether argument validity checking should be
  19  * performed or not.  If get_fs() == USER_DS, checking is performed, with
  20  * get_fs() == KERNEL_DS, checking is bypassed.
  21  *
  22  * For historical reasons, these macros are grossly misnamed.
  23  */
  24 #ifdef CONFIG_32BIT
  25
  26 #define __UA_LIMIT      0x80000000UL
  27
  28 #define __UA_ADDR       ".word"
  29 #define __UA_LA         "la"
  30 #define __UA_ADDU       "addu"
  31 #define __UA_t0         "$8"
  32 #define __UA_t1         "$9"
  33
  34 #endif /* CONFIG_32BIT */
  35
  36 #ifdef CONFIG_64BIT
  37
  38 #define __UA_LIMIT      (- TASK_SIZE)
  39
  40 #define __UA_ADDR       ".dword"
  41 #define __UA_LA         "dla"
  42 #define __UA_ADDU       "daddu"
  43 #define __UA_t0         "$12"
  44 #define __UA_t1         "$13"
  45
  46 #endif /* CONFIG_64BIT */
  47
  48 /*
  49  * USER_DS is a bitmask that has the bits set that may not be set in a valid
  50  * userspace address.  Note that we limit 32-bit userspace to 0x7fff8000 but
  51  * the arithmetic we're doing only works if the limit is a power of two, so
  52  * we use 0x80000000 here on 32-bit kernels.  If a process passes an invalid
  53  * address in this range it's the process's problem, not ours :-)
  54  */
  55
  56 #define KERNEL_DS       ((mm_segment_t) { 0UL })
  57 #define USER_DS         ((mm_segment_t) { __UA_LIMIT })
  58
  59 #define VERIFY_READ    0
  60 #define VERIFY_WRITE   1
  61
  62 #define get_ds()        (KERNEL_DS)
  63 #define get_fs()        (current_thread_info()->addr_limit)
  64 #define set_fs(x)       (current_thread_info()->addr_limit = (x))
  65
  66 #define segment_eq(a, b)        ((a).seg == (b).seg)
  67
  68
  69 /*
  70  * Is a address valid? This does a straighforward calculation rather
  71  * than tests.
  72  *
  73  * Address valid if:
  74  *  - "addr" doesn't have any high-bits set
  75  *  - AND "size" doesn't have any high-bits set
  76  *  - AND "addr+size" doesn't have any high-bits set
  77  *  - OR we are in kernel mode.
  78  *
  79  * __ua_size() is a trick to avoid runtime checking of positive constant
  80  * sizes; for those we already know at compile time that the size is ok.
  81  */
  82 #define __ua_size(size)                                                 \
  83         ((__builtin_constant_p(size) && (signed long) (size) > 0) ? 0 : (size))
  84
  85 /*
  86  * access_ok: - Checks if a user space pointer is valid
  87  * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE.  Note that
  88  *        %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
  89  *        to write to a block, it is always safe to read from it.
  90  * @addr: User space pointer to start of block to check
  91  * @size: Size of block to check
  92  *
  93  * Context: User context only.  This function may sleep.
  94  *
  95  * Checks if a pointer to a block of memory in user space is valid.
  96  *
  97  * Returns true (nonzero) if the memory block may be valid, false (zero)
  98  * if it is definitely invalid.
  99  *
 100  * Note that, depending on architecture, this function probably just
 101  * checks that the pointer is in the user space range - after calling
 102  * this function, memory access functions may still return -EFAULT.
 103  */
 104
 105 #define __access_mask get_fs().seg
 106
 107 #define __access_ok(addr, size, mask)                                   \
 108 ({                                                                      \
 109         unsigned long __addr = (unsigned long) (addr);                  \
 110         unsigned long __size = size;                                    \
 111         unsigned long __mask = mask;                                    \
 112         unsigned long __ok;                                             \
 113                                                                         \
 114         __chk_user_ptr(addr);                                           \
 115         __ok = (signed long)(__mask & (__addr | (__addr + __size) |     \
 116                 __ua_size(__size)));                                    \
 117         __ok == 0;                                                      \
 118 })
 119
 120 #define access_ok(type, addr, size)                                     \
 121         likely(__access_ok((addr), (size), __access_mask))
 122
 123 /*
 124  * put_user: - Write a simple value into user space.
 125  * @x:   Value to copy to user space.
 126  * @ptr: Destination address, in user space.
 127  *
 128  * Context: User context only.  This function may sleep.
 129  *
 130  * This macro copies a single simple value from kernel space to user
 131  * space.  It supports simple types like char and int, but not larger
 132  * data types like structures or arrays.
 133  *
 134  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 135  * to the result of dereferencing @ptr.
 136  *
 137  * Returns zero on success, or -EFAULT on error.
 138  */
 139 #define put_user(x,ptr) \
 140         __put_user_check((x), (ptr), sizeof(*(ptr)))
 141
 142 /*
 143  * get_user: - Get a simple variable from user space.
 144  * @x:   Variable to store result.
 145  * @ptr: Source address, in user space.
 146  *
 147  * Context: User context only.  This function may sleep.
 148  *
 149  * This macro copies a single simple variable from user space to kernel
 150  * space.  It supports simple types like char and int, but not larger
 151  * data types like structures or arrays.
 152  *
 153  * @ptr must have pointer-to-simple-variable type, and the result of
 154  * dereferencing @ptr must be assignable to @x without a cast.
 155  *
 156  * Returns zero on success, or -EFAULT on error.
 157  * On error, the variable @x is set to zero.
 158  */
 159 #define get_user(x,ptr) \
 160         __get_user_check((x), (ptr), sizeof(*(ptr)))
 161
 162 /*
 163  * __put_user: - Write a simple value into user space, with less checking.
 164  * @x:   Value to copy to user space.
 165  * @ptr: Destination address, in user space.
 166  *
 167  * Context: User context only.  This function may sleep.
 168  *
 169  * This macro copies a single simple value from kernel space to user
 170  * space.  It supports simple types like char and int, but not larger
 171  * data types like structures or arrays.
 172  *
 173  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 174  * to the result of dereferencing @ptr.
 175  *
 176  * Caller must check the pointer with access_ok() before calling this
 177  * function.
 178  *
 179  * Returns zero on success, or -EFAULT on error.
 180  */
 181 #define __put_user(x,ptr) \
 182         __put_user_nocheck((x), (ptr), sizeof(*(ptr)))
 183
 184 /*
 185  * __get_user: - Get a simple variable from user space, with less checking.
 186  * @x:   Variable to store result.
 187  * @ptr: Source address, in user space.
 188  *
 189  * Context: User context only.  This function may sleep.
 190  *
 191  * This macro copies a single simple variable from user space to kernel
 192  * space.  It supports simple types like char and int, but not larger
 193  * data types like structures or arrays.
 194  *
 195  * @ptr must have pointer-to-simple-variable type, and the result of
 196  * dereferencing @ptr must be assignable to @x without a cast.
 197  *
 198  * Caller must check the pointer with access_ok() before calling this
 199  * function.
 200  *
 201  * Returns zero on success, or -EFAULT on error.
 202  * On error, the variable @x is set to zero.
 203  */
 204 #define __get_user(x,ptr) \
 205         __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
 206
 207 struct __large_struct { unsigned long buf[100]; };
 208 #define __m(x) (*(struct __large_struct __user *)(x))
 209
 210 /*
 211  * Yuck.  We need two variants, one for 64bit operation and one
 212  * for 32 bit mode and old iron.
 213  */
 214 #ifdef CONFIG_32BIT
 215 #define __GET_USER_DW(val, ptr) __get_user_asm_ll32(val, ptr)
 216 #endif
 217 #ifdef CONFIG_64BIT
 218 #define __GET_USER_DW(val, ptr) __get_user_asm(val, "ld", ptr)
 219 #endif
 220
 221 extern void __get_user_unknown(void);
 222
 223 #define __get_user_common(val, size, ptr)                               \
 224 do {                                                                    \
 225         switch (size) {                                                 \
 226         case 1: __get_user_asm(val, "lb", ptr); break;                  \
 227         case 2: __get_user_asm(val, "lh", ptr); break;                  \
 228         case 4: __get_user_asm(val, "lw", ptr); break;                  \
 229         case 8: __GET_USER_DW(val, ptr); break;                         \
 230         default: __get_user_unknown(); break;                           \
 231         }                                                               \
 232 } while (0)
 233
 234 #define __get_user_nocheck(x, ptr, size)                                \
 235 ({                                                                      \
 236         int __gu_err;                                                   \
 237                                                                         \
 238         __chk_user_ptr(ptr);                                            \
 239         __get_user_common((x), size, ptr);                              \
 240         __gu_err;                                                       \
 241 })
 242
 243 #define __get_user_check(x, ptr, size)                                  \
 244 ({                                                                      \
 245         int __gu_err = -EFAULT;                                         \
 246         const __typeof__(*(ptr)) __user * __gu_ptr = (ptr);             \
 247                                                                         \
 248         might_fault();                                                  \
 249         if (likely(access_ok(VERIFY_READ,  __gu_ptr, size)))            \
 250                 __get_user_common((x), size, __gu_ptr);                 \
 251                                                                         \
 252         __gu_err;                                                       \
 253 })
 254
 255 #define __get_user_asm(val, insn, addr)                                 \
 256 {                                                                       \
 257         long __gu_tmp;                                                  \
 258                                                                         \
 259         __asm__ __volatile__(                                           \
 260         "1:     " insn "        %1, %3                          \n"     \
 261         "2:                                                     \n"     \
 262         "       .section .fixup,\"ax\"                          \n"     \
 263         "3:     li      %0, %4                                  \n"     \
 264         "       j       2b                                      \n"     \
 265         "       .previous                                       \n"     \
 266         "       .section __ex_table,\"a\"                       \n"     \
 267         "       "__UA_ADDR "\t1b, 3b                            \n"     \
 268         "       .previous                                       \n"     \
 269         : "=r" (__gu_err), "=r" (__gu_tmp)                              \
 270         : "0" (0), "o" (__m(addr)), "i" (-EFAULT));                     \
 271                                                                         \
 272         (val) = (__typeof__(*(addr))) __gu_tmp;                         \
 273 }
 274
 275 /*
 276  * Get a long long 64 using 32 bit registers.
 277  */
 278 #define __get_user_asm_ll32(val, addr)                                  \
 279 {                                                                       \
 280         union {                                                         \
 281                 unsigned long long      l;                              \
 282                 __typeof__(*(addr))     t;                              \
 283         } __gu_tmp;                                                     \
 284                                                                         \
 285         __asm__ __volatile__(                                           \
 286         "1:     lw      %1, (%3)                                \n"     \
 287         "2:     lw      %D1, 4(%3)                              \n"     \
 288         "3:     .section        .fixup,\"ax\"                   \n"     \
 289         "4:     li      %0, %4                                  \n"     \
 290         "       move    %1, $0                                  \n"     \
 291         "       move    %D1, $0                                 \n"     \
 292         "       j       3b                                      \n"     \
 293         "       .previous                                       \n"     \
 294         "       .section        __ex_table,\"a\"                \n"     \
 295         "       " __UA_ADDR "   1b, 4b                          \n"     \
 296         "       " __UA_ADDR "   2b, 4b                          \n"     \
 297         "       .previous                                       \n"     \
 298         : "=r" (__gu_err), "=&r" (__gu_tmp.l)                           \
 299         : "0" (0), "r" (addr), "i" (-EFAULT));                          \
 300                                                                         \
 301         (val) = __gu_tmp.t;                                             \
 302 }
 303
 304 /*
 305  * Yuck.  We need two variants, one for 64bit operation and one
 306  * for 32 bit mode and old iron.
 307  */
 308 #ifdef CONFIG_32BIT
 309 #define __PUT_USER_DW(ptr) __put_user_asm_ll32(ptr)
 310 #endif
 311 #ifdef CONFIG_64BIT
 312 #define __PUT_USER_DW(ptr) __put_user_asm("sd", ptr)
 313 #endif
 314
 315 #define __put_user_nocheck(x, ptr, size)                                \
 316 ({                                                                      \
 317         __typeof__(*(ptr)) __pu_val;                                    \
 318         int __pu_err = 0;                                               \
 319                                                                         \
 320         __chk_user_ptr(ptr);                                            \
 321         __pu_val = (x);                                                 \
 322         switch (size) {                                                 \
 323         case 1: __put_user_asm("sb", ptr); break;                       \
 324         case 2: __put_user_asm("sh", ptr); break;                       \
 325         case 4: __put_user_asm("sw", ptr); break;                       \
 326         case 8: __PUT_USER_DW(ptr); break;                              \
 327         default: __put_user_unknown(); break;                           \
 328         }                                                               \
 329         __pu_err;                                                       \
 330 })
 331
 332 #define __put_user_check(x, ptr, size)                                  \
 333 ({                                                                      \
 334         __typeof__(*(ptr)) __user *__pu_addr = (ptr);                   \
 335         __typeof__(*(ptr)) __pu_val = (x);                              \
 336         int __pu_err = -EFAULT;                                         \
 337                                                                         \
 338         might_fault();                                                  \
 339         if (likely(access_ok(VERIFY_WRITE,  __pu_addr, size))) {        \
 340                 switch (size) {                                         \
 341                 case 1: __put_user_asm("sb", __pu_addr); break;         \
 342                 case 2: __put_user_asm("sh", __pu_addr); break;         \
 343                 case 4: __put_user_asm("sw", __pu_addr); break;         \
 344                 case 8: __PUT_USER_DW(__pu_addr); break;                \
 345                 default: __put_user_unknown(); break;                   \
 346                 }                                                       \
 347         }                                                               \
 348         __pu_err;                                                       \
 349 })
 350
 351 #define __put_user_asm(insn, ptr)                                       \
 352 {                                                                       \
 353         __asm__ __volatile__(                                           \
 354         "1:     " insn "        %z2, %3         # __put_user_asm\n"     \
 355         "2:                                                     \n"     \
 356         "       .section        .fixup,\"ax\"                   \n"     \
 357         "3:     li      %0, %4                                  \n"     \
 358         "       j       2b                                      \n"     \
 359         "       .previous                                       \n"     \
 360         "       .section        __ex_table,\"a\"                \n"     \
 361         "       " __UA_ADDR "   1b, 3b                          \n"     \
 362         "       .previous                                       \n"     \
 363         : "=r" (__pu_err)                                               \
 364         : "0" (0), "Jr" (__pu_val), "o" (__m(ptr)),                     \
 365           "i" (-EFAULT));                                               \
 366 }
 367
 368 #define __put_user_asm_ll32(ptr)                                        \
 369 {                                                                       \
 370         __asm__ __volatile__(                                           \
 371         "1:     sw      %2, (%3)        # __put_user_asm_ll32   \n"     \
 372         "2:     sw      %D2, 4(%3)                              \n"     \
 373         "3:                                                     \n"     \
 374         "       .section        .fixup,\"ax\"                   \n"     \
 375         "4:     li      %0, %4                                  \n"     \
 376         "       j       3b                                      \n"     \
 377         "       .previous                                       \n"     \
 378         "       .section        __ex_table,\"a\"                \n"     \
 379         "       " __UA_ADDR "   1b, 4b                          \n"     \
 380         "       " __UA_ADDR "   2b, 4b                          \n"     \
 381         "       .previous"                                              \
 382         : "=r" (__pu_err)                                               \
 383         : "0" (0), "r" (__pu_val), "r" (ptr),                           \
 384           "i" (-EFAULT));                                               \
 385 }
 386
 387 extern void __put_user_unknown(void);
 388
 389 /*
 390  * put_user_unaligned: - Write a simple value into user space.
 391  * @x:   Value to copy to user space.
 392  * @ptr: Destination address, in user space.
 393  *
 394  * Context: User context only.  This function may sleep.
 395  *
 396  * This macro copies a single simple value from kernel space to user
 397  * space.  It supports simple types like char and int, but not larger
 398  * data types like structures or arrays.
 399  *
 400  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 401  * to the result of dereferencing @ptr.
 402  *
 403  * Returns zero on success, or -EFAULT on error.
 404  */
 405 #define put_user_unaligned(x,ptr)       \
 406         __put_user_unaligned_check((x),(ptr),sizeof(*(ptr)))
 407
 408 /*
 409  * get_user_unaligned: - Get a simple variable from user space.
 410  * @x:   Variable to store result.
 411  * @ptr: Source address, in user space.
 412  *
 413  * Context: User context only.  This function may sleep.
 414  *
 415  * This macro copies a single simple variable from user space to kernel
 416  * space.  It supports simple types like char and int, but not larger
 417  * data types like structures or arrays.
 418  *
 419  * @ptr must have pointer-to-simple-variable type, and the result of
 420  * dereferencing @ptr must be assignable to @x without a cast.
 421  *
 422  * Returns zero on success, or -EFAULT on error.
 423  * On error, the variable @x is set to zero.
 424  */
 425 #define get_user_unaligned(x,ptr) \
 426         __get_user_unaligned_check((x),(ptr),sizeof(*(ptr)))
 427
 428 /*
 429  * __put_user_unaligned: - Write a simple value into user space, with less checking.
 430  * @x:   Value to copy to user space.
 431  * @ptr: Destination address, in user space.
 432  *
 433  * Context: User context only.  This function may sleep.
 434  *
 435  * This macro copies a single simple value from kernel space to user
 436  * space.  It supports simple types like char and int, but not larger
 437  * data types like structures or arrays.
 438  *
 439  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 440  * to the result of dereferencing @ptr.
 441  *
 442  * Caller must check the pointer with access_ok() before calling this
 443  * function.
 444  *
 445  * Returns zero on success, or -EFAULT on error.
 446  */
 447 #define __put_user_unaligned(x,ptr) \
 448         __put_user_unaligned_nocheck((x),(ptr),sizeof(*(ptr)))
 449
 450 /*
 451  * __get_user_unaligned: - Get a simple variable from user space, with less checking.
 452  * @x:   Variable to store result.
 453  * @ptr: Source address, in user space.
 454  *
 455  * Context: User context only.  This function may sleep.
 456  *
 457  * This macro copies a single simple variable from user space to kernel
 458  * space.  It supports simple types like char and int, but not larger
 459  * data types like structures or arrays.
 460  *
 461  * @ptr must have pointer-to-simple-variable type, and the result of
 462  * dereferencing @ptr must be assignable to @x without a cast.
 463  *
 464  * Caller must check the pointer with access_ok() before calling this
 465  * function.
 466  *
 467  * Returns zero on success, or -EFAULT on error.
 468  * On error, the variable @x is set to zero.
 469  */
 470 #define __get_user_unaligned(x,ptr) \
 471         __get_user__unalignednocheck((x),(ptr),sizeof(*(ptr)))
 472
 473 /*
 474  * Yuck.  We need two variants, one for 64bit operation and one
 475  * for 32 bit mode and old iron.
 476  */
 477 #ifdef CONFIG_32BIT
 478 #define __GET_USER_UNALIGNED_DW(val, ptr)                               \
 479         __get_user_unaligned_asm_ll32(val, ptr)
 480 #endif
 481 #ifdef CONFIG_64BIT
 482 #define __GET_USER_UNALIGNED_DW(val, ptr)                               \
 483         __get_user_unaligned_asm(val, "uld", ptr)
 484 #endif
 485
 486 extern void __get_user_unaligned_unknown(void);
 487
 488 #define __get_user_unaligned_common(val, size, ptr)                     \
 489 do {                                                                    \
 490         switch (size) {                                                 \
 491         case 1: __get_user_asm(val, "lb", ptr); break;                  \
 492         case 2: __get_user_unaligned_asm(val, "ulh", ptr); break;       \
 493         case 4: __get_user_unaligned_asm(val, "ulw", ptr); break;       \
 494         case 8: __GET_USER_UNALIGNED_DW(val, ptr); break;               \
 495         default: __get_user_unaligned_unknown(); break;                 \
 496         }                                                               \
 497 } while (0)
 498
 499 #define __get_user_unaligned_nocheck(x,ptr,size)                        \
 500 ({                                                                      \
 501         int __gu_err;                                                   \
 502                                                                         \
 503         __get_user_unaligned_common((x), size, ptr);                    \
 504         __gu_err;                                                       \
 505 })
 506
 507 #define __get_user_unaligned_check(x,ptr,size)                          \
 508 ({                                                                      \
 509         int __gu_err = -EFAULT;                                         \
 510         const __typeof__(*(ptr)) __user * __gu_ptr = (ptr);             \
 511                                                                         \
 512         if (likely(access_ok(VERIFY_READ,  __gu_ptr, size)))            \
 513                 __get_user_unaligned_common((x), size, __gu_ptr);       \
 514                                                                         \
 515         __gu_err;                                                       \
 516 })
 517
 518 #define __get_user_unaligned_asm(val, insn, addr)                       \
 519 {                                                                       \
 520         long __gu_tmp;                                                  \
 521                                                                         \
 522         __asm__ __volatile__(                                           \
 523         "1:     " insn "        %1, %3                          \n"     \
 524         "2:                                                     \n"     \
 525         "       .section .fixup,\"ax\"                          \n"     \
 526         "3:     li      %0, %4                                  \n"     \
 527         "       j       2b                                      \n"     \
 528         "       .previous                                       \n"     \
 529         "       .section __ex_table,\"a\"                       \n"     \
 530         "       "__UA_ADDR "\t1b, 3b                            \n"     \
 531         "       "__UA_ADDR "\t1b + 4, 3b                        \n"     \
 532         "       .previous                                       \n"     \
 533         : "=r" (__gu_err), "=r" (__gu_tmp)                              \
 534         : "0" (0), "o" (__m(addr)), "i" (-EFAULT));                     \
 535                                                                         \
 536         (val) = (__typeof__(*(addr))) __gu_tmp;                         \
 537 }
 538
 539 /*
 540  * Get a long long 64 using 32 bit registers.
 541  */
 542 #define __get_user_unaligned_asm_ll32(val, addr)                        \
 543 {                                                                       \
 544         unsigned long long __gu_tmp;                                    \
 545                                                                         \
 546         __asm__ __volatile__(                                           \
 547         "1:     ulw     %1, (%3)                                \n"     \
 548         "2:     ulw     %D1, 4(%3)                              \n"     \
 549         "       move    %0, $0                                  \n"     \
 550         "3:     .section        .fixup,\"ax\"                   \n"     \
 551         "4:     li      %0, %4                                  \n"     \
 552         "       move    %1, $0                                  \n"     \
 553         "       move    %D1, $0                                 \n"     \
 554         "       j       3b                                      \n"     \
 555         "       .previous                                       \n"     \
 556         "       .section        __ex_table,\"a\"                \n"     \
 557         "       " __UA_ADDR "   1b, 4b                          \n"     \
 558         "       " __UA_ADDR "   1b + 4, 4b                      \n"     \
 559         "       " __UA_ADDR "   2b, 4b                          \n"     \
 560         "       " __UA_ADDR "   2b + 4, 4b                      \n"     \
 561         "       .previous                                       \n"     \
 562         : "=r" (__gu_err), "=&r" (__gu_tmp)                             \
 563         : "0" (0), "r" (addr), "i" (-EFAULT));                          \
 564         (val) = (__typeof__(*(addr))) __gu_tmp;                         \
 565 }
 566
 567 /*
 568  * Yuck.  We need two variants, one for 64bit operation and one
 569  * for 32 bit mode and old iron.
 570  */
 571 #ifdef CONFIG_32BIT
 572 #define __PUT_USER_UNALIGNED_DW(ptr) __put_user_unaligned_asm_ll32(ptr)
 573 #endif
 574 #ifdef CONFIG_64BIT
 575 #define __PUT_USER_UNALIGNED_DW(ptr) __put_user_unaligned_asm("usd", ptr)
 576 #endif
 577
 578 #define __put_user_unaligned_nocheck(x,ptr,size)                        \
 579 ({                                                                      \
 580         __typeof__(*(ptr)) __pu_val;                                    \
 581         int __pu_err = 0;                                               \
 582                                                                         \
 583         __pu_val = (x);                                                 \
 584         switch (size) {                                                 \
 585         case 1: __put_user_asm("sb", ptr); break;                       \
 586         case 2: __put_user_unaligned_asm("ush", ptr); break;            \
 587         case 4: __put_user_unaligned_asm("usw", ptr); break;            \
 588         case 8: __PUT_USER_UNALIGNED_DW(ptr); break;                    \
 589         default: __put_user_unaligned_unknown(); break;                 \
 590         }                                                               \
 591         __pu_err;                                                       \
 592 })
 593
 594 #define __put_user_unaligned_check(x,ptr,size)                          \
 595 ({                                                                      \
 596         __typeof__(*(ptr)) __user *__pu_addr = (ptr);                   \
 597         __typeof__(*(ptr)) __pu_val = (x);                              \
 598         int __pu_err = -EFAULT;                                         \
 599                                                                         \
 600         if (likely(access_ok(VERIFY_WRITE,  __pu_addr, size))) {        \
 601                 switch (size) {                                         \
 602                 case 1: __put_user_asm("sb", __pu_addr); break;         \
 603                 case 2: __put_user_unaligned_asm("ush", __pu_addr); break; \
 604                 case 4: __put_user_unaligned_asm("usw", __pu_addr); break; \
 605                 case 8: __PUT_USER_UNALGINED_DW(__pu_addr); break;      \
 606                 default: __put_user_unaligned_unknown(); break;         \
 607                 }                                                       \
 608         }                                                               \
 609         __pu_err;                                                       \
 610 })
 611
 612 #define __put_user_unaligned_asm(insn, ptr)                             \
 613 {                                                                       \
 614         __asm__ __volatile__(                                           \
 615         "1:     " insn "        %z2, %3         # __put_user_unaligned_asm\n" \
 616         "2:                                                     \n"     \
 617         "       .section        .fixup,\"ax\"                   \n"     \
 618         "3:     li      %0, %4                                  \n"     \
 619         "       j       2b                                      \n"     \
 620         "       .previous                                       \n"     \
 621         "       .section        __ex_table,\"a\"                \n"     \
 622         "       " __UA_ADDR "   1b, 3b                          \n"     \
 623         "       .previous                                       \n"     \
 624         : "=r" (__pu_err)                                               \
 625         : "0" (0), "Jr" (__pu_val), "o" (__m(ptr)),                     \
 626           "i" (-EFAULT));                                               \
 627 }
 628
 629 #define __put_user_unaligned_asm_ll32(ptr)                              \
 630 {                                                                       \
 631         __asm__ __volatile__(                                           \
 632         "1:     sw      %2, (%3)        # __put_user_unaligned_asm_ll32 \n" \
 633         "2:     sw      %D2, 4(%3)                              \n"     \
 634         "3:                                                     \n"     \
 635         "       .section        .fixup,\"ax\"                   \n"     \
 636         "4:     li      %0, %4                                  \n"     \
 637         "       j       3b                                      \n"     \
 638         "       .previous                                       \n"     \
 639         "       .section        __ex_table,\"a\"                \n"     \
 640         "       " __UA_ADDR "   1b, 4b                          \n"     \
 641         "       " __UA_ADDR "   1b + 4, 4b                      \n"     \
 642         "       " __UA_ADDR "   2b, 4b                          \n"     \
 643         "       " __UA_ADDR "   2b + 4, 4b                      \n"     \
 644         "       .previous"                                              \
 645         : "=r" (__pu_err)                                               \
 646         : "0" (0), "r" (__pu_val), "r" (ptr),                           \
 647           "i" (-EFAULT));                                               \
 648 }
 649
 650 extern void __put_user_unaligned_unknown(void);
 651
 652 /*
 653  * We're generating jump to subroutines which will be outside the range of
 654  * jump instructions
 655  */
 656 #ifdef MODULE
 657 #define __MODULE_JAL(destination)                                       \
 658         ".set\tnoat\n\t"                                                \
 659         __UA_LA "\t$1, " #destination "\n\t"                            \
 660         "jalr\t$1\n\t"                                                  \
 661         ".set\tat\n\t"
 662 #else
 663 #define __MODULE_JAL(destination)                                       \
 664         "jal\t" #destination "\n\t"
 665 #endif
 666
 667 #ifndef CONFIG_CPU_DADDI_WORKAROUNDS
 668 #define DADDI_SCRATCH "$0"
 669 #else
 670 #define DADDI_SCRATCH "$3"
 671 #endif
 672
 673 extern size_t __copy_user(void *__to, const void *__from, size_t __n);
 674
 675 #define __invoke_copy_to_user(to, from, n)                              \
 676 ({                                                                      \
 677         register void __user *__cu_to_r __asm__("$4");                  \
 678         register const void *__cu_from_r __asm__("$5");                 \
 679         register long __cu_len_r __asm__("$6");                         \
 680                                                                         \
 681         __cu_to_r = (to);                                               \
 682         __cu_from_r = (from);                                           \
 683         __cu_len_r = (n);                                               \
 684         __asm__ __volatile__(                                           \
 685         __MODULE_JAL(__copy_user)                                       \
 686         : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)       \
 687         :                                                               \
 688         : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31",         \
 689           DADDI_SCRATCH, "memory");                                     \
 690         __cu_len_r;                                                     \
 691 })
 692
 693 /*
 694  * __copy_to_user: - Copy a block of data into user space, with less checking.
 695  * @to:   Destination address, in user space.
 696  * @from: Source address, in kernel space.
 697  * @n:    Number of bytes to copy.
 698  *
 699  * Context: User context only.  This function may sleep.
 700  *
 701  * Copy data from kernel space to user space.  Caller must check
 702  * the specified block with access_ok() before calling this function.
 703  *
 704  * Returns number of bytes that could not be copied.
 705  * On success, this will be zero.
 706  */
 707 #define __copy_to_user(to, from, n)                                     \
 708 ({                                                                      \
 709         void __user *__cu_to;                                           \
 710         const void *__cu_from;                                          \
 711         long __cu_len;                                                  \
 712                                                                         \
 713         __cu_to = (to);                                                 \
 714         __cu_from = (from);                                             \
 715         __cu_len = (n);                                                 \
 716         might_fault();                                                  \
 717         __cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len); \
 718         __cu_len;                                                       \
 719 })
 720
 721 extern size_t __copy_user_inatomic(void *__to, const void *__from, size_t __n);
 722
 723 #define __copy_to_user_inatomic(to, from, n)                            \
 724 ({                                                                      \
 725         void __user *__cu_to;                                           \
 726         const void *__cu_from;                                          \
 727         long __cu_len;                                                  \
 728                                                                         \
 729         __cu_to = (to);                                                 \
 730         __cu_from = (from);                                             \
 731         __cu_len = (n);                                                 \
 732         __cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len); \
 733         __cu_len;                                                       \
 734 })
 735
 736 #define __copy_from_user_inatomic(to, from, n)                          \
 737 ({                                                                      \
 738         void *__cu_to;                                                  \
 739         const void __user *__cu_from;                                   \
 740         long __cu_len;                                                  \
 741                                                                         \
 742         __cu_to = (to);                                                 \
 743         __cu_from = (from);                                             \
 744         __cu_len = (n);                                                 \
 745         __cu_len = __invoke_copy_from_user_inatomic(__cu_to, __cu_from, \
 746                                                     __cu_len);          \
 747         __cu_len;                                                       \
 748 })
 749
 750 /*
 751  * copy_to_user: - Copy a block of data into user space.
 752  * @to:   Destination address, in user space.
 753  * @from: Source address, in kernel space.
 754  * @n:    Number of bytes to copy.
 755  *
 756  * Context: User context only.  This function may sleep.
 757  *
 758  * Copy data from kernel space to user space.
 759  *
 760  * Returns number of bytes that could not be copied.
 761  * On success, this will be zero.
 762  */
 763 #define copy_to_user(to, from, n)                                       \
 764 ({                                                                      \
 765         void __user *__cu_to;                                           \
 766         const void *__cu_from;                                          \
 767         long __cu_len;                                                  \
 768                                                                         \
 769         __cu_to = (to);                                                 \
 770         __cu_from = (from);                                             \
 771         __cu_len = (n);                                                 \
 772         if (access_ok(VERIFY_WRITE, __cu_to, __cu_len)) {               \
 773                 might_fault();                                          \
 774                 __cu_len = __invoke_copy_to_user(__cu_to, __cu_from,    \
 775                                                  __cu_len);             \
 776         }                                                               \
 777         __cu_len;                                                       \
 778 })
 779
 780 #define __invoke_copy_from_user(to, from, n)                            \
 781 ({                                                                      \
 782         register void *__cu_to_r __asm__("$4");                         \
 783         register const void __user *__cu_from_r __asm__("$5");          \
 784         register long __cu_len_r __asm__("$6");                         \
 785                                                                         \
 786         __cu_to_r = (to);                                               \
 787         __cu_from_r = (from);                                           \
 788         __cu_len_r = (n);                                               \
 789         __asm__ __volatile__(                                           \
 790         ".set\tnoreorder\n\t"                                           \
 791         __MODULE_JAL(__copy_user)                                       \
 792         ".set\tnoat\n\t"                                                \
 793         __UA_ADDU "\t$1, %1, %2\n\t"                                    \
 794         ".set\tat\n\t"                                                  \
 795         ".set\treorder"                                                 \
 796         : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)       \
 797         :                                                               \
 798         : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31",         \
 799           DADDI_SCRATCH, "memory");                                     \
 800         __cu_len_r;                                                     \
 801 })
 802
 803 #define __invoke_copy_from_user_inatomic(to, from, n)                   \
 804 ({                                                                      \
 805         register void *__cu_to_r __asm__("$4");                         \
 806         register const void __user *__cu_from_r __asm__("$5");          \
 807         register long __cu_len_r __asm__("$6");                         \
 808                                                                         \
 809         __cu_to_r = (to);                                               \
 810         __cu_from_r = (from);                                           \
 811         __cu_len_r = (n);                                               \
 812         __asm__ __volatile__(                                           \
 813         ".set\tnoreorder\n\t"                                           \
 814         __MODULE_JAL(__copy_user_inatomic)                              \
 815         ".set\tnoat\n\t"                                                \
 816         __UA_ADDU "\t$1, %1, %2\n\t"                                    \
 817         ".set\tat\n\t"                                                  \
 818         ".set\treorder"                                                 \
 819         : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)       \
 820         :                                                               \
 821         : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31",         \
 822           DADDI_SCRATCH, "memory");                                     \
 823         __cu_len_r;                                                     \
 824 })
 825
 826 /*
 827  * __copy_from_user: - Copy a block of data from user space, with less checking.
 828  * @to:   Destination address, in kernel space.
 829  * @from: Source address, in user space.
 830  * @n:    Number of bytes to copy.
 831  *
 832  * Context: User context only.  This function may sleep.
 833  *
 834  * Copy data from user space to kernel space.  Caller must check
 835  * the specified block with access_ok() before calling this function.
 836  *
 837  * Returns number of bytes that could not be copied.
 838  * On success, this will be zero.
 839  *
 840  * If some data could not be copied, this function will pad the copied
 841  * data to the requested size using zero bytes.
 842  */
 843 #define __copy_from_user(to, from, n)                                   \
 844 ({                                                                      \
 845         void *__cu_to;                                                  \
 846         const void __user *__cu_from;                                   \
 847         long __cu_len;                                                  \
 848                                                                         \
 849         __cu_to = (to);                                                 \
 850         __cu_from = (from);                                             \
 851         __cu_len = (n);                                                 \
 852         might_fault();                                                  \
 853         __cu_len = __invoke_copy_from_user(__cu_to, __cu_from,          \
 854                                            __cu_len);                   \
 855         __cu_len;                                                       \
 856 })
 857
 858 /*
 859  * copy_from_user: - Copy a block of data from user space.
 860  * @to:   Destination address, in kernel space.
 861  * @from: Source address, in user space.
 862  * @n:    Number of bytes to copy.
 863  *
 864  * Context: User context only.  This function may sleep.
 865  *
 866  * Copy data from user space to kernel space.
 867  *
 868  * Returns number of bytes that could not be copied.
 869  * On success, this will be zero.
 870  *
 871  * If some data could not be copied, this function will pad the copied
 872  * data to the requested size using zero bytes.
 873  */
 874 #define copy_from_user(to, from, n)                                     \
 875 ({                                                                      \
 876         void *__cu_to;                                                  \
 877         const void __user *__cu_from;                                   \
 878         long __cu_len;                                                  \
 879                                                                         \
 880         __cu_to = (to);                                                 \
 881         __cu_from = (from);                                             \
 882         __cu_len = (n);                                                 \
 883         if (access_ok(VERIFY_READ, __cu_from, __cu_len)) {              \
 884                 might_fault();                                          \
 885                 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from,  \
 886                                                    __cu_len);           \
 887         }                                                               \
 888         __cu_len;                                                       \
 889 })
 890
 891 #define __copy_in_user(to, from, n)                                     \
 892 ({                                                                      \
 893         void __user *__cu_to;                                           \
 894         const void __user *__cu_from;                                   \
 895         long __cu_len;                                                  \
 896                                                                         \
 897         __cu_to = (to);                                                 \
 898         __cu_from = (from);                                             \
 899         __cu_len = (n);                                                 \
 900         might_fault();                                                  \
 901         __cu_len = __invoke_copy_from_user(__cu_to, __cu_from,          \
 902                                            __cu_len);                   \
 903         __cu_len;                                                       \
 904 })
 905
 906 #define copy_in_user(to, from, n)                                       \
 907 ({                                                                      \
 908         void __user *__cu_to;                                           \
 909         const void __user *__cu_from;                                   \
 910         long __cu_len;                                                  \
 911                                                                         \
 912         __cu_to = (to);                                                 \
 913         __cu_from = (from);                                             \
 914         __cu_len = (n);                                                 \
 915         if (likely(access_ok(VERIFY_READ, __cu_from, __cu_len) &&       \
 916                    access_ok(VERIFY_WRITE, __cu_to, __cu_len))) {       \
 917                 might_fault();                                          \
 918                 __cu_len = __invoke_copy_from_user(__cu_to, __cu_from,  \
 919                                                    __cu_len);           \
 920         }                                                               \
 921         __cu_len;                                                       \
 922 })
 923
 924 /*
 925  * __clear_user: - Zero a block of memory in user space, with less checking.
 926  * @to:   Destination address, in user space.
 927  * @n:    Number of bytes to zero.
 928  *
 929  * Zero a block of memory in user space.  Caller must check
 930  * the specified block with access_ok() before calling this function.
 931  *
 932  * Returns number of bytes that could not be cleared.
 933  * On success, this will be zero.
 934  */
 935 static inline __kernel_size_t
 936 __clear_user(void __user *addr, __kernel_size_t size)
 937 {
 938         __kernel_size_t res;
 939
 940         might_fault();
 941         __asm__ __volatile__(
 942                 "move\t$4, %1\n\t"
 943                 "move\t$5, $0\n\t"
 944                 "move\t$6, %2\n\t"
 945                 __MODULE_JAL(__bzero)
 946                 "move\t%0, $6"
 947                 : "=r" (res)
 948                 : "r" (addr), "r" (size)
 949                 : "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
 950
 951         return res;
 952 }
 953
 954 #define clear_user(addr,n)                                              \
 955 ({                                                                      \
 956         void __user * __cl_addr = (addr);                               \
 957         unsigned long __cl_size = (n);                                  \
 958         if (__cl_size && access_ok(VERIFY_WRITE,                        \
 959                 ((unsigned long)(__cl_addr)), __cl_size))               \
 960                 __cl_size = __clear_user(__cl_addr, __cl_size);         \
 961         __cl_size;                                                      \
 962 })
 963
 964 /*
 965  * __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking.
 966  * @dst:   Destination address, in kernel space.  This buffer must be at
 967  *         least @count bytes long.
 968  * @src:   Source address, in user space.
 969  * @count: Maximum number of bytes to copy, including the trailing NUL.
 970  *
 971  * Copies a NUL-terminated string from userspace to kernel space.
 972  * Caller must check the specified block with access_ok() before calling
 973  * this function.
 974  *
 975  * On success, returns the length of the string (not including the trailing
 976  * NUL).
 977  *
 978  * If access to userspace fails, returns -EFAULT (some data may have been
 979  * copied).
 980  *
 981  * If @count is smaller than the length of the string, copies @count bytes
 982  * and returns @count.
 983  */
 984 static inline long
 985 __strncpy_from_user(char *__to, const char __user *__from, long __len)
 986 {
 987         long res;
 988
 989         might_fault();
 990         __asm__ __volatile__(
 991                 "move\t$4, %1\n\t"
 992                 "move\t$5, %2\n\t"
 993                 "move\t$6, %3\n\t"
 994                 __MODULE_JAL(__strncpy_from_user_nocheck_asm)
 995                 "move\t%0, $2"
 996                 : "=r" (res)
 997                 : "r" (__to), "r" (__from), "r" (__len)
 998                 : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
 999
1000         return res;
1001 }
1002
1003 /*
1004  * strncpy_from_user: - Copy a NUL terminated string from userspace.
1005  * @dst:   Destination address, in kernel space.  This buffer must be at
1006  *         least @count bytes long.
1007  * @src:   Source address, in user space.
1008  * @count: Maximum number of bytes to copy, including the trailing NUL.
1009  *
1010  * Copies a NUL-terminated string from userspace to kernel space.
1011  *
1012  * On success, returns the length of the string (not including the trailing
1013  * NUL).
1014  *
1015  * If access to userspace fails, returns -EFAULT (some data may have been
1016  * copied).
1017  *
1018  * If @count is smaller than the length of the string, copies @count bytes
1019  * and returns @count.
1020  */
1021 static inline long
1022 strncpy_from_user(char *__to, const char __user *__from, long __len)
1023 {
1024         long res;
1025
1026         might_fault();
1027         __asm__ __volatile__(
1028                 "move\t$4, %1\n\t"
1029                 "move\t$5, %2\n\t"
1030                 "move\t$6, %3\n\t"
1031                 __MODULE_JAL(__strncpy_from_user_asm)
1032                 "move\t%0, $2"
1033                 : "=r" (res)
1034                 : "r" (__to), "r" (__from), "r" (__len)
1035                 : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
1036
1037         return res;
1038 }
1039
1040 /* Returns: 0 if bad, string length+1 (memory size) of string if ok */
1041 static inline long __strlen_user(const char __user *s)
1042 {
1043         long res;
1044
1045         might_fault();
1046         __asm__ __volatile__(
1047                 "move\t$4, %1\n\t"
1048                 __MODULE_JAL(__strlen_user_nocheck_asm)
1049                 "move\t%0, $2"
1050                 : "=r" (res)
1051                 : "r" (s)
1052                 : "$2", "$4", __UA_t0, "$31");
1053
1054         return res;
1055 }
1056
1057 /*
1058  * strlen_user: - Get the size of a string in user space.
1059  * @str: The string to measure.
1060  *
1061  * Context: User context only.  This function may sleep.
1062  *
1063  * Get the size of a NUL-terminated string in user space.
1064  *
1065  * Returns the size of the string INCLUDING the terminating NUL.
1066  * On exception, returns 0.
1067  *
1068  * If there is a limit on the length of a valid string, you may wish to
1069  * consider using strnlen_user() instead.
1070  */
1071 static inline long strlen_user(const char __user *s)
1072 {
1073         long res;
1074
1075         might_fault();
1076         __asm__ __volatile__(
1077                 "move\t$4, %1\n\t"
1078                 __MODULE_JAL(__strlen_user_asm)
1079                 "move\t%0, $2"
1080                 : "=r" (res)
1081                 : "r" (s)
1082                 : "$2", "$4", __UA_t0, "$31");
1083
1084         return res;
1085 }
1086
1087 /* Returns: 0 if bad, string length+1 (memory size) of string if ok */
1088 static inline long __strnlen_user(const char __user *s, long n)
1089 {
1090         long res;
1091
1092         might_fault();
1093         __asm__ __volatile__(
1094                 "move\t$4, %1\n\t"
1095                 "move\t$5, %2\n\t"
1096                 __MODULE_JAL(__strnlen_user_nocheck_asm)
1097                 "move\t%0, $2"
1098                 : "=r" (res)
1099                 : "r" (s), "r" (n)
1100                 : "$2", "$4", "$5", __UA_t0, "$31");
1101
1102         return res;
1103 }
1104
1105 /*
1106  * strlen_user: - Get the size of a string in user space.
1107  * @str: The string to measure.
1108  *
1109  * Context: User context only.  This function may sleep.
1110  *
1111  * Get the size of a NUL-terminated string in user space.
1112  *
1113  * Returns the size of the string INCLUDING the terminating NUL.
1114  * On exception, returns 0.
1115  *
1116  * If there is a limit on the length of a valid string, you may wish to
1117  * consider using strnlen_user() instead.
1118  */
1119 static inline long strnlen_user(const char __user *s, long n)
1120 {
1121         long res;
1122
1123         might_fault();
1124         __asm__ __volatile__(
1125                 "move\t$4, %1\n\t"
1126                 "move\t$5, %2\n\t"
1127                 __MODULE_JAL(__strnlen_user_asm)
1128                 "move\t%0, $2"
1129                 : "=r" (res)
1130                 : "r" (s), "r" (n)
1131                 : "$2", "$4", "$5", __UA_t0, "$31");
1132
1133         return res;
1134 }
1135
1136 struct exception_table_entry
1137 {
1138         unsigned long insn;
1139         unsigned long nextinsn;
1140 };
1141
1142 extern int fixup_exception(struct pt_regs *regs);
1143
1144 #endif /* _ASM_UACCESS_H */