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  * Copyright (C) 2014, Imagination Technologies Ltd.
  10  */
  11 #ifndef _ASM_UACCESS_H
  12 #define _ASM_UACCESS_H
  13
  14 #include <linux/kernel.h>
  15 #include <linux/string.h>
  16 #include <asm/asm-eva.h>
  17 #include <asm/extable.h>
  18
  19 /*
  20  * The fs value determines whether argument validity checking should be
  21  * performed or not.  If get_fs() == USER_DS, checking is performed, with
  22  * get_fs() == KERNEL_DS, checking is bypassed.
  23  *
  24  * For historical reasons, these macros are grossly misnamed.
  25  */
  26 #ifdef CONFIG_32BIT
  27
  28 #ifdef CONFIG_KVM_GUEST
  29 #define __UA_LIMIT 0x40000000UL
  30 #else
  31 #define __UA_LIMIT 0x80000000UL
  32 #endif
  33
  34 #define __UA_ADDR       ".word"
  35 #define __UA_LA         "la"
  36 #define __UA_ADDU       "addu"
  37 #define __UA_t0         "$8"
  38 #define __UA_t1         "$9"
  39
  40 #endif /* CONFIG_32BIT */
  41
  42 #ifdef CONFIG_64BIT
  43
  44 extern u64 __ua_limit;
  45
  46 #define __UA_LIMIT      __ua_limit
  47
  48 #define __UA_ADDR       ".dword"
  49 #define __UA_LA         "dla"
  50 #define __UA_ADDU       "daddu"
  51 #define __UA_t0         "$12"
  52 #define __UA_t1         "$13"
  53
  54 #endif /* CONFIG_64BIT */
  55
  56 /*
  57  * USER_DS is a bitmask that has the bits set that may not be set in a valid
  58  * userspace address.  Note that we limit 32-bit userspace to 0x7fff8000 but
  59  * the arithmetic we're doing only works if the limit is a power of two, so
  60  * we use 0x80000000 here on 32-bit kernels.  If a process passes an invalid
  61  * address in this range it's the process's problem, not ours :-)
  62  */
  63
  64 #ifdef CONFIG_KVM_GUEST
  65 #define KERNEL_DS       ((mm_segment_t) { 0x80000000UL })
  66 #define USER_DS         ((mm_segment_t) { 0xC0000000UL })
  67 #else
  68 #define KERNEL_DS       ((mm_segment_t) { 0UL })
  69 #define USER_DS         ((mm_segment_t) { __UA_LIMIT })
  70 #endif
  71
  72 #define get_ds()        (KERNEL_DS)
  73 #define get_fs()        (current_thread_info()->addr_limit)
  74 #define set_fs(x)       (current_thread_info()->addr_limit = (x))
  75
  76 #define segment_eq(a, b)        ((a).seg == (b).seg)
  77
  78 /*
  79  * eva_kernel_access() - determine whether kernel memory access on an EVA system
  80  *
  81  * Determines whether memory accesses should be performed to kernel memory
  82  * on a system using Extended Virtual Addressing (EVA).
  83  *
  84  * Return: true if a kernel memory access on an EVA system, else false.
  85  */
  86 static inline bool eva_kernel_access(void)
  87 {
  88         if (!IS_ENABLED(CONFIG_EVA))
  89                 return false;
  90
  91         return uaccess_kernel();
  92 }
  93
  94 /*
  95  * Is a address valid? This does a straightforward calculation rather
  96  * than tests.
  97  *
  98  * Address valid if:
  99  *  - "addr" doesn't have any high-bits set
 100  *  - AND "size" doesn't have any high-bits set
 101  *  - AND "addr+size" doesn't have any high-bits set
 102  *  - OR we are in kernel mode.
 103  *
 104  * __ua_size() is a trick to avoid runtime checking of positive constant
 105  * sizes; for those we already know at compile time that the size is ok.
 106  */
 107 #define __ua_size(size)                                                 \
 108         ((__builtin_constant_p(size) && (signed long) (size) > 0) ? 0 : (size))
 109
 110 /*
 111  * access_ok: - Checks if a user space pointer is valid
 112  * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE.  Note that
 113  *        %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
 114  *        to write to a block, it is always safe to read from it.
 115  * @addr: User space pointer to start of block to check
 116  * @size: Size of block to check
 117  *
 118  * Context: User context only. This function may sleep if pagefaults are
 119  *          enabled.
 120  *
 121  * Checks if a pointer to a block of memory in user space is valid.
 122  *
 123  * Returns true (nonzero) if the memory block may be valid, false (zero)
 124  * if it is definitely invalid.
 125  *
 126  * Note that, depending on architecture, this function probably just
 127  * checks that the pointer is in the user space range - after calling
 128  * this function, memory access functions may still return -EFAULT.
 129  */
 130
 131 static inline int __access_ok(const void __user *p, unsigned long size)
 132 {
 133         unsigned long addr = (unsigned long)p;
 134         return (get_fs().seg & (addr | (addr + size) | __ua_size(size))) == 0;
 135 }
 136
 137 #define access_ok(type, addr, size)                                     \
 138         likely(__access_ok((addr), (size)))
 139
 140 /*
 141  * put_user: - Write a simple value into user space.
 142  * @x:   Value to copy to user space.
 143  * @ptr: Destination address, in user space.
 144  *
 145  * Context: User context only. This function may sleep if pagefaults are
 146  *          enabled.
 147  *
 148  * This macro copies a single simple value from kernel space to user
 149  * space.  It supports simple types like char and int, but not larger
 150  * data types like structures or arrays.
 151  *
 152  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 153  * to the result of dereferencing @ptr.
 154  *
 155  * Returns zero on success, or -EFAULT on error.
 156  */
 157 #define put_user(x,ptr) \
 158         __put_user_check((x), (ptr), sizeof(*(ptr)))
 159
 160 /*
 161  * get_user: - Get a simple variable from user space.
 162  * @x:   Variable to store result.
 163  * @ptr: Source address, in user space.
 164  *
 165  * Context: User context only. This function may sleep if pagefaults are
 166  *          enabled.
 167  *
 168  * This macro copies a single simple variable from user space to kernel
 169  * space.  It supports simple types like char and int, but not larger
 170  * data types like structures or arrays.
 171  *
 172  * @ptr must have pointer-to-simple-variable type, and the result of
 173  * dereferencing @ptr must be assignable to @x without a cast.
 174  *
 175  * Returns zero on success, or -EFAULT on error.
 176  * On error, the variable @x is set to zero.
 177  */
 178 #define get_user(x,ptr) \
 179         __get_user_check((x), (ptr), sizeof(*(ptr)))
 180
 181 /*
 182  * __put_user: - Write a simple value into user space, with less checking.
 183  * @x:   Value to copy to user space.
 184  * @ptr: Destination address, in user space.
 185  *
 186  * Context: User context only. This function may sleep if pagefaults are
 187  *          enabled.
 188  *
 189  * This macro copies a single simple value from kernel space to user
 190  * space.  It supports simple types like char and int, but not larger
 191  * data types like structures or arrays.
 192  *
 193  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 194  * to the result of dereferencing @ptr.
 195  *
 196  * Caller must check the pointer with access_ok() before calling this
 197  * function.
 198  *
 199  * Returns zero on success, or -EFAULT on error.
 200  */
 201 #define __put_user(x,ptr) \
 202         __put_user_nocheck((x), (ptr), sizeof(*(ptr)))
 203
 204 /*
 205  * __get_user: - Get a simple variable from user space, with less checking.
 206  * @x:   Variable to store result.
 207  * @ptr: Source address, in user space.
 208  *
 209  * Context: User context only. This function may sleep if pagefaults are
 210  *          enabled.
 211  *
 212  * This macro copies a single simple variable from user space to kernel
 213  * space.  It supports simple types like char and int, but not larger
 214  * data types like structures or arrays.
 215  *
 216  * @ptr must have pointer-to-simple-variable type, and the result of
 217  * dereferencing @ptr must be assignable to @x without a cast.
 218  *
 219  * Caller must check the pointer with access_ok() before calling this
 220  * function.
 221  *
 222  * Returns zero on success, or -EFAULT on error.
 223  * On error, the variable @x is set to zero.
 224  */
 225 #define __get_user(x,ptr) \
 226         __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
 227
 228 struct __large_struct { unsigned long buf[100]; };
 229 #define __m(x) (*(struct __large_struct __user *)(x))
 230
 231 /*
 232  * Yuck.  We need two variants, one for 64bit operation and one
 233  * for 32 bit mode and old iron.
 234  */
 235 #ifndef CONFIG_EVA
 236 #define __get_kernel_common(val, size, ptr) __get_user_common(val, size, ptr)
 237 #else
 238 /*
 239  * Kernel specific functions for EVA. We need to use normal load instructions
 240  * to read data from kernel when operating in EVA mode. We use these macros to
 241  * avoid redefining __get_user_asm for EVA.
 242  */
 243 #undef _loadd
 244 #undef _loadw
 245 #undef _loadh
 246 #undef _loadb
 247 #ifdef CONFIG_32BIT
 248 #define _loadd                  _loadw
 249 #else
 250 #define _loadd(reg, addr)       "ld " reg ", " addr
 251 #endif
 252 #define _loadw(reg, addr)       "lw " reg ", " addr
 253 #define _loadh(reg, addr)       "lh " reg ", " addr
 254 #define _loadb(reg, addr)       "lb " reg ", " addr
 255
 256 #define __get_kernel_common(val, size, ptr)                             \
 257 do {                                                                    \
 258         switch (size) {                                                 \
 259         case 1: __get_data_asm(val, _loadb, ptr); break;                \
 260         case 2: __get_data_asm(val, _loadh, ptr); break;                \
 261         case 4: __get_data_asm(val, _loadw, ptr); break;                \
 262         case 8: __GET_DW(val, _loadd, ptr); break;                      \
 263         default: __get_user_unknown(); break;                           \
 264         }                                                               \
 265 } while (0)
 266 #endif
 267
 268 #ifdef CONFIG_32BIT
 269 #define __GET_DW(val, insn, ptr) __get_data_asm_ll32(val, insn, ptr)
 270 #endif
 271 #ifdef CONFIG_64BIT
 272 #define __GET_DW(val, insn, ptr) __get_data_asm(val, insn, ptr)
 273 #endif
 274
 275 extern void __get_user_unknown(void);
 276
 277 #define __get_user_common(val, size, ptr)                               \
 278 do {                                                                    \
 279         switch (size) {                                                 \
 280         case 1: __get_data_asm(val, user_lb, ptr); break;               \
 281         case 2: __get_data_asm(val, user_lh, ptr); break;               \
 282         case 4: __get_data_asm(val, user_lw, ptr); break;               \
 283         case 8: __GET_DW(val, user_ld, ptr); break;                     \
 284         default: __get_user_unknown(); break;                           \
 285         }                                                               \
 286 } while (0)
 287
 288 #define __get_user_nocheck(x, ptr, size)                                \
 289 ({                                                                      \
 290         int __gu_err;                                                   \
 291                                                                         \
 292         if (eva_kernel_access()) {                                      \
 293                 __get_kernel_common((x), size, ptr);                    \
 294         } else {                                                        \
 295                 __chk_user_ptr(ptr);                                    \
 296                 __get_user_common((x), size, ptr);                      \
 297         }                                                               \
 298         __gu_err;                                                       \
 299 })
 300
 301 #define __get_user_check(x, ptr, size)                                  \
 302 ({                                                                      \
 303         int __gu_err = -EFAULT;                                         \
 304         const __typeof__(*(ptr)) __user * __gu_ptr = (ptr);             \
 305                                                                         \
 306         might_fault();                                                  \
 307         if (likely(access_ok(VERIFY_READ,  __gu_ptr, size))) {          \
 308                 if (eva_kernel_access())                                \
 309                         __get_kernel_common((x), size, __gu_ptr);       \
 310                 else                                                    \
 311                         __get_user_common((x), size, __gu_ptr);         \
 312         } else                                                          \
 313                 (x) = 0;                                                \
 314                                                                         \
 315         __gu_err;                                                       \
 316 })
 317
 318 #define __get_data_asm(val, insn, addr)                                 \
 319 {                                                                       \
 320         long __gu_tmp;                                                  \
 321                                                                         \
 322         __asm__ __volatile__(                                           \
 323         "1:     "insn("%1", "%3")"                              \n"     \
 324         "2:                                                     \n"     \
 325         "       .insn                                           \n"     \
 326         "       .section .fixup,\"ax\"                          \n"     \
 327         "3:     li      %0, %4                                  \n"     \
 328         "       move    %1, $0                                  \n"     \
 329         "       j       2b                                      \n"     \
 330         "       .previous                                       \n"     \
 331         "       .section __ex_table,\"a\"                       \n"     \
 332         "       "__UA_ADDR "\t1b, 3b                            \n"     \
 333         "       .previous                                       \n"     \
 334         : "=r" (__gu_err), "=r" (__gu_tmp)                              \
 335         : "0" (0), "o" (__m(addr)), "i" (-EFAULT));                     \
 336                                                                         \
 337         (val) = (__typeof__(*(addr))) __gu_tmp;                         \
 338 }
 339
 340 /*
 341  * Get a long long 64 using 32 bit registers.
 342  */
 343 #define __get_data_asm_ll32(val, insn, addr)                            \
 344 {                                                                       \
 345         union {                                                         \
 346                 unsigned long long      l;                              \
 347                 __typeof__(*(addr))     t;                              \
 348         } __gu_tmp;                                                     \
 349                                                                         \
 350         __asm__ __volatile__(                                           \
 351         "1:     " insn("%1", "(%3)")"                           \n"     \
 352         "2:     " insn("%D1", "4(%3)")"                         \n"     \
 353         "3:                                                     \n"     \
 354         "       .insn                                           \n"     \
 355         "       .section        .fixup,\"ax\"                   \n"     \
 356         "4:     li      %0, %4                                  \n"     \
 357         "       move    %1, $0                                  \n"     \
 358         "       move    %D1, $0                                 \n"     \
 359         "       j       3b                                      \n"     \
 360         "       .previous                                       \n"     \
 361         "       .section        __ex_table,\"a\"                \n"     \
 362         "       " __UA_ADDR "   1b, 4b                          \n"     \
 363         "       " __UA_ADDR "   2b, 4b                          \n"     \
 364         "       .previous                                       \n"     \
 365         : "=r" (__gu_err), "=&r" (__gu_tmp.l)                           \
 366         : "0" (0), "r" (addr), "i" (-EFAULT));                          \
 367                                                                         \
 368         (val) = __gu_tmp.t;                                             \
 369 }
 370
 371 #ifndef CONFIG_EVA
 372 #define __put_kernel_common(ptr, size) __put_user_common(ptr, size)
 373 #else
 374 /*
 375  * Kernel specific functions for EVA. We need to use normal load instructions
 376  * to read data from kernel when operating in EVA mode. We use these macros to
 377  * avoid redefining __get_data_asm for EVA.
 378  */
 379 #undef _stored
 380 #undef _storew
 381 #undef _storeh
 382 #undef _storeb
 383 #ifdef CONFIG_32BIT
 384 #define _stored                 _storew
 385 #else
 386 #define _stored(reg, addr)      "ld " reg ", " addr
 387 #endif
 388
 389 #define _storew(reg, addr)      "sw " reg ", " addr
 390 #define _storeh(reg, addr)      "sh " reg ", " addr
 391 #define _storeb(reg, addr)      "sb " reg ", " addr
 392
 393 #define __put_kernel_common(ptr, size)                                  \
 394 do {                                                                    \
 395         switch (size) {                                                 \
 396         case 1: __put_data_asm(_storeb, ptr); break;                    \
 397         case 2: __put_data_asm(_storeh, ptr); break;                    \
 398         case 4: __put_data_asm(_storew, ptr); break;                    \
 399         case 8: __PUT_DW(_stored, ptr); break;                          \
 400         default: __put_user_unknown(); break;                           \
 401         }                                                               \
 402 } while(0)
 403 #endif
 404
 405 /*
 406  * Yuck.  We need two variants, one for 64bit operation and one
 407  * for 32 bit mode and old iron.
 408  */
 409 #ifdef CONFIG_32BIT
 410 #define __PUT_DW(insn, ptr) __put_data_asm_ll32(insn, ptr)
 411 #endif
 412 #ifdef CONFIG_64BIT
 413 #define __PUT_DW(insn, ptr) __put_data_asm(insn, ptr)
 414 #endif
 415
 416 #define __put_user_common(ptr, size)                                    \
 417 do {                                                                    \
 418         switch (size) {                                                 \
 419         case 1: __put_data_asm(user_sb, ptr); break;                    \
 420         case 2: __put_data_asm(user_sh, ptr); break;                    \
 421         case 4: __put_data_asm(user_sw, ptr); break;                    \
 422         case 8: __PUT_DW(user_sd, ptr); break;                          \
 423         default: __put_user_unknown(); break;                           \
 424         }                                                               \
 425 } while (0)
 426
 427 #define __put_user_nocheck(x, ptr, size)                                \
 428 ({                                                                      \
 429         __typeof__(*(ptr)) __pu_val;                                    \
 430         int __pu_err = 0;                                               \
 431                                                                         \
 432         __pu_val = (x);                                                 \
 433         if (eva_kernel_access()) {                                      \
 434                 __put_kernel_common(ptr, size);                         \
 435         } else {                                                        \
 436                 __chk_user_ptr(ptr);                                    \
 437                 __put_user_common(ptr, size);                           \
 438         }                                                               \
 439         __pu_err;                                                       \
 440 })
 441
 442 #define __put_user_check(x, ptr, size)                                  \
 443 ({                                                                      \
 444         __typeof__(*(ptr)) __user *__pu_addr = (ptr);                   \
 445         __typeof__(*(ptr)) __pu_val = (x);                              \
 446         int __pu_err = -EFAULT;                                         \
 447                                                                         \
 448         might_fault();                                                  \
 449         if (likely(access_ok(VERIFY_WRITE,  __pu_addr, size))) {        \
 450                 if (eva_kernel_access())                                \
 451                         __put_kernel_common(__pu_addr, size);           \
 452                 else                                                    \
 453                         __put_user_common(__pu_addr, size);             \
 454         }                                                               \
 455                                                                         \
 456         __pu_err;                                                       \
 457 })
 458
 459 #define __put_data_asm(insn, ptr)                                       \
 460 {                                                                       \
 461         __asm__ __volatile__(                                           \
 462         "1:     "insn("%z2", "%3")"     # __put_data_asm        \n"     \
 463         "2:                                                     \n"     \
 464         "       .insn                                           \n"     \
 465         "       .section        .fixup,\"ax\"                   \n"     \
 466         "3:     li      %0, %4                                  \n"     \
 467         "       j       2b                                      \n"     \
 468         "       .previous                                       \n"     \
 469         "       .section        __ex_table,\"a\"                \n"     \
 470         "       " __UA_ADDR "   1b, 3b                          \n"     \
 471         "       .previous                                       \n"     \
 472         : "=r" (__pu_err)                                               \
 473         : "0" (0), "Jr" (__pu_val), "o" (__m(ptr)),                     \
 474           "i" (-EFAULT));                                               \
 475 }
 476
 477 #define __put_data_asm_ll32(insn, ptr)                                  \
 478 {                                                                       \
 479         __asm__ __volatile__(                                           \
 480         "1:     "insn("%2", "(%3)")"    # __put_data_asm_ll32   \n"     \
 481         "2:     "insn("%D2", "4(%3)")"                          \n"     \
 482         "3:                                                     \n"     \
 483         "       .insn                                           \n"     \
 484         "       .section        .fixup,\"ax\"                   \n"     \
 485         "4:     li      %0, %4                                  \n"     \
 486         "       j       3b                                      \n"     \
 487         "       .previous                                       \n"     \
 488         "       .section        __ex_table,\"a\"                \n"     \
 489         "       " __UA_ADDR "   1b, 4b                          \n"     \
 490         "       " __UA_ADDR "   2b, 4b                          \n"     \
 491         "       .previous"                                              \
 492         : "=r" (__pu_err)                                               \
 493         : "0" (0), "r" (__pu_val), "r" (ptr),                           \
 494           "i" (-EFAULT));                                               \
 495 }
 496
 497 extern void __put_user_unknown(void);
 498
 499 /*
 500  * We're generating jump to subroutines which will be outside the range of
 501  * jump instructions
 502  */
 503 #ifdef MODULE
 504 #define __MODULE_JAL(destination)                                       \
 505         ".set\tnoat\n\t"                                                \
 506         __UA_LA "\t$1, " #destination "\n\t"                            \
 507         "jalr\t$1\n\t"                                                  \
 508         ".set\tat\n\t"
 509 #else
 510 #define __MODULE_JAL(destination)                                       \
 511         "jal\t" #destination "\n\t"
 512 #endif
 513
 514 #if defined(CONFIG_CPU_DADDI_WORKAROUNDS) || (defined(CONFIG_EVA) &&    \
 515                                               defined(CONFIG_CPU_HAS_PREFETCH))
 516 #define DADDI_SCRATCH "$3"
 517 #else
 518 #define DADDI_SCRATCH "$0"
 519 #endif
 520
 521 extern size_t __copy_user(void *__to, const void *__from, size_t __n);
 522
 523 #define __invoke_copy_from(func, to, from, n)                           \
 524 ({                                                                      \
 525         register void *__cu_to_r __asm__("$4");                         \
 526         register const void __user *__cu_from_r __asm__("$5");          \
 527         register long __cu_len_r __asm__("$6");                         \
 528                                                                         \
 529         __cu_to_r = (to);                                               \
 530         __cu_from_r = (from);                                           \
 531         __cu_len_r = (n);                                               \
 532         __asm__ __volatile__(                                           \
 533         ".set\tnoreorder\n\t"                                           \
 534         __MODULE_JAL(func)                                              \
 535         ".set\tnoat\n\t"                                                \
 536         __UA_ADDU "\t$1, %1, %2\n\t"                                    \
 537         ".set\tat\n\t"                                                  \
 538         ".set\treorder"                                                 \
 539         : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)       \
 540         :                                                               \
 541         : "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",  \
 542           DADDI_SCRATCH, "memory");                                     \
 543         __cu_len_r;                                                     \
 544 })
 545
 546 #define __invoke_copy_to(func, to, from, n)                             \
 547 ({                                                                      \
 548         register void __user *__cu_to_r __asm__("$4");                  \
 549         register const void *__cu_from_r __asm__("$5");                 \
 550         register long __cu_len_r __asm__("$6");                         \
 551                                                                         \
 552         __cu_to_r = (to);                                               \
 553         __cu_from_r = (from);                                           \
 554         __cu_len_r = (n);                                               \
 555         __asm__ __volatile__(                                           \
 556         __MODULE_JAL(func)                                              \
 557         : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)       \
 558         :                                                               \
 559         : "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",  \
 560           DADDI_SCRATCH, "memory");                                     \
 561         __cu_len_r;                                                     \
 562 })
 563
 564 #define __invoke_copy_from_kernel(to, from, n)                          \
 565         __invoke_copy_from(__copy_user, to, from, n)
 566
 567 #define __invoke_copy_to_kernel(to, from, n)                            \
 568         __invoke_copy_to(__copy_user, to, from, n)
 569
 570 #define ___invoke_copy_in_kernel(to, from, n)                           \
 571         __invoke_copy_from(__copy_user, to, from, n)
 572
 573 #ifndef CONFIG_EVA
 574 #define __invoke_copy_from_user(to, from, n)                            \
 575         __invoke_copy_from(__copy_user, to, from, n)
 576
 577 #define __invoke_copy_to_user(to, from, n)                              \
 578         __invoke_copy_to(__copy_user, to, from, n)
 579
 580 #define ___invoke_copy_in_user(to, from, n)                             \
 581         __invoke_copy_from(__copy_user, to, from, n)
 582
 583 #else
 584
 585 /* EVA specific functions */
 586
 587 extern size_t __copy_from_user_eva(void *__to, const void *__from,
 588                                    size_t __n);
 589 extern size_t __copy_to_user_eva(void *__to, const void *__from,
 590                                  size_t __n);
 591 extern size_t __copy_in_user_eva(void *__to, const void *__from, size_t __n);
 592
 593 /*
 594  * Source or destination address is in userland. We need to go through
 595  * the TLB
 596  */
 597 #define __invoke_copy_from_user(to, from, n)                            \
 598         __invoke_copy_from(__copy_from_user_eva, to, from, n)
 599
 600 #define __invoke_copy_to_user(to, from, n)                              \
 601         __invoke_copy_to(__copy_to_user_eva, to, from, n)
 602
 603 #define ___invoke_copy_in_user(to, from, n)                             \
 604         __invoke_copy_from(__copy_in_user_eva, to, from, n)
 605
 606 #endif /* CONFIG_EVA */
 607
 608 static inline unsigned long
 609 raw_copy_to_user(void __user *to, const void *from, unsigned long n)
 610 {
 611         if (eva_kernel_access())
 612                 return __invoke_copy_to_kernel(to, from, n);
 613         else
 614                 return __invoke_copy_to_user(to, from, n);
 615 }
 616
 617 static inline unsigned long
 618 raw_copy_from_user(void *to, const void __user *from, unsigned long n)
 619 {
 620         if (eva_kernel_access())
 621                 return __invoke_copy_from_kernel(to, from, n);
 622         else
 623                 return __invoke_copy_from_user(to, from, n);
 624 }
 625
 626 #define INLINE_COPY_FROM_USER
 627 #define INLINE_COPY_TO_USER
 628
 629 static inline unsigned long
 630 raw_copy_in_user(void __user*to, const void __user *from, unsigned long n)
 631 {
 632         if (eva_kernel_access())
 633                 return ___invoke_copy_in_kernel(to, from, n);
 634         else
 635                 return ___invoke_copy_in_user(to, from, n);
 636 }
 637
 638 extern __kernel_size_t __bzero_kernel(void __user *addr, __kernel_size_t size);
 639 extern __kernel_size_t __bzero(void __user *addr, __kernel_size_t size);
 640
 641 /*
 642  * __clear_user: - Zero a block of memory in user space, with less checking.
 643  * @to:   Destination address, in user space.
 644  * @n:    Number of bytes to zero.
 645  *
 646  * Zero a block of memory in user space.  Caller must check
 647  * the specified block with access_ok() before calling this function.
 648  *
 649  * Returns number of bytes that could not be cleared.
 650  * On success, this will be zero.
 651  */
 652 static inline __kernel_size_t
 653 __clear_user(void __user *addr, __kernel_size_t size)
 654 {
 655         __kernel_size_t res;
 656
 657 #ifdef CONFIG_CPU_MICROMIPS
 658 /* micromips memset / bzero also clobbers t7 & t8 */
 659 #define bzero_clobbers "$4", "$5", "$6", __UA_t0, __UA_t1, "$15", "$24", "$31"
 660 #else
 661 #define bzero_clobbers "$4", "$5", "$6", __UA_t0, __UA_t1, "$31"
 662 #endif /* CONFIG_CPU_MICROMIPS */
 663
 664         if (eva_kernel_access()) {
 665                 __asm__ __volatile__(
 666                         "move\t$4, %1\n\t"
 667                         "move\t$5, $0\n\t"
 668                         "move\t$6, %2\n\t"
 669                         __MODULE_JAL(__bzero_kernel)
 670                         "move\t%0, $6"
 671                         : "=r" (res)
 672                         : "r" (addr), "r" (size)
 673                         : bzero_clobbers);
 674         } else {
 675                 might_fault();
 676                 __asm__ __volatile__(
 677                         "move\t$4, %1\n\t"
 678                         "move\t$5, $0\n\t"
 679                         "move\t$6, %2\n\t"
 680                         __MODULE_JAL(__bzero)
 681                         "move\t%0, $6"
 682                         : "=r" (res)
 683                         : "r" (addr), "r" (size)
 684                         : bzero_clobbers);
 685         }
 686
 687         return res;
 688 }
 689
 690 #define clear_user(addr,n)                                              \
 691 ({                                                                      \
 692         void __user * __cl_addr = (addr);                               \
 693         unsigned long __cl_size = (n);                                  \
 694         if (__cl_size && access_ok(VERIFY_WRITE,                        \
 695                                         __cl_addr, __cl_size))          \
 696                 __cl_size = __clear_user(__cl_addr, __cl_size);         \
 697         __cl_size;                                                      \
 698 })
 699
 700 extern long __strncpy_from_kernel_asm(char *__to, const char __user *__from, long __len);
 701 extern long __strncpy_from_user_asm(char *__to, const char __user *__from, long __len);
 702
 703 /*
 704  * strncpy_from_user: - Copy a NUL terminated string from userspace.
 705  * @dst:   Destination address, in kernel space.  This buffer must be at
 706  *         least @count bytes long.
 707  * @src:   Source address, in user space.
 708  * @count: Maximum number of bytes to copy, including the trailing NUL.
 709  *
 710  * Copies a NUL-terminated string from userspace to kernel space.
 711  *
 712  * On success, returns the length of the string (not including the trailing
 713  * NUL).
 714  *
 715  * If access to userspace fails, returns -EFAULT (some data may have been
 716  * copied).
 717  *
 718  * If @count is smaller than the length of the string, copies @count bytes
 719  * and returns @count.
 720  */
 721 static inline long
 722 strncpy_from_user(char *__to, const char __user *__from, long __len)
 723 {
 724         long res;
 725
 726         if (eva_kernel_access()) {
 727                 __asm__ __volatile__(
 728                         "move\t$4, %1\n\t"
 729                         "move\t$5, %2\n\t"
 730                         "move\t$6, %3\n\t"
 731                         __MODULE_JAL(__strncpy_from_kernel_asm)
 732                         "move\t%0, $2"
 733                         : "=r" (res)
 734                         : "r" (__to), "r" (__from), "r" (__len)
 735                         : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
 736         } else {
 737                 might_fault();
 738                 __asm__ __volatile__(
 739                         "move\t$4, %1\n\t"
 740                         "move\t$5, %2\n\t"
 741                         "move\t$6, %3\n\t"
 742                         __MODULE_JAL(__strncpy_from_user_asm)
 743                         "move\t%0, $2"
 744                         : "=r" (res)
 745                         : "r" (__to), "r" (__from), "r" (__len)
 746                         : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory");
 747         }
 748
 749         return res;
 750 }
 751
 752 extern long __strnlen_kernel_asm(const char __user *s, long n);
 753 extern long __strnlen_user_asm(const char __user *s, long n);
 754
 755 /*
 756  * strnlen_user: - Get the size of a string in user space.
 757  * @str: The string to measure.
 758  *
 759  * Context: User context only. This function may sleep if pagefaults are
 760  *          enabled.
 761  *
 762  * Get the size of a NUL-terminated string in user space.
 763  *
 764  * Returns the size of the string INCLUDING the terminating NUL.
 765  * On exception, returns 0.
 766  * If the string is too long, returns a value greater than @n.
 767  */
 768 static inline long strnlen_user(const char __user *s, long n)
 769 {
 770         long res;
 771
 772         might_fault();
 773         if (eva_kernel_access()) {
 774                 __asm__ __volatile__(
 775                         "move\t$4, %1\n\t"
 776                         "move\t$5, %2\n\t"
 777                         __MODULE_JAL(__strnlen_kernel_asm)
 778                         "move\t%0, $2"
 779                         : "=r" (res)
 780                         : "r" (s), "r" (n)
 781                         : "$2", "$4", "$5", __UA_t0, "$31");
 782         } else {
 783                 __asm__ __volatile__(
 784                         "move\t$4, %1\n\t"
 785                         "move\t$5, %2\n\t"
 786                         __MODULE_JAL(__strnlen_user_asm)
 787                         "move\t%0, $2"
 788                         : "=r" (res)
 789                         : "r" (s), "r" (n)
 790                         : "$2", "$4", "$5", __UA_t0, "$31");
 791         }
 792
 793         return res;
 794 }
 795
 796 #endif /* _ASM_UACCESS_H */