kernel/arch/m32r/include/asm/uaccess.h

   1 #ifndef _ASM_M32R_UACCESS_H
   2 #define _ASM_M32R_UACCESS_H
   3
   4 /*
   5  *  linux/include/asm-m32r/uaccess.h
   6  *
   7  *  M32R version.
   8  *    Copyright (C) 2004, 2006  Hirokazu Takata <takata at linux-m32r.org>
   9  */
  10
  11 /*
  12  * User space memory access functions
  13  */
  14 #include <linux/errno.h>
  15 #include <linux/thread_info.h>
  16 #include <asm/page.h>
  17 #include <asm/setup.h>
  18
  19 #define VERIFY_READ 0
  20 #define VERIFY_WRITE 1
  21
  22 /*
  23  * The fs value determines whether argument validity checking should be
  24  * performed or not.  If get_fs() == USER_DS, checking is performed, with
  25  * get_fs() == KERNEL_DS, checking is bypassed.
  26  *
  27  * For historical reasons, these macros are grossly misnamed.
  28  */
  29
  30 #define MAKE_MM_SEG(s)  ((mm_segment_t) { (s) })
  31
  32 #ifdef CONFIG_MMU
  33
  34 #define KERNEL_DS       MAKE_MM_SEG(0xFFFFFFFF)
  35 #define USER_DS         MAKE_MM_SEG(PAGE_OFFSET)
  36 #define get_ds()        (KERNEL_DS)
  37 #define get_fs()        (current_thread_info()->addr_limit)
  38 #define set_fs(x)       (current_thread_info()->addr_limit = (x))
  39
  40 #else /* not CONFIG_MMU */
  41
  42 #define KERNEL_DS       MAKE_MM_SEG(0xFFFFFFFF)
  43 #define USER_DS         MAKE_MM_SEG(0xFFFFFFFF)
  44 #define get_ds()        (KERNEL_DS)
  45
  46 static inline mm_segment_t get_fs(void)
  47 {
  48         return USER_DS;
  49 }
  50
  51 static inline void set_fs(mm_segment_t s)
  52 {
  53 }
  54
  55 #endif /* not CONFIG_MMU */
  56
  57 #define segment_eq(a, b)        ((a).seg == (b).seg)
  58
  59 #define __addr_ok(addr) \
  60         ((unsigned long)(addr) < (current_thread_info()->addr_limit.seg))
  61
  62 /*
  63  * Test whether a block of memory is a valid user space address.
  64  * Returns 0 if the range is valid, nonzero otherwise.
  65  *
  66  * This is equivalent to the following test:
  67  * (u33)addr + (u33)size >= (u33)current->addr_limit.seg
  68  *
  69  * This needs 33-bit arithmetic. We have a carry...
  70  */
  71 #define __range_ok(addr, size) ({                                       \
  72         unsigned long flag, roksum;                                     \
  73         __chk_user_ptr(addr);                                           \
  74         asm (                                                           \
  75                 "       cmpu    %1, %1    ; clear cbit\n"               \
  76                 "       addx    %1, %3    ; set cbit if overflow\n"     \
  77                 "       subx    %0, %0\n"                               \
  78                 "       cmpu    %4, %1\n"                               \
  79                 "       subx    %0, %5\n"                               \
  80                 : "=&r" (flag), "=r" (roksum)                           \
  81                 : "1" (addr), "r" ((int)(size)),                        \
  82                   "r" (current_thread_info()->addr_limit.seg), "r" (0)  \
  83                 : "cbit" );                                             \
  84         flag; })
  85
  86 /**
  87  * access_ok: - Checks if a user space pointer is valid
  88  * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE.  Note that
  89  *        %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
  90  *        to write to a block, it is always safe to read from it.
  91  * @addr: User space pointer to start of block to check
  92  * @size: Size of block to check
  93  *
  94  * Context: User context only. This function may sleep if pagefaults are
  95  *          enabled.
  96  *
  97  * Checks if a pointer to a block of memory in user space is valid.
  98  *
  99  * Returns true (nonzero) if the memory block may be valid, false (zero)
 100  * if it is definitely invalid.
 101  *
 102  * Note that, depending on architecture, this function probably just
 103  * checks that the pointer is in the user space range - after calling
 104  * this function, memory access functions may still return -EFAULT.
 105  */
 106 #ifdef CONFIG_MMU
 107 #define access_ok(type, addr, size) (likely(__range_ok(addr, size) == 0))
 108 #else
 109 static inline int access_ok(int type, const void *addr, unsigned long size)
 110 {
 111         unsigned long val = (unsigned long)addr;
 112
 113         return ((val >= memory_start) && ((val + size) < memory_end));
 114 }
 115 #endif /* CONFIG_MMU */
 116
 117 /*
 118  * The exception table consists of pairs of addresses: the first is the
 119  * address of an instruction that is allowed to fault, and the second is
 120  * the address at which the program should continue.  No registers are
 121  * modified, so it is entirely up to the continuation code to figure out
 122  * what to do.
 123  *
 124  * All the routines below use bits of fixup code that are out of line
 125  * with the main instruction path.  This means when everything is well,
 126  * we don't even have to jump over them.  Further, they do not intrude
 127  * on our cache or tlb entries.
 128  */
 129
 130 struct exception_table_entry
 131 {
 132         unsigned long insn, fixup;
 133 };
 134
 135 extern int fixup_exception(struct pt_regs *regs);
 136
 137 /*
 138  * These are the main single-value transfer routines.  They automatically
 139  * use the right size if we just have the right pointer type.
 140  *
 141  * This gets kind of ugly. We want to return _two_ values in "get_user()"
 142  * and yet we don't want to do any pointers, because that is too much
 143  * of a performance impact. Thus we have a few rather ugly macros here,
 144  * and hide all the uglyness from the user.
 145  *
 146  * The "__xxx" versions of the user access functions are versions that
 147  * do not verify the address space, that must have been done previously
 148  * with a separate "access_ok()" call (this is used when we do multiple
 149  * accesses to the same area of user memory).
 150  */
 151
 152 /* Careful: we have to cast the result to the type of the pointer for sign
 153    reasons */
 154 /**
 155  * get_user: - Get a simple variable from user space.
 156  * @x:   Variable to store result.
 157  * @ptr: Source address, in user space.
 158  *
 159  * Context: User context only. This function may sleep if pagefaults are
 160  *          enabled.
 161  *
 162  * This macro copies a single simple variable from user space to kernel
 163  * space.  It supports simple types like char and int, but not larger
 164  * data types like structures or arrays.
 165  *
 166  * @ptr must have pointer-to-simple-variable type, and the result of
 167  * dereferencing @ptr must be assignable to @x without a cast.
 168  *
 169  * Returns zero on success, or -EFAULT on error.
 170  * On error, the variable @x is set to zero.
 171  */
 172 #define get_user(x, ptr)                                                        \
 173         __get_user_check((x), (ptr), sizeof(*(ptr)))
 174
 175 /**
 176  * put_user: - Write a simple value into user space.
 177  * @x:   Value to copy to user space.
 178  * @ptr: Destination address, in user space.
 179  *
 180  * Context: User context only. This function may sleep if pagefaults are
 181  *          enabled.
 182  *
 183  * This macro copies a single simple value from kernel space to user
 184  * space.  It supports simple types like char and int, but not larger
 185  * data types like structures or arrays.
 186  *
 187  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 188  * to the result of dereferencing @ptr.
 189  *
 190  * Returns zero on success, or -EFAULT on error.
 191  */
 192 #define put_user(x, ptr)                                                        \
 193         __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
 194
 195 /**
 196  * __get_user: - Get a simple variable from user space, with less checking.
 197  * @x:   Variable to store result.
 198  * @ptr: Source address, in user space.
 199  *
 200  * Context: User context only. This function may sleep if pagefaults are
 201  *          enabled.
 202  *
 203  * This macro copies a single simple variable from user space to kernel
 204  * space.  It supports simple types like char and int, but not larger
 205  * data types like structures or arrays.
 206  *
 207  * @ptr must have pointer-to-simple-variable type, and the result of
 208  * dereferencing @ptr must be assignable to @x without a cast.
 209  *
 210  * Caller must check the pointer with access_ok() before calling this
 211  * function.
 212  *
 213  * Returns zero on success, or -EFAULT on error.
 214  * On error, the variable @x is set to zero.
 215  */
 216 #define __get_user(x, ptr) \
 217         __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
 218
 219 #define __get_user_nocheck(x, ptr, size)                                \
 220 ({                                                                      \
 221         long __gu_err = 0;                                              \
 222         unsigned long __gu_val;                                         \
 223         might_fault();                                                  \
 224         __get_user_size(__gu_val, (ptr), (size), __gu_err);             \
 225         (x) = (__force __typeof__(*(ptr)))__gu_val;                     \
 226         __gu_err;                                                       \
 227 })
 228
 229 #define __get_user_check(x, ptr, size)                                  \
 230 ({                                                                      \
 231         long __gu_err = -EFAULT;                                        \
 232         unsigned long __gu_val = 0;                                     \
 233         const __typeof__(*(ptr)) __user *__gu_addr = (ptr);             \
 234         might_fault();                                                  \
 235         if (access_ok(VERIFY_READ, __gu_addr, size))                    \
 236                 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
 237         (x) = (__force __typeof__(*(ptr)))__gu_val;                     \
 238         __gu_err;                                                       \
 239 })
 240
 241 extern long __get_user_bad(void);
 242
 243 #define __get_user_size(x, ptr, size, retval)                           \
 244 do {                                                                    \
 245         retval = 0;                                                     \
 246         __chk_user_ptr(ptr);                                            \
 247         switch (size) {                                                 \
 248           case 1: __get_user_asm(x, ptr, retval, "ub"); break;          \
 249           case 2: __get_user_asm(x, ptr, retval, "uh"); break;          \
 250           case 4: __get_user_asm(x, ptr, retval, ""); break;            \
 251           default: (x) = __get_user_bad();                              \
 252         }                                                               \
 253 } while (0)
 254
 255 #define __get_user_asm(x, addr, err, itype)                             \
 256         __asm__ __volatile__(                                           \
 257                 "       .fillinsn\n"                                    \
 258                 "1:     ld"itype" %1,@%2\n"                             \
 259                 "       .fillinsn\n"                                    \
 260                 "2:\n"                                                  \
 261                 ".section .fixup,\"ax\"\n"                              \
 262                 "       .balign 4\n"                                    \
 263                 "3:     ldi %0,%3\n"                                    \
 264                 "       seth r14,#high(2b)\n"                           \
 265                 "       or3 r14,r14,#low(2b)\n"                         \
 266                 "       jmp r14\n"                                      \
 267                 ".previous\n"                                           \
 268                 ".section __ex_table,\"a\"\n"                           \
 269                 "       .balign 4\n"                                    \
 270                 "       .long 1b,3b\n"                                  \
 271                 ".previous"                                             \
 272                 : "=&r" (err), "=&r" (x)                                \
 273                 : "r" (addr), "i" (-EFAULT), "0" (err)                  \
 274                 : "r14", "memory")
 275
 276 /**
 277  * __put_user: - Write a simple value into user space, with less checking.
 278  * @x:   Value to copy to user space.
 279  * @ptr: Destination address, in user space.
 280  *
 281  * Context: User context only. This function may sleep if pagefaults are
 282  *          enabled.
 283  *
 284  * This macro copies a single simple value from kernel space to user
 285  * space.  It supports simple types like char and int, but not larger
 286  * data types like structures or arrays.
 287  *
 288  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 289  * to the result of dereferencing @ptr.
 290  *
 291  * Caller must check the pointer with access_ok() before calling this
 292  * function.
 293  *
 294  * Returns zero on success, or -EFAULT on error.
 295  */
 296 #define __put_user(x, ptr) \
 297         __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
 298
 299
 300 #define __put_user_nocheck(x, ptr, size)                                \
 301 ({                                                                      \
 302         long __pu_err;                                                  \
 303         might_fault();                                                  \
 304         __put_user_size((x), (ptr), (size), __pu_err);                  \
 305         __pu_err;                                                       \
 306 })
 307
 308
 309 #define __put_user_check(x, ptr, size)                                  \
 310 ({                                                                      \
 311         long __pu_err = -EFAULT;                                        \
 312         __typeof__(*(ptr)) __user *__pu_addr = (ptr);                   \
 313         might_fault();                                                  \
 314         if (access_ok(VERIFY_WRITE, __pu_addr, size))                   \
 315                 __put_user_size((x), __pu_addr, (size), __pu_err);      \
 316         __pu_err;                                                       \
 317 })
 318
 319 #if defined(__LITTLE_ENDIAN__)
 320 #define __put_user_u64(x, addr, err)                                    \
 321         __asm__ __volatile__(                                           \
 322                 "       .fillinsn\n"                                    \
 323                 "1:     st %L1,@%2\n"                                   \
 324                 "       .fillinsn\n"                                    \
 325                 "2:     st %H1,@(4,%2)\n"                               \
 326                 "       .fillinsn\n"                                    \
 327                 "3:\n"                                                  \
 328                 ".section .fixup,\"ax\"\n"                              \
 329                 "       .balign 4\n"                                    \
 330                 "4:     ldi %0,%3\n"                                    \
 331                 "       seth r14,#high(3b)\n"                           \
 332                 "       or3 r14,r14,#low(3b)\n"                         \
 333                 "       jmp r14\n"                                      \
 334                 ".previous\n"                                           \
 335                 ".section __ex_table,\"a\"\n"                           \
 336                 "       .balign 4\n"                                    \
 337                 "       .long 1b,4b\n"                                  \
 338                 "       .long 2b,4b\n"                                  \
 339                 ".previous"                                             \
 340                 : "=&r" (err)                                           \
 341                 : "r" (x), "r" (addr), "i" (-EFAULT), "0" (err)         \
 342                 : "r14", "memory")
 343
 344 #elif defined(__BIG_ENDIAN__)
 345 #define __put_user_u64(x, addr, err)                                    \
 346         __asm__ __volatile__(                                           \
 347                 "       .fillinsn\n"                                    \
 348                 "1:     st %H1,@%2\n"                                   \
 349                 "       .fillinsn\n"                                    \
 350                 "2:     st %L1,@(4,%2)\n"                               \
 351                 "       .fillinsn\n"                                    \
 352                 "3:\n"                                                  \
 353                 ".section .fixup,\"ax\"\n"                              \
 354                 "       .balign 4\n"                                    \
 355                 "4:     ldi %0,%3\n"                                    \
 356                 "       seth r14,#high(3b)\n"                           \
 357                 "       or3 r14,r14,#low(3b)\n"                         \
 358                 "       jmp r14\n"                                      \
 359                 ".previous\n"                                           \
 360                 ".section __ex_table,\"a\"\n"                           \
 361                 "       .balign 4\n"                                    \
 362                 "       .long 1b,4b\n"                                  \
 363                 "       .long 2b,4b\n"                                  \
 364                 ".previous"                                             \
 365                 : "=&r" (err)                                           \
 366                 : "r" (x), "r" (addr), "i" (-EFAULT), "0" (err)         \
 367                 : "r14", "memory")
 368 #else
 369 #error no endian defined
 370 #endif
 371
 372 extern void __put_user_bad(void);
 373
 374 #define __put_user_size(x, ptr, size, retval)                           \
 375 do {                                                                    \
 376         retval = 0;                                                     \
 377         __chk_user_ptr(ptr);                                            \
 378         switch (size) {                                                 \
 379           case 1: __put_user_asm(x, ptr, retval, "b"); break;           \
 380           case 2: __put_user_asm(x, ptr, retval, "h"); break;           \
 381           case 4: __put_user_asm(x, ptr, retval, ""); break;            \
 382           case 8: __put_user_u64((__typeof__(*ptr))(x), ptr, retval); break;\
 383           default: __put_user_bad();                                    \
 384         }                                                               \
 385 } while (0)
 386
 387 struct __large_struct { unsigned long buf[100]; };
 388 #define __m(x) (*(struct __large_struct *)(x))
 389
 390 /*
 391  * Tell gcc we read from memory instead of writing: this is because
 392  * we do not write to any memory gcc knows about, so there are no
 393  * aliasing issues.
 394  */
 395 #define __put_user_asm(x, addr, err, itype)                             \
 396         __asm__ __volatile__(                                           \
 397                 "       .fillinsn\n"                                    \
 398                 "1:     st"itype" %1,@%2\n"                             \
 399                 "       .fillinsn\n"                                    \
 400                 "2:\n"                                                  \
 401                 ".section .fixup,\"ax\"\n"                              \
 402                 "       .balign 4\n"                                    \
 403                 "3:     ldi %0,%3\n"                                    \
 404                 "       seth r14,#high(2b)\n"                           \
 405                 "       or3 r14,r14,#low(2b)\n"                         \
 406                 "       jmp r14\n"                                      \
 407                 ".previous\n"                                           \
 408                 ".section __ex_table,\"a\"\n"                           \
 409                 "       .balign 4\n"                                    \
 410                 "       .long 1b,3b\n"                                  \
 411                 ".previous"                                             \
 412                 : "=&r" (err)                                           \
 413                 : "r" (x), "r" (addr), "i" (-EFAULT), "0" (err)         \
 414                 : "r14", "memory")
 415
 416 /*
 417  * Here we special-case 1, 2 and 4-byte copy_*_user invocations.  On a fault
 418  * we return the initial request size (1, 2 or 4), as copy_*_user should do.
 419  * If a store crosses a page boundary and gets a fault, the m32r will not write
 420  * anything, so this is accurate.
 421  */
 422
 423 /*
 424  * Copy To/From Userspace
 425  */
 426
 427 /* Generic arbitrary sized copy.  */
 428 /* Return the number of bytes NOT copied.  */
 429 #define __copy_user(to, from, size)                                     \
 430 do {                                                                    \
 431         unsigned long __dst, __src, __c;                                \
 432         __asm__ __volatile__ (                                          \
 433                 "       mv      r14, %0\n"                              \
 434                 "       or      r14, %1\n"                              \
 435                 "       beq     %0, %1, 9f\n"                           \
 436                 "       beqz    %2, 9f\n"                               \
 437                 "       and3    r14, r14, #3\n"                         \
 438                 "       bnez    r14, 2f\n"                              \
 439                 "       and3    %2, %2, #3\n"                           \
 440                 "       beqz    %3, 2f\n"                               \
 441                 "       addi    %0, #-4         ; word_copy \n"         \
 442                 "       .fillinsn\n"                                    \
 443                 "0:     ld      r14, @%1+\n"                            \
 444                 "       addi    %3, #-1\n"                              \
 445                 "       .fillinsn\n"                                    \
 446                 "1:     st      r14, @+%0\n"                            \
 447                 "       bnez    %3, 0b\n"                               \
 448                 "       beqz    %2, 9f\n"                               \
 449                 "       addi    %0, #4\n"                               \
 450                 "       .fillinsn\n"                                    \
 451                 "2:     ldb     r14, @%1        ; byte_copy \n"         \
 452                 "       .fillinsn\n"                                    \
 453                 "3:     stb     r14, @%0\n"                             \
 454                 "       addi    %1, #1\n"                               \
 455                 "       addi    %2, #-1\n"                              \
 456                 "       addi    %0, #1\n"                               \
 457                 "       bnez    %2, 2b\n"                               \
 458                 "       .fillinsn\n"                                    \
 459                 "9:\n"                                                  \
 460                 ".section .fixup,\"ax\"\n"                              \
 461                 "       .balign 4\n"                                    \
 462                 "5:     addi    %3, #1\n"                               \
 463                 "       addi    %1, #-4\n"                              \
 464                 "       .fillinsn\n"                                    \
 465                 "6:     slli    %3, #2\n"                               \
 466                 "       add     %2, %3\n"                               \
 467                 "       addi    %0, #4\n"                               \
 468                 "       .fillinsn\n"                                    \
 469                 "7:     seth    r14, #high(9b)\n"                       \
 470                 "       or3     r14, r14, #low(9b)\n"                   \
 471                 "       jmp     r14\n"                                  \
 472                 ".previous\n"                                           \
 473                 ".section __ex_table,\"a\"\n"                           \
 474                 "       .balign 4\n"                                    \
 475                 "       .long 0b,6b\n"                                  \
 476                 "       .long 1b,5b\n"                                  \
 477                 "       .long 2b,9b\n"                                  \
 478                 "       .long 3b,9b\n"                                  \
 479                 ".previous\n"                                           \
 480                 : "=&r" (__dst), "=&r" (__src), "=&r" (size),           \
 481                   "=&r" (__c)                                           \
 482                 : "0" (to), "1" (from), "2" (size), "3" (size / 4)      \
 483                 : "r14", "memory");                                     \
 484 } while (0)
 485
 486 #define __copy_user_zeroing(to, from, size)                             \
 487 do {                                                                    \
 488         unsigned long __dst, __src, __c;                                \
 489         __asm__ __volatile__ (                                          \
 490                 "       mv      r14, %0\n"                              \
 491                 "       or      r14, %1\n"                              \
 492                 "       beq     %0, %1, 9f\n"                           \
 493                 "       beqz    %2, 9f\n"                               \
 494                 "       and3    r14, r14, #3\n"                         \
 495                 "       bnez    r14, 2f\n"                              \
 496                 "       and3    %2, %2, #3\n"                           \
 497                 "       beqz    %3, 2f\n"                               \
 498                 "       addi    %0, #-4         ; word_copy \n"         \
 499                 "       .fillinsn\n"                                    \
 500                 "0:     ld      r14, @%1+\n"                            \
 501                 "       addi    %3, #-1\n"                              \
 502                 "       .fillinsn\n"                                    \
 503                 "1:     st      r14, @+%0\n"                            \
 504                 "       bnez    %3, 0b\n"                               \
 505                 "       beqz    %2, 9f\n"                               \
 506                 "       addi    %0, #4\n"                               \
 507                 "       .fillinsn\n"                                    \
 508                 "2:     ldb     r14, @%1        ; byte_copy \n"         \
 509                 "       .fillinsn\n"                                    \
 510                 "3:     stb     r14, @%0\n"                             \
 511                 "       addi    %1, #1\n"                               \
 512                 "       addi    %2, #-1\n"                              \
 513                 "       addi    %0, #1\n"                               \
 514                 "       bnez    %2, 2b\n"                               \
 515                 "       .fillinsn\n"                                    \
 516                 "9:\n"                                                  \
 517                 ".section .fixup,\"ax\"\n"                              \
 518                 "       .balign 4\n"                                    \
 519                 "5:     addi    %3, #1\n"                               \
 520                 "       addi    %1, #-4\n"                              \
 521                 "       .fillinsn\n"                                    \
 522                 "6:     slli    %3, #2\n"                               \
 523                 "       add     %2, %3\n"                               \
 524                 "       addi    %0, #4\n"                               \
 525                 "       .fillinsn\n"                                    \
 526                 "7:     ldi     r14, #0         ; store zero \n"        \
 527                 "       .fillinsn\n"                                    \
 528                 "8:     addi    %2, #-1\n"                              \
 529                 "       stb     r14, @%0        ; ACE? \n"              \
 530                 "       addi    %0, #1\n"                               \
 531                 "       bnez    %2, 8b\n"                               \
 532                 "       seth    r14, #high(9b)\n"                       \
 533                 "       or3     r14, r14, #low(9b)\n"                   \
 534                 "       jmp     r14\n"                                  \
 535                 ".previous\n"                                           \
 536                 ".section __ex_table,\"a\"\n"                           \
 537                 "       .balign 4\n"                                    \
 538                 "       .long 0b,6b\n"                                  \
 539                 "       .long 1b,5b\n"                                  \
 540                 "       .long 2b,7b\n"                                  \
 541                 "       .long 3b,7b\n"                                  \
 542                 ".previous\n"                                           \
 543                 : "=&r" (__dst), "=&r" (__src), "=&r" (size),           \
 544                   "=&r" (__c)                                           \
 545                 : "0" (to), "1" (from), "2" (size), "3" (size / 4)      \
 546                 : "r14", "memory");                                     \
 547 } while (0)
 548
 549
 550 /* We let the __ versions of copy_from/to_user inline, because they're often
 551  * used in fast paths and have only a small space overhead.
 552  */
 553 static inline unsigned long __generic_copy_from_user_nocheck(void *to,
 554         const void __user *from, unsigned long n)
 555 {
 556         __copy_user_zeroing(to, from, n);
 557         return n;
 558 }
 559
 560 static inline unsigned long __generic_copy_to_user_nocheck(void __user *to,
 561         const void *from, unsigned long n)
 562 {
 563         __copy_user(to, from, n);
 564         return n;
 565 }
 566
 567 unsigned long __generic_copy_to_user(void __user *, const void *, unsigned long);
 568 unsigned long __generic_copy_from_user(void *, const void __user *, unsigned long);
 569
 570 /**
 571  * __copy_to_user: - Copy a block of data into user space, with less checking.
 572  * @to:   Destination address, in user space.
 573  * @from: Source address, in kernel space.
 574  * @n:    Number of bytes to copy.
 575  *
 576  * Context: User context only. This function may sleep if pagefaults are
 577  *          enabled.
 578  *
 579  * Copy data from kernel space to user space.  Caller must check
 580  * the specified block with access_ok() before calling this function.
 581  *
 582  * Returns number of bytes that could not be copied.
 583  * On success, this will be zero.
 584  */
 585 #define __copy_to_user(to, from, n)                     \
 586         __generic_copy_to_user_nocheck((to), (from), (n))
 587
 588 #define __copy_to_user_inatomic __copy_to_user
 589 #define __copy_from_user_inatomic __copy_from_user
 590
 591 /**
 592  * copy_to_user: - Copy a block of data into user space.
 593  * @to:   Destination address, in user space.
 594  * @from: Source address, in kernel space.
 595  * @n:    Number of bytes to copy.
 596  *
 597  * Context: User context only. This function may sleep if pagefaults are
 598  *          enabled.
 599  *
 600  * Copy data from kernel space to user space.
 601  *
 602  * Returns number of bytes that could not be copied.
 603  * On success, this will be zero.
 604  */
 605 #define copy_to_user(to, from, n)                       \
 606 ({                                                      \
 607         might_fault();                                  \
 608         __generic_copy_to_user((to), (from), (n));      \
 609 })
 610
 611 /**
 612  * __copy_from_user: - Copy a block of data from user space, with less checking. * @to:   Destination address, in kernel space.
 613  * @from: Source address, in user space.
 614  * @n:    Number of bytes to copy.
 615  *
 616  * Context: User context only. This function may sleep if pagefaults are
 617  *          enabled.
 618  *
 619  * Copy data from user space to kernel space.  Caller must check
 620  * the specified block with access_ok() before calling this function.
 621  *
 622  * Returns number of bytes that could not be copied.
 623  * On success, this will be zero.
 624  *
 625  * If some data could not be copied, this function will pad the copied
 626  * data to the requested size using zero bytes.
 627  */
 628 #define __copy_from_user(to, from, n)                   \
 629         __generic_copy_from_user_nocheck((to), (from), (n))
 630
 631 /**
 632  * copy_from_user: - Copy a block of data from user space.
 633  * @to:   Destination address, in kernel space.
 634  * @from: Source address, in user space.
 635  * @n:    Number of bytes to copy.
 636  *
 637  * Context: User context only. This function may sleep if pagefaults are
 638  *          enabled.
 639  *
 640  * Copy data from user space to kernel space.
 641  *
 642  * Returns number of bytes that could not be copied.
 643  * On success, this will be zero.
 644  *
 645  * If some data could not be copied, this function will pad the copied
 646  * data to the requested size using zero bytes.
 647  */
 648 #define copy_from_user(to, from, n)                     \
 649 ({                                                      \
 650         might_fault();                                  \
 651         __generic_copy_from_user((to), (from), (n));    \
 652 })
 653
 654 long __must_check strncpy_from_user(char *dst, const char __user *src,
 655                                 long count);
 656 long __must_check __strncpy_from_user(char *dst,
 657                                 const char __user *src, long count);
 658
 659 /**
 660  * __clear_user: - Zero a block of memory in user space, with less checking.
 661  * @to:   Destination address, in user space.
 662  * @n:    Number of bytes to zero.
 663  *
 664  * Zero a block of memory in user space.  Caller must check
 665  * the specified block with access_ok() before calling this function.
 666  *
 667  * Returns number of bytes that could not be cleared.
 668  * On success, this will be zero.
 669  */
 670 unsigned long __clear_user(void __user *mem, unsigned long len);
 671
 672 /**
 673  * clear_user: - Zero a block of memory in user space.
 674  * @to:   Destination address, in user space.
 675  * @n:    Number of bytes to zero.
 676  *
 677  * Zero a block of memory in user space.  Caller must check
 678  * the specified block with access_ok() before calling this function.
 679  *
 680  * Returns number of bytes that could not be cleared.
 681  * On success, this will be zero.
 682  */
 683 unsigned long clear_user(void __user *mem, unsigned long len);
 684
 685 /**
 686  * strlen_user: - Get the size of a string in user space.
 687  * @str: The string to measure.
 688  *
 689  * Context: User context only. This function may sleep if pagefaults are
 690  *          enabled.
 691  *
 692  * Get the size of a NUL-terminated string in user space.
 693  *
 694  * Returns the size of the string INCLUDING the terminating NUL.
 695  * On exception, returns 0.
 696  *
 697  * If there is a limit on the length of a valid string, you may wish to
 698  * consider using strnlen_user() instead.
 699  */
 700 #define strlen_user(str) strnlen_user(str, ~0UL >> 1)
 701 long strnlen_user(const char __user *str, long n);
 702
 703 #endif /* _ASM_M32R_UACCESS_H */