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