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/config.h>
  15 #include <linux/errno.h>
  16 #include <linux/thread_info.h>
  17 #include <asm/page.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, sum;                                        \
  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" (sum)                              \
  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.
  95  *
  96  * Checks if a pointer to a block of memory in user space is valid.
  97  *
  98  * Returns true (nonzero) if the memory block may be valid, false (zero)
  99  * if it is definitely invalid.
 100  *
 101  * Note that, depending on architecture, this function probably just
 102  * checks that the pointer is in the user space range - after calling
 103  * this function, memory access functions may still return -EFAULT.
 104  */
 105 #ifdef CONFIG_MMU
 106 #define access_ok(type,addr,size) (likely(__range_ok(addr,size) == 0))
 107 #else
 108 static inline int access_ok(int type, const void *addr, unsigned long size)
 109 {
 110         extern unsigned long memory_start, memory_end;
 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.
 160  *
 161  * This macro copies a single simple variable from user space to kernel
 162  * space.  It supports simple types like char and int, but not larger
 163  * data types like structures or arrays.
 164  *
 165  * @ptr must have pointer-to-simple-variable type, and the result of
 166  * dereferencing @ptr must be assignable to @x without a cast.
 167  *
 168  * Returns zero on success, or -EFAULT on error.
 169  * On error, the variable @x is set to zero.
 170  */
 171 #define get_user(x,ptr)                                                 \
 172         __get_user_check((x),(ptr),sizeof(*(ptr)))
 173
 174 /**
 175  * put_user: - Write a simple value into user space.
 176  * @x:   Value to copy to user space.
 177  * @ptr: Destination address, in user space.
 178  *
 179  * Context: User context only.  This function may sleep.
 180  *
 181  * This macro copies a single simple value from kernel space to user
 182  * space.  It supports simple types like char and int, but not larger
 183  * data types like structures or arrays.
 184  *
 185  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 186  * to the result of dereferencing @ptr.
 187  *
 188  * Returns zero on success, or -EFAULT on error.
 189  */
 190 #define put_user(x,ptr)                                                 \
 191         __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
 192
 193 /**
 194  * __get_user: - Get a simple variable from user space, with less checking.
 195  * @x:   Variable to store result.
 196  * @ptr: Source address, in user space.
 197  *
 198  * Context: User context only.  This function may sleep.
 199  *
 200  * This macro copies a single simple variable from user space to kernel
 201  * space.  It supports simple types like char and int, but not larger
 202  * data types like structures or arrays.
 203  *
 204  * @ptr must have pointer-to-simple-variable type, and the result of
 205  * dereferencing @ptr must be assignable to @x without a cast.
 206  *
 207  * Caller must check the pointer with access_ok() before calling this
 208  * function.
 209  *
 210  * Returns zero on success, or -EFAULT on error.
 211  * On error, the variable @x is set to zero.
 212  */
 213 #define __get_user(x,ptr) \
 214         __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
 215
 216 #define __get_user_nocheck(x,ptr,size)                                  \
 217 ({                                                                      \
 218         long __gu_err = 0;                                              \
 219         unsigned long __gu_val;                                         \
 220         might_sleep();                                                  \
 221         __get_user_size(__gu_val,(ptr),(size),__gu_err);                \
 222         (x) = (__typeof__(*(ptr)))__gu_val;                             \
 223         __gu_err;                                                       \
 224 })
 225
 226 #define __get_user_check(x,ptr,size)                                    \
 227 ({                                                                      \
 228         long __gu_err = -EFAULT;                                        \
 229         unsigned long __gu_val = 0;                                     \
 230         const __typeof__(*(ptr)) __user *__gu_addr = (ptr);             \
 231         might_sleep();                                                  \
 232         if (access_ok(VERIFY_READ,__gu_addr,size))                      \
 233                 __get_user_size(__gu_val,__gu_addr,(size),__gu_err);    \
 234         (x) = (__typeof__(*(ptr)))__gu_val;                             \
 235         __gu_err;                                                       \
 236 })
 237
 238 extern long __get_user_bad(void);
 239
 240 #define __get_user_size(x,ptr,size,retval)                              \
 241 do {                                                                    \
 242         retval = 0;                                                     \
 243         __chk_user_ptr(ptr);                                            \
 244         switch (size) {                                                 \
 245           case 1: __get_user_asm(x,ptr,retval,"ub"); break;             \
 246           case 2: __get_user_asm(x,ptr,retval,"uh"); break;             \
 247           case 4: __get_user_asm(x,ptr,retval,""); break;               \
 248           default: (x) = __get_user_bad();                              \
 249         }                                                               \
 250 } while (0)
 251
 252 #define __get_user_asm(x, addr, err, itype)                             \
 253         __asm__ __volatile__(                                           \
 254                 "       .fillinsn\n"                                    \
 255                 "1:     ld"itype" %1,@%2\n"                             \
 256                 "       .fillinsn\n"                                    \
 257                 "2:\n"                                                  \
 258                 ".section .fixup,\"ax\"\n"                              \
 259                 "       .balign 4\n"                                    \
 260                 "3:     ldi %0,%3\n"                                    \
 261                 "       seth r14,#high(2b)\n"                           \
 262                 "       or3 r14,r14,#low(2b)\n"                         \
 263                 "       jmp r14\n"                                      \
 264                 ".previous\n"                                           \
 265                 ".section __ex_table,\"a\"\n"                           \
 266                 "       .balign 4\n"                                    \
 267                 "       .long 1b,3b\n"                                  \
 268                 ".previous"                                             \
 269                 : "=&r" (err), "=&r" (x)                                \
 270                 : "r" (addr), "i" (-EFAULT), "0" (err)                  \
 271                 : "r14", "memory")
 272
 273 /**
 274  * __put_user: - Write a simple value into user space, with less checking.
 275  * @x:   Value to copy to user space.
 276  * @ptr: Destination address, in user space.
 277  *
 278  * Context: User context only.  This function may sleep.
 279  *
 280  * This macro copies a single simple value from kernel space to user
 281  * space.  It supports simple types like char and int, but not larger
 282  * data types like structures or arrays.
 283  *
 284  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 285  * to the result of dereferencing @ptr.
 286  *
 287  * Caller must check the pointer with access_ok() before calling this
 288  * function.
 289  *
 290  * Returns zero on success, or -EFAULT on error.
 291  */
 292 #define __put_user(x,ptr) \
 293         __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
 294
 295
 296 #define __put_user_nocheck(x,ptr,size)                                  \
 297 ({                                                                      \
 298         long __pu_err;                                                  \
 299         might_sleep();                                                  \
 300         __put_user_size((x),(ptr),(size),__pu_err);                     \
 301         __pu_err;                                                       \
 302 })
 303
 304
 305 #define __put_user_check(x,ptr,size)                                    \
 306 ({                                                                      \
 307         long __pu_err = -EFAULT;                                        \
 308         __typeof__(*(ptr)) __user *__pu_addr = (ptr);                   \
 309         might_sleep();                                                  \
 310         if (access_ok(VERIFY_WRITE,__pu_addr,size))                     \
 311                 __put_user_size((x),__pu_addr,(size),__pu_err);         \
 312         __pu_err;                                                       \
 313 })
 314
 315 #if defined(__LITTLE_ENDIAN__)
 316 #define __put_user_u64(x, addr, err)                                    \
 317         __asm__ __volatile__(                                           \
 318                 "       .fillinsn\n"                                    \
 319                 "1:     st %L1,@%2\n"                                   \
 320                 "       .fillinsn\n"                                    \
 321                 "2:     st %H1,@(4,%2)\n"                               \
 322                 "       .fillinsn\n"                                    \
 323                 "3:\n"                                                  \
 324                 ".section .fixup,\"ax\"\n"                              \
 325                 "       .balign 4\n"                                    \
 326                 "4:     ldi %0,%3\n"                                    \
 327                 "       seth r14,#high(3b)\n"                           \
 328                 "       or3 r14,r14,#low(3b)\n"                         \
 329                 "       jmp r14\n"                                      \
 330                 ".previous\n"                                           \
 331                 ".section __ex_table,\"a\"\n"                           \
 332                 "       .balign 4\n"                                    \
 333                 "       .long 1b,4b\n"                                  \
 334                 "       .long 2b,4b\n"                                  \
 335                 ".previous"                                             \
 336                 : "=&r" (err)                                           \
 337                 : "r" (x), "r" (addr), "i" (-EFAULT), "0" (err)         \
 338                 : "r14", "memory")
 339
 340 #elif defined(__BIG_ENDIAN__)
 341 #define __put_user_u64(x, addr, err)                                    \
 342         __asm__ __volatile__(                                           \
 343                 "       .fillinsn\n"                                    \
 344                 "1:     st %H1,@%2\n"                                   \
 345                 "       .fillinsn\n"                                    \
 346                 "2:     st %L1,@(4,%2)\n"                               \
 347                 "       .fillinsn\n"                                    \
 348                 "3:\n"                                                  \
 349                 ".section .fixup,\"ax\"\n"                              \
 350                 "       .balign 4\n"                                    \
 351                 "4:     ldi %0,%3\n"                                    \
 352                 "       seth r14,#high(3b)\n"                           \
 353                 "       or3 r14,r14,#low(3b)\n"                         \
 354                 "       jmp r14\n"                                      \
 355                 ".previous\n"                                           \
 356                 ".section __ex_table,\"a\"\n"                           \
 357                 "       .balign 4\n"                                    \
 358                 "       .long 1b,4b\n"                                  \
 359                 "       .long 2b,4b\n"                                  \
 360                 ".previous"                                             \
 361                 : "=&r" (err)                                           \
 362                 : "r" (x), "r" (addr), "i" (-EFAULT), "0" (err)         \
 363                 : "r14", "memory")
 364 #else
 365 #error no endian defined
 366 #endif
 367
 368 extern void __put_user_bad(void);
 369
 370 #define __put_user_size(x,ptr,size,retval)                              \
 371 do {                                                                    \
 372         retval = 0;                                                     \
 373         __chk_user_ptr(ptr);                                            \
 374         switch (size) {                                                 \
 375           case 1: __put_user_asm(x,ptr,retval,"b"); break;              \
 376           case 2: __put_user_asm(x,ptr,retval,"h"); break;              \
 377           case 4: __put_user_asm(x,ptr,retval,""); break;               \
 378           case 8: __put_user_u64((__typeof__(*ptr))(x),ptr,retval); break;\
 379           default: __put_user_bad();                                    \
 380         }                                                               \
 381 } while (0)
 382
 383 struct __large_struct { unsigned long buf[100]; };
 384 #define __m(x) (*(struct __large_struct *)(x))
 385
 386 /*
 387  * Tell gcc we read from memory instead of writing: this is because
 388  * we do not write to any memory gcc knows about, so there are no
 389  * aliasing issues.
 390  */
 391 #define __put_user_asm(x, addr, err, itype)                             \
 392         __asm__ __volatile__(                                           \
 393                 "       .fillinsn\n"                                    \
 394                 "1:     st"itype" %1,@%2\n"                             \
 395                 "       .fillinsn\n"                                    \
 396                 "2:\n"                                                  \
 397                 ".section .fixup,\"ax\"\n"                              \
 398                 "       .balign 4\n"                                    \
 399                 "3:     ldi %0,%3\n"                                    \
 400                 "       seth r14,#high(2b)\n"                           \
 401                 "       or3 r14,r14,#low(2b)\n"                         \
 402                 "       jmp r14\n"                                      \
 403                 ".previous\n"                                           \
 404                 ".section __ex_table,\"a\"\n"                           \
 405                 "       .balign 4\n"                                    \
 406                 "       .long 1b,3b\n"                                  \
 407                 ".previous"                                             \
 408                 : "=&r" (err)                                           \
 409                 : "r" (x), "r" (addr), "i" (-EFAULT), "0" (err)         \
 410                 : "r14", "memory")
 411
 412 /*
 413  * Here we special-case 1, 2 and 4-byte copy_*_user invocations.  On a fault
 414  * we return the initial request size (1, 2 or 4), as copy_*_user should do.
 415  * If a store crosses a page boundary and gets a fault, the m32r will not write
 416  * anything, so this is accurate.
 417  */
 418
 419 /*
 420  * Copy To/From Userspace
 421  */
 422
 423 /* Generic arbitrary sized copy.  */
 424 /* Return the number of bytes NOT copied.  */
 425 #define __copy_user(to,from,size)                                       \
 426 do {                                                                    \
 427         unsigned long __dst, __src, __c;                                \
 428         __asm__ __volatile__ (                                          \
 429                 "       mv      r14, %0\n"                              \
 430                 "       or      r14, %1\n"                              \
 431                 "       beq     %0, %1, 9f\n"                           \
 432                 "       beqz    %2, 9f\n"                               \
 433                 "       and3    r14, r14, #3\n"                         \
 434                 "       bnez    r14, 2f\n"                              \
 435                 "       and3    %2, %2, #3\n"                           \
 436                 "       beqz    %3, 2f\n"                               \
 437                 "       addi    %0, #-4         ; word_copy \n"         \
 438                 "       .fillinsn\n"                                    \
 439                 "0:     ld      r14, @%1+\n"                            \
 440                 "       addi    %3, #-1\n"                              \
 441                 "       .fillinsn\n"                                    \
 442                 "1:     st      r14, @+%0\n"                            \
 443                 "       bnez    %3, 0b\n"                               \
 444                 "       beqz    %2, 9f\n"                               \
 445                 "       addi    %0, #4\n"                               \
 446                 "       .fillinsn\n"                                    \
 447                 "2:     ldb     r14, @%1        ; byte_copy \n"         \
 448                 "       .fillinsn\n"                                    \
 449                 "3:     stb     r14, @%0\n"                             \
 450                 "       addi    %1, #1\n"                               \
 451                 "       addi    %2, #-1\n"                              \
 452                 "       addi    %0, #1\n"                               \
 453                 "       bnez    %2, 2b\n"                               \
 454                 "       .fillinsn\n"                                    \
 455                 "9:\n"                                                  \
 456                 ".section .fixup,\"ax\"\n"                              \
 457                 "       .balign 4\n"                                    \
 458                 "5:     addi    %3, #1\n"                               \
 459                 "       addi    %1, #-4\n"                              \
 460                 "       .fillinsn\n"                                    \
 461                 "6:     slli    %3, #2\n"                               \
 462                 "       add     %2, %3\n"                               \
 463                 "       addi    %0, #4\n"                               \
 464                 "       .fillinsn\n"                                    \
 465                 "7:     seth    r14, #high(9b)\n"                       \
 466                 "       or3     r14, r14, #low(9b)\n"                   \
 467                 "       jmp     r14\n"                                  \
 468                 ".previous\n"                                           \
 469                 ".section __ex_table,\"a\"\n"                           \
 470                 "       .balign 4\n"                                    \
 471                 "       .long 0b,6b\n"                                  \
 472                 "       .long 1b,5b\n"                                  \
 473                 "       .long 2b,9b\n"                                  \
 474                 "       .long 3b,9b\n"                                  \
 475                 ".previous\n"                                           \
 476                 : "=&r" (__dst), "=&r" (__src), "=&r" (size),           \
 477                   "=&r" (__c)                                           \
 478                 : "0" (to), "1" (from), "2" (size), "3" (size / 4)      \
 479                 : "r14", "memory");                                     \
 480 } while (0)
 481
 482 #define __copy_user_zeroing(to,from,size)                               \
 483 do {                                                                    \
 484         unsigned long __dst, __src, __c;                                \
 485         __asm__ __volatile__ (                                          \
 486                 "       mv      r14, %0\n"                              \
 487                 "       or      r14, %1\n"                              \
 488                 "       beq     %0, %1, 9f\n"                           \
 489                 "       beqz    %2, 9f\n"                               \
 490                 "       and3    r14, r14, #3\n"                         \
 491                 "       bnez    r14, 2f\n"                              \
 492                 "       and3    %2, %2, #3\n"                           \
 493                 "       beqz    %3, 2f\n"                               \
 494                 "       addi    %0, #-4         ; word_copy \n"         \
 495                 "       .fillinsn\n"                                    \
 496                 "0:     ld      r14, @%1+\n"                            \
 497                 "       addi    %3, #-1\n"                              \
 498                 "       .fillinsn\n"                                    \
 499                 "1:     st      r14, @+%0\n"                            \
 500                 "       bnez    %3, 0b\n"                               \
 501                 "       beqz    %2, 9f\n"                               \
 502                 "       addi    %0, #4\n"                               \
 503                 "       .fillinsn\n"                                    \
 504                 "2:     ldb     r14, @%1        ; byte_copy \n"         \
 505                 "       .fillinsn\n"                                    \
 506                 "3:     stb     r14, @%0\n"                             \
 507                 "       addi    %1, #1\n"                               \
 508                 "       addi    %2, #-1\n"                              \
 509                 "       addi    %0, #1\n"                               \
 510                 "       bnez    %2, 2b\n"                               \
 511                 "       .fillinsn\n"                                    \
 512                 "9:\n"                                                  \
 513                 ".section .fixup,\"ax\"\n"                              \
 514                 "       .balign 4\n"                                    \
 515                 "5:     addi    %3, #1\n"                               \
 516                 "       addi    %1, #-4\n"                              \
 517                 "       .fillinsn\n"                                    \
 518                 "6:     slli    %3, #2\n"                               \
 519                 "       add     %2, %3\n"                               \
 520                 "       addi    %0, #4\n"                               \
 521                 "       .fillinsn\n"                                    \
 522                 "7:     ldi     r14, #0         ; store zero \n"        \
 523                 "       .fillinsn\n"                                    \
 524                 "8:     addi    %2, #-1\n"                              \
 525                 "       stb     r14, @%0        ; ACE? \n"              \
 526                 "       addi    %0, #1\n"                               \
 527                 "       bnez    %2, 8b\n"                               \
 528                 "       seth    r14, #high(9b)\n"                       \
 529                 "       or3     r14, r14, #low(9b)\n"                   \
 530                 "       jmp     r14\n"                                  \
 531                 ".previous\n"                                           \
 532                 ".section __ex_table,\"a\"\n"                           \
 533                 "       .balign 4\n"                                    \
 534                 "       .long 0b,6b\n"                                  \
 535                 "       .long 1b,5b\n"                                  \
 536                 "       .long 2b,7b\n"                                  \
 537                 "       .long 3b,7b\n"                                  \
 538                 ".previous\n"                                           \
 539                 : "=&r" (__dst), "=&r" (__src), "=&r" (size),           \
 540                   "=&r" (__c)                                           \
 541                 : "0" (to), "1" (from), "2" (size), "3" (size / 4)      \
 542                 : "r14", "memory");                                     \
 543 } while (0)
 544
 545
 546 /* We let the __ versions of copy_from/to_user inline, because they're often
 547  * used in fast paths and have only a small space overhead.
 548  */
 549 static inline unsigned long __generic_copy_from_user_nocheck(void *to,
 550         const void __user *from, unsigned long n)
 551 {
 552         __copy_user_zeroing(to,from,n);
 553         return n;
 554 }
 555
 556 static inline unsigned long __generic_copy_to_user_nocheck(void __user *to,
 557         const void *from, unsigned long n)
 558 {
 559         __copy_user(to,from,n);
 560         return n;
 561 }
 562
 563 unsigned long __generic_copy_to_user(void __user *, const void *, unsigned long);
 564 unsigned long __generic_copy_from_user(void *, const void __user *, unsigned long);
 565
 566 /**
 567  * __copy_to_user: - Copy a block of data into user space, with less checking.
 568  * @to:   Destination address, in user space.
 569  * @from: Source address, in kernel space.
 570  * @n:    Number of bytes to copy.
 571  *
 572  * Context: User context only.  This function may sleep.
 573  *
 574  * Copy data from kernel space to user space.  Caller must check
 575  * the specified block with access_ok() before calling this function.
 576  *
 577  * Returns number of bytes that could not be copied.
 578  * On success, this will be zero.
 579  */
 580 #define __copy_to_user(to,from,n)                       \
 581         __generic_copy_to_user_nocheck((to),(from),(n))
 582
 583 #define __copy_to_user_inatomic __copy_to_user
 584 #define __copy_from_user_inatomic __copy_from_user
 585
 586 /**
 587  * copy_to_user: - Copy a block of data into user space.
 588  * @to:   Destination address, in user space.
 589  * @from: Source address, in kernel space.
 590  * @n:    Number of bytes to copy.
 591  *
 592  * Context: User context only.  This function may sleep.
 593  *
 594  * Copy data from kernel space to user space.
 595  *
 596  * Returns number of bytes that could not be copied.
 597  * On success, this will be zero.
 598  */
 599 #define copy_to_user(to,from,n)                         \
 600 ({                                                      \
 601         might_sleep();                                  \
 602         __generic_copy_to_user((to),(from),(n));        \
 603 })
 604
 605 /**
 606  * __copy_from_user: - Copy a block of data from user space, with less checking. * @to:   Destination address, in kernel space.
 607  * @from: Source address, in user space.
 608  * @n:    Number of bytes to copy.
 609  *
 610  * Context: User context only.  This function may sleep.
 611  *
 612  * Copy data from user space to kernel space.  Caller must check
 613  * the specified block with access_ok() before calling this function.
 614  *
 615  * Returns number of bytes that could not be copied.
 616  * On success, this will be zero.
 617  *
 618  * If some data could not be copied, this function will pad the copied
 619  * data to the requested size using zero bytes.
 620  */
 621 #define __copy_from_user(to,from,n)                     \
 622         __generic_copy_from_user_nocheck((to),(from),(n))
 623
 624 /**
 625  * copy_from_user: - Copy a block of data from user space.
 626  * @to:   Destination address, in kernel space.
 627  * @from: Source address, in user space.
 628  * @n:    Number of bytes to copy.
 629  *
 630  * Context: User context only.  This function may sleep.
 631  *
 632  * Copy data from user space to kernel space.
 633  *
 634  * Returns number of bytes that could not be copied.
 635  * On success, this will be zero.
 636  *
 637  * If some data could not be copied, this function will pad the copied
 638  * data to the requested size using zero bytes.
 639  */
 640 #define copy_from_user(to,from,n)                       \
 641 ({                                                      \
 642         might_sleep();                                  \
 643         __generic_copy_from_user((to),(from),(n));      \
 644 })
 645
 646 long __must_check strncpy_from_user(char *dst, const char __user *src,
 647                                 long count);
 648 long __must_check __strncpy_from_user(char *dst,
 649                                 const char __user *src, long count);
 650
 651 /**
 652  * __clear_user: - Zero a block of memory in user space, with less checking.
 653  * @to:   Destination address, in user space.
 654  * @n:    Number of bytes to zero.
 655  *
 656  * Zero a block of memory in user space.  Caller must check
 657  * the specified block with access_ok() before calling this function.
 658  *
 659  * Returns number of bytes that could not be cleared.
 660  * On success, this will be zero.
 661  */
 662 unsigned long __clear_user(void __user *mem, unsigned long len);
 663
 664 /**
 665  * clear_user: - Zero a block of memory in user space.
 666  * @to:   Destination address, in user space.
 667  * @n:    Number of bytes to zero.
 668  *
 669  * Zero a block of memory in user space.  Caller must check
 670  * the specified block with access_ok() before calling this function.
 671  *
 672  * Returns number of bytes that could not be cleared.
 673  * On success, this will be zero.
 674  */
 675 unsigned long clear_user(void __user *mem, unsigned long len);
 676
 677 /**
 678  * strlen_user: - Get the size of a string in user space.
 679  * @str: The string to measure.
 680  *
 681  * Context: User context only.  This function may sleep.
 682  *
 683  * Get the size of a NUL-terminated string in user space.
 684  *
 685  * Returns the size of the string INCLUDING the terminating NUL.
 686  * On exception, returns 0.
 687  *
 688  * If there is a limit on the length of a valid string, you may wish to
 689  * consider using strnlen_user() instead.
 690  */
 691 #define strlen_user(str) strnlen_user(str, ~0UL >> 1)
 692 long strnlen_user(const char __user *str, long n);
 693
 694 #endif /* _ASM_M32R_UACCESS_H */