linux/arch/h8300/include/asm/uaccess.h
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   1#ifndef __H8300_UACCESS_H
   2#define __H8300_UACCESS_H
   3
   4/*
   5 * User space memory access functions
   6 */
   7#include <linux/sched.h>
   8#include <linux/mm.h>
   9#include <linux/string.h>
  10
  11#include <asm/segment.h>
  12
  13#define VERIFY_READ     0
  14#define VERIFY_WRITE    1
  15
  16/* We let the MMU do all checking */
  17#define access_ok(type, addr, size) __access_ok((unsigned long)addr,size)
  18static inline int __access_ok(unsigned long addr, unsigned long size)
  19{
  20#define RANGE_CHECK_OK(addr, size, lower, upper) \
  21        (((addr) >= (lower)) && (((addr) + (size)) < (upper)))
  22
  23        extern unsigned long _ramend;
  24        return(RANGE_CHECK_OK(addr, size, 0L, (unsigned long)&_ramend));
  25}
  26
  27/*
  28 * The exception table consists of pairs of addresses: the first is the
  29 * address of an instruction that is allowed to fault, and the second is
  30 * the address at which the program should continue.  No registers are
  31 * modified, so it is entirely up to the continuation code to figure out
  32 * what to do.
  33 *
  34 * All the routines below use bits of fixup code that are out of line
  35 * with the main instruction path.  This means when everything is well,
  36 * we don't even have to jump over them.  Further, they do not intrude
  37 * on our cache or tlb entries.
  38 */
  39
  40struct exception_table_entry
  41{
  42        unsigned long insn, fixup;
  43};
  44
  45/* Returns 0 if exception not found and fixup otherwise.  */
  46extern unsigned long search_exception_table(unsigned long);
  47
  48
  49/*
  50 * These are the main single-value transfer routines.  They automatically
  51 * use the right size if we just have the right pointer type.
  52 */
  53
  54#define put_user(x, ptr)                                \
  55({                                                      \
  56    int __pu_err = 0;                                   \
  57    typeof(*(ptr)) __pu_val = (x);                      \
  58    switch (sizeof (*(ptr))) {                          \
  59    case 1:                                             \
  60    case 2:                                             \
  61    case 4:                                             \
  62        *(ptr) = (__pu_val);                            \
  63        break;                                          \
  64    case 8:                                             \
  65        memcpy(ptr, &__pu_val, sizeof (*(ptr)));        \
  66        break;                                          \
  67    default:                                            \
  68        __pu_err = __put_user_bad();                    \
  69        break;                                          \
  70    }                                                   \
  71    __pu_err;                                           \
  72})
  73#define __put_user(x, ptr) put_user(x, ptr)
  74
  75extern int __put_user_bad(void);
  76
  77/*
  78 * Tell gcc we read from memory instead of writing: this is because
  79 * we do not write to any memory gcc knows about, so there are no
  80 * aliasing issues.
  81 */
  82
  83#define __ptr(x) ((unsigned long *)(x))
  84
  85/*
  86 * Tell gcc we read from memory instead of writing: this is because
  87 * we do not write to any memory gcc knows about, so there are no
  88 * aliasing issues.
  89 */
  90
  91#define get_user(x, ptr)                                        \
  92({                                                              \
  93    int __gu_err = 0;                                           \
  94    typeof(*(ptr)) __gu_val = *ptr;                             \
  95    switch (sizeof(*(ptr))) {                                   \
  96    case 1:                                                     \
  97    case 2:                                                     \
  98    case 4:                                                     \
  99    case 8:                                                     \
 100        break;                                                  \
 101    default:                                                    \
 102        __gu_err = __get_user_bad();                            \
 103        __gu_val = 0;                                           \
 104        break;                                                  \
 105    }                                                           \
 106    (x) = __gu_val;                                             \
 107    __gu_err;                                                   \
 108})
 109#define __get_user(x, ptr) get_user(x, ptr)
 110
 111extern int __get_user_bad(void);
 112
 113#define copy_from_user(to, from, n)             (memcpy(to, from, n), 0)
 114#define copy_to_user(to, from, n)               (memcpy(to, from, n), 0)
 115
 116#define __copy_from_user(to, from, n) copy_from_user(to, from, n)
 117#define __copy_to_user(to, from, n) copy_to_user(to, from, n)
 118#define __copy_to_user_inatomic __copy_to_user
 119#define __copy_from_user_inatomic __copy_from_user
 120
 121#define copy_to_user_ret(to,from,n,retval) ({ if (copy_to_user(to,from,n)) return retval; })
 122
 123#define copy_from_user_ret(to,from,n,retval) ({ if (copy_from_user(to,from,n)) return retval; })
 124
 125/*
 126 * Copy a null terminated string from userspace.
 127 */
 128
 129static inline long
 130strncpy_from_user(char *dst, const char *src, long count)
 131{
 132        char *tmp;
 133        strncpy(dst, src, count);
 134        for (tmp = dst; *tmp && count > 0; tmp++, count--)
 135                ;
 136        return(tmp - dst); /* DAVIDM should we count a NUL ?  check getname */
 137}
 138
 139/*
 140 * Return the size of a string (including the ending 0)
 141 *
 142 * Return 0 on exception, a value greater than N if too long
 143 */
 144static inline long strnlen_user(const char *src, long n)
 145{
 146        return(strlen(src) + 1); /* DAVIDM make safer */
 147}
 148
 149#define strlen_user(str) strnlen_user(str, 32767)
 150
 151/*
 152 * Zero Userspace
 153 */
 154
 155static inline unsigned long
 156clear_user(void *to, unsigned long n)
 157{
 158        memset(to, 0, n);
 159        return 0;
 160}
 161
 162#endif /* _H8300_UACCESS_H */
 163
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