include/asm-v850/uaccess.h

   1 #ifndef __V850_UACCESS_H__
   2 #define __V850_UACCESS_H__
   3
   4 /*
   5  * User space memory access functions
   6  */
   7
   8 #include <linux/errno.h>
   9 #include <linux/string.h>
  10
  11 #include <asm/segment.h>
  12 #include <asm/machdep.h>
  13
  14 #define VERIFY_READ     0
  15 #define VERIFY_WRITE    1
  16
  17 extern inline int access_ok (int type, const void *addr, unsigned long size)
  18 {
  19         /* XXX I guess we should check against real ram bounds at least, and
  20            possibly make sure ADDR is not within the kernel.
  21            For now we just check to make sure it's not a small positive
  22            or negative value, as that will at least catch some kinds of
  23            error.  In particular, we make sure that ADDR's not within the
  24            interrupt vector area, which we know starts at zero, or within the
  25            peripheral-I/O area, which is located just _before_ zero.  */
  26         unsigned long val = (unsigned long)addr;
  27         return val >= (0x80 + NUM_CPU_IRQS*16) && val < 0xFFFFF000;
  28 }
  29
  30 extern inline int verify_area (int type, const void *addr, unsigned long size)
  31 {
  32         return access_ok (type, addr, size) ? 0 : -EFAULT;
  33 }
  34
  35 /*
  36  * The exception table consists of pairs of addresses: the first is the
  37  * address of an instruction that is allowed to fault, and the second is
  38  * the address at which the program should continue.  No registers are
  39  * modified, so it is entirely up to the continuation code to figure out
  40  * what to do.
  41  *
  42  * All the routines below use bits of fixup code that are out of line
  43  * with the main instruction path.  This means when everything is well,
  44  * we don't even have to jump over them.  Further, they do not intrude
  45  * on our cache or tlb entries.
  46  */
  47
  48 struct exception_table_entry
  49 {
  50         unsigned long insn, fixup;
  51 };
  52
  53 /* Returns 0 if exception not found and fixup otherwise.  */
  54 extern unsigned long search_exception_table (unsigned long);
  55
  56
  57 /*
  58  * These are the main single-value transfer routines.  They automatically
  59  * use the right size if we just have the right pointer type.
  60  */
  61
  62 extern int bad_user_access_length (void);
  63
  64 #define __get_user(var, ptr)                                                  \
  65   ({                                                                          \
  66           int __gu_err = 0;                                                   \
  67           typeof(*(ptr)) __gu_val = 0;                                        \
  68           switch (sizeof (*(ptr))) {                                          \
  69           case 1:                                                             \
  70           case 2:                                                             \
  71           case 4:                                                             \
  72                   __gu_val = *(ptr);                                          \
  73                   break;                                                      \
  74           case 8:                                                             \
  75                   memcpy(&__gu_val, ptr, sizeof(__gu_val));                   \
  76                   break;                                                      \
  77           default:                                                            \
  78                   __gu_val = 0;                                               \
  79                   __gu_err = __get_user_bad ();                               \
  80                   break;                                                      \
  81           }                                                                   \
  82           (var) = __gu_val;                                                   \
  83           __gu_err;                                                           \
  84   })
  85 #define __get_user_bad()        (bad_user_access_length (), (-EFAULT))
  86
  87 #define __put_user(var, ptr)                                                  \
  88   ({                                                                          \
  89           int __pu_err = 0;                                                   \
  90           switch (sizeof (*(ptr))) {                                          \
  91           case 1:                                                             \
  92           case 2:                                                             \
  93           case 4:                                                             \
  94                   *(ptr) = (var);                                             \
  95                   break;                                                      \
  96           case 8: {                                                           \
  97                   typeof(*(ptr)) __pu_val = 0;                                \
  98                   memcpy(ptr, &__pu_val, sizeof(__pu_val));                   \
  99                   }                                                           \
 100                   break;                                                      \
 101           default:                                                            \
 102                   __pu_err = __put_user_bad ();                               \
 103                   break;                                                      \
 104           }                                                                   \
 105           __pu_err;                                                           \
 106   })
 107 #define __put_user_bad()        (bad_user_access_length (), (-EFAULT))
 108
 109 #define put_user(x, ptr)        __put_user(x, ptr)
 110 #define get_user(x, ptr)        __get_user(x, ptr)
 111
 112 #define __copy_from_user(to, from, n)   (memcpy (to, from, n), 0)
 113 #define __copy_to_user(to, from, n)     (memcpy(to, from, n), 0)
 114
 115 #define __copy_to_user_inatomic __copy_to_user
 116 #define __copy_from_user_inatomic __copy_from_user
 117
 118 #define copy_from_user(to, from, n)     __copy_from_user (to, from, n)
 119 #define copy_to_user(to, from, n)       __copy_to_user(to, from, n)
 120
 121 #define copy_to_user_ret(to,from,n,retval) \
 122   ({ if (copy_to_user (to,from,n)) return retval; })
 123
 124 #define copy_from_user_ret(to,from,n,retval) \
 125   ({ if (copy_from_user (to,from,n)) return retval; })
 126
 127 /*
 128  * Copy a null terminated string from userspace.
 129  */
 130
 131 static inline long
 132 strncpy_from_user (char *dst, const char *src, long count)
 133 {
 134         char *tmp;
 135         strncpy (dst, src, count);
 136         for (tmp = dst; *tmp && count > 0; tmp++, count--)
 137                 ;
 138         return tmp - dst;
 139 }
 140
 141 /*
 142  * Return the size of a string (including the ending 0)
 143  *
 144  * Return 0 on exception, a value greater than N if too long
 145  */
 146 static inline long strnlen_user (const char *src, long n)
 147 {
 148         return strlen (src) + 1;
 149 }
 150
 151 #define strlen_user(str)        strnlen_user (str, 32767)
 152
 153 /*
 154  * Zero Userspace
 155  */
 156
 157 static inline unsigned long
 158 clear_user (void *to, unsigned long n)
 159 {
 160         memset (to, 0, n);
 161         return 0;
 162 }
 163
 164 #endif /* __V850_UACCESS_H__ */