include/asm-m68knommu/uaccess.h

   1 #ifndef __M68KNOMMU_UACCESS_H
   2 #define __M68KNOMMU_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 extern inline int access_ok(int type, const void * addr, unsigned long size)
  18 {
  19 #define RANGE_CHECK_OK(addr, size, lower, upper) \
  20         (((addr) >= (lower)) && (((addr) + (size)) < (upper)))
  21
  22 #ifdef CONFIG_COLDFIRE
  23         extern unsigned long _ramend;
  24         return(RANGE_CHECK_OK((unsigned long) addr, size, 0L, _ramend) ||
  25                         (is_in_rom((unsigned long) addr) &&
  26                                         is_in_rom((unsigned long) addr + size)));
  27 #else
  28         /* DAVIDM - this could be restricted a lot more */
  29         return(RANGE_CHECK_OK((unsigned long)addr, size, 0, 0x10f00000));
  30 #endif
  31 }
  32
  33 extern inline int verify_area(int type, const void * addr, unsigned long size)
  34 {
  35         return access_ok(type,addr,size)?0:-EFAULT;
  36 }
  37
  38 /*
  39  * The exception table consists of pairs of addresses: the first is the
  40  * address of an instruction that is allowed to fault, and the second is
  41  * the address at which the program should continue.  No registers are
  42  * modified, so it is entirely up to the continuation code to figure out
  43  * what to do.
  44  *
  45  * All the routines below use bits of fixup code that are out of line
  46  * with the main instruction path.  This means when everything is well,
  47  * we don't even have to jump over them.  Further, they do not intrude
  48  * on our cache or tlb entries.
  49  */
  50
  51 struct exception_table_entry
  52 {
  53         unsigned long insn, fixup;
  54 };
  55
  56 /* Returns 0 if exception not found and fixup otherwise.  */
  57 extern unsigned long search_exception_table(unsigned long);
  58
  59
  60 /*
  61  * These are the main single-value transfer routines.  They automatically
  62  * use the right size if we just have the right pointer type.
  63  */
  64
  65 #define put_user(x, ptr)                                \
  66 ({                                                      \
  67     int __pu_err = 0;                                   \
  68     typeof(*(ptr)) __pu_val = (x);                      \
  69     switch (sizeof (*(ptr))) {                          \
  70     case 1:                                             \
  71         __put_user_asm(__pu_err, __pu_val, ptr, b);     \
  72         break;                                          \
  73     case 2:                                             \
  74         __put_user_asm(__pu_err, __pu_val, ptr, w);     \
  75         break;                                          \
  76     case 4:                                             \
  77         __put_user_asm(__pu_err, __pu_val, ptr, l);     \
  78         break;                                          \
  79     case 8:                                             \
  80         memcpy(ptr, &__pu_val, sizeof (*(ptr))); \
  81         break;                                          \
  82     default:                                            \
  83         __pu_err = __put_user_bad();                    \
  84         break;                                          \
  85     }                                                   \
  86     __pu_err;                                           \
  87 })
  88 #define __put_user(x, ptr) put_user(x, ptr)
  89
  90 extern int __put_user_bad(void);
  91
  92 /*
  93  * Tell gcc we read from memory instead of writing: this is because
  94  * we do not write to any memory gcc knows about, so there are no
  95  * aliasing issues.
  96  */
  97
  98 #define __ptr(x) ((unsigned long *)(x))
  99
 100 #define __put_user_asm(err,x,ptr,bwl)                           \
 101         __asm__ ("move" #bwl " %0,%1"                           \
 102                 : /* no outputs */                                              \
 103                 :"d" (x),"m" (*__ptr(ptr)) : "memory")
 104
 105 #define get_user(x, ptr)                                        \
 106 ({                                                              \
 107     int __gu_err = 0;                                           \
 108     typeof(*(ptr)) __gu_val = 0;                                \
 109     switch (sizeof(*(ptr))) {                                   \
 110     case 1:                                                     \
 111         __get_user_asm(__gu_err, __gu_val, ptr, b, "=d");       \
 112         break;                                                  \
 113     case 2:                                                     \
 114         __get_user_asm(__gu_err, __gu_val, ptr, w, "=r");       \
 115         break;                                                  \
 116     case 4:                                                     \
 117         __get_user_asm(__gu_err, __gu_val, ptr, l, "=r");       \
 118         break;                                                  \
 119     case 8:                                                     \
 120         memcpy(&__gu_val, ptr, sizeof (*(ptr))); \
 121         break;                                                  \
 122     default:                                                    \
 123         __gu_val = 0;                                           \
 124         __gu_err = __get_user_bad();                            \
 125         break;                                                  \
 126     }                                                           \
 127     (x) = __gu_val;                                             \
 128     __gu_err;                                                   \
 129 })
 130 #define __get_user(x, ptr) get_user(x, ptr)
 131
 132 extern int __get_user_bad(void);
 133
 134 #define __get_user_asm(err,x,ptr,bwl,reg)       \
 135         __asm__ ("move" #bwl " %1,%0"                   \
 136                  : "=d" (x)                                                     \
 137                  : "m" (*__ptr(ptr)))
 138
 139 #define copy_from_user(to, from, n)             (memcpy(to, from, n), 0)
 140 #define copy_to_user(to, from, n)               (memcpy(to, from, n), 0)
 141
 142 #define __copy_from_user(to, from, n) copy_from_user(to, from, n)
 143 #define __copy_to_user(to, from, n) copy_to_user(to, from, n)
 144
 145 #define copy_to_user_ret(to,from,n,retval) ({ if (copy_to_user(to,from,n)) return retval; })
 146
 147 #define copy_from_user_ret(to,from,n,retval) ({ if (copy_from_user(to,from,n)) return retval; })
 148
 149 /*
 150  * Copy a null terminated string from userspace.
 151  */
 152
 153 static inline long
 154 strncpy_from_user(char *dst, const char *src, long count)
 155 {
 156         char *tmp;
 157         strncpy(dst, src, count);
 158         for (tmp = dst; *tmp && count > 0; tmp++, count--)
 159                 ;
 160         return(tmp - dst); /* DAVIDM should we count a NUL ?  check getname */
 161 }
 162
 163 /*
 164  * Return the size of a string (including the ending 0)
 165  *
 166  * Return 0 on exception, a value greater than N if too long
 167  */
 168 static inline long strnlen_user(const char *src, long n)
 169 {
 170         return(strlen(src) + 1); /* DAVIDM make safer */
 171 }
 172
 173 #define strlen_user(str) strnlen_user(str, 32767)
 174
 175 /*
 176  * Zero Userspace
 177  */
 178
 179 static inline unsigned long
 180 clear_user(void *to, unsigned long n)
 181 {
 182         memset(to, 0, n);
 183         return 0;
 184 }
 185
 186 #endif /* _M68KNOMMU_UACCESS_H */