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 #define access_ok(type,addr,size)       _access_ok((unsigned long)(addr),(size))
  17
  18 static inline int _access_ok(unsigned long addr, unsigned long size)
  19 {
  20         extern unsigned long memory_start, memory_end;
  21
  22         return (((addr >= memory_start) && (addr+size < memory_end)) ||
  23                 (is_in_rom(addr) && is_in_rom(addr+size)));
  24 }
  25
  26 /* this function will go away soon - use access_ok() instead */
  27 extern inline int __deprecated verify_area(int type, const void * addr, unsigned long size)
  28 {
  29         return access_ok(type,addr,size)?0:-EFAULT;
  30 }
  31
  32 /*
  33  * The exception table consists of pairs of addresses: the first is the
  34  * address of an instruction that is allowed to fault, and the second is
  35  * the address at which the program should continue.  No registers are
  36  * modified, so it is entirely up to the continuation code to figure out
  37  * what to do.
  38  *
  39  * All the routines below use bits of fixup code that are out of line
  40  * with the main instruction path.  This means when everything is well,
  41  * we don't even have to jump over them.  Further, they do not intrude
  42  * on our cache or tlb entries.
  43  */
  44
  45 struct exception_table_entry
  46 {
  47         unsigned long insn, fixup;
  48 };
  49
  50 /* Returns 0 if exception not found and fixup otherwise.  */
  51 extern unsigned long search_exception_table(unsigned long);
  52
  53
  54 /*
  55  * These are the main single-value transfer routines.  They automatically
  56  * use the right size if we just have the right pointer type.
  57  */
  58
  59 #define put_user(x, ptr)                                \
  60 ({                                                      \
  61     int __pu_err = 0;                                   \
  62     typeof(*(ptr)) __pu_val = (x);                      \
  63     switch (sizeof (*(ptr))) {                          \
  64     case 1:                                             \
  65         __put_user_asm(__pu_err, __pu_val, ptr, b);     \
  66         break;                                          \
  67     case 2:                                             \
  68         __put_user_asm(__pu_err, __pu_val, ptr, w);     \
  69         break;                                          \
  70     case 4:                                             \
  71         __put_user_asm(__pu_err, __pu_val, ptr, l);     \
  72         break;                                          \
  73     case 8:                                             \
  74         memcpy(ptr, &__pu_val, sizeof (*(ptr))); \
  75         break;                                          \
  76     default:                                            \
  77         __pu_err = __put_user_bad();                    \
  78         break;                                          \
  79     }                                                   \
  80     __pu_err;                                           \
  81 })
  82 #define __put_user(x, ptr) put_user(x, ptr)
  83
  84 extern int __put_user_bad(void);
  85
  86 /*
  87  * Tell gcc we read from memory instead of writing: this is because
  88  * we do not write to any memory gcc knows about, so there are no
  89  * aliasing issues.
  90  */
  91
  92 #define __ptr(x) ((unsigned long *)(x))
  93
  94 #define __put_user_asm(err,x,ptr,bwl)                           \
  95         __asm__ ("move" #bwl " %0,%1"                           \
  96                 : /* no outputs */                                              \
  97                 :"d" (x),"m" (*__ptr(ptr)) : "memory")
  98
  99 #define get_user(x, ptr)                                        \
 100 ({                                                              \
 101     int __gu_err = 0;                                           \
 102     typeof(*(ptr)) __gu_val = 0;                                \
 103     switch (sizeof(*(ptr))) {                                   \
 104     case 1:                                                     \
 105         __get_user_asm(__gu_err, __gu_val, ptr, b, "=d");       \
 106         break;                                                  \
 107     case 2:                                                     \
 108         __get_user_asm(__gu_err, __gu_val, ptr, w, "=r");       \
 109         break;                                                  \
 110     case 4:                                                     \
 111         __get_user_asm(__gu_err, __gu_val, ptr, l, "=r");       \
 112         break;                                                  \
 113     case 8:                                                     \
 114         memcpy(&__gu_val, ptr, sizeof (*(ptr))); \
 115         break;                                                  \
 116     default:                                                    \
 117         __gu_val = 0;                                           \
 118         __gu_err = __get_user_bad();                            \
 119         break;                                                  \
 120     }                                                           \
 121     (x) = __gu_val;                                             \
 122     __gu_err;                                                   \
 123 })
 124 #define __get_user(x, ptr) get_user(x, ptr)
 125
 126 extern int __get_user_bad(void);
 127
 128 #define __get_user_asm(err,x,ptr,bwl,reg)       \
 129         __asm__ ("move" #bwl " %1,%0"                   \
 130                  : "=d" (x)                                                     \
 131                  : "m" (*__ptr(ptr)))
 132
 133 #define copy_from_user(to, from, n)             (memcpy(to, from, n), 0)
 134 #define copy_to_user(to, from, n)               (memcpy(to, from, n), 0)
 135
 136 #define __copy_from_user(to, from, n) copy_from_user(to, from, n)
 137 #define __copy_to_user(to, from, n) copy_to_user(to, from, n)
 138 #define __copy_to_user_inatomic __copy_to_user
 139 #define __copy_from_user_inatomic __copy_from_user
 140
 141 #define copy_to_user_ret(to,from,n,retval) ({ if (copy_to_user(to,from,n)) return retval; })
 142
 143 #define copy_from_user_ret(to,from,n,retval) ({ if (copy_from_user(to,from,n)) return retval; })
 144
 145 /*
 146  * Copy a null terminated string from userspace.
 147  */
 148
 149 static inline long
 150 strncpy_from_user(char *dst, const char *src, long count)
 151 {
 152         char *tmp;
 153         strncpy(dst, src, count);
 154         for (tmp = dst; *tmp && count > 0; tmp++, count--)
 155                 ;
 156         return(tmp - dst); /* DAVIDM should we count a NUL ?  check getname */
 157 }
 158
 159 /*
 160  * Return the size of a string (including the ending 0)
 161  *
 162  * Return 0 on exception, a value greater than N if too long
 163  */
 164 static inline long strnlen_user(const char *src, long n)
 165 {
 166         return(strlen(src) + 1); /* DAVIDM make safer */
 167 }
 168
 169 #define strlen_user(str) strnlen_user(str, 32767)
 170
 171 /*
 172  * Zero Userspace
 173  */
 174
 175 static inline unsigned long
 176 clear_user(void *to, unsigned long n)
 177 {
 178         memset(to, 0, n);
 179         return 0;
 180 }
 181
 182 #endif /* _M68KNOMMU_UACCESS_H */