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