arch/m68k/include/asm/uaccess_no.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __M68KNOMMU_UACCESS_H
   3 #define __M68KNOMMU_UACCESS_H
   4
   5 /*
   6  * User space memory access functions
   7  */
   8 #include <linux/mm.h>
   9 #include <linux/string.h>
  10
  11 #include <asm/segment.h>
  12
  13 #define access_ok(addr,size)    _access_ok((unsigned long)(addr),(size))
  14
  15 /*
  16  * It is not enough to just have access_ok check for a real RAM address.
  17  * This would disallow the case of code/ro-data running XIP in flash/rom.
  18  * Ideally we would check the possible flash ranges too, but that is
  19  * currently not so easy.
  20  */
  21 static inline int _access_ok(unsigned long addr, unsigned long size)
  22 {
  23         return 1;
  24 }
  25
  26 /*
  27  * These are the main single-value transfer routines.  They automatically
  28  * use the right size if we just have the right pointer type.
  29  */
  30
  31 #define put_user(x, ptr)                                \
  32 ({                                                      \
  33     int __pu_err = 0;                                   \
  34     typeof(*(ptr)) __pu_val = (x);                      \
  35     switch (sizeof (*(ptr))) {                          \
  36     case 1:                                             \
  37         __put_user_asm(__pu_err, __pu_val, ptr, b);     \
  38         break;                                          \
  39     case 2:                                             \
  40         __put_user_asm(__pu_err, __pu_val, ptr, w);     \
  41         break;                                          \
  42     case 4:                                             \
  43         __put_user_asm(__pu_err, __pu_val, ptr, l);     \
  44         break;                                          \
  45     case 8:                                             \
  46         memcpy(ptr, &__pu_val, sizeof (*(ptr))); \
  47         break;                                          \
  48     default:                                            \
  49         __pu_err = __put_user_bad();                    \
  50         break;                                          \
  51     }                                                   \
  52     __pu_err;                                           \
  53 })
  54 #define __put_user(x, ptr) put_user(x, ptr)
  55
  56 extern int __put_user_bad(void);
  57
  58 /*
  59  * Tell gcc we read from memory instead of writing: this is because
  60  * we do not write to any memory gcc knows about, so there are no
  61  * aliasing issues.
  62  */
  63
  64 #define __ptr(x) ((unsigned long *)(x))
  65
  66 #define __put_user_asm(err,x,ptr,bwl)                           \
  67         __asm__ ("move" #bwl " %0,%1"                           \
  68                 : /* no outputs */                                              \
  69                 :"d" (x),"m" (*__ptr(ptr)) : "memory")
  70
  71 #define get_user(x, ptr)                                        \
  72 ({                                                              \
  73     int __gu_err = 0;                                           \
  74     switch (sizeof(*(ptr))) {                                   \
  75     case 1:                                                     \
  76         __get_user_asm(__gu_err, x, ptr, b, "=d");              \
  77         break;                                                  \
  78     case 2:                                                     \
  79         __get_user_asm(__gu_err, x, ptr, w, "=r");              \
  80         break;                                                  \
  81     case 4:                                                     \
  82         __get_user_asm(__gu_err, x, ptr, l, "=r");              \
  83         break;                                                  \
  84     case 8: {                                                   \
  85         union {                                                 \
  86             u64 l;                                              \
  87             __typeof__(*(ptr)) t;                               \
  88         } __gu_val;                                             \
  89         memcpy(&__gu_val.l, ptr, sizeof(__gu_val.l));           \
  90         (x) = __gu_val.t;                                       \
  91         break;                                                  \
  92     }                                                           \
  93     default:                                                    \
  94         __gu_err = __get_user_bad();                            \
  95         break;                                                  \
  96     }                                                           \
  97     __gu_err;                                                   \
  98 })
  99 #define __get_user(x, ptr) get_user(x, ptr)
 100
 101 extern int __get_user_bad(void);
 102
 103 #define __get_user_asm(err,x,ptr,bwl,reg)                       \
 104         __asm__ ("move" #bwl " %1,%0"                           \
 105                  : "=d" (x)                                     \
 106                  : "m" (*__ptr(ptr)))
 107
 108 static inline unsigned long
 109 raw_copy_from_user(void *to, const void __user *from, unsigned long n)
 110 {
 111         memcpy(to, (__force const void *)from, n);
 112         return 0;
 113 }
 114
 115 static inline unsigned long
 116 raw_copy_to_user(void __user *to, const void *from, unsigned long n)
 117 {
 118         memcpy((__force void *)to, from, n);
 119         return 0;
 120 }
 121 #define INLINE_COPY_FROM_USER
 122 #define INLINE_COPY_TO_USER
 123
 124 /*
 125  * Copy a null terminated string from userspace.
 126  */
 127
 128 static inline long
 129 strncpy_from_user(char *dst, const char *src, long count)
 130 {
 131         char *tmp;
 132         strncpy(dst, src, count);
 133         for (tmp = dst; *tmp && count > 0; tmp++, count--)
 134                 ;
 135         return(tmp - dst); /* DAVIDM should we count a NUL ?  check getname */
 136 }
 137
 138 /*
 139  * Return the size of a string (including the ending 0)
 140  *
 141  * Return 0 on exception, a value greater than N if too long
 142  */
 143 static inline long strnlen_user(const char *src, long n)
 144 {
 145         return(strlen(src) + 1); /* DAVIDM make safer */
 146 }
 147
 148 /*
 149  * Zero Userspace
 150  */
 151
 152 static inline unsigned long
 153 __clear_user(void *to, unsigned long n)
 154 {
 155         memset(to, 0, n);
 156         return 0;
 157 }
 158
 159 #define clear_user(to,n)        __clear_user(to,n)
 160
 161 #endif /* _M68KNOMMU_UACCESS_H */