arch/microblaze/include/asm/uaccess.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
   4  * Copyright (C) 2008-2009 PetaLogix
   5  * Copyright (C) 2006 Atmark Techno, Inc.
   6  */
   7
   8 #ifndef _ASM_MICROBLAZE_UACCESS_H
   9 #define _ASM_MICROBLAZE_UACCESS_H
  10
  11 #include <linux/kernel.h>
  12
  13 #include <asm/mmu.h>
  14 #include <asm/page.h>
  15 #include <linux/pgtable.h>
  16 #include <asm/extable.h>
  17 #include <linux/string.h>
  18 #include <asm-generic/access_ok.h>
  19
  20 # define __FIXUP_SECTION        ".section .fixup,\"ax\"\n"
  21 # define __EX_TABLE_SECTION     ".section __ex_table,\"a\"\n"
  22
  23 extern unsigned long __copy_tofrom_user(void __user *to,
  24                 const void __user *from, unsigned long size);
  25
  26 /* Return: number of not copied bytes, i.e. 0 if OK or non-zero if fail. */
  27 static inline unsigned long __must_check __clear_user(void __user *to,
  28                                                         unsigned long n)
  29 {
  30         /* normal memset with two words to __ex_table */
  31         __asm__ __volatile__ (                          \
  32                         "1:     sb      r0, %1, r0;"    \
  33                         "       addik   %0, %0, -1;"    \
  34                         "       bneid   %0, 1b;"        \
  35                         "       addik   %1, %1, 1;"     \
  36                         "2:                     "       \
  37                         __EX_TABLE_SECTION              \
  38                         ".word  1b,2b;"                 \
  39                         ".previous;"                    \
  40                 : "=r"(n), "=r"(to)                     \
  41                 : "0"(n), "1"(to)
  42         );
  43         return n;
  44 }
  45
  46 static inline unsigned long __must_check clear_user(void __user *to,
  47                                                         unsigned long n)
  48 {
  49         might_fault();
  50         if (unlikely(!access_ok(to, n)))
  51                 return n;
  52
  53         return __clear_user(to, n);
  54 }
  55
  56 /* put_user and get_user macros */
  57 extern long __user_bad(void);
  58
  59 #define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err)      \
  60 ({                                                              \
  61         __asm__ __volatile__ (                                  \
  62                         "1:"    insn    " %1, %2, r0;"          \
  63                         "       addk    %0, r0, r0;"            \
  64                         "2:                     "               \
  65                         __FIXUP_SECTION                         \
  66                         "3:     brid    2b;"                    \
  67                         "       addik   %0, r0, %3;"            \
  68                         ".previous;"                            \
  69                         __EX_TABLE_SECTION                      \
  70                         ".word  1b,3b;"                         \
  71                         ".previous;"                            \
  72                 : "=&r"(__gu_err), "=r"(__gu_val)               \
  73                 : "r"(__gu_ptr), "i"(-EFAULT)                   \
  74         );                                                      \
  75 })
  76
  77 /**
  78  * get_user: - Get a simple variable from user space.
  79  * @x:   Variable to store result.
  80  * @ptr: Source address, in user space.
  81  *
  82  * Context: User context only. This function may sleep if pagefaults are
  83  *          enabled.
  84  *
  85  * This macro copies a single simple variable from user space to kernel
  86  * space.  It supports simple types like char and int, but not larger
  87  * data types like structures or arrays.
  88  *
  89  * @ptr must have pointer-to-simple-variable type, and the result of
  90  * dereferencing @ptr must be assignable to @x without a cast.
  91  *
  92  * Returns zero on success, or -EFAULT on error.
  93  * On error, the variable @x is set to zero.
  94  */
  95 #define get_user(x, ptr) ({                             \
  96         const typeof(*(ptr)) __user *__gu_ptr = (ptr);  \
  97         access_ok(__gu_ptr, sizeof(*__gu_ptr)) ?        \
  98                 __get_user(x, __gu_ptr) : -EFAULT;      \
  99 })
 100
 101 #define __get_user(x, ptr)                                              \
 102 ({                                                                      \
 103         long __gu_err;                                                  \
 104         switch (sizeof(*(ptr))) {                                       \
 105         case 1:                                                         \
 106                 __get_user_asm("lbu", (ptr), x, __gu_err);              \
 107                 break;                                                  \
 108         case 2:                                                         \
 109                 __get_user_asm("lhu", (ptr), x, __gu_err);              \
 110                 break;                                                  \
 111         case 4:                                                         \
 112                 __get_user_asm("lw", (ptr), x, __gu_err);               \
 113                 break;                                                  \
 114         case 8: {                                                       \
 115                 __u64 __x = 0;                                          \
 116                 __gu_err = raw_copy_from_user(&__x, ptr, 8) ?           \
 117                                                         -EFAULT : 0;    \
 118                 (x) = (typeof(x))(typeof((x) - (x)))__x;                \
 119                 break;                                                  \
 120         }                                                               \
 121         default:                                                        \
 122                 /* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\
 123         }                                                               \
 124         __gu_err;                                                       \
 125 })
 126
 127
 128 #define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err)      \
 129 ({                                                              \
 130         __asm__ __volatile__ (                                  \
 131                         "1:"    insn    " %1, %2, r0;"          \
 132                         "       addk    %0, r0, r0;"            \
 133                         "2:                     "               \
 134                         __FIXUP_SECTION                         \
 135                         "3:     brid    2b;"                    \
 136                         "       addik   %0, r0, %3;"            \
 137                         ".previous;"                            \
 138                         __EX_TABLE_SECTION                      \
 139                         ".word  1b,3b;"                         \
 140                         ".previous;"                            \
 141                 : "=&r"(__gu_err)                               \
 142                 : "r"(__gu_val), "r"(__gu_ptr), "i"(-EFAULT)    \
 143         );                                                      \
 144 })
 145
 146 #define __put_user_asm_8(__gu_ptr, __gu_val, __gu_err)          \
 147 ({                                                              \
 148         __asm__ __volatile__ (" lwi     %0, %1, 0;"             \
 149                         "1:     swi     %0, %2, 0;"             \
 150                         "       lwi     %0, %1, 4;"             \
 151                         "2:     swi     %0, %2, 4;"             \
 152                         "       addk    %0, r0, r0;"            \
 153                         "3:                     "               \
 154                         __FIXUP_SECTION                         \
 155                         "4:     brid    3b;"                    \
 156                         "       addik   %0, r0, %3;"            \
 157                         ".previous;"                            \
 158                         __EX_TABLE_SECTION                      \
 159                         ".word  1b,4b,2b,4b;"                   \
 160                         ".previous;"                            \
 161                 : "=&r"(__gu_err)                               \
 162                 : "r"(&__gu_val), "r"(__gu_ptr), "i"(-EFAULT)   \
 163                 );                                              \
 164 })
 165
 166 /**
 167  * put_user: - Write a simple value into user space.
 168  * @x:   Value to copy to user space.
 169  * @ptr: Destination address, in user space.
 170  *
 171  * Context: User context only. This function may sleep if pagefaults are
 172  *          enabled.
 173  *
 174  * This macro copies a single simple value from kernel space to user
 175  * space.  It supports simple types like char and int, but not larger
 176  * data types like structures or arrays.
 177  *
 178  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 179  * to the result of dereferencing @ptr.
 180  *
 181  * Returns zero on success, or -EFAULT on error.
 182  */
 183 #define put_user(x, ptr)                                                \
 184         __put_user_check((x), (ptr), sizeof(*(ptr)))
 185
 186 #define __put_user_check(x, ptr, size)                                  \
 187 ({                                                                      \
 188         typeof(*(ptr)) volatile __pu_val = x;                           \
 189         typeof(*(ptr)) __user *__pu_addr = (ptr);                       \
 190         int __pu_err = 0;                                               \
 191                                                                         \
 192         if (access_ok(__pu_addr, size)) {                       \
 193                 switch (size) {                                         \
 194                 case 1:                                                 \
 195                         __put_user_asm("sb", __pu_addr, __pu_val,       \
 196                                        __pu_err);                       \
 197                         break;                                          \
 198                 case 2:                                                 \
 199                         __put_user_asm("sh", __pu_addr, __pu_val,       \
 200                                        __pu_err);                       \
 201                         break;                                          \
 202                 case 4:                                                 \
 203                         __put_user_asm("sw", __pu_addr, __pu_val,       \
 204                                        __pu_err);                       \
 205                         break;                                          \
 206                 case 8:                                                 \
 207                         __put_user_asm_8(__pu_addr, __pu_val, __pu_err);\
 208                         break;                                          \
 209                 default:                                                \
 210                         __pu_err = __user_bad();                        \
 211                         break;                                          \
 212                 }                                                       \
 213         } else {                                                        \
 214                 __pu_err = -EFAULT;                                     \
 215         }                                                               \
 216         __pu_err;                                                       \
 217 })
 218
 219 #define __put_user(x, ptr)                                              \
 220 ({                                                                      \
 221         __typeof__(*(ptr)) volatile __gu_val = (x);                     \
 222         long __gu_err = 0;                                              \
 223         switch (sizeof(__gu_val)) {                                     \
 224         case 1:                                                         \
 225                 __put_user_asm("sb", (ptr), __gu_val, __gu_err);        \
 226                 break;                                                  \
 227         case 2:                                                         \
 228                 __put_user_asm("sh", (ptr), __gu_val, __gu_err);        \
 229                 break;                                                  \
 230         case 4:                                                         \
 231                 __put_user_asm("sw", (ptr), __gu_val, __gu_err);        \
 232                 break;                                                  \
 233         case 8:                                                         \
 234                 __put_user_asm_8((ptr), __gu_val, __gu_err);            \
 235                 break;                                                  \
 236         default:                                                        \
 237                 /*__gu_err = -EINVAL;*/ __gu_err = __user_bad();        \
 238         }                                                               \
 239         __gu_err;                                                       \
 240 })
 241
 242 static inline unsigned long
 243 raw_copy_from_user(void *to, const void __user *from, unsigned long n)
 244 {
 245         return __copy_tofrom_user((__force void __user *)to, from, n);
 246 }
 247
 248 static inline unsigned long
 249 raw_copy_to_user(void __user *to, const void *from, unsigned long n)
 250 {
 251         return __copy_tofrom_user(to, (__force const void __user *)from, n);
 252 }
 253 #define INLINE_COPY_FROM_USER
 254 #define INLINE_COPY_TO_USER
 255
 256 /*
 257  * Copy a null terminated string from userspace.
 258  */
 259 __must_check long strncpy_from_user(char *dst, const char __user *src,
 260                                     long count);
 261
 262 /*
 263  * Return the size of a string (including the ending 0)
 264  *
 265  * Return 0 on exception, a value greater than N if too long
 266  */
 267 __must_check long strnlen_user(const char __user *sstr, long len);
 268
 269 #endif /* _ASM_MICROBLAZE_UACCESS_H */