arch/cris/include/asm/uaccess.h

   1 /*
   2  * Authors:    Bjorn Wesen (bjornw@axis.com)
   3  *             Hans-Peter Nilsson (hp@axis.com)
   4  */
   5
   6 /* Asm:s have been tweaked (within the domain of correctness) to give
   7    satisfactory results for "gcc version 2.96 20000427 (experimental)".
   8
   9    Check regularly...
  10
  11    Register $r9 is chosen for temporaries, being a call-clobbered register
  12    first in line to be used (notably for local blocks), not colliding with
  13    parameter registers.  */
  14
  15 #ifndef _CRIS_UACCESS_H
  16 #define _CRIS_UACCESS_H
  17
  18 #include <asm/processor.h>
  19 #include <asm/page.h>
  20
  21 /*
  22  * The fs value determines whether argument validity checking should be
  23  * performed or not.  If get_fs() == USER_DS, checking is performed, with
  24  * get_fs() == KERNEL_DS, checking is bypassed.
  25  *
  26  * For historical reasons, these macros are grossly misnamed.
  27  */
  28
  29 #define MAKE_MM_SEG(s)  ((mm_segment_t) { (s) })
  30
  31 /* addr_limit is the maximum accessible address for the task. we misuse
  32  * the KERNEL_DS and USER_DS values to both assign and compare the
  33  * addr_limit values through the equally misnamed get/set_fs macros.
  34  * (see above)
  35  */
  36
  37 #define KERNEL_DS       MAKE_MM_SEG(0xFFFFFFFF)
  38 #define USER_DS         MAKE_MM_SEG(TASK_SIZE)
  39
  40 #define get_ds()        (KERNEL_DS)
  41 #define get_fs()        (current_thread_info()->addr_limit)
  42 #define set_fs(x)       (current_thread_info()->addr_limit = (x))
  43
  44 #define segment_eq(a, b)        ((a).seg == (b).seg)
  45
  46 #define __kernel_ok (uaccess_kernel())
  47 #define __user_ok(addr, size) \
  48         (((size) <= TASK_SIZE) && ((addr) <= TASK_SIZE-(size)))
  49 #define __access_ok(addr, size) (__kernel_ok || __user_ok((addr), (size)))
  50 #define access_ok(type, addr, size) __access_ok((unsigned long)(addr), (size))
  51
  52 #include <arch/uaccess.h>
  53 #include <asm/extable.h>
  54
  55 /*
  56  * These are the main single-value transfer routines.  They automatically
  57  * use the right size if we just have the right pointer type.
  58  *
  59  * This gets kind of ugly. We want to return _two_ values in "get_user()"
  60  * and yet we don't want to do any pointers, because that is too much
  61  * of a performance impact. Thus we have a few rather ugly macros here,
  62  * and hide all the ugliness from the user.
  63  *
  64  * The "__xxx" versions of the user access functions are versions that
  65  * do not verify the address space, that must have been done previously
  66  * with a separate "access_ok()" call (this is used when we do multiple
  67  * accesses to the same area of user memory).
  68  *
  69  * As we use the same address space for kernel and user data on
  70  * CRIS, we can just do these as direct assignments.  (Of course, the
  71  * exception handling means that it's no longer "just"...)
  72  */
  73 #define get_user(x, ptr) \
  74         __get_user_check((x), (ptr), sizeof(*(ptr)))
  75 #define put_user(x, ptr) \
  76         __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
  77
  78 #define __get_user(x, ptr) \
  79         __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
  80 #define __put_user(x, ptr) \
  81         __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
  82
  83 extern long __put_user_bad(void);
  84
  85 #define __put_user_size(x, ptr, size, retval)                           \
  86 do {                                                                    \
  87         retval = 0;                                                     \
  88         switch (size) {                                                 \
  89         case 1:                                                         \
  90                 __put_user_asm(x, ptr, retval, "move.b");               \
  91                 break;                                                  \
  92         case 2:                                                         \
  93                 __put_user_asm(x, ptr, retval, "move.w");               \
  94                 break;                                                  \
  95         case 4:                                                         \
  96                 __put_user_asm(x, ptr, retval, "move.d");               \
  97                 break;                                                  \
  98         case 8:                                                         \
  99                 __put_user_asm_64(x, ptr, retval);                      \
 100                 break;                                                  \
 101         default:                                                        \
 102                 __put_user_bad();                                       \
 103         }                                                               \
 104 } while (0)
 105
 106 #define __get_user_size(x, ptr, size, retval)                           \
 107 do {                                                                    \
 108         retval = 0;                                                     \
 109         switch (size) {                                                 \
 110         case 1:                                                         \
 111                 __get_user_asm(x, ptr, retval, "move.b");               \
 112                 break;                                                  \
 113         case 2:                                                         \
 114                 __get_user_asm(x, ptr, retval, "move.w");               \
 115                 break;                                                  \
 116         case 4:                                                         \
 117                 __get_user_asm(x, ptr, retval, "move.d");               \
 118                 break;                                                  \
 119         case 8:                                                         \
 120                 __get_user_asm_64(x, ptr, retval);                      \
 121                 break;                                                  \
 122         default:                                                        \
 123                 (x) = __get_user_bad();                                 \
 124         }                                                               \
 125 } while (0)
 126
 127 #define __put_user_nocheck(x, ptr, size)                \
 128 ({                                                      \
 129         long __pu_err;                                  \
 130         __put_user_size((x), (ptr), (size), __pu_err);  \
 131         __pu_err;                                       \
 132 })
 133
 134 #define __put_user_check(x, ptr, size)                                  \
 135 ({                                                                      \
 136         long __pu_err = -EFAULT;                                        \
 137         __typeof__(*(ptr)) *__pu_addr = (ptr);                          \
 138         if (access_ok(VERIFY_WRITE, __pu_addr, size))                   \
 139                 __put_user_size((x), __pu_addr, (size), __pu_err);      \
 140         __pu_err;                                                       \
 141 })
 142
 143 struct __large_struct { unsigned long buf[100]; };
 144 #define __m(x) (*(struct __large_struct *)(x))
 145
 146
 147
 148 #define __get_user_nocheck(x, ptr, size)                        \
 149 ({                                                              \
 150         long __gu_err, __gu_val;                                \
 151         __get_user_size(__gu_val, (ptr), (size), __gu_err);     \
 152         (x) = (__force __typeof__(*(ptr)))__gu_val;             \
 153         __gu_err;                                               \
 154 })
 155
 156 #define __get_user_check(x, ptr, size)                                  \
 157 ({                                                                      \
 158         long __gu_err = -EFAULT, __gu_val = 0;                          \
 159         const __typeof__(*(ptr)) *__gu_addr = (ptr);                    \
 160         if (access_ok(VERIFY_READ, __gu_addr, size))                    \
 161                 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
 162         (x) = (__force __typeof__(*(ptr)))__gu_val;                     \
 163         __gu_err;                                                       \
 164 })
 165
 166 extern long __get_user_bad(void);
 167
 168 /* More complex functions.  Most are inline, but some call functions that
 169    live in lib/usercopy.c  */
 170
 171 extern unsigned long __copy_user(void __user *to, const void *from, unsigned long n);
 172 extern unsigned long __copy_user_in(void *to, const void __user *from, unsigned long n);
 173 extern unsigned long __do_clear_user(void __user *to, unsigned long n);
 174
 175 static inline long
 176 strncpy_from_user(char *dst, const char __user *src, long count)
 177 {
 178         long res = -EFAULT;
 179
 180         if (access_ok(VERIFY_READ, src, 1))
 181                 res = __do_strncpy_from_user(dst, src, count);
 182         return res;
 183 }
 184
 185
 186 /* Note that these expand awfully if made into switch constructs, so
 187    don't do that.  */
 188
 189 static inline unsigned long
 190 __constant_copy_from_user(void *to, const void __user *from, unsigned long n)
 191 {
 192         unsigned long ret = 0;
 193
 194         if (n == 0)
 195                 ;
 196         else if (n == 1)
 197                 __asm_copy_from_user_1(to, from, ret);
 198         else if (n == 2)
 199                 __asm_copy_from_user_2(to, from, ret);
 200         else if (n == 3)
 201                 __asm_copy_from_user_3(to, from, ret);
 202         else if (n == 4)
 203                 __asm_copy_from_user_4(to, from, ret);
 204         else if (n == 5)
 205                 __asm_copy_from_user_5(to, from, ret);
 206         else if (n == 6)
 207                 __asm_copy_from_user_6(to, from, ret);
 208         else if (n == 7)
 209                 __asm_copy_from_user_7(to, from, ret);
 210         else if (n == 8)
 211                 __asm_copy_from_user_8(to, from, ret);
 212         else if (n == 9)
 213                 __asm_copy_from_user_9(to, from, ret);
 214         else if (n == 10)
 215                 __asm_copy_from_user_10(to, from, ret);
 216         else if (n == 11)
 217                 __asm_copy_from_user_11(to, from, ret);
 218         else if (n == 12)
 219                 __asm_copy_from_user_12(to, from, ret);
 220         else if (n == 13)
 221                 __asm_copy_from_user_13(to, from, ret);
 222         else if (n == 14)
 223                 __asm_copy_from_user_14(to, from, ret);
 224         else if (n == 15)
 225                 __asm_copy_from_user_15(to, from, ret);
 226         else if (n == 16)
 227                 __asm_copy_from_user_16(to, from, ret);
 228         else if (n == 20)
 229                 __asm_copy_from_user_20(to, from, ret);
 230         else if (n == 24)
 231                 __asm_copy_from_user_24(to, from, ret);
 232         else
 233                 ret = __copy_user_in(to, from, n);
 234
 235         return ret;
 236 }
 237
 238 /* Ditto, don't make a switch out of this.  */
 239
 240 static inline unsigned long
 241 __constant_copy_to_user(void __user *to, const void *from, unsigned long n)
 242 {
 243         unsigned long ret = 0;
 244
 245         if (n == 0)
 246                 ;
 247         else if (n == 1)
 248                 __asm_copy_to_user_1(to, from, ret);
 249         else if (n == 2)
 250                 __asm_copy_to_user_2(to, from, ret);
 251         else if (n == 3)
 252                 __asm_copy_to_user_3(to, from, ret);
 253         else if (n == 4)
 254                 __asm_copy_to_user_4(to, from, ret);
 255         else if (n == 5)
 256                 __asm_copy_to_user_5(to, from, ret);
 257         else if (n == 6)
 258                 __asm_copy_to_user_6(to, from, ret);
 259         else if (n == 7)
 260                 __asm_copy_to_user_7(to, from, ret);
 261         else if (n == 8)
 262                 __asm_copy_to_user_8(to, from, ret);
 263         else if (n == 9)
 264                 __asm_copy_to_user_9(to, from, ret);
 265         else if (n == 10)
 266                 __asm_copy_to_user_10(to, from, ret);
 267         else if (n == 11)
 268                 __asm_copy_to_user_11(to, from, ret);
 269         else if (n == 12)
 270                 __asm_copy_to_user_12(to, from, ret);
 271         else if (n == 13)
 272                 __asm_copy_to_user_13(to, from, ret);
 273         else if (n == 14)
 274                 __asm_copy_to_user_14(to, from, ret);
 275         else if (n == 15)
 276                 __asm_copy_to_user_15(to, from, ret);
 277         else if (n == 16)
 278                 __asm_copy_to_user_16(to, from, ret);
 279         else if (n == 20)
 280                 __asm_copy_to_user_20(to, from, ret);
 281         else if (n == 24)
 282                 __asm_copy_to_user_24(to, from, ret);
 283         else
 284                 ret = __copy_user(to, from, n);
 285
 286         return ret;
 287 }
 288
 289 /* No switch, please.  */
 290
 291 static inline unsigned long
 292 __constant_clear_user(void __user *to, unsigned long n)
 293 {
 294         unsigned long ret = 0;
 295
 296         if (n == 0)
 297                 ;
 298         else if (n == 1)
 299                 __asm_clear_1(to, ret);
 300         else if (n == 2)
 301                 __asm_clear_2(to, ret);
 302         else if (n == 3)
 303                 __asm_clear_3(to, ret);
 304         else if (n == 4)
 305                 __asm_clear_4(to, ret);
 306         else if (n == 8)
 307                 __asm_clear_8(to, ret);
 308         else if (n == 12)
 309                 __asm_clear_12(to, ret);
 310         else if (n == 16)
 311                 __asm_clear_16(to, ret);
 312         else if (n == 20)
 313                 __asm_clear_20(to, ret);
 314         else if (n == 24)
 315                 __asm_clear_24(to, ret);
 316         else
 317                 ret = __do_clear_user(to, n);
 318
 319         return ret;
 320 }
 321
 322
 323 static inline size_t clear_user(void __user *to, size_t n)
 324 {
 325         if (unlikely(!access_ok(VERIFY_WRITE, to, n)))
 326                 return n;
 327         if (__builtin_constant_p(n))
 328                 return __constant_clear_user(to, n);
 329         else
 330                 return __do_clear_user(to, n);
 331 }
 332
 333 static inline unsigned long
 334 raw_copy_from_user(void *to, const void __user *from, unsigned long n)
 335 {
 336         if (__builtin_constant_p(n))
 337                 return __constant_copy_from_user(to, from, n);
 338         else
 339                 return __copy_user_in(to, from, n);
 340 }
 341
 342 static inline unsigned long
 343 raw_copy_to_user(void __user *to, const void *from, unsigned long n)
 344 {
 345         if (__builtin_constant_p(n))
 346                 return __constant_copy_to_user(to, from, n);
 347         else
 348                 return __copy_user(to, from, n);
 349 }
 350
 351 #define INLINE_COPY_FROM_USER
 352 #define INLINE_COPY_TO_USER
 353
 354 static inline unsigned long
 355 __clear_user(void __user *to, unsigned long n)
 356 {
 357         return __do_clear_user(to, n);
 358 }
 359
 360 #endif  /* _CRIS_UACCESS_H */