arch/microblaze/include/asm/uaccess.h

   1 /*
   2  * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
   3  * Copyright (C) 2008-2009 PetaLogix
   4  * Copyright (C) 2006 Atmark Techno, Inc.
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License. See the file "COPYING" in the main directory of this archive
   8  * for more details.
   9  */
  10
  11 #ifndef _ASM_MICROBLAZE_UACCESS_H
  12 #define _ASM_MICROBLAZE_UACCESS_H
  13
  14 #include <linux/kernel.h>
  15 #include <linux/mm.h>
  16
  17 #include <asm/mmu.h>
  18 #include <asm/page.h>
  19 #include <asm/pgtable.h>
  20 #include <asm/extable.h>
  21 #include <linux/string.h>
  22
  23 /*
  24  * On Microblaze the fs value is actually the top of the corresponding
  25  * address space.
  26  *
  27  * The fs value determines whether argument validity checking should be
  28  * performed or not. If get_fs() == USER_DS, checking is performed, with
  29  * get_fs() == KERNEL_DS, checking is bypassed.
  30  *
  31  * For historical reasons, these macros are grossly misnamed.
  32  *
  33  * For non-MMU arch like Microblaze, KERNEL_DS and USER_DS is equal.
  34  */
  35 # define MAKE_MM_SEG(s)       ((mm_segment_t) { (s) })
  36
  37 #  ifndef CONFIG_MMU
  38 #  define KERNEL_DS     MAKE_MM_SEG(0)
  39 #  define USER_DS       KERNEL_DS
  40 #  else
  41 #  define KERNEL_DS     MAKE_MM_SEG(0xFFFFFFFF)
  42 #  define USER_DS       MAKE_MM_SEG(TASK_SIZE - 1)
  43 #  endif
  44
  45 # define get_fs()       (current_thread_info()->addr_limit)
  46 # define set_fs(val)    (current_thread_info()->addr_limit = (val))
  47
  48 # define segment_eq(a, b)       ((a).seg == (b).seg)
  49
  50 #ifndef CONFIG_MMU
  51
  52 /* Check against bounds of physical memory */
  53 static inline int ___range_ok(unsigned long addr, unsigned long size)
  54 {
  55         return ((addr < memory_start) ||
  56                 ((addr + size - 1) > (memory_start + memory_size - 1)));
  57 }
  58
  59 #define __range_ok(addr, size) \
  60                 ___range_ok((unsigned long)(addr), (unsigned long)(size))
  61
  62 #define access_ok(addr, size) (__range_ok((addr), (size)) == 0)
  63
  64 #else
  65
  66 static inline int access_ok(const void __user *addr, unsigned long size)
  67 {
  68         if (!size)
  69                 goto ok;
  70
  71         if ((get_fs().seg < ((unsigned long)addr)) ||
  72                         (get_fs().seg < ((unsigned long)addr + size - 1))) {
  73                 pr_devel("ACCESS fail at 0x%08x (size 0x%x), seg 0x%08x\n",
  74                         (__force u32)addr, (u32)size,
  75                         (u32)get_fs().seg);
  76                 return 0;
  77         }
  78 ok:
  79         pr_devel("ACCESS OK at 0x%08x (size 0x%x), seg 0x%08x\n",
  80                         (__force u32)addr, (u32)size,
  81                         (u32)get_fs().seg);
  82         return 1;
  83 }
  84 #endif
  85
  86 #ifdef CONFIG_MMU
  87 # define __FIXUP_SECTION        ".section .fixup,\"ax\"\n"
  88 # define __EX_TABLE_SECTION     ".section __ex_table,\"a\"\n"
  89 #else
  90 # define __FIXUP_SECTION        ".section .discard,\"ax\"\n"
  91 # define __EX_TABLE_SECTION     ".section .discard,\"ax\"\n"
  92 #endif
  93
  94 extern unsigned long __copy_tofrom_user(void __user *to,
  95                 const void __user *from, unsigned long size);
  96
  97 /* Return: number of not copied bytes, i.e. 0 if OK or non-zero if fail. */
  98 static inline unsigned long __must_check __clear_user(void __user *to,
  99                                                         unsigned long n)
 100 {
 101         /* normal memset with two words to __ex_table */
 102         __asm__ __volatile__ (                          \
 103                         "1:     sb      r0, %1, r0;"    \
 104                         "       addik   %0, %0, -1;"    \
 105                         "       bneid   %0, 1b;"        \
 106                         "       addik   %1, %1, 1;"     \
 107                         "2:                     "       \
 108                         __EX_TABLE_SECTION              \
 109                         ".word  1b,2b;"                 \
 110                         ".previous;"                    \
 111                 : "=r"(n), "=r"(to)                     \
 112                 : "0"(n), "1"(to)
 113         );
 114         return n;
 115 }
 116
 117 static inline unsigned long __must_check clear_user(void __user *to,
 118                                                         unsigned long n)
 119 {
 120         might_fault();
 121         if (unlikely(!access_ok(to, n)))
 122                 return n;
 123
 124         return __clear_user(to, n);
 125 }
 126
 127 /* put_user and get_user macros */
 128 extern long __user_bad(void);
 129
 130 #define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err)      \
 131 ({                                                              \
 132         __asm__ __volatile__ (                                  \
 133                         "1:"    insn    " %1, %2, r0;"          \
 134                         "       addk    %0, r0, r0;"            \
 135                         "2:                     "               \
 136                         __FIXUP_SECTION                         \
 137                         "3:     brid    2b;"                    \
 138                         "       addik   %0, r0, %3;"            \
 139                         ".previous;"                            \
 140                         __EX_TABLE_SECTION                      \
 141                         ".word  1b,3b;"                         \
 142                         ".previous;"                            \
 143                 : "=&r"(__gu_err), "=r"(__gu_val)               \
 144                 : "r"(__gu_ptr), "i"(-EFAULT)                   \
 145         );                                                      \
 146 })
 147
 148 /**
 149  * get_user: - Get a simple variable from user space.
 150  * @x:   Variable to store result.
 151  * @ptr: Source address, in user space.
 152  *
 153  * Context: User context only. This function may sleep if pagefaults are
 154  *          enabled.
 155  *
 156  * This macro copies a single simple variable from user space to kernel
 157  * space.  It supports simple types like char and int, but not larger
 158  * data types like structures or arrays.
 159  *
 160  * @ptr must have pointer-to-simple-variable type, and the result of
 161  * dereferencing @ptr must be assignable to @x without a cast.
 162  *
 163  * Returns zero on success, or -EFAULT on error.
 164  * On error, the variable @x is set to zero.
 165  */
 166 #define get_user(x, ptr)                                                \
 167         __get_user_check((x), (ptr), sizeof(*(ptr)))
 168
 169 #define __get_user_check(x, ptr, size)                                  \
 170 ({                                                                      \
 171         unsigned long __gu_val = 0;                                     \
 172         const typeof(*(ptr)) __user *__gu_addr = (ptr);                 \
 173         int __gu_err = 0;                                               \
 174                                                                         \
 175         if (access_ok(__gu_addr, size)) {                       \
 176                 switch (size) {                                         \
 177                 case 1:                                                 \
 178                         __get_user_asm("lbu", __gu_addr, __gu_val,      \
 179                                        __gu_err);                       \
 180                         break;                                          \
 181                 case 2:                                                 \
 182                         __get_user_asm("lhu", __gu_addr, __gu_val,      \
 183                                        __gu_err);                       \
 184                         break;                                          \
 185                 case 4:                                                 \
 186                         __get_user_asm("lw", __gu_addr, __gu_val,       \
 187                                        __gu_err);                       \
 188                         break;                                          \
 189                 default:                                                \
 190                         __gu_err = __user_bad();                        \
 191                         break;                                          \
 192                 }                                                       \
 193         } else {                                                        \
 194                 __gu_err = -EFAULT;                                     \
 195         }                                                               \
 196         x = (__force typeof(*(ptr)))__gu_val;                           \
 197         __gu_err;                                                       \
 198 })
 199
 200 #define __get_user(x, ptr)                                              \
 201 ({                                                                      \
 202         unsigned long __gu_val = 0;                                     \
 203         /*unsigned long __gu_ptr = (unsigned long)(ptr);*/              \
 204         long __gu_err;                                                  \
 205         switch (sizeof(*(ptr))) {                                       \
 206         case 1:                                                         \
 207                 __get_user_asm("lbu", (ptr), __gu_val, __gu_err);       \
 208                 break;                                                  \
 209         case 2:                                                         \
 210                 __get_user_asm("lhu", (ptr), __gu_val, __gu_err);       \
 211                 break;                                                  \
 212         case 4:                                                         \
 213                 __get_user_asm("lw", (ptr), __gu_val, __gu_err);        \
 214                 break;                                                  \
 215         default:                                                        \
 216                 /* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\
 217         }                                                               \
 218         x = (__force __typeof__(*(ptr))) __gu_val;                      \
 219         __gu_err;                                                       \
 220 })
 221
 222
 223 #define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err)      \
 224 ({                                                              \
 225         __asm__ __volatile__ (                                  \
 226                         "1:"    insn    " %1, %2, r0;"          \
 227                         "       addk    %0, r0, r0;"            \
 228                         "2:                     "               \
 229                         __FIXUP_SECTION                         \
 230                         "3:     brid    2b;"                    \
 231                         "       addik   %0, r0, %3;"            \
 232                         ".previous;"                            \
 233                         __EX_TABLE_SECTION                      \
 234                         ".word  1b,3b;"                         \
 235                         ".previous;"                            \
 236                 : "=&r"(__gu_err)                               \
 237                 : "r"(__gu_val), "r"(__gu_ptr), "i"(-EFAULT)    \
 238         );                                                      \
 239 })
 240
 241 #define __put_user_asm_8(__gu_ptr, __gu_val, __gu_err)          \
 242 ({                                                              \
 243         __asm__ __volatile__ (" lwi     %0, %1, 0;"             \
 244                         "1:     swi     %0, %2, 0;"             \
 245                         "       lwi     %0, %1, 4;"             \
 246                         "2:     swi     %0, %2, 4;"             \
 247                         "       addk    %0, r0, r0;"            \
 248                         "3:                     "               \
 249                         __FIXUP_SECTION                         \
 250                         "4:     brid    3b;"                    \
 251                         "       addik   %0, r0, %3;"            \
 252                         ".previous;"                            \
 253                         __EX_TABLE_SECTION                      \
 254                         ".word  1b,4b,2b,4b;"                   \
 255                         ".previous;"                            \
 256                 : "=&r"(__gu_err)                               \
 257                 : "r"(&__gu_val), "r"(__gu_ptr), "i"(-EFAULT)   \
 258                 );                                              \
 259 })
 260
 261 /**
 262  * put_user: - Write a simple value into user space.
 263  * @x:   Value to copy to user space.
 264  * @ptr: Destination address, in user space.
 265  *
 266  * Context: User context only. This function may sleep if pagefaults are
 267  *          enabled.
 268  *
 269  * This macro copies a single simple value from kernel space to user
 270  * space.  It supports simple types like char and int, but not larger
 271  * data types like structures or arrays.
 272  *
 273  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 274  * to the result of dereferencing @ptr.
 275  *
 276  * Returns zero on success, or -EFAULT on error.
 277  */
 278 #define put_user(x, ptr)                                                \
 279         __put_user_check((x), (ptr), sizeof(*(ptr)))
 280
 281 #define __put_user_check(x, ptr, size)                                  \
 282 ({                                                                      \
 283         typeof(*(ptr)) volatile __pu_val = x;                           \
 284         typeof(*(ptr)) __user *__pu_addr = (ptr);                       \
 285         int __pu_err = 0;                                               \
 286                                                                         \
 287         if (access_ok(__pu_addr, size)) {                       \
 288                 switch (size) {                                         \
 289                 case 1:                                                 \
 290                         __put_user_asm("sb", __pu_addr, __pu_val,       \
 291                                        __pu_err);                       \
 292                         break;                                          \
 293                 case 2:                                                 \
 294                         __put_user_asm("sh", __pu_addr, __pu_val,       \
 295                                        __pu_err);                       \
 296                         break;                                          \
 297                 case 4:                                                 \
 298                         __put_user_asm("sw", __pu_addr, __pu_val,       \
 299                                        __pu_err);                       \
 300                         break;                                          \
 301                 case 8:                                                 \
 302                         __put_user_asm_8(__pu_addr, __pu_val, __pu_err);\
 303                         break;                                          \
 304                 default:                                                \
 305                         __pu_err = __user_bad();                        \
 306                         break;                                          \
 307                 }                                                       \
 308         } else {                                                        \
 309                 __pu_err = -EFAULT;                                     \
 310         }                                                               \
 311         __pu_err;                                                       \
 312 })
 313
 314 #define __put_user(x, ptr)                                              \
 315 ({                                                                      \
 316         __typeof__(*(ptr)) volatile __gu_val = (x);                     \
 317         long __gu_err = 0;                                              \
 318         switch (sizeof(__gu_val)) {                                     \
 319         case 1:                                                         \
 320                 __put_user_asm("sb", (ptr), __gu_val, __gu_err);        \
 321                 break;                                                  \
 322         case 2:                                                         \
 323                 __put_user_asm("sh", (ptr), __gu_val, __gu_err);        \
 324                 break;                                                  \
 325         case 4:                                                         \
 326                 __put_user_asm("sw", (ptr), __gu_val, __gu_err);        \
 327                 break;                                                  \
 328         case 8:                                                         \
 329                 __put_user_asm_8((ptr), __gu_val, __gu_err);            \
 330                 break;                                                  \
 331         default:                                                        \
 332                 /*__gu_err = -EINVAL;*/ __gu_err = __user_bad();        \
 333         }                                                               \
 334         __gu_err;                                                       \
 335 })
 336
 337 static inline unsigned long
 338 raw_copy_from_user(void *to, const void __user *from, unsigned long n)
 339 {
 340         return __copy_tofrom_user((__force void __user *)to, from, n);
 341 }
 342
 343 static inline unsigned long
 344 raw_copy_to_user(void __user *to, const void *from, unsigned long n)
 345 {
 346         return __copy_tofrom_user(to, (__force const void __user *)from, n);
 347 }
 348 #define INLINE_COPY_FROM_USER
 349 #define INLINE_COPY_TO_USER
 350
 351 /*
 352  * Copy a null terminated string from userspace.
 353  */
 354 extern int __strncpy_user(char *to, const char __user *from, int len);
 355
 356 static inline long
 357 strncpy_from_user(char *dst, const char __user *src, long count)
 358 {
 359         if (!access_ok(src, 1))
 360                 return -EFAULT;
 361         return __strncpy_user(dst, src, count);
 362 }
 363
 364 /*
 365  * Return the size of a string (including the ending 0)
 366  *
 367  * Return 0 on exception, a value greater than N if too long
 368  */
 369 extern int __strnlen_user(const char __user *sstr, int len);
 370
 371 static inline long strnlen_user(const char __user *src, long n)
 372 {
 373         if (!access_ok(src, 1))
 374                 return 0;
 375         return __strnlen_user(src, n);
 376 }
 377
 378 #endif /* _ASM_MICROBLAZE_UACCESS_H */