include/asm-sh/uaccess.h

   1 /*
   2  * User space memory access functions
   3  *
   4  * Copyright (C) 1999 Niibe Yutaka
   5  *
   6  *  Based on:
   7  *     MIPS implementation version 1.15 by
   8  *              Copyright (C) 1996, 1997, 1998 by Ralf Baechle
   9  *     and i386 version.
  10  */
  11 #ifndef __ASM_SH_UACCESS_H
  12 #define __ASM_SH_UACCESS_H
  13
  14 #include <linux/errno.h>
  15 #include <linux/sched.h>
  16
  17 #define VERIFY_READ    0
  18 #define VERIFY_WRITE   1
  19
  20 /*
  21  * The fs value determines whether argument validity checking should be
  22  * performed or not.  If get_fs() == USER_DS, checking is performed, with
  23  * get_fs() == KERNEL_DS, checking is bypassed.
  24  *
  25  * For historical reasons (Data Segment Register?), these macros are misnamed.
  26  */
  27
  28 #define MAKE_MM_SEG(s)  ((mm_segment_t) { (s) })
  29
  30 #define KERNEL_DS       MAKE_MM_SEG(0xFFFFFFFF)
  31 #define USER_DS         MAKE_MM_SEG(0x80000000)
  32
  33 #define get_ds()        (KERNEL_DS)
  34 #define get_fs()        (current->addr_limit)
  35 #define set_fs(x)       (current->addr_limit=(x))
  36
  37 #define segment_eq(a,b) ((a).seg == (b).seg)
  38
  39 #define __addr_ok(addr) ((unsigned long)(addr) < (current->addr_limit.seg))
  40
  41 /*
  42  * Uhhuh, this needs 33-bit arithmetic. We have a carry..
  43  *
  44  * sum := addr + size;  carry? --> flag = true;
  45  * if (sum >= addr_limit) flag = true;
  46  */
  47 #define __range_ok(addr,size) ({ \
  48         unsigned long flag,sum; \
  49         __asm__("clrt; addc %3,%1; movt %0; cmp/hi %4,%1; rotcl %0" \
  50                 :"=&r" (flag), "=r" (sum) \
  51                 :"1" (addr), "r" (size), "r" (current->addr_limit.seg)); \
  52         flag; })
  53
  54 #define access_ok(type,addr,size) (__range_ok(addr,size) == 0)
  55 #define __access_ok(addr,size) (__range_ok(addr,size) == 0)
  56
  57 extern inline int verify_area(int type, const void * addr, unsigned long size)
  58 {
  59         return access_ok(type,addr,size) ? 0 : -EFAULT;
  60 }
  61
  62 /*
  63  * Uh, these should become the main single-value transfer routines ...
  64  * They automatically use the right size if we just have the right
  65  * pointer type ...
  66  *
  67  * As MIPS uses the same address space for kernel and user data, we
  68  * can just do these as direct assignments.
  69  *
  70  * Careful to not
  71  * (a) re-use the arguments for side effects (sizeof is ok)
  72  * (b) require any knowledge of processes at this stage
  73  */
  74 #define put_user(x,ptr) __put_user_check((x),(ptr),sizeof(*(ptr)))
  75 #define get_user(x,ptr) __get_user_check((x),(ptr),sizeof(*(ptr)))
  76
  77 /*
  78  * The "__xxx" versions do not do address space checking, useful when
  79  * doing multiple accesses to the same area (the user has to do the
  80  * checks by hand with "access_ok()")
  81  */
  82 #define __put_user(x,ptr) __put_user_nocheck((x),(ptr),sizeof(*(ptr)))
  83 #define __get_user(x,ptr) __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
  84
  85 /*
  86  * The "xxx_ret" versions return constant specified in third argument, if
  87  * something bad happens. These macros can be optimized for the
  88  * case of just returning from the function xxx_ret is used.
  89  */
  90
  91 #define put_user_ret(x,ptr,ret) ({ \
  92 if (put_user(x,ptr)) return ret; })
  93
  94 #define get_user_ret(x,ptr,ret) ({ \
  95 if (get_user(x,ptr)) return ret; })
  96
  97 #define __put_user_ret(x,ptr,ret) ({ \
  98 if (__put_user(x,ptr)) return ret; })
  99
 100 #define __get_user_ret(x,ptr,ret) ({ \
 101 if (__get_user(x,ptr)) return ret; })
 102
 103 struct __large_struct { unsigned long buf[100]; };
 104 #define __m(x) (*(struct __large_struct *)(x))
 105
 106 #define __get_user_nocheck(x,ptr,size) ({ \
 107 long __gu_err; \
 108 __typeof(*(ptr)) __gu_val; \
 109 long __gu_addr; \
 110 __asm__("":"=r" (__gu_val)); \
 111 __gu_addr = (long) (ptr); \
 112 __asm__("":"=r" (__gu_err)); \
 113 switch (size) { \
 114 case 1: __get_user_asm("b"); break; \
 115 case 2: __get_user_asm("w"); break; \
 116 case 4: __get_user_asm("l"); break; \
 117 default: __get_user_unknown(); break; \
 118 } x = (__typeof__(*(ptr))) __gu_val; __gu_err; })
 119
 120 #define __get_user_check(x,ptr,size) ({ \
 121 long __gu_err; \
 122 __typeof__(*(ptr)) __gu_val; \
 123 long __gu_addr; \
 124 __asm__("":"=r" (__gu_val)); \
 125 __gu_addr = (long) (ptr); \
 126 __asm__("":"=r" (__gu_err)); \
 127 if (__access_ok(__gu_addr,size)) { \
 128 switch (size) { \
 129 case 1: __get_user_asm("b"); break; \
 130 case 2: __get_user_asm("w"); break; \
 131 case 4: __get_user_asm("l"); break; \
 132 default: __get_user_unknown(); break; \
 133 } } x = (__typeof__(*(ptr))) __gu_val; __gu_err; })
 134
 135 #define __get_user_asm(insn) \
 136 ({ \
 137 __asm__ __volatile__( \
 138         "1:\n\t" \
 139         "mov." insn "   %2,%1\n\t" \
 140         "mov    #0,%0\n" \
 141         "2:\n\t" \
 142         ".section       .fixup,\"ax\"\n" \
 143         "3:\n\t" \
 144         "mov    #0,%1\n\t" \
 145         "mov.l  4f,%0\n\t" \
 146         "jmp    @%0\n\t" \
 147         " mov   %3,%0\n" \
 148         "4:     .long   2b\n\t" \
 149         ".previous\n\t" \
 150         ".section       __ex_table,\"a\"\n\t" \
 151         ".long  1b, 3b\n\t" \
 152         ".previous" \
 153         :"=&r" (__gu_err), "=&r" (__gu_val) \
 154         :"m" (__m(__gu_addr)), "i" (-EFAULT)); })
 155
 156 extern void __get_user_unknown(void);
 157
 158 #define __put_user_nocheck(x,ptr,size) ({ \
 159 long __pu_err; \
 160 __typeof__(*(ptr)) __pu_val; \
 161 long __pu_addr; \
 162 __pu_val = (x); \
 163 __pu_addr = (long) (ptr); \
 164 __asm__("":"=r" (__pu_err)); \
 165 switch (size) { \
 166 case 1: __put_user_asm("b"); break; \
 167 case 2: __put_user_asm("w"); break; \
 168 case 4: __put_user_asm("l"); break; \
 169 default: __put_user_unknown(); break; \
 170 } __pu_err; })
 171
 172 #define __put_user_check(x,ptr,size) ({ \
 173 long __pu_err; \
 174 __typeof__(*(ptr)) __pu_val; \
 175 long __pu_addr; \
 176 __pu_val = (x); \
 177 __pu_addr = (long) (ptr); \
 178 __asm__("":"=r" (__pu_err)); \
 179 if (__access_ok(__pu_addr,size)) { \
 180 switch (size) { \
 181 case 1: __put_user_asm("b"); break; \
 182 case 2: __put_user_asm("w"); break; \
 183 case 4: __put_user_asm("l"); break; \
 184 default: __put_user_unknown(); break; \
 185 } } __pu_err; })
 186
 187 #define __put_user_asm(insn) \
 188 ({ \
 189 __asm__ __volatile__( \
 190         "1:\n\t" \
 191         "mov." insn "   %1,%2\n\t" \
 192         "mov    #0,%0\n" \
 193         "2:\n\t" \
 194         ".section       .fixup,\"ax\"\n" \
 195         "3:\n\t" \
 196         "nop\n\t" \
 197         "mov.l  4f,%0\n\t" \
 198         "jmp    @%0\n\t" \
 199         "mov    %3,%0\n" \
 200         "4:     .long   2b\n\t" \
 201         ".previous\n\t" \
 202         ".section       __ex_table,\"a\"\n\t" \
 203         ".long  1b, 3b\n\t" \
 204         ".previous" \
 205         :"=&r" (__pu_err) \
 206         :"r" (__pu_val), "m" (__m(__pu_addr)), "i" (-EFAULT)); })
 207
 208 extern void __put_user_unknown(void);
 209 \f
 210 /* Generic arbitrary sized copy.  */
 211 /* XXX: should be such that: 4byte and the rest. */
 212 extern __inline__ __kernel_size_t
 213 __copy_user(void *__to, const void *__from, __kernel_size_t __n)
 214 {
 215         unsigned long __dummy, _f, _t;
 216         __kernel_size_t res;
 217
 218         __asm__ __volatile__(
 219                 "9:\n\t"
 220                 "mov.b  @%2+,%1\n\t"
 221                 "dt     %0\n"
 222                 "1:\n\t"
 223                 "mov.b  %1,@%3\n\t"
 224                 "bf/s   9b\n\t"
 225                 " add   #1,%3\n"
 226                 "2:"
 227                 ".section .fixup,\"ax\"\n"
 228                 "3:\n\t"
 229                 "mov.l  5f,%1\n\t"
 230                 "jmp    @%1\n\t"
 231                 " mov   %7,%0\n\t"
 232                 ".align 4\n"
 233                 "5:     .long 2b\n"
 234                 ".previous\n"
 235                 ".section __ex_table,\"a\"\n"
 236                 "       .align 4\n"
 237                 "       .long 9b,3b\n"
 238                 "       .long 1b,2b\n"
 239                 ".previous"
 240                 : "=&r" (res), "=&z" (__dummy), "=&r" (_f), "=&r" (_t)
 241                 : "2" (__from), "3" (__to), "0" (__n), "i" (-EFAULT)
 242                 : "memory");
 243
 244         return res;
 245 }
 246
 247 #define copy_to_user(to,from,n) ({ \
 248 void *__copy_to = (void *) (to); \
 249 __kernel_size_t __copy_size = (__kernel_size_t) (n); \
 250 __kernel_size_t __copy_res; \
 251 if(__copy_size && __access_ok((unsigned long)__copy_to, __copy_size)) { \
 252 __copy_res = __copy_user(__copy_to, (void *) (from), __copy_size); \
 253 } else __copy_res = __copy_size; \
 254 __copy_res; })
 255
 256 #define copy_to_user_ret(to,from,n,retval) ({ \
 257 if (copy_to_user(to,from,n)) \
 258         return retval; \
 259 })
 260
 261 #define __copy_to_user(to,from,n)               \
 262         __copy_user((void *)(to),               \
 263                     (void *)(from), n)
 264
 265 #define __copy_to_user_ret(to,from,n,retval) ({ \
 266 if (__copy_to_user(to,from,n)) \
 267         return retval; \
 268 })
 269
 270 #define copy_from_user(to,from,n) ({ \
 271 void *__copy_to = (void *) (to); \
 272 void *__copy_from = (void *) (from); \
 273 __kernel_size_t __copy_size = (__kernel_size_t) (n); \
 274 __kernel_size_t __copy_res; \
 275 if(__copy_size && __access_ok((unsigned long)__copy_from, __copy_size)) { \
 276 __copy_res = __copy_user(__copy_to, __copy_from, __copy_size); \
 277 } else __copy_res = __copy_size; \
 278 __copy_res; })
 279
 280 #define copy_from_user_ret(to,from,n,retval) ({ \
 281 if (copy_from_user(to,from,n)) \
 282         return retval; \
 283 })
 284
 285 #define __copy_from_user(to,from,n)             \
 286         __copy_user((void *)(to),               \
 287                     (void *)(from), n)
 288
 289 #define __copy_from_user_ret(to,from,n,retval) ({ \
 290 if (__copy_from_user(to,from,n)) \
 291         return retval; \
 292 })
 293
 294 /* XXX: Not sure it works well..
 295    should be such that: 4byte clear and the rest. */
 296 extern __inline__ __kernel_size_t
 297 __clear_user(void *addr, __kernel_size_t size)
 298 {
 299         __kernel_size_t res;
 300         unsigned long __a, __s;
 301
 302         __asm__ __volatile__(
 303                 "9:\n\t"
 304                 "dt     %2\n"
 305                 "1:\n\t"
 306                 "mov.b  %5,@%1\n\t"
 307                 "bf/s   9b\n\t"
 308                 " add   #1,%1\n\t"
 309                 "sub    %2,%0\n"
 310                 "2:\n"
 311                 ".section .fixup,\"ax\"\n"
 312                 "3:\n\t"
 313                 "mov.l  4f,%0\n\t"
 314                 "jmp    @%0\n\t"
 315                 " mov   %7,%0\n"
 316                 ".align 4\n"
 317                 "4:     .long 2b\n"
 318                 ".previous\n"
 319                 ".section __ex_table,\"a\"\n"
 320                 "       .align 4\n"
 321                 "       .long 1b,3b\n"
 322                 ".previous"
 323                 : "=&r" (res), "=&r" (__a), "=&r" (__s)
 324                 : "1" (addr), "2" (size), "r" (0), "0" (size), "i" (-EFAULT));
 325
 326         return res;
 327 }
 328
 329 #define clear_user(addr,n) ({ \
 330 void * __cl_addr = (addr); \
 331 unsigned long __cl_size = (n); \
 332 if (__cl_size && __access_ok(((unsigned long)(__cl_addr)), __cl_size)) \
 333 __cl_size = __clear_user(__cl_addr, __cl_size); \
 334 __cl_size; })
 335
 336 extern __inline__ int
 337 __strncpy_from_user(unsigned long __dest, unsigned long __src, int __count)
 338 {
 339         __kernel_size_t res;
 340         unsigned long __dummy, _d, _s;
 341
 342         __asm__ __volatile__(
 343                 "9:\n"
 344                 "mov.b  @%2+,%1\n\t"
 345                 "cmp/eq #0,%1\n\t"
 346                 "bt/s   2f\n"
 347                 "1:\n"
 348                 "mov.b  %1,@%3\n\t"
 349                 "dt     %0\n\t"
 350                 "bf/s   9b\n\t"
 351                 " add   #1,%3\n\t"
 352                 "sub    %6,%0\n"
 353                 "2:\n"
 354                 ".section .fixup,\"ax\"\n"
 355                 "3:\n\t"
 356                 "mov.l  4f,%1\n\t"
 357                 "jmp    @%1\n\t"
 358                 " mov   %8,%0\n\t"
 359                 ".align 4\n"
 360                 "4:     .long 2b\n"
 361                 ".previous\n"
 362                 ".section __ex_table,\"a\"\n"
 363                 "       .align 4\n"
 364                 "       .long 9b,3b\n"
 365                 "       .long 1b,2b\n"
 366                 ".previous"
 367                 : "=&r" (res), "=&z" (__dummy), "=&r" (_s), "=&r" (_d)
 368                 : "2" (__src), "3" (__dest), "r" (__count), "0" (__count),
 369                   "i" (-EFAULT)
 370                 : "memory");
 371
 372         return res;
 373 }
 374
 375 #define strncpy_from_user(dest,src,count) ({ \
 376 unsigned long __sfu_src = (unsigned long) (src); \
 377 int __sfu_count = (int) (count); \
 378 long __sfu_res = -EFAULT; \
 379 if(__access_ok(__sfu_src, __sfu_count)) { \
 380 __sfu_res = __strncpy_from_user((unsigned long) (dest), __sfu_src, __sfu_count); \
 381 } __sfu_res; })
 382
 383 /*
 384  * Return the size of a string (including the ending 0!)
 385  */
 386 extern __inline__ long __strlen_user(const char *__s)
 387 {
 388         unsigned long res;
 389         unsigned long __dummy;
 390
 391         __asm__ __volatile__(
 392                 "mov    #-1,%1\n"
 393                 "9:\n"
 394                 "cmp/eq #0,%1\n\t"
 395                 "bf/s   9b\n\t"
 396                 "1:\t"
 397                 " mov.b @%0+,%1\n\t"
 398                 "sub    %3,%0\n"
 399                 "2:\n"
 400                 ".section .fixup,\"ax\"\n"
 401                 "3:\n\t"
 402                 "mov.l  4f,%1\n\t"
 403                 "jmp    @%1\n\t"
 404                 " mov   %4,%0\n"
 405                 ".align 4\n"
 406                 "4:     .long 2b\n"
 407                 ".previous\n"
 408                 ".section __ex_table,\"a\"\n"
 409                 "       .align 4\n"
 410                 "       .long 1b,3b\n"
 411                 ".previous"
 412                 : "=&r" (res), "=&z" (__dummy)
 413                 : "0" (__s), "r" (__s), "i" (-EFAULT));
 414         return res;
 415 }
 416
 417 extern __inline__ long strlen_user(const char *s)
 418 {
 419         if(!access_ok(VERIFY_READ, s, 0))
 420                 return 0;
 421         else
 422                 return __strlen_user(s);
 423 }
 424
 425 struct exception_table_entry
 426 {
 427         unsigned long insn, fixup;
 428 };
 429
 430 /* Returns 0 if exception not found and fixup.unit otherwise.  */
 431 extern unsigned long search_exception_table(unsigned long addr);
 432
 433 /* Returns the new pc */
 434 #define fixup_exception(map_reg, fixup_unit, pc)                \
 435 ({                                                              \
 436         fixup_unit;                                             \
 437 })
 438
 439 #endif /* __ASM_SH_UACCESS_H */