include/asm-sparc/uaccess.h

   1 /* $Id: uaccess.h,v 1.21 2000/01/08 16:38:23 anton Exp $
   2  * uaccess.h: User space memore access functions.
   3  *
   4  * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
   5  * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
   6  */
   7 #ifndef _ASM_UACCESS_H
   8 #define _ASM_UACCESS_H
   9
  10 #ifdef __KERNEL__
  11 #include <linux/sched.h>
  12 #include <linux/string.h>
  13 #include <asm/vac-ops.h>
  14 #include <asm/a.out.h>
  15 #endif
  16
  17 #ifndef __ASSEMBLY__
  18
  19 /* Sparc is not segmented, however we need to be able to fool verify_area()
  20  * when doing system calls from kernel mode legitimately.
  21  *
  22  * "For historical reasons, these macros are grossly misnamed." -Linus
  23  */
  24
  25 #define KERNEL_DS   ((mm_segment_t) { 0 })
  26 #define USER_DS     ((mm_segment_t) { -1 })
  27
  28 #define VERIFY_READ     0
  29 #define VERIFY_WRITE    1
  30
  31 #define get_ds()        (KERNEL_DS)
  32 #define get_fs()        (current->thread.current_ds)
  33 #define set_fs(val)     ((current->thread.current_ds) = (val))
  34
  35 #define segment_eq(a,b) ((a).seg == (b).seg)
  36
  37 /* We have there a nice not-mapped page at PAGE_OFFSET - PAGE_SIZE, so that this test
  38  * can be fairly lightweight.
  39  * No one can read/write anything from userland in the kernel space by setting
  40  * large size and address near to PAGE_OFFSET - a fault will break his intentions.
  41  */
  42 #define __user_ok(addr,size) ((addr) < STACK_TOP)
  43 #define __kernel_ok (segment_eq(get_fs(), KERNEL_DS))
  44 #define __access_ok(addr,size) (__user_ok((addr) & get_fs().seg,(size)))
  45 #define access_ok(type,addr,size) __access_ok((unsigned long)(addr),(size))
  46
  47 extern inline int verify_area(int type, const void * addr, unsigned long size)
  48 {
  49         return access_ok(type,addr,size)?0:-EFAULT;
  50 }
  51
  52 /*
  53  * The exception table consists of pairs of addresses: the first is the
  54  * address of an instruction that is allowed to fault, and the second is
  55  * the address at which the program should continue.  No registers are
  56  * modified, so it is entirely up to the continuation code to figure out
  57  * what to do.
  58  *
  59  * All the routines below use bits of fixup code that are out of line
  60  * with the main instruction path.  This means when everything is well,
  61  * we don't even have to jump over them.  Further, they do not intrude
  62  * on our cache or tlb entries.
  63  *
  64  * There is a special way how to put a range of potentially faulting
  65  * insns (like twenty ldd/std's with now intervening other instructions)
  66  * You specify address of first in insn and 0 in fixup and in the next
  67  * exception_table_entry you specify last potentially faulting insn + 1
  68  * and in fixup the routine which should handle the fault.
  69  * That fixup code will get
  70  * (faulting_insn_address - first_insn_in_the_range_address)/4
  71  * in %g2 (ie. index of the faulting instruction in the range).
  72  */
  73
  74 struct exception_table_entry
  75 {
  76         unsigned long insn, fixup;
  77 };
  78
  79 /* Returns 0 if exception not found and fixup otherwise.  */
  80 extern unsigned long search_exception_table(unsigned long, unsigned long *);
  81
  82 extern void __ret_efault(void);
  83
  84 /* Uh, these should become the main single-value transfer routines..
  85  * They automatically use the right size if we just have the right
  86  * pointer type..
  87  *
  88  * This gets kind of ugly. We want to return _two_ values in "get_user()"
  89  * and yet we don't want to do any pointers, because that is too much
  90  * of a performance impact. Thus we have a few rather ugly macros here,
  91  * and hide all the uglyness from the user.
  92  */
  93 #define put_user(x,ptr) ({ \
  94 unsigned long __pu_addr = (unsigned long)(ptr); \
  95 __put_user_check((__typeof__(*(ptr)))(x),__pu_addr,sizeof(*(ptr))); })
  96
  97 #define put_user_ret(x,ptr,retval) ({ \
  98 unsigned long __pu_addr = (unsigned long)(ptr); \
  99 __put_user_check_ret((__typeof__(*(ptr)))(x),__pu_addr,sizeof(*(ptr)),retval); })
 100
 101 #define get_user(x,ptr) ({ \
 102 unsigned long __gu_addr = (unsigned long)(ptr); \
 103 __get_user_check((x),__gu_addr,sizeof(*(ptr)),__typeof__(*(ptr))); })
 104
 105 #define get_user_ret(x,ptr,retval) ({ \
 106 unsigned long __gu_addr = (unsigned long)(ptr); \
 107 __get_user_check_ret((x),__gu_addr,sizeof(*(ptr)),__typeof__(*(ptr)),retval); })
 108
 109 /*
 110  * The "__xxx" versions do not do address space checking, useful when
 111  * doing multiple accesses to the same area (the user has to do the
 112  * checks by hand with "access_ok()")
 113  */
 114 #define __put_user(x,ptr) __put_user_nocheck((x),(ptr),sizeof(*(ptr)))
 115 #define __put_user_ret(x,ptr,retval) __put_user_nocheck_ret((x),(ptr),sizeof(*(ptr)),retval)
 116 #define __get_user(x,ptr) __get_user_nocheck((x),(ptr),sizeof(*(ptr)),__typeof__(*(ptr)))
 117 #define __get_user_ret(x,ptr,retval) __get_user_nocheck_ret((x),(ptr),sizeof(*(ptr)),__typeof__(*(ptr)),retval)
 118
 119 struct __large_struct { unsigned long buf[100]; };
 120 #define __m(x) ((struct __large_struct *)(x))
 121
 122 #define __put_user_check(x,addr,size) ({ \
 123 register int __pu_ret; \
 124 if (__access_ok(addr,size)) { \
 125 switch (size) { \
 126 case 1: __put_user_asm(x,b,addr,__pu_ret); break; \
 127 case 2: __put_user_asm(x,h,addr,__pu_ret); break; \
 128 case 4: __put_user_asm(x,,addr,__pu_ret); break; \
 129 default: __pu_ret = __put_user_bad(); break; \
 130 } } else { __pu_ret = -EFAULT; } __pu_ret; })
 131
 132 #define __put_user_check_ret(x,addr,size,retval) ({ \
 133 register int __foo __asm__ ("l1"); \
 134 if (__access_ok(addr,size)) { \
 135 switch (size) { \
 136 case 1: __put_user_asm_ret(x,b,addr,retval,__foo); break; \
 137 case 2: __put_user_asm_ret(x,h,addr,retval,__foo); break; \
 138 case 4: __put_user_asm_ret(x,,addr,retval,__foo); break; \
 139 default: if (__put_user_bad()) return retval; break; \
 140 } } else return retval; })
 141
 142 #define __put_user_nocheck(x,addr,size) ({ \
 143 register int __pu_ret; \
 144 switch (size) { \
 145 case 1: __put_user_asm(x,b,addr,__pu_ret); break; \
 146 case 2: __put_user_asm(x,h,addr,__pu_ret); break; \
 147 case 4: __put_user_asm(x,,addr,__pu_ret); break; \
 148 default: __pu_ret = __put_user_bad(); break; \
 149 } __pu_ret; })
 150
 151 #define __put_user_nocheck_ret(x,addr,size,retval) ({ \
 152 register int __foo __asm__ ("l1"); \
 153 switch (size) { \
 154 case 1: __put_user_asm_ret(x,b,addr,retval,__foo); break; \
 155 case 2: __put_user_asm_ret(x,h,addr,retval,__foo); break; \
 156 case 4: __put_user_asm_ret(x,,addr,retval,__foo); break; \
 157 default: if (__put_user_bad()) return retval; break; \
 158 } })
 159
 160 #define __put_user_asm(x,size,addr,ret)                                 \
 161 __asm__ __volatile__(                                                   \
 162         "/* Put user asm, inline. */\n"                                 \
 163 "1:\t"  "st"#size " %1, %2\n\t"                                         \
 164         "clr    %0\n"                                                   \
 165 "2:\n\n\t"                                                              \
 166         ".section .fixup,#alloc,#execinstr\n\t"                         \
 167         ".align 4\n"                                                    \
 168 "3:\n\t"                                                                \
 169         "b      2b\n\t"                                                 \
 170         " mov   %3, %0\n\t"                                             \
 171         ".previous\n\n\t"                                               \
 172         ".section __ex_table,#alloc\n\t"                                \
 173         ".align 4\n\t"                                                  \
 174         ".word  1b, 3b\n\t"                                             \
 175         ".previous\n\n\t"                                               \
 176        : "=&r" (ret) : "r" (x), "m" (*__m(addr)),                       \
 177          "i" (-EFAULT))
 178
 179 #define __put_user_asm_ret(x,size,addr,ret,foo)                         \
 180 if (__builtin_constant_p(ret) && ret == -EFAULT)                        \
 181 __asm__ __volatile__(                                                   \
 182         "/* Put user asm ret, inline. */\n"                             \
 183 "1:\t"  "st"#size " %1, %2\n\n\t"                                       \
 184         ".section __ex_table,#alloc\n\t"                                \
 185         ".align 4\n\t"                                                  \
 186         ".word  1b, __ret_efault\n\n\t"                                 \
 187         ".previous\n\n\t"                                               \
 188        : "=r" (foo) : "r" (x), "m" (*__m(addr)));                       \
 189 else                                                                    \
 190 __asm__ __volatile(                                                     \
 191         "/* Put user asm ret, inline. */\n"                             \
 192 "1:\t"  "st"#size " %1, %2\n\n\t"                                       \
 193         ".section .fixup,#alloc,#execinstr\n\t"                         \
 194         ".align 4\n"                                                    \
 195 "3:\n\t"                                                                \
 196         "ret\n\t"                                                       \
 197         " restore %%g0, %3, %%o0\n\t"                                   \
 198         ".previous\n\n\t"                                               \
 199         ".section __ex_table,#alloc\n\t"                                \
 200         ".align 4\n\t"                                                  \
 201         ".word  1b, 3b\n\n\t"                                           \
 202         ".previous\n\n\t"                                               \
 203        : "=r" (foo) : "r" (x), "m" (*__m(addr)), "i" (ret))
 204
 205 extern int __put_user_bad(void);
 206
 207 #define __get_user_check(x,addr,size,type) ({ \
 208 register int __gu_ret; \
 209 register unsigned long __gu_val; \
 210 if (__access_ok(addr,size)) { \
 211 switch (size) { \
 212 case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \
 213 case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \
 214 case 4: __get_user_asm(__gu_val,,addr,__gu_ret); break; \
 215 default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \
 216 } } else { __gu_val = 0; __gu_ret = -EFAULT; } x = (type) __gu_val; __gu_ret; })
 217
 218 #define __get_user_check_ret(x,addr,size,type,retval) ({ \
 219 register unsigned long __gu_val __asm__ ("l1"); \
 220 if (__access_ok(addr,size)) { \
 221 switch (size) { \
 222 case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \
 223 case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \
 224 case 4: __get_user_asm_ret(__gu_val,,addr,retval); break; \
 225 default: if (__get_user_bad()) return retval; \
 226 } x = (type) __gu_val; } else return retval; })
 227
 228 #define __get_user_nocheck(x,addr,size,type) ({ \
 229 register int __gu_ret; \
 230 register unsigned long __gu_val; \
 231 switch (size) { \
 232 case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \
 233 case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \
 234 case 4: __get_user_asm(__gu_val,,addr,__gu_ret); break; \
 235 default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \
 236 } x = (type) __gu_val; __gu_ret; })
 237
 238 #define __get_user_nocheck_ret(x,addr,size,type,retval) ({ \
 239 register unsigned long __gu_val __asm__ ("l1"); \
 240 switch (size) { \
 241 case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \
 242 case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \
 243 case 4: __get_user_asm_ret(__gu_val,,addr,retval); break; \
 244 default: if (__get_user_bad()) return retval; \
 245 } x = (type) __gu_val; })
 246
 247 #define __get_user_asm(x,size,addr,ret)                                 \
 248 __asm__ __volatile__(                                                   \
 249         "/* Get user asm, inline. */\n"                                 \
 250 "1:\t"  "ld"#size " %2, %1\n\t"                                         \
 251         "clr    %0\n"                                                   \
 252 "2:\n\n\t"                                                              \
 253         ".section .fixup,#alloc,#execinstr\n\t"                         \
 254         ".align 4\n"                                                    \
 255 "3:\n\t"                                                                \
 256         "clr    %1\n\t"                                                 \
 257         "b      2b\n\t"                                                 \
 258         " mov   %3, %0\n\n\t"                                           \
 259         ".previous\n\t"                                                 \
 260         ".section __ex_table,#alloc\n\t"                                \
 261         ".align 4\n\t"                                                  \
 262         ".word  1b, 3b\n\n\t"                                           \
 263         ".previous\n\t"                                                 \
 264        : "=&r" (ret), "=&r" (x) : "m" (*__m(addr)),                     \
 265          "i" (-EFAULT))
 266
 267 #define __get_user_asm_ret(x,size,addr,retval)                          \
 268 if (__builtin_constant_p(retval) && retval == -EFAULT)                  \
 269 __asm__ __volatile__(                                                   \
 270         "/* Get user asm ret, inline. */\n"                             \
 271 "1:\t"  "ld"#size " %1, %0\n\n\t"                                       \
 272         ".section __ex_table,#alloc\n\t"                                \
 273         ".align 4\n\t"                                                  \
 274         ".word  1b,__ret_efault\n\n\t"                                  \
 275         ".previous\n\t"                                                 \
 276        : "=&r" (x) : "m" (*__m(addr)));                                 \
 277 else                                                                    \
 278 __asm__ __volatile__(                                                   \
 279         "/* Get user asm ret, inline. */\n"                             \
 280 "1:\t"  "ld"#size " %1, %0\n\n\t"                                       \
 281         ".section .fixup,#alloc,#execinstr\n\t"                         \
 282         ".align 4\n"                                                    \
 283 "3:\n\t"                                                                \
 284         "ret\n\t"                                                       \
 285         " restore %%g0, %2, %%o0\n\n\t"                                 \
 286         ".previous\n\t"                                                 \
 287         ".section __ex_table,#alloc\n\t"                                \
 288         ".align 4\n\t"                                                  \
 289         ".word  1b, 3b\n\n\t"                                           \
 290         ".previous\n\t"                                                 \
 291        : "=&r" (x) : "m" (*__m(addr)), "i" (retval))
 292
 293 extern int __get_user_bad(void);
 294
 295 extern __kernel_size_t __copy_user(void *to, void *from, __kernel_size_t size);
 296
 297 #define copy_to_user(to,from,n) ({ \
 298 void *__copy_to = (void *) (to); \
 299 __kernel_size_t __copy_size = (__kernel_size_t) (n); \
 300 __kernel_size_t __copy_res; \
 301 if(__copy_size && __access_ok((unsigned long)__copy_to, __copy_size)) { \
 302 __copy_res = __copy_user(__copy_to, (void *) (from), __copy_size); \
 303 } else __copy_res = __copy_size; \
 304 __copy_res; })
 305
 306 #define copy_to_user_ret(to,from,n,retval) ({ \
 307 if (copy_to_user(to,from,n)) \
 308         return retval; \
 309 })
 310
 311 #define __copy_to_user(to,from,n)               \
 312         __copy_user((void *)(to),               \
 313                     (void *)(from), n)
 314
 315 #define __copy_to_user_ret(to,from,n,retval) ({ \
 316 if (__copy_to_user(to,from,n)) \
 317         return retval; \
 318 })
 319
 320 #define copy_from_user(to,from,n) ({ \
 321 void *__copy_to = (void *) (to); \
 322 void *__copy_from = (void *) (from); \
 323 __kernel_size_t __copy_size = (__kernel_size_t) (n); \
 324 __kernel_size_t __copy_res; \
 325 if(__copy_size && __access_ok((unsigned long)__copy_from, __copy_size)) { \
 326 __copy_res = __copy_user(__copy_to, __copy_from, __copy_size); \
 327 } else __copy_res = __copy_size; \
 328 __copy_res; })
 329
 330 #define copy_from_user_ret(to,from,n,retval) ({ \
 331 if (copy_from_user(to,from,n)) \
 332         return retval; \
 333 })
 334
 335 #define __copy_from_user(to,from,n)             \
 336         __copy_user((void *)(to),               \
 337                     (void *)(from), n)
 338
 339 #define __copy_from_user_ret(to,from,n,retval) ({ \
 340 if (__copy_from_user(to,from,n)) \
 341         return retval; \
 342 })
 343
 344 extern __inline__ __kernel_size_t __clear_user(void *addr, __kernel_size_t size)
 345 {
 346   __kernel_size_t ret;
 347   __asm__ __volatile__ ("
 348         .section __ex_table,#alloc
 349         .align 4
 350         .word 1f,3
 351         .previous
 352         mov %2, %%o1
 353 1:      call __bzero
 354          mov %1, %%o0
 355         mov %%o0, %0
 356         " : "=r" (ret) : "r" (addr), "r" (size) :
 357         "o0", "o1", "o2", "o3", "o4", "o5", "o7",
 358         "g1", "g2", "g3", "g4", "g5", "g7", "cc");
 359   return ret;
 360 }
 361
 362 #define clear_user(addr,n) ({ \
 363 void *__clear_addr = (void *) (addr); \
 364 __kernel_size_t __clear_size = (__kernel_size_t) (n); \
 365 __kernel_size_t __clear_res; \
 366 if(__clear_size && __access_ok((unsigned long)__clear_addr, __clear_size)) { \
 367 __clear_res = __clear_user(__clear_addr, __clear_size); \
 368 } else __clear_res = __clear_size; \
 369 __clear_res; })
 370
 371 #define clear_user_ret(addr,size,retval) ({ \
 372 if (clear_user(addr,size)) \
 373         return retval; \
 374 })
 375
 376 extern int __strncpy_from_user(unsigned long dest, unsigned long src, int count);
 377
 378 #define strncpy_from_user(dest,src,count) ({ \
 379 unsigned long __sfu_src = (unsigned long) (src); \
 380 int __sfu_count = (int) (count); \
 381 long __sfu_res = -EFAULT; \
 382 if(__access_ok(__sfu_src, __sfu_count)) { \
 383 __sfu_res = __strncpy_from_user((unsigned long) (dest), __sfu_src, __sfu_count); \
 384 } __sfu_res; })
 385
 386 extern int __strlen_user(const char *);
 387 extern int __strnlen_user(const char *, long len);
 388
 389 extern __inline__ int strlen_user(const char *str)
 390 {
 391         if(!access_ok(VERIFY_READ, str, 0))
 392                 return 0;
 393         else
 394                 return __strlen_user(str);
 395 }
 396
 397 extern __inline__ int strnlen_user(const char *str, long len)
 398 {
 399         if(!access_ok(VERIFY_READ, str, 0))
 400                 return 0;
 401         else
 402                 return __strnlen_user(str, len);
 403 }
 404
 405 #endif  /* __ASSEMBLY__ */
 406
 407 #endif /* _ASM_UACCESS_H */