include/asm-sparc/uaccess.h

   1 /* $Id: uaccess.h,v 1.1.1.1 2005/04/11 02:50:56 jack 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 get_user(x,ptr) ({ \
  98 unsigned long __gu_addr = (unsigned long)(ptr); \
  99 __get_user_check((x),__gu_addr,sizeof(*(ptr)),__typeof__(*(ptr))); })
 100
 101 /*
 102  * The "__xxx" versions do not do address space checking, useful when
 103  * doing multiple accesses to the same area (the user has to do the
 104  * checks by hand with "access_ok()")
 105  */
 106 #define __put_user(x,ptr) __put_user_nocheck((x),(ptr),sizeof(*(ptr)))
 107 #define __get_user(x,ptr) __get_user_nocheck((x),(ptr),sizeof(*(ptr)),__typeof__(*(ptr)))
 108
 109 struct __large_struct { unsigned long buf[100]; };
 110 #define __m(x) ((struct __large_struct *)(x))
 111
 112 #define __put_user_check(x,addr,size) ({ \
 113 register int __pu_ret; \
 114 if (__access_ok(addr,size)) { \
 115 switch (size) { \
 116 case 1: __put_user_asm(x,b,addr,__pu_ret); break; \
 117 case 2: __put_user_asm(x,h,addr,__pu_ret); break; \
 118 case 4: __put_user_asm(x,,addr,__pu_ret); break; \
 119 case 8: __put_user_asm(x,d,addr,__pu_ret); break; \
 120 default: __pu_ret = __put_user_bad(); break; \
 121 } } else { __pu_ret = -EFAULT; } __pu_ret; })
 122
 123 #define __put_user_check_ret(x,addr,size,retval) ({ \
 124 register int __foo __asm__ ("l1"); \
 125 if (__access_ok(addr,size)) { \
 126 switch (size) { \
 127 case 1: __put_user_asm_ret(x,b,addr,retval,__foo); break; \
 128 case 2: __put_user_asm_ret(x,h,addr,retval,__foo); break; \
 129 case 4: __put_user_asm_ret(x,,addr,retval,__foo); break; \
 130 case 8: __put_user_asm_ret(x,d,addr,retval,__foo); break; \
 131 default: if (__put_user_bad()) return retval; break; \
 132 } } else return retval; })
 133
 134 #define __put_user_nocheck(x,addr,size) ({ \
 135 register int __pu_ret; \
 136 switch (size) { \
 137 case 1: __put_user_asm(x,b,addr,__pu_ret); break; \
 138 case 2: __put_user_asm(x,h,addr,__pu_ret); break; \
 139 case 4: __put_user_asm(x,,addr,__pu_ret); break; \
 140 case 8: __put_user_asm(x,d,addr,__pu_ret); break; \
 141 default: __pu_ret = __put_user_bad(); break; \
 142 } __pu_ret; })
 143
 144 #define __put_user_nocheck_ret(x,addr,size,retval) ({ \
 145 register int __foo __asm__ ("l1"); \
 146 switch (size) { \
 147 case 1: __put_user_asm_ret(x,b,addr,retval,__foo); break; \
 148 case 2: __put_user_asm_ret(x,h,addr,retval,__foo); break; \
 149 case 4: __put_user_asm_ret(x,,addr,retval,__foo); break; \
 150 case 8: __put_user_asm_ret(x,d,addr,retval,__foo); break; \
 151 default: if (__put_user_bad()) return retval; break; \
 152 } })
 153
 154 #define __put_user_asm(x,size,addr,ret)                                 \
 155 __asm__ __volatile__(                                                   \
 156         "/* Put user asm, inline. */\n"                                 \
 157 "1:\t"  "st"#size " %1, %2\n\t"                                         \
 158         "clr    %0\n"                                                   \
 159 "2:\n\n\t"                                                              \
 160         ".section .fixup,#alloc,#execinstr\n\t"                         \
 161         ".align 4\n"                                                    \
 162 "3:\n\t"                                                                \
 163         "b      2b\n\t"                                                 \
 164         " mov   %3, %0\n\t"                                             \
 165         ".previous\n\n\t"                                               \
 166         ".section __ex_table,#alloc\n\t"                                \
 167         ".align 4\n\t"                                                  \
 168         ".word  1b, 3b\n\t"                                             \
 169         ".previous\n\n\t"                                               \
 170        : "=&r" (ret) : "r" (x), "m" (*__m(addr)),                       \
 171          "i" (-EFAULT))
 172
 173 #define __put_user_asm_ret(x,size,addr,ret,foo)                         \
 174 if (__builtin_constant_p(ret) && ret == -EFAULT)                        \
 175 __asm__ __volatile__(                                                   \
 176         "/* Put user asm ret, inline. */\n"                             \
 177 "1:\t"  "st"#size " %1, %2\n\n\t"                                       \
 178         ".section __ex_table,#alloc\n\t"                                \
 179         ".align 4\n\t"                                                  \
 180         ".word  1b, __ret_efault\n\n\t"                                 \
 181         ".previous\n\n\t"                                               \
 182        : "=r" (foo) : "r" (x), "m" (*__m(addr)));                       \
 183 else                                                                    \
 184 __asm__ __volatile(                                                     \
 185         "/* Put user asm ret, inline. */\n"                             \
 186 "1:\t"  "st"#size " %1, %2\n\n\t"                                       \
 187         ".section .fixup,#alloc,#execinstr\n\t"                         \
 188         ".align 4\n"                                                    \
 189 "3:\n\t"                                                                \
 190         "ret\n\t"                                                       \
 191         " restore %%g0, %3, %%o0\n\t"                                   \
 192         ".previous\n\n\t"                                               \
 193         ".section __ex_table,#alloc\n\t"                                \
 194         ".align 4\n\t"                                                  \
 195         ".word  1b, 3b\n\n\t"                                           \
 196         ".previous\n\n\t"                                               \
 197        : "=r" (foo) : "r" (x), "m" (*__m(addr)), "i" (ret))
 198
 199 extern int __put_user_bad(void);
 200
 201 #define __get_user_check(x,addr,size,type) ({ \
 202 register int __gu_ret; \
 203 register unsigned long __gu_val; \
 204 if (__access_ok(addr,size)) { \
 205 switch (size) { \
 206 case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \
 207 case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \
 208 case 4: __get_user_asm(__gu_val,,addr,__gu_ret); break; \
 209 case 8: __get_user_asm(__gu_val,d,addr,__gu_ret); break; \
 210 default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \
 211 } } else { __gu_val = 0; __gu_ret = -EFAULT; } x = (type) __gu_val; __gu_ret; })
 212
 213 #define __get_user_check_ret(x,addr,size,type,retval) ({ \
 214 register unsigned long __gu_val __asm__ ("l1"); \
 215 if (__access_ok(addr,size)) { \
 216 switch (size) { \
 217 case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \
 218 case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \
 219 case 4: __get_user_asm_ret(__gu_val,,addr,retval); break; \
 220 case 8: __get_user_asm_ret(__gu_val,d,addr,retval); break; \
 221 default: if (__get_user_bad()) return retval; \
 222 } x = (type) __gu_val; } else return retval; })
 223
 224 #define __get_user_nocheck(x,addr,size,type) ({ \
 225 register int __gu_ret; \
 226 register unsigned long __gu_val; \
 227 switch (size) { \
 228 case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \
 229 case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \
 230 case 4: __get_user_asm(__gu_val,,addr,__gu_ret); break; \
 231 case 8: __get_user_asm(__gu_val,d,addr,__gu_ret); break; \
 232 default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \
 233 } x = (type) __gu_val; __gu_ret; })
 234
 235 #define __get_user_nocheck_ret(x,addr,size,type,retval) ({ \
 236 register unsigned long __gu_val __asm__ ("l1"); \
 237 switch (size) { \
 238 case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \
 239 case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \
 240 case 4: __get_user_asm_ret(__gu_val,,addr,retval); break; \
 241 case 8: __get_user_asm_ret(__gu_val,d,addr,retval); break; \
 242 default: if (__get_user_bad()) return retval; \
 243 } x = (type) __gu_val; })
 244
 245 #define __get_user_asm(x,size,addr,ret)                                 \
 246 __asm__ __volatile__(                                                   \
 247         "/* Get user asm, inline. */\n"                                 \
 248 "1:\t"  "ld"#size " %2, %1\n\t"                                         \
 249         "clr    %0\n"                                                   \
 250 "2:\n\n\t"                                                              \
 251         ".section .fixup,#alloc,#execinstr\n\t"                         \
 252         ".align 4\n"                                                    \
 253 "3:\n\t"                                                                \
 254         "clr    %1\n\t"                                                 \
 255         "b      2b\n\t"                                                 \
 256         " mov   %3, %0\n\n\t"                                           \
 257         ".previous\n\t"                                                 \
 258         ".section __ex_table,#alloc\n\t"                                \
 259         ".align 4\n\t"                                                  \
 260         ".word  1b, 3b\n\n\t"                                           \
 261         ".previous\n\t"                                                 \
 262        : "=&r" (ret), "=&r" (x) : "m" (*__m(addr)),                     \
 263          "i" (-EFAULT))
 264
 265 #define __get_user_asm_ret(x,size,addr,retval)                          \
 266 if (__builtin_constant_p(retval) && retval == -EFAULT)                  \
 267 __asm__ __volatile__(                                                   \
 268         "/* Get user asm ret, inline. */\n"                             \
 269 "1:\t"  "ld"#size " %1, %0\n\n\t"                                       \
 270         ".section __ex_table,#alloc\n\t"                                \
 271         ".align 4\n\t"                                                  \
 272         ".word  1b,__ret_efault\n\n\t"                                  \
 273         ".previous\n\t"                                                 \
 274        : "=&r" (x) : "m" (*__m(addr)));                                 \
 275 else                                                                    \
 276 __asm__ __volatile__(                                                   \
 277         "/* Get user asm ret, inline. */\n"                             \
 278 "1:\t"  "ld"#size " %1, %0\n\n\t"                                       \
 279         ".section .fixup,#alloc,#execinstr\n\t"                         \
 280         ".align 4\n"                                                    \
 281 "3:\n\t"                                                                \
 282         "ret\n\t"                                                       \
 283         " restore %%g0, %2, %%o0\n\n\t"                                 \
 284         ".previous\n\t"                                                 \
 285         ".section __ex_table,#alloc\n\t"                                \
 286         ".align 4\n\t"                                                  \
 287         ".word  1b, 3b\n\n\t"                                           \
 288         ".previous\n\t"                                                 \
 289        : "=&r" (x) : "m" (*__m(addr)), "i" (retval))
 290
 291 extern int __get_user_bad(void);
 292
 293 extern __kernel_size_t __copy_user(void *to, void *from, __kernel_size_t size);
 294
 295 #define copy_to_user(to,from,n) ({ \
 296 void *__copy_to = (void *) (to); \
 297 __kernel_size_t __copy_size = (__kernel_size_t) (n); \
 298 __kernel_size_t __copy_res; \
 299 if(__copy_size && __access_ok((unsigned long)__copy_to, __copy_size)) { \
 300 __copy_res = __copy_user(__copy_to, (void *) (from), __copy_size); \
 301 } else __copy_res = __copy_size; \
 302 __copy_res; })
 303
 304 #define __copy_to_user(to,from,n)               \
 305         __copy_user((void *)(to),               \
 306                     (void *)(from), n)
 307
 308 #define copy_from_user(to,from,n) ({ \
 309 void *__copy_to = (void *) (to); \
 310 void *__copy_from = (void *) (from); \
 311 __kernel_size_t __copy_size = (__kernel_size_t) (n); \
 312 __kernel_size_t __copy_res; \
 313 if(__copy_size && __access_ok((unsigned long)__copy_from, __copy_size)) { \
 314 __copy_res = __copy_user(__copy_to, __copy_from, __copy_size); \
 315 } else __copy_res = __copy_size; \
 316 __copy_res; })
 317
 318 #define __copy_from_user(to,from,n)             \
 319         __copy_user((void *)(to),               \
 320                     (void *)(from), n)
 321
 322 extern __inline__ __kernel_size_t __clear_user(void *addr, __kernel_size_t size)
 323 {
 324   __kernel_size_t ret;
 325   __asm__ __volatile__ (
 326         ".section __ex_table,#alloc\n\t"
 327         ".align 4\n\t"
 328         ".word 1f,3\n\t"
 329         ".previous\n\t"
 330         "mov %2, %%o1\n"
 331         "1:\n\t"
 332         "call __bzero\n\t"
 333         " mov %1, %%o0\n\t"
 334         "mov %%o0, %0\n"
 335         : "=r" (ret) : "r" (addr), "r" (size) :
 336         "o0", "o1", "o2", "o3", "o4", "o5", "o7",
 337         "g1", "g2", "g3", "g4", "g5", "g7", "cc");
 338   return ret;
 339 }
 340
 341 #define clear_user(addr,n) ({ \
 342 void *__clear_addr = (void *) (addr); \
 343 __kernel_size_t __clear_size = (__kernel_size_t) (n); \
 344 __kernel_size_t __clear_res; \
 345 if(__clear_size && __access_ok((unsigned long)__clear_addr, __clear_size)) { \
 346 __clear_res = __clear_user(__clear_addr, __clear_size); \
 347 } else __clear_res = __clear_size; \
 348 __clear_res; })
 349
 350 extern int __strncpy_from_user(unsigned long dest, unsigned long src, int count);
 351
 352 #define strncpy_from_user(dest,src,count) ({ \
 353 unsigned long __sfu_src = (unsigned long) (src); \
 354 int __sfu_count = (int) (count); \
 355 long __sfu_res = -EFAULT; \
 356 if(__access_ok(__sfu_src, __sfu_count)) { \
 357 __sfu_res = __strncpy_from_user((unsigned long) (dest), __sfu_src, __sfu_count); \
 358 } __sfu_res; })
 359
 360 extern int __strlen_user(const char *);
 361 extern int __strnlen_user(const char *, long len);
 362
 363 extern __inline__ int strlen_user(const char *str)
 364 {
 365         if(!access_ok(VERIFY_READ, str, 0))
 366                 return 0;
 367         else
 368                 return __strlen_user(str);
 369 }
 370
 371 extern __inline__ int strnlen_user(const char *str, long len)
 372 {
 373         if(!access_ok(VERIFY_READ, str, 0))
 374                 return 0;
 375         else
 376                 return __strnlen_user(str, len);
 377 }
 378
 379 #endif  /* __ASSEMBLY__ */
 380
 381 #endif /* _ASM_UACCESS_H */