include/asm-sparc/uaccess.h

   1 /* $Id: uaccess.h,v 1.24 2001/10/30 04:32:24 davem 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/compiler.h>
  12 #include <linux/sched.h>
  13 #include <linux/string.h>
  14 #include <linux/errno.h>
  15 #include <asm/vac-ops.h>
  16 #include <asm/a.out.h>
  17 #endif
  18
  19 #ifndef __ASSEMBLY__
  20
  21 /* Sparc is not segmented, however we need to be able to fool access_ok()
  22  * when doing system calls from kernel mode legitimately.
  23  *
  24  * "For historical reasons, these macros are grossly misnamed." -Linus
  25  */
  26
  27 #define KERNEL_DS   ((mm_segment_t) { 0 })
  28 #define USER_DS     ((mm_segment_t) { -1 })
  29
  30 #define VERIFY_READ     0
  31 #define VERIFY_WRITE    1
  32
  33 #define get_ds()        (KERNEL_DS)
  34 #define get_fs()        (current->thread.current_ds)
  35 #define set_fs(val)     ((current->thread.current_ds) = (val))
  36
  37 #define segment_eq(a,b) ((a).seg == (b).seg)
  38
  39 /* We have there a nice not-mapped page at PAGE_OFFSET - PAGE_SIZE, so that this test
  40  * can be fairly lightweight.
  41  * No one can read/write anything from userland in the kernel space by setting
  42  * large size and address near to PAGE_OFFSET - a fault will break his intentions.
  43  */
  44 #define __user_ok(addr,size) ((addr) < STACK_TOP)
  45 #define __kernel_ok (segment_eq(get_fs(), KERNEL_DS))
  46 #define __access_ok(addr,size) (__user_ok((addr) & get_fs().seg,(size)))
  47 #define access_ok(type,addr,size) __access_ok((unsigned long)(addr),(size))
  48
  49 /* this function will go away soon - use access_ok() instead */
  50 static inline int __deprecated verify_area(int type, const void __user * addr, unsigned long size)
  51 {
  52         return access_ok(type,addr,size) ? 0 : -EFAULT;
  53 }
  54
  55 /*
  56  * The exception table consists of pairs of addresses: the first is the
  57  * address of an instruction that is allowed to fault, and the second is
  58  * the address at which the program should continue.  No registers are
  59  * modified, so it is entirely up to the continuation code to figure out
  60  * what to do.
  61  *
  62  * All the routines below use bits of fixup code that are out of line
  63  * with the main instruction path.  This means when everything is well,
  64  * we don't even have to jump over them.  Further, they do not intrude
  65  * on our cache or tlb entries.
  66  *
  67  * There is a special way how to put a range of potentially faulting
  68  * insns (like twenty ldd/std's with now intervening other instructions)
  69  * You specify address of first in insn and 0 in fixup and in the next
  70  * exception_table_entry you specify last potentially faulting insn + 1
  71  * and in fixup the routine which should handle the fault.
  72  * That fixup code will get
  73  * (faulting_insn_address - first_insn_in_the_range_address)/4
  74  * in %g2 (ie. index of the faulting instruction in the range).
  75  */
  76
  77 struct exception_table_entry
  78 {
  79         unsigned long insn, fixup;
  80 };
  81
  82 /* Returns 0 if exception not found and fixup otherwise.  */
  83 extern unsigned long search_extables_range(unsigned long addr, unsigned long *g2);
  84
  85 extern void __ret_efault(void);
  86
  87 /* Uh, these should become the main single-value transfer routines..
  88  * They automatically use the right size if we just have the right
  89  * pointer type..
  90  *
  91  * This gets kind of ugly. We want to return _two_ values in "get_user()"
  92  * and yet we don't want to do any pointers, because that is too much
  93  * of a performance impact. Thus we have a few rather ugly macros here,
  94  * and hide all the ugliness from the user.
  95  */
  96 #define put_user(x,ptr) ({ \
  97 unsigned long __pu_addr = (unsigned long)(ptr); \
  98 __chk_user_ptr(ptr); \
  99 __put_user_check((__typeof__(*(ptr)))(x),__pu_addr,sizeof(*(ptr))); })
 100
 101 #define get_user(x,ptr) ({ \
 102 unsigned long __gu_addr = (unsigned long)(ptr); \
 103 __chk_user_ptr(ptr); \
 104 __get_user_check((x),__gu_addr,sizeof(*(ptr)),__typeof__(*(ptr))); })
 105
 106 /*
 107  * The "__xxx" versions do not do address space checking, useful when
 108  * doing multiple accesses to the same area (the user has to do the
 109  * checks by hand with "access_ok()")
 110  */
 111 #define __put_user(x,ptr) __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
 112 #define __get_user(x,ptr) __get_user_nocheck((x),(ptr),sizeof(*(ptr)),__typeof__(*(ptr)))
 113
 114 struct __large_struct { unsigned long buf[100]; };
 115 #define __m(x) ((struct __large_struct __user *)(x))
 116
 117 #define __put_user_check(x,addr,size) ({ \
 118 register int __pu_ret; \
 119 if (__access_ok(addr,size)) { \
 120 switch (size) { \
 121 case 1: __put_user_asm(x,b,addr,__pu_ret); break; \
 122 case 2: __put_user_asm(x,h,addr,__pu_ret); break; \
 123 case 4: __put_user_asm(x,,addr,__pu_ret); break; \
 124 case 8: __put_user_asm(x,d,addr,__pu_ret); break; \
 125 default: __pu_ret = __put_user_bad(); break; \
 126 } } else { __pu_ret = -EFAULT; } __pu_ret; })
 127
 128 #define __put_user_check_ret(x,addr,size,retval) ({ \
 129 register int __foo __asm__ ("l1"); \
 130 if (__access_ok(addr,size)) { \
 131 switch (size) { \
 132 case 1: __put_user_asm_ret(x,b,addr,retval,__foo); break; \
 133 case 2: __put_user_asm_ret(x,h,addr,retval,__foo); break; \
 134 case 4: __put_user_asm_ret(x,,addr,retval,__foo); break; \
 135 case 8: __put_user_asm_ret(x,d,addr,retval,__foo); break; \
 136 default: if (__put_user_bad()) return retval; break; \
 137 } } else return retval; })
 138
 139 #define __put_user_nocheck(x,addr,size) ({ \
 140 register int __pu_ret; \
 141 switch (size) { \
 142 case 1: __put_user_asm(x,b,addr,__pu_ret); break; \
 143 case 2: __put_user_asm(x,h,addr,__pu_ret); break; \
 144 case 4: __put_user_asm(x,,addr,__pu_ret); break; \
 145 case 8: __put_user_asm(x,d,addr,__pu_ret); break; \
 146 default: __pu_ret = __put_user_bad(); break; \
 147 } __pu_ret; })
 148
 149 #define __put_user_nocheck_ret(x,addr,size,retval) ({ \
 150 register int __foo __asm__ ("l1"); \
 151 switch (size) { \
 152 case 1: __put_user_asm_ret(x,b,addr,retval,__foo); break; \
 153 case 2: __put_user_asm_ret(x,h,addr,retval,__foo); break; \
 154 case 4: __put_user_asm_ret(x,,addr,retval,__foo); break; \
 155 case 8: __put_user_asm_ret(x,d,addr,retval,__foo); break; \
 156 default: if (__put_user_bad()) return retval; break; \
 157 } })
 158
 159 #define __put_user_asm(x,size,addr,ret)                                 \
 160 __asm__ __volatile__(                                                   \
 161         "/* Put user asm, inline. */\n"                                 \
 162 "1:\t"  "st"#size " %1, %2\n\t"                                         \
 163         "clr    %0\n"                                                   \
 164 "2:\n\n\t"                                                              \
 165         ".section .fixup,#alloc,#execinstr\n\t"                         \
 166         ".align 4\n"                                                    \
 167 "3:\n\t"                                                                \
 168         "b      2b\n\t"                                                 \
 169         " mov   %3, %0\n\t"                                             \
 170         ".previous\n\n\t"                                               \
 171         ".section __ex_table,#alloc\n\t"                                \
 172         ".align 4\n\t"                                                  \
 173         ".word  1b, 3b\n\t"                                             \
 174         ".previous\n\n\t"                                               \
 175        : "=&r" (ret) : "r" (x), "m" (*__m(addr)),                       \
 176          "i" (-EFAULT))
 177
 178 #define __put_user_asm_ret(x,size,addr,ret,foo)                         \
 179 if (__builtin_constant_p(ret) && ret == -EFAULT)                        \
 180 __asm__ __volatile__(                                                   \
 181         "/* Put user asm ret, inline. */\n"                             \
 182 "1:\t"  "st"#size " %1, %2\n\n\t"                                       \
 183         ".section __ex_table,#alloc\n\t"                                \
 184         ".align 4\n\t"                                                  \
 185         ".word  1b, __ret_efault\n\n\t"                                 \
 186         ".previous\n\n\t"                                               \
 187        : "=r" (foo) : "r" (x), "m" (*__m(addr)));                       \
 188 else                                                                    \
 189 __asm__ __volatile(                                                     \
 190         "/* Put user asm ret, inline. */\n"                             \
 191 "1:\t"  "st"#size " %1, %2\n\n\t"                                       \
 192         ".section .fixup,#alloc,#execinstr\n\t"                         \
 193         ".align 4\n"                                                    \
 194 "3:\n\t"                                                                \
 195         "ret\n\t"                                                       \
 196         " restore %%g0, %3, %%o0\n\t"                                   \
 197         ".previous\n\n\t"                                               \
 198         ".section __ex_table,#alloc\n\t"                                \
 199         ".align 4\n\t"                                                  \
 200         ".word  1b, 3b\n\n\t"                                           \
 201         ".previous\n\n\t"                                               \
 202        : "=r" (foo) : "r" (x), "m" (*__m(addr)), "i" (ret))
 203
 204 extern int __put_user_bad(void);
 205
 206 #define __get_user_check(x,addr,size,type) ({ \
 207 register int __gu_ret; \
 208 register unsigned long __gu_val; \
 209 if (__access_ok(addr,size)) { \
 210 switch (size) { \
 211 case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \
 212 case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \
 213 case 4: __get_user_asm(__gu_val,,addr,__gu_ret); break; \
 214 case 8: __get_user_asm(__gu_val,d,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 case 8: __get_user_asm_ret(__gu_val,d,addr,retval); break; \
 226 default: if (__get_user_bad()) return retval; \
 227 } x = (type) __gu_val; } else return retval; })
 228
 229 #define __get_user_nocheck(x,addr,size,type) ({ \
 230 register int __gu_ret; \
 231 register unsigned long __gu_val; \
 232 switch (size) { \
 233 case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \
 234 case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \
 235 case 4: __get_user_asm(__gu_val,,addr,__gu_ret); break; \
 236 case 8: __get_user_asm(__gu_val,d,addr,__gu_ret); break; \
 237 default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \
 238 } x = (type) __gu_val; __gu_ret; })
 239
 240 #define __get_user_nocheck_ret(x,addr,size,type,retval) ({ \
 241 register unsigned long __gu_val __asm__ ("l1"); \
 242 switch (size) { \
 243 case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \
 244 case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \
 245 case 4: __get_user_asm_ret(__gu_val,,addr,retval); break; \
 246 case 8: __get_user_asm_ret(__gu_val,d,addr,retval); break; \
 247 default: if (__get_user_bad()) return retval; \
 248 } x = (type) __gu_val; })
 249
 250 #define __get_user_asm(x,size,addr,ret)                                 \
 251 __asm__ __volatile__(                                                   \
 252         "/* Get user asm, inline. */\n"                                 \
 253 "1:\t"  "ld"#size " %2, %1\n\t"                                         \
 254         "clr    %0\n"                                                   \
 255 "2:\n\n\t"                                                              \
 256         ".section .fixup,#alloc,#execinstr\n\t"                         \
 257         ".align 4\n"                                                    \
 258 "3:\n\t"                                                                \
 259         "clr    %1\n\t"                                                 \
 260         "b      2b\n\t"                                                 \
 261         " mov   %3, %0\n\n\t"                                           \
 262         ".previous\n\t"                                                 \
 263         ".section __ex_table,#alloc\n\t"                                \
 264         ".align 4\n\t"                                                  \
 265         ".word  1b, 3b\n\n\t"                                           \
 266         ".previous\n\t"                                                 \
 267        : "=&r" (ret), "=&r" (x) : "m" (*__m(addr)),                     \
 268          "i" (-EFAULT))
 269
 270 #define __get_user_asm_ret(x,size,addr,retval)                          \
 271 if (__builtin_constant_p(retval) && retval == -EFAULT)                  \
 272 __asm__ __volatile__(                                                   \
 273         "/* Get user asm ret, inline. */\n"                             \
 274 "1:\t"  "ld"#size " %1, %0\n\n\t"                                       \
 275         ".section __ex_table,#alloc\n\t"                                \
 276         ".align 4\n\t"                                                  \
 277         ".word  1b,__ret_efault\n\n\t"                                  \
 278         ".previous\n\t"                                                 \
 279        : "=&r" (x) : "m" (*__m(addr)));                                 \
 280 else                                                                    \
 281 __asm__ __volatile__(                                                   \
 282         "/* Get user asm ret, inline. */\n"                             \
 283 "1:\t"  "ld"#size " %1, %0\n\n\t"                                       \
 284         ".section .fixup,#alloc,#execinstr\n\t"                         \
 285         ".align 4\n"                                                    \
 286 "3:\n\t"                                                                \
 287         "ret\n\t"                                                       \
 288         " restore %%g0, %2, %%o0\n\n\t"                                 \
 289         ".previous\n\t"                                                 \
 290         ".section __ex_table,#alloc\n\t"                                \
 291         ".align 4\n\t"                                                  \
 292         ".word  1b, 3b\n\n\t"                                           \
 293         ".previous\n\t"                                                 \
 294        : "=&r" (x) : "m" (*__m(addr)), "i" (retval))
 295
 296 extern int __get_user_bad(void);
 297
 298 extern unsigned long __copy_user(void __user *to, const void __user *from, unsigned long size);
 299
 300 static inline unsigned long copy_to_user(void __user *to, const void *from, unsigned long n)
 301 {
 302         if (n && __access_ok((unsigned long) to, n))
 303                 return __copy_user(to, (__force void __user *) from, n);
 304         else
 305                 return n;
 306 }
 307
 308 static inline unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
 309 {
 310         return __copy_user(to, (__force void __user *) from, n);
 311 }
 312
 313 static inline unsigned long copy_from_user(void *to, const void __user *from, unsigned long n)
 314 {
 315         if (n && __access_ok((unsigned long) from, n))
 316                 return __copy_user((__force void __user *) to, from, n);
 317         else
 318                 return n;
 319 }
 320
 321 static inline unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n)
 322 {
 323         return __copy_user((__force void __user *) to, from, n);
 324 }
 325
 326 #define __copy_to_user_inatomic __copy_to_user
 327 #define __copy_from_user_inatomic __copy_from_user
 328
 329 static inline unsigned long __clear_user(void __user *addr, unsigned long size)
 330 {
 331         unsigned long ret;
 332
 333         __asm__ __volatile__ (
 334                 ".section __ex_table,#alloc\n\t"
 335                 ".align 4\n\t"
 336                 ".word 1f,3\n\t"
 337                 ".previous\n\t"
 338                 "mov %2, %%o1\n"
 339                 "1:\n\t"
 340                 "call __bzero\n\t"
 341                 " mov %1, %%o0\n\t"
 342                 "mov %%o0, %0\n"
 343                 : "=r" (ret) : "r" (addr), "r" (size) :
 344                 "o0", "o1", "o2", "o3", "o4", "o5", "o7",
 345                 "g1", "g2", "g3", "g4", "g5", "g7", "cc");
 346
 347         return ret;
 348 }
 349
 350 static inline unsigned long clear_user(void __user *addr, unsigned long n)
 351 {
 352         if (n && __access_ok((unsigned long) addr, n))
 353                 return __clear_user(addr, n);
 354         else
 355                 return n;
 356 }
 357
 358 extern long __strncpy_from_user(char *dest, const char __user *src, long count);
 359
 360 static inline long strncpy_from_user(char *dest, const char __user *src, long count)
 361 {
 362         if (__access_ok((unsigned long) src, count))
 363                 return __strncpy_from_user(dest, src, count);
 364         else
 365                 return -EFAULT;
 366 }
 367
 368 extern long __strlen_user(const char __user *);
 369 extern long __strnlen_user(const char __user *, long len);
 370
 371 static inline long strlen_user(const char __user *str)
 372 {
 373         if (!access_ok(VERIFY_READ, str, 0))
 374                 return 0;
 375         else
 376                 return __strlen_user(str);
 377 }
 378
 379 static inline long strnlen_user(const char __user *str, long len)
 380 {
 381         if (!access_ok(VERIFY_READ, str, 0))
 382                 return 0;
 383         else
 384                 return __strnlen_user(str, len);
 385 }
 386
 387 #endif  /* __ASSEMBLY__ */
 388
 389 #endif /* _ASM_UACCESS_H */