arch/sparc/include/asm/uaccess_32.h

   1 /*
   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 #endif
  16
  17 #ifndef __ASSEMBLY__
  18
  19 #include <asm/processor.h>
  20
  21 #define ARCH_HAS_SORT_EXTABLE
  22 #define ARCH_HAS_SEARCH_EXTABLE
  23
  24 /* Sparc is not segmented, however we need to be able to fool access_ok()
  25  * when doing system calls from kernel mode legitimately.
  26  *
  27  * "For historical reasons, these macros are grossly misnamed." -Linus
  28  */
  29
  30 #define KERNEL_DS   ((mm_segment_t) { 0 })
  31 #define USER_DS     ((mm_segment_t) { -1 })
  32
  33 #define VERIFY_READ     0
  34 #define VERIFY_WRITE    1
  35
  36 #define get_ds()        (KERNEL_DS)
  37 #define get_fs()        (current->thread.current_ds)
  38 #define set_fs(val)     ((current->thread.current_ds) = (val))
  39
  40 #define segment_eq(a,b) ((a).seg == (b).seg)
  41
  42 /* We have there a nice not-mapped page at PAGE_OFFSET - PAGE_SIZE, so that this test
  43  * can be fairly lightweight.
  44  * No one can read/write anything from userland in the kernel space by setting
  45  * large size and address near to PAGE_OFFSET - a fault will break his intentions.
  46  */
  47 #define __user_ok(addr, size) ({ (void)(size); (addr) < STACK_TOP; })
  48 #define __kernel_ok (segment_eq(get_fs(), KERNEL_DS))
  49 #define __access_ok(addr,size) (__user_ok((addr) & get_fs().seg,(size)))
  50 #define access_ok(type, addr, size)                                     \
  51         ({ (void)(type); __access_ok((unsigned long)(addr), size); })
  52
  53 /*
  54  * The exception table consists of pairs of addresses: the first is the
  55  * address of an instruction that is allowed to fault, and the second is
  56  * the address at which the program should continue.  No registers are
  57  * modified, so it is entirely up to the continuation code to figure out
  58  * what to do.
  59  *
  60  * All the routines below use bits of fixup code that are out of line
  61  * with the main instruction path.  This means when everything is well,
  62  * we don't even have to jump over them.  Further, they do not intrude
  63  * on our cache or tlb entries.
  64  *
  65  * There is a special way how to put a range of potentially faulting
  66  * insns (like twenty ldd/std's with now intervening other instructions)
  67  * You specify address of first in insn and 0 in fixup and in the next
  68  * exception_table_entry you specify last potentially faulting insn + 1
  69  * and in fixup the routine which should handle the fault.
  70  * That fixup code will get
  71  * (faulting_insn_address - first_insn_in_the_range_address)/4
  72  * in %g2 (ie. index of the faulting instruction in the range).
  73  */
  74
  75 struct exception_table_entry
  76 {
  77         unsigned long insn, fixup;
  78 };
  79
  80 /* Returns 0 if exception not found and fixup otherwise.  */
  81 extern unsigned long search_extables_range(unsigned long addr, unsigned long *g2);
  82
  83 extern void __ret_efault(void);
  84
  85 /* Uh, these should become the main single-value transfer routines..
  86  * They automatically use the right size if we just have the right
  87  * pointer type..
  88  *
  89  * This gets kind of ugly. We want to return _two_ values in "get_user()"
  90  * and yet we don't want to do any pointers, because that is too much
  91  * of a performance impact. Thus we have a few rather ugly macros here,
  92  * and hide all the ugliness from the user.
  93  */
  94 #define put_user(x,ptr) ({ \
  95 unsigned long __pu_addr = (unsigned long)(ptr); \
  96 __chk_user_ptr(ptr); \
  97 __put_user_check((__typeof__(*(ptr)))(x),__pu_addr,sizeof(*(ptr))); })
  98
  99 #define get_user(x,ptr) ({ \
 100 unsigned long __gu_addr = (unsigned long)(ptr); \
 101 __chk_user_ptr(ptr); \
 102 __get_user_check((x),__gu_addr,sizeof(*(ptr)),__typeof__(*(ptr))); })
 103
 104 /*
 105  * The "__xxx" versions do not do address space checking, useful when
 106  * doing multiple accesses to the same area (the user has to do the
 107  * checks by hand with "access_ok()")
 108  */
 109 #define __put_user(x,ptr) __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
 110 #define __get_user(x,ptr) __get_user_nocheck((x),(ptr),sizeof(*(ptr)),__typeof__(*(ptr)))
 111
 112 struct __large_struct { unsigned long buf[100]; };
 113 #define __m(x) ((struct __large_struct __user *)(x))
 114
 115 #define __put_user_check(x,addr,size) ({ \
 116 register int __pu_ret; \
 117 if (__access_ok(addr,size)) { \
 118 switch (size) { \
 119 case 1: __put_user_asm(x,b,addr,__pu_ret); break; \
 120 case 2: __put_user_asm(x,h,addr,__pu_ret); break; \
 121 case 4: __put_user_asm(x,,addr,__pu_ret); break; \
 122 case 8: __put_user_asm(x,d,addr,__pu_ret); break; \
 123 default: __pu_ret = __put_user_bad(); break; \
 124 } } else { __pu_ret = -EFAULT; } __pu_ret; })
 125
 126 #define __put_user_nocheck(x,addr,size) ({ \
 127 register int __pu_ret; \
 128 switch (size) { \
 129 case 1: __put_user_asm(x,b,addr,__pu_ret); break; \
 130 case 2: __put_user_asm(x,h,addr,__pu_ret); break; \
 131 case 4: __put_user_asm(x,,addr,__pu_ret); break; \
 132 case 8: __put_user_asm(x,d,addr,__pu_ret); break; \
 133 default: __pu_ret = __put_user_bad(); break; \
 134 } __pu_ret; })
 135
 136 #define __put_user_asm(x,size,addr,ret)                                 \
 137 __asm__ __volatile__(                                                   \
 138         "/* Put user asm, inline. */\n"                                 \
 139 "1:\t"  "st"#size " %1, %2\n\t"                                         \
 140         "clr    %0\n"                                                   \
 141 "2:\n\n\t"                                                              \
 142         ".section .fixup,#alloc,#execinstr\n\t"                         \
 143         ".align 4\n"                                                    \
 144 "3:\n\t"                                                                \
 145         "b      2b\n\t"                                                 \
 146         " mov   %3, %0\n\t"                                             \
 147         ".previous\n\n\t"                                               \
 148         ".section __ex_table,#alloc\n\t"                                \
 149         ".align 4\n\t"                                                  \
 150         ".word  1b, 3b\n\t"                                             \
 151         ".previous\n\n\t"                                               \
 152        : "=&r" (ret) : "r" (x), "m" (*__m(addr)),                       \
 153          "i" (-EFAULT))
 154
 155 extern int __put_user_bad(void);
 156
 157 #define __get_user_check(x,addr,size,type) ({ \
 158 register int __gu_ret; \
 159 register unsigned long __gu_val; \
 160 if (__access_ok(addr,size)) { \
 161 switch (size) { \
 162 case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \
 163 case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \
 164 case 4: __get_user_asm(__gu_val,,addr,__gu_ret); break; \
 165 case 8: __get_user_asm(__gu_val,d,addr,__gu_ret); break; \
 166 default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \
 167 } } else { __gu_val = 0; __gu_ret = -EFAULT; } x = (type) __gu_val; __gu_ret; })
 168
 169 #define __get_user_check_ret(x,addr,size,type,retval) ({ \
 170 register unsigned long __gu_val __asm__ ("l1"); \
 171 if (__access_ok(addr,size)) { \
 172 switch (size) { \
 173 case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \
 174 case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \
 175 case 4: __get_user_asm_ret(__gu_val,,addr,retval); break; \
 176 case 8: __get_user_asm_ret(__gu_val,d,addr,retval); break; \
 177 default: if (__get_user_bad()) return retval; \
 178 } x = (type) __gu_val; } else return retval; })
 179
 180 #define __get_user_nocheck(x,addr,size,type) ({ \
 181 register int __gu_ret; \
 182 register unsigned long __gu_val; \
 183 switch (size) { \
 184 case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \
 185 case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \
 186 case 4: __get_user_asm(__gu_val,,addr,__gu_ret); break; \
 187 case 8: __get_user_asm(__gu_val,d,addr,__gu_ret); break; \
 188 default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \
 189 } x = (type) __gu_val; __gu_ret; })
 190
 191 #define __get_user_nocheck_ret(x,addr,size,type,retval) ({ \
 192 register unsigned long __gu_val __asm__ ("l1"); \
 193 switch (size) { \
 194 case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \
 195 case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \
 196 case 4: __get_user_asm_ret(__gu_val,,addr,retval); break; \
 197 case 8: __get_user_asm_ret(__gu_val,d,addr,retval); break; \
 198 default: if (__get_user_bad()) return retval; \
 199 } x = (type) __gu_val; })
 200
 201 #define __get_user_asm(x,size,addr,ret)                                 \
 202 __asm__ __volatile__(                                                   \
 203         "/* Get user asm, inline. */\n"                                 \
 204 "1:\t"  "ld"#size " %2, %1\n\t"                                         \
 205         "clr    %0\n"                                                   \
 206 "2:\n\n\t"                                                              \
 207         ".section .fixup,#alloc,#execinstr\n\t"                         \
 208         ".align 4\n"                                                    \
 209 "3:\n\t"                                                                \
 210         "clr    %1\n\t"                                                 \
 211         "b      2b\n\t"                                                 \
 212         " mov   %3, %0\n\n\t"                                           \
 213         ".previous\n\t"                                                 \
 214         ".section __ex_table,#alloc\n\t"                                \
 215         ".align 4\n\t"                                                  \
 216         ".word  1b, 3b\n\n\t"                                           \
 217         ".previous\n\t"                                                 \
 218        : "=&r" (ret), "=&r" (x) : "m" (*__m(addr)),                     \
 219          "i" (-EFAULT))
 220
 221 #define __get_user_asm_ret(x,size,addr,retval)                          \
 222 if (__builtin_constant_p(retval) && retval == -EFAULT)                  \
 223 __asm__ __volatile__(                                                   \
 224         "/* Get user asm ret, inline. */\n"                             \
 225 "1:\t"  "ld"#size " %1, %0\n\n\t"                                       \
 226         ".section __ex_table,#alloc\n\t"                                \
 227         ".align 4\n\t"                                                  \
 228         ".word  1b,__ret_efault\n\n\t"                                  \
 229         ".previous\n\t"                                                 \
 230        : "=&r" (x) : "m" (*__m(addr)));                                 \
 231 else                                                                    \
 232 __asm__ __volatile__(                                                   \
 233         "/* Get user asm ret, inline. */\n"                             \
 234 "1:\t"  "ld"#size " %1, %0\n\n\t"                                       \
 235         ".section .fixup,#alloc,#execinstr\n\t"                         \
 236         ".align 4\n"                                                    \
 237 "3:\n\t"                                                                \
 238         "ret\n\t"                                                       \
 239         " restore %%g0, %2, %%o0\n\n\t"                                 \
 240         ".previous\n\t"                                                 \
 241         ".section __ex_table,#alloc\n\t"                                \
 242         ".align 4\n\t"                                                  \
 243         ".word  1b, 3b\n\n\t"                                           \
 244         ".previous\n\t"                                                 \
 245        : "=&r" (x) : "m" (*__m(addr)), "i" (retval))
 246
 247 extern int __get_user_bad(void);
 248
 249 extern unsigned long __copy_user(void __user *to, const void __user *from, unsigned long size);
 250
 251 static inline unsigned long copy_to_user(void __user *to, const void *from, unsigned long n)
 252 {
 253         if (n && __access_ok((unsigned long) to, n))
 254                 return __copy_user(to, (__force void __user *) from, n);
 255         else
 256                 return n;
 257 }
 258
 259 static inline unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
 260 {
 261         return __copy_user(to, (__force void __user *) from, n);
 262 }
 263
 264 static inline unsigned long copy_from_user(void *to, const void __user *from, unsigned long n)
 265 {
 266         if (n && __access_ok((unsigned long) from, n))
 267                 return __copy_user((__force void __user *) to, from, n);
 268         else
 269                 return n;
 270 }
 271
 272 static inline unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n)
 273 {
 274         return __copy_user((__force void __user *) to, from, n);
 275 }
 276
 277 #define __copy_to_user_inatomic __copy_to_user
 278 #define __copy_from_user_inatomic __copy_from_user
 279
 280 static inline unsigned long __clear_user(void __user *addr, unsigned long size)
 281 {
 282         unsigned long ret;
 283
 284         __asm__ __volatile__ (
 285                 ".section __ex_table,#alloc\n\t"
 286                 ".align 4\n\t"
 287                 ".word 1f,3\n\t"
 288                 ".previous\n\t"
 289                 "mov %2, %%o1\n"
 290                 "1:\n\t"
 291                 "call __bzero\n\t"
 292                 " mov %1, %%o0\n\t"
 293                 "mov %%o0, %0\n"
 294                 : "=r" (ret) : "r" (addr), "r" (size) :
 295                 "o0", "o1", "o2", "o3", "o4", "o5", "o7",
 296                 "g1", "g2", "g3", "g4", "g5", "g7", "cc");
 297
 298         return ret;
 299 }
 300
 301 static inline unsigned long clear_user(void __user *addr, unsigned long n)
 302 {
 303         if (n && __access_ok((unsigned long) addr, n))
 304                 return __clear_user(addr, n);
 305         else
 306                 return n;
 307 }
 308
 309 extern __must_check long strlen_user(const char __user *str);
 310 extern __must_check long strnlen_user(const char __user *str, long n);
 311
 312 #endif  /* __ASSEMBLY__ */
 313
 314 #endif /* _ASM_UACCESS_H */