include/asm-arm26/uaccess.h

   1 #ifndef _ASMARM_UACCESS_H
   2 #define _ASMARM_UACCESS_H
   3
   4 /*
   5  * User space memory access functions
   6  */
   7 #include <linux/sched.h>
   8 #include <asm/errno.h>
   9
  10 #define VERIFY_READ 0
  11 #define VERIFY_WRITE 1
  12
  13 /*
  14  * The exception table consists of pairs of addresses: the first is the
  15  * address of an instruction that is allowed to fault, and the second is
  16  * the address at which the program should continue.  No registers are
  17  * modified, so it is entirely up to the continuation code to figure out
  18  * what to do.
  19  *
  20  * All the routines below use bits of fixup code that are out of line
  21  * with the main instruction path.  This means when everything is well,
  22  * we don't even have to jump over them.  Further, they do not intrude
  23  * on our cache or tlb entries.
  24  */
  25
  26 struct exception_table_entry
  27 {
  28         unsigned long insn, fixup;
  29 };
  30
  31 /* Returns 0 if exception not found and fixup otherwise.  */
  32 extern unsigned long search_exception_table(unsigned long);
  33 extern int fixup_exception(struct pt_regs *regs);
  34
  35 #define get_ds()        (KERNEL_DS)
  36 #define get_fs()        (current_thread_info()->addr_limit)
  37 #define segment_eq(a,b) ((a) == (b))
  38
  39 #include <asm/uaccess-asm.h>
  40
  41 #define access_ok(type,addr,size)       (__range_ok(addr,size) == 0)
  42
  43 /* this function will go away soon - use access_ok() instead */
  44 static inline int __deprecated verify_area(int type, const void * addr, unsigned long size)
  45 {
  46         return access_ok(type, addr, size) ? 0 : -EFAULT;
  47 }
  48
  49 /*
  50  * Single-value transfer routines.  They automatically use the right
  51  * size if we just have the right pointer type.  Note that the functions
  52  * which read from user space (*get_*) need to take care not to leak
  53  * kernel data even if the calling code is buggy and fails to check
  54  * the return value.  This means zeroing out the destination variable
  55  * or buffer on error.  Normally this is done out of line by the
  56  * fixup code, but there are a few places where it intrudes on the
  57  * main code path.  When we only write to user space, there is no
  58  * problem.
  59  *
  60  * The "__xxx" versions of the user access functions do not verify the
  61  * address space - it must have been done previously with a separate
  62  * "access_ok()" call.
  63  *
  64  * The "xxx_error" versions set the third argument to EFAULT if an
  65  * error occurs, and leave it unchanged on success.  Note that these
  66  * versions are void (ie, don't return a value as such).
  67  */
  68
  69 extern int __get_user_1(void *);
  70 extern int __get_user_2(void *);
  71 extern int __get_user_4(void *);
  72 extern int __get_user_8(void *);
  73 extern int __get_user_bad(void);
  74
  75 #define __get_user_x(__r1,__p,__e,__s,__i...)                           \
  76            __asm__ __volatile__ ("bl    __get_user_" #__s               \
  77                 : "=&r" (__e), "=r" (__r1)                              \
  78                 : "0" (__p)                                             \
  79                 : __i)
  80
  81 #define get_user(x,p)                                                   \
  82         ({                                                              \
  83                 const register typeof(*(p)) *__p asm("r0") = (p);       \
  84                 register typeof(*(p)) __r1 asm("r1");                   \
  85                 register int __e asm("r0");                             \
  86                 switch (sizeof(*(p))) {                                 \
  87                 case 1:                                                 \
  88                         __get_user_x(__r1, __p, __e, 1, "lr");          \
  89                         break;                                          \
  90                 case 2:                                                 \
  91                         __get_user_x(__r1, __p, __e, 2, "r2", "lr");    \
  92                         break;                                          \
  93                 case 4:                                                 \
  94                         __get_user_x(__r1, __p, __e, 4, "lr");          \
  95                         break;                                          \
  96                 case 8:                                                 \
  97                         __get_user_x(__r1, __p, __e, 8, "lr");          \
  98                         break;                                          \
  99                 default: __e = __get_user_bad(); break;                 \
 100                 }                                                       \
 101                 x = __r1;                                               \
 102                 __e;                                                    \
 103         })
 104
 105
 106 #define __get_user(x,ptr)                                               \
 107 ({                                                                      \
 108         long __gu_err = 0;                                              \
 109         __get_user_err((x),(ptr),__gu_err);                             \
 110         __gu_err;                                                       \
 111 })
 112
 113 #define __get_user_error(x,ptr,err)                                     \
 114 ({                                                                      \
 115         __get_user_err((x),(ptr),err);                                  \
 116         (void) 0;                                                       \
 117 })
 118
 119 #define __get_user_err(x,ptr,err)                                       \
 120 do {                                                                    \
 121         unsigned long __gu_addr = (unsigned long)(ptr);                 \
 122         unsigned long __gu_val;                                         \
 123         switch (sizeof(*(ptr))) {                                       \
 124         case 1: __get_user_asm_byte(__gu_val,__gu_addr,err);    break;  \
 125         case 2: __get_user_asm_half(__gu_val,__gu_addr,err);    break;  \
 126         case 4: __get_user_asm_word(__gu_val,__gu_addr,err);    break;  \
 127         default: (__gu_val) = __get_user_bad();                         \
 128         }                                                               \
 129         (x) = (__typeof__(*(ptr)))__gu_val;                             \
 130 } while (0)
 131
 132 extern int __put_user_1(void *, unsigned int);
 133 extern int __put_user_2(void *, unsigned int);
 134 extern int __put_user_4(void *, unsigned int);
 135 extern int __put_user_8(void *, unsigned long long);
 136 extern int __put_user_bad(void);
 137
 138 #define __put_user_x(__r1,__p,__e,__s)                                  \
 139            __asm__ __volatile__ (                                       \
 140                 __asmeq("%0", "r0") __asmeq("%2", "r1")                 \
 141                 "bl     __put_user_" #__s                               \
 142                 : "=&r" (__e)                                           \
 143                 : "0" (__p), "r" (__r1)                                 \
 144                 : "ip", "lr", "cc")
 145
 146 #define put_user(x,p)                                                   \
 147         ({                                                              \
 148                 const register typeof(*(p)) __r1 asm("r1") = (x);       \
 149                 const register typeof(*(p)) *__p asm("r0") = (p);       \
 150                 register int __e asm("r0");                             \
 151                 switch (sizeof(*(__p))) {                               \
 152                 case 1:                                                 \
 153                         __put_user_x(__r1, __p, __e, 1);                \
 154                         break;                                          \
 155                 case 2:                                                 \
 156                         __put_user_x(__r1, __p, __e, 2);                \
 157                         break;                                          \
 158                 case 4:                                                 \
 159                         __put_user_x(__r1, __p, __e, 4);                \
 160                         break;                                          \
 161                 case 8:                                                 \
 162                         __put_user_x(__r1, __p, __e, 8);                \
 163                         break;                                          \
 164                 default: __e = __put_user_bad(); break;                 \
 165                 }                                                       \
 166                 __e;                                                    \
 167         })
 168
 169 #if 0
 170 /*********************   OLD METHOD *******************/
 171 #define __put_user_x(__r1,__p,__e,__s,__i...)                           \
 172            __asm__ __volatile__ ("bl    __put_user_" #__s               \
 173                 : "=&r" (__e)                                           \
 174                 : "0" (__p), "r" (__r1)                                 \
 175                 : __i)
 176
 177 #define put_user(x,p)                                                   \
 178         ({                                                              \
 179                 const register typeof(*(p)) __r1 asm("r1") = (x);       \
 180                 const register typeof(*(p)) *__p asm("r0") = (p);       \
 181                 register int __e asm("r0");                             \
 182                 switch (sizeof(*(p))) {                                 \
 183                 case 1:                                                 \
 184                         __put_user_x(__r1, __p, __e, 1, "r2", "lr");    \
 185                         break;                                          \
 186                 case 2:                                                 \
 187                         __put_user_x(__r1, __p, __e, 2, "r2", "lr");    \
 188                         break;                                          \
 189                 case 4:                                                 \
 190                         __put_user_x(__r1, __p, __e, 4, "r2", "lr");    \
 191                         break;                                          \
 192                 case 8:                                                 \
 193                         __put_user_x(__r1, __p, __e, 8, "r2", "ip", "lr");      \
 194                         break;                                          \
 195                 default: __e = __put_user_bad(); break;                 \
 196                 }                                                       \
 197                 __e;                                                    \
 198         })
 199 /*************************************************/
 200 #endif
 201
 202 #define __put_user(x,ptr)                                               \
 203 ({                                                                      \
 204         long __pu_err = 0;                                              \
 205         __put_user_err((x),(ptr),__pu_err);                             \
 206         __pu_err;                                                       \
 207 })
 208
 209 #define __put_user_error(x,ptr,err)                                     \
 210 ({                                                                      \
 211         __put_user_err((x),(ptr),err);                                  \
 212         (void) 0;                                                       \
 213 })
 214
 215 #define __put_user_err(x,ptr,err)                                       \
 216 do {                                                                    \
 217         unsigned long __pu_addr = (unsigned long)(ptr);                 \
 218         __typeof__(*(ptr)) __pu_val = (x);                              \
 219         switch (sizeof(*(ptr))) {                                       \
 220         case 1: __put_user_asm_byte(__pu_val,__pu_addr,err);    break;  \
 221         case 2: __put_user_asm_half(__pu_val,__pu_addr,err);    break;  \
 222         case 4: __put_user_asm_word(__pu_val,__pu_addr,err);    break;  \
 223         case 8: __put_user_asm_dword(__pu_val,__pu_addr,err);   break;  \
 224         default: __put_user_bad();                                      \
 225         }                                                               \
 226 } while (0)
 227
 228 static __inline__ unsigned long copy_from_user(void *to, const void *from, unsigned long n)
 229 {
 230         if (access_ok(VERIFY_READ, from, n))
 231                 __do_copy_from_user(to, from, n);
 232         else /* security hole - plug it */
 233                 memzero(to, n);
 234         return n;
 235 }
 236
 237 static __inline__ unsigned long __copy_from_user(void *to, const void *from, unsigned long n)
 238 {
 239         __do_copy_from_user(to, from, n);
 240         return n;
 241 }
 242
 243 static __inline__ unsigned long copy_to_user(void *to, const void *from, unsigned long n)
 244 {
 245         if (access_ok(VERIFY_WRITE, to, n))
 246                 __do_copy_to_user(to, from, n);
 247         return n;
 248 }
 249
 250 static __inline__ unsigned long __copy_to_user(void *to, const void *from, unsigned long n)
 251 {
 252         __do_copy_to_user(to, from, n);
 253         return n;
 254 }
 255
 256 #define __copy_to_user_inatomic __copy_to_user
 257 #define __copy_from_user_inatomic __copy_from_user
 258
 259 static __inline__ unsigned long clear_user (void *to, unsigned long n)
 260 {
 261         if (access_ok(VERIFY_WRITE, to, n))
 262                 __do_clear_user(to, n);
 263         return n;
 264 }
 265
 266 static __inline__ unsigned long __clear_user (void *to, unsigned long n)
 267 {
 268         __do_clear_user(to, n);
 269         return n;
 270 }
 271
 272 static __inline__ long strncpy_from_user (char *dst, const char *src, long count)
 273 {
 274         long res = -EFAULT;
 275         if (access_ok(VERIFY_READ, src, 1))
 276                 __do_strncpy_from_user(dst, src, count, res);
 277         return res;
 278 }
 279
 280 static __inline__ long __strncpy_from_user (char *dst, const char *src, long count)
 281 {
 282         long res;
 283         __do_strncpy_from_user(dst, src, count, res);
 284         return res;
 285 }
 286
 287 #define strlen_user(s)  strnlen_user(s, ~0UL >> 1)
 288
 289 static inline long strnlen_user(const char *s, long n)
 290 {
 291         unsigned long res = 0;
 292
 293         if (__addr_ok(s))
 294                 __do_strnlen_user(s, n, res);
 295
 296         return res;
 297 }
 298
 299 #endif /* _ASMARM_UACCESS_H */