arch/frv/include/asm/uaccess.h

   1 /* uaccess.h: userspace accessor functions
   2  *
   3  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #ifndef _ASM_UACCESS_H
  13 #define _ASM_UACCESS_H
  14
  15 /*
  16  * User space memory access functions
  17  */
  18 #include <linux/sched.h>
  19 #include <linux/mm.h>
  20 #include <asm/segment.h>
  21 #include <asm/sections.h>
  22
  23 #define HAVE_ARCH_UNMAPPED_AREA /* we decide where to put mmaps */
  24
  25 #define __ptr(x) ((unsigned long __force *)(x))
  26
  27 #define VERIFY_READ     0
  28 #define VERIFY_WRITE    1
  29
  30 /*
  31  * check that a range of addresses falls within the current address limit
  32  */
  33 static inline int ___range_ok(unsigned long addr, unsigned long size)
  34 {
  35 #ifdef CONFIG_MMU
  36         int flag = -EFAULT, tmp;
  37
  38         asm volatile (
  39                 "       addcc   %3,%2,%1,icc0   \n"     /* set C-flag if addr+size>4GB */
  40                 "       subcc.p %1,%4,gr0,icc1  \n"     /* jump if addr+size>limit */
  41                 "       bc      icc0,#0,0f      \n"
  42                 "       bhi     icc1,#0,0f      \n"
  43                 "       setlos  #0,%0           \n"     /* mark okay */
  44                 "0:                             \n"
  45                 : "=r"(flag), "=&r"(tmp)
  46                 : "r"(addr), "r"(size), "r"(get_addr_limit()), "0"(flag)
  47                 );
  48
  49         return flag;
  50
  51 #else
  52
  53         if (addr < memory_start ||
  54             addr > memory_end ||
  55             size > memory_end - memory_start ||
  56             addr + size > memory_end)
  57                 return -EFAULT;
  58
  59         return 0;
  60 #endif
  61 }
  62
  63 #define __range_ok(addr,size) ___range_ok((unsigned long) (addr), (unsigned long) (size))
  64
  65 #define access_ok(type,addr,size) (__range_ok((void __user *)(addr), (size)) == 0)
  66 #define __access_ok(addr,size) (__range_ok((addr), (size)) == 0)
  67
  68 /*
  69  * The exception table consists of pairs of addresses: the first is the
  70  * address of an instruction that is allowed to fault, and the second is
  71  * the address at which the program should continue.  No registers are
  72  * modified, so it is entirely up to the continuation code to figure out
  73  * what to do.
  74  *
  75  * All the routines below use bits of fixup code that are out of line
  76  * with the main instruction path.  This means when everything is well,
  77  * we don't even have to jump over them.  Further, they do not intrude
  78  * on our cache or tlb entries.
  79  */
  80 struct exception_table_entry
  81 {
  82         unsigned long insn, fixup;
  83 };
  84
  85 /* Returns 0 if exception not found and fixup otherwise.  */
  86 extern unsigned long search_exception_table(unsigned long);
  87
  88
  89 /*
  90  * These are the main single-value transfer routines.  They automatically
  91  * use the right size if we just have the right pointer type.
  92  */
  93 #define __put_user(x, ptr)                                              \
  94 ({                                                                      \
  95         int __pu_err = 0;                                               \
  96                                                                         \
  97         typeof(*(ptr)) __pu_val = (x);                                  \
  98         __chk_user_ptr(ptr);                                            \
  99                                                                         \
 100         switch (sizeof (*(ptr))) {                                      \
 101         case 1:                                                         \
 102                 __put_user_asm(__pu_err, __pu_val, ptr, "b", "r");      \
 103                 break;                                                  \
 104         case 2:                                                         \
 105                 __put_user_asm(__pu_err, __pu_val, ptr, "h", "r");      \
 106                 break;                                                  \
 107         case 4:                                                         \
 108                 __put_user_asm(__pu_err, __pu_val, ptr, "",  "r");      \
 109                 break;                                                  \
 110         case 8:                                                         \
 111                 __put_user_asm(__pu_err, __pu_val, ptr, "d", "e");      \
 112                 break;                                                  \
 113         default:                                                        \
 114                 __pu_err = __put_user_bad();                            \
 115                 break;                                                  \
 116         }                                                               \
 117         __pu_err;                                                       \
 118 })
 119
 120 #define put_user(x, ptr)                        \
 121 ({                                              \
 122         typeof(*(ptr)) __user *_p = (ptr);      \
 123         int _e;                                 \
 124                                                 \
 125         _e = __range_ok(_p, sizeof(*_p));       \
 126         if (_e == 0)                            \
 127                 _e = __put_user((x), _p);       \
 128         _e;                                     \
 129 })
 130
 131 extern int __put_user_bad(void);
 132
 133 /*
 134  * Tell gcc we read from memory instead of writing: this is because
 135  * we do not write to any memory gcc knows about, so there are no
 136  * aliasing issues.
 137  */
 138
 139 #ifdef CONFIG_MMU
 140
 141 #define __put_user_asm(err,x,ptr,dsize,constraint)                                      \
 142 do {                                                                                    \
 143         asm volatile("1:        st"dsize"%I1    %2,%M1  \n"                             \
 144                      "2:                                \n"                             \
 145                      ".subsection 2                     \n"                             \
 146                      "3:        setlos          %3,%0   \n"                             \
 147                      "          bra             2b      \n"                             \
 148                      ".previous                         \n"                             \
 149                      ".section __ex_table,\"a\"         \n"                             \
 150                      "          .balign         8       \n"                             \
 151                      "          .long           1b,3b   \n"                             \
 152                      ".previous"                                                        \
 153                      : "=r" (err)                                                       \
 154                      : "m" (*__ptr(ptr)), constraint (x), "i"(-EFAULT), "0"(err)        \
 155                      : "memory");                                                       \
 156 } while (0)
 157
 158 #else
 159
 160 #define __put_user_asm(err,x,ptr,bwl,con)       \
 161 do {                                            \
 162         asm("   st"bwl"%I0      %1,%M0  \n"     \
 163             "   membar                  \n"     \
 164             :                                   \
 165             : "m" (*__ptr(ptr)), con (x)        \
 166             : "memory");                        \
 167 } while (0)
 168
 169 #endif
 170
 171 /*****************************************************************************/
 172 /*
 173  *
 174  */
 175 #define __get_user(x, ptr)                                              \
 176 ({                                                                      \
 177         int __gu_err = 0;                                               \
 178         __chk_user_ptr(ptr);                                            \
 179                                                                         \
 180         switch (sizeof(*(ptr))) {                                       \
 181         case 1: {                                                       \
 182                 unsigned char __gu_val;                                 \
 183                 __get_user_asm(__gu_err, __gu_val, ptr, "ub", "=r");    \
 184                 (x) = *(__force __typeof__(*(ptr)) *) &__gu_val;        \
 185                 break;                                                  \
 186         }                                                               \
 187         case 2: {                                                       \
 188                 unsigned short __gu_val;                                \
 189                 __get_user_asm(__gu_err, __gu_val, ptr, "uh", "=r");    \
 190                 (x) = *(__force __typeof__(*(ptr)) *) &__gu_val;        \
 191                 break;                                                  \
 192         }                                                               \
 193         case 4: {                                                       \
 194                 unsigned int __gu_val;                                  \
 195                 __get_user_asm(__gu_err, __gu_val, ptr, "", "=r");      \
 196                 (x) = *(__force __typeof__(*(ptr)) *) &__gu_val;        \
 197                 break;                                                  \
 198         }                                                               \
 199         case 8: {                                                       \
 200                 unsigned long long __gu_val;                            \
 201                 __get_user_asm(__gu_err, __gu_val, ptr, "d", "=e");     \
 202                 (x) = *(__force __typeof__(*(ptr)) *) &__gu_val;        \
 203                 break;                                                  \
 204         }                                                               \
 205         default:                                                        \
 206                 __gu_err = __get_user_bad();                            \
 207                 break;                                                  \
 208         }                                                               \
 209         __gu_err;                                                       \
 210 })
 211
 212 #define get_user(x, ptr)                        \
 213 ({                                              \
 214         const typeof(*(ptr)) __user *_p = (ptr);\
 215         int _e;                                 \
 216                                                 \
 217         _e = __range_ok(_p, sizeof(*_p));       \
 218         if (likely(_e == 0))                    \
 219                 _e = __get_user((x), _p);       \
 220         else                                    \
 221                 (x) = (typeof(x)) 0;            \
 222         _e;                                     \
 223 })
 224
 225 extern int __get_user_bad(void);
 226
 227 #ifdef CONFIG_MMU
 228
 229 #define __get_user_asm(err,x,ptr,dtype,constraint)      \
 230 do {                                                    \
 231         asm("1:         ld"dtype"%I2    %M2,%1  \n"     \
 232             "2:                                 \n"     \
 233             ".subsection 2                      \n"     \
 234             "3:         setlos          %3,%0   \n"     \
 235             "           setlos          #0,%1   \n"     \
 236             "           bra             2b      \n"     \
 237             ".previous                          \n"     \
 238             ".section __ex_table,\"a\"          \n"     \
 239             "           .balign         8       \n"     \
 240             "           .long           1b,3b   \n"     \
 241             ".previous"                                 \
 242             : "=r" (err), constraint (x)                \
 243             : "m" (*__ptr(ptr)), "i"(-EFAULT), "0"(err) \
 244             );                                          \
 245 } while(0)
 246
 247 #else
 248
 249 #define __get_user_asm(err,x,ptr,bwl,con)       \
 250         asm("   ld"bwl"%I1      %M1,%0  \n"     \
 251             "   membar                  \n"     \
 252             : con(x)                            \
 253             : "m" (*__ptr(ptr)))
 254
 255 #endif
 256
 257 /*****************************************************************************/
 258 /*
 259  *
 260  */
 261 #define ____force(x) (__force void *)(void __user *)(x)
 262 #ifdef CONFIG_MMU
 263 extern long __memset_user(void *dst, unsigned long count);
 264 extern long __memcpy_user(void *dst, const void *src, unsigned long count);
 265
 266 #define clear_user(dst,count)                   __memset_user(____force(dst), (count))
 267 #define __copy_from_user_inatomic(to, from, n)  __memcpy_user((to), ____force(from), (n))
 268 #define __copy_to_user_inatomic(to, from, n)    __memcpy_user(____force(to), (from), (n))
 269
 270 #else
 271
 272 #define clear_user(dst,count)                   (memset(____force(dst), 0, (count)), 0)
 273 #define __copy_from_user_inatomic(to, from, n)  (memcpy((to), ____force(from), (n)), 0)
 274 #define __copy_to_user_inatomic(to, from, n)    (memcpy(____force(to), (from), (n)), 0)
 275
 276 #endif
 277
 278 #define __clear_user clear_user
 279
 280 static inline unsigned long __must_check
 281 __copy_to_user(void __user *to, const void *from, unsigned long n)
 282 {
 283        might_sleep();
 284        return __copy_to_user_inatomic(to, from, n);
 285 }
 286
 287 static inline unsigned long
 288 __copy_from_user(void *to, const void __user *from, unsigned long n)
 289 {
 290        might_sleep();
 291        return __copy_from_user_inatomic(to, from, n);
 292 }
 293
 294 static inline long copy_from_user(void *to, const void __user *from, unsigned long n)
 295 {
 296         unsigned long ret = n;
 297
 298         if (likely(__access_ok(from, n)))
 299                 ret = __copy_from_user(to, from, n);
 300
 301         if (unlikely(ret != 0))
 302                 memset(to + (n - ret), 0, ret);
 303
 304         return ret;
 305 }
 306
 307 static inline long copy_to_user(void __user *to, const void *from, unsigned long n)
 308 {
 309         return likely(__access_ok(to, n)) ? __copy_to_user(to, from, n) : n;
 310 }
 311
 312 extern long strncpy_from_user(char *dst, const char __user *src, long count);
 313 extern long strnlen_user(const char __user *src, long count);
 314
 315 #define strlen_user(str) strnlen_user(str, 32767)
 316
 317 extern unsigned long search_exception_table(unsigned long addr);
 318
 319 #endif /* _ASM_UACCESS_H */