arch/parisc/include/asm/uaccess.h

   1 #ifndef __PARISC_UACCESS_H
   2 #define __PARISC_UACCESS_H
   3
   4 /*
   5  * User space memory access functions
   6  */
   7 #include <asm/page.h>
   8 #include <asm/cache.h>
   9 #include <asm/errno.h>
  10 #include <asm-generic/uaccess-unaligned.h>
  11
  12 #define VERIFY_READ 0
  13 #define VERIFY_WRITE 1
  14
  15 #define KERNEL_DS       ((mm_segment_t){0})
  16 #define USER_DS         ((mm_segment_t){1})
  17
  18 #define segment_eq(a,b) ((a).seg == (b).seg)
  19
  20 #define get_ds()        (KERNEL_DS)
  21 #define get_fs()        (current_thread_info()->addr_limit)
  22 #define set_fs(x)       (current_thread_info()->addr_limit = (x))
  23
  24 /*
  25  * Note that since kernel addresses are in a separate address space on
  26  * parisc, we don't need to do anything for access_ok().
  27  * We just let the page fault handler do the right thing. This also means
  28  * that put_user is the same as __put_user, etc.
  29  */
  30
  31 extern int __get_kernel_bad(void);
  32 extern int __get_user_bad(void);
  33 extern int __put_kernel_bad(void);
  34 extern int __put_user_bad(void);
  35
  36 static inline long access_ok(int type, const void __user * addr,
  37                 unsigned long size)
  38 {
  39         return 1;
  40 }
  41
  42 #define put_user __put_user
  43 #define get_user __get_user
  44
  45 #if !defined(CONFIG_64BIT)
  46 #define LDD_KERNEL(ptr)         __get_kernel_bad();
  47 #define LDD_USER(ptr)           __get_user_bad();
  48 #define STD_KERNEL(x, ptr)      __put_kernel_asm64(x,ptr)
  49 #define STD_USER(x, ptr)        __put_user_asm64(x,ptr)
  50 #define ASM_WORD_INSN           ".word\t"
  51 #else
  52 #define LDD_KERNEL(ptr)         __get_kernel_asm("ldd",ptr)
  53 #define LDD_USER(ptr)           __get_user_asm("ldd",ptr)
  54 #define STD_KERNEL(x, ptr)      __put_kernel_asm("std",x,ptr)
  55 #define STD_USER(x, ptr)        __put_user_asm("std",x,ptr)
  56 #define ASM_WORD_INSN           ".dword\t"
  57 #endif
  58
  59 /*
  60  * The exception table contains two values: the first is an address
  61  * for an instruction that is allowed to fault, and the second is
  62  * the address to the fixup routine. Even on a 64bit kernel we could
  63  * use a 32bit (unsigned int) address here.
  64  */
  65
  66 struct exception_table_entry {
  67         unsigned long insn;     /* address of insn that is allowed to fault. */
  68         unsigned long fixup;    /* fixup routine */
  69 };
  70
  71 #define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr )\
  72         ".section __ex_table,\"aw\"\n"                     \
  73         ASM_WORD_INSN #fault_addr ", " #except_addr "\n\t" \
  74         ".previous\n"
  75
  76 /*
  77  * The page fault handler stores, in a per-cpu area, the following information
  78  * if a fixup routine is available.
  79  */
  80 struct exception_data {
  81         unsigned long fault_ip;
  82         unsigned long fault_space;
  83         unsigned long fault_addr;
  84 };
  85
  86 #define __get_user(x,ptr)                               \
  87 ({                                                      \
  88         register long __gu_err __asm__ ("r8") = 0;      \
  89         register long __gu_val __asm__ ("r9") = 0;      \
  90                                                         \
  91         if (segment_eq(get_fs(),KERNEL_DS)) {           \
  92             switch (sizeof(*(ptr))) {                   \
  93             case 1: __get_kernel_asm("ldb",ptr); break; \
  94             case 2: __get_kernel_asm("ldh",ptr); break; \
  95             case 4: __get_kernel_asm("ldw",ptr); break; \
  96             case 8: LDD_KERNEL(ptr); break;             \
  97             default: __get_kernel_bad(); break;         \
  98             }                                           \
  99         }                                               \
 100         else {                                          \
 101             switch (sizeof(*(ptr))) {                   \
 102             case 1: __get_user_asm("ldb",ptr); break;   \
 103             case 2: __get_user_asm("ldh",ptr); break;   \
 104             case 4: __get_user_asm("ldw",ptr); break;   \
 105             case 8: LDD_USER(ptr);  break;              \
 106             default: __get_user_bad(); break;           \
 107             }                                           \
 108         }                                               \
 109                                                         \
 110         (x) = (__typeof__(*(ptr))) __gu_val;            \
 111         __gu_err;                                       \
 112 })
 113
 114 #define __get_kernel_asm(ldx,ptr)                       \
 115         __asm__("\n1:\t" ldx "\t0(%2),%0\n\t"           \
 116                 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_1)\
 117                 : "=r"(__gu_val), "=r"(__gu_err)        \
 118                 : "r"(ptr), "1"(__gu_err)               \
 119                 : "r1");
 120
 121 #define __get_user_asm(ldx,ptr)                         \
 122         __asm__("\n1:\t" ldx "\t0(%%sr3,%2),%0\n\t"     \
 123                 ASM_EXCEPTIONTABLE_ENTRY(1b,fixup_get_user_skip_1)\
 124                 : "=r"(__gu_val), "=r"(__gu_err)        \
 125                 : "r"(ptr), "1"(__gu_err)               \
 126                 : "r1");
 127
 128 #define __put_user(x,ptr)                                       \
 129 ({                                                              \
 130         register long __pu_err __asm__ ("r8") = 0;              \
 131         __typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x);       \
 132                                                                 \
 133         if (segment_eq(get_fs(),KERNEL_DS)) {                   \
 134             switch (sizeof(*(ptr))) {                           \
 135             case 1: __put_kernel_asm("stb",__x,ptr); break;     \
 136             case 2: __put_kernel_asm("sth",__x,ptr); break;     \
 137             case 4: __put_kernel_asm("stw",__x,ptr); break;     \
 138             case 8: STD_KERNEL(__x,ptr); break;                 \
 139             default: __put_kernel_bad(); break;                 \
 140             }                                                   \
 141         }                                                       \
 142         else {                                                  \
 143             switch (sizeof(*(ptr))) {                           \
 144             case 1: __put_user_asm("stb",__x,ptr); break;       \
 145             case 2: __put_user_asm("sth",__x,ptr); break;       \
 146             case 4: __put_user_asm("stw",__x,ptr); break;       \
 147             case 8: STD_USER(__x,ptr); break;                   \
 148             default: __put_user_bad(); break;                   \
 149             }                                                   \
 150         }                                                       \
 151                                                                 \
 152         __pu_err;                                               \
 153 })
 154
 155 /*
 156  * The "__put_user/kernel_asm()" macros tell gcc they read from memory
 157  * instead of writing. This is because they do not write to any memory
 158  * gcc knows about, so there are no aliasing issues. These macros must
 159  * also be aware that "fixup_put_user_skip_[12]" are executed in the
 160  * context of the fault, and any registers used there must be listed
 161  * as clobbers. In this case only "r1" is used by the current routines.
 162  * r8/r9 are already listed as err/val.
 163  */
 164
 165 #define __put_kernel_asm(stx,x,ptr)                         \
 166         __asm__ __volatile__ (                              \
 167                 "\n1:\t" stx "\t%2,0(%1)\n\t"               \
 168                 ASM_EXCEPTIONTABLE_ENTRY(1b,fixup_put_user_skip_1)\
 169                 : "=r"(__pu_err)                            \
 170                 : "r"(ptr), "r"(x), "0"(__pu_err)           \
 171                 : "r1")
 172
 173 #define __put_user_asm(stx,x,ptr)                           \
 174         __asm__ __volatile__ (                              \
 175                 "\n1:\t" stx "\t%2,0(%%sr3,%1)\n\t"         \
 176                 ASM_EXCEPTIONTABLE_ENTRY(1b,fixup_put_user_skip_1)\
 177                 : "=r"(__pu_err)                            \
 178                 : "r"(ptr), "r"(x), "0"(__pu_err)           \
 179                 : "r1")
 180
 181
 182 #if !defined(CONFIG_64BIT)
 183
 184 #define __put_kernel_asm64(__val,ptr) do {                  \
 185         __asm__ __volatile__ (                              \
 186                 "\n1:\tstw %2,0(%1)"                        \
 187                 "\n2:\tstw %R2,4(%1)\n\t"                   \
 188                 ASM_EXCEPTIONTABLE_ENTRY(1b,fixup_put_user_skip_2)\
 189                 ASM_EXCEPTIONTABLE_ENTRY(2b,fixup_put_user_skip_1)\
 190                 : "=r"(__pu_err)                            \
 191                 : "r"(ptr), "r"(__val), "0"(__pu_err) \
 192                 : "r1");                                    \
 193 } while (0)
 194
 195 #define __put_user_asm64(__val,ptr) do {                    \
 196         __asm__ __volatile__ (                              \
 197                 "\n1:\tstw %2,0(%%sr3,%1)"                  \
 198                 "\n2:\tstw %R2,4(%%sr3,%1)\n\t"             \
 199                 ASM_EXCEPTIONTABLE_ENTRY(1b,fixup_put_user_skip_2)\
 200                 ASM_EXCEPTIONTABLE_ENTRY(2b,fixup_put_user_skip_1)\
 201                 : "=r"(__pu_err)                            \
 202                 : "r"(ptr), "r"(__val), "0"(__pu_err) \
 203                 : "r1");                                    \
 204 } while (0)
 205
 206 #endif /* !defined(CONFIG_64BIT) */
 207
 208
 209 /*
 210  * Complex access routines -- external declarations
 211  */
 212
 213 extern unsigned long lcopy_to_user(void __user *, const void *, unsigned long);
 214 extern unsigned long lcopy_from_user(void *, const void __user *, unsigned long);
 215 extern unsigned long lcopy_in_user(void __user *, const void __user *, unsigned long);
 216 extern long strncpy_from_user(char *, const char __user *, long);
 217 extern unsigned lclear_user(void __user *,unsigned long);
 218 extern long lstrnlen_user(const char __user *,long);
 219 /*
 220  * Complex access routines -- macros
 221  */
 222 #define user_addr_max() (~0UL)
 223
 224 #define strnlen_user lstrnlen_user
 225 #define strlen_user(str) lstrnlen_user(str, 0x7fffffffL)
 226 #define clear_user lclear_user
 227 #define __clear_user lclear_user
 228
 229 unsigned long copy_to_user(void __user *dst, const void *src, unsigned long len);
 230 #define __copy_to_user copy_to_user
 231 unsigned long __copy_from_user(void *dst, const void __user *src, unsigned long len);
 232 unsigned long copy_in_user(void __user *dst, const void __user *src, unsigned long len);
 233 #define __copy_in_user copy_in_user
 234 #define __copy_to_user_inatomic __copy_to_user
 235 #define __copy_from_user_inatomic __copy_from_user
 236
 237 extern void copy_from_user_overflow(void)
 238 #ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
 239         __compiletime_error("copy_from_user() buffer size is not provably correct")
 240 #else
 241         __compiletime_warning("copy_from_user() buffer size is not provably correct")
 242 #endif
 243 ;
 244
 245 static inline unsigned long __must_check copy_from_user(void *to,
 246                                           const void __user *from,
 247                                           unsigned long n)
 248 {
 249         int sz = __compiletime_object_size(to);
 250         int ret = -EFAULT;
 251
 252         if (likely(sz == -1 || !__builtin_constant_p(n) || sz >= n))
 253                 ret = __copy_from_user(to, from, n);
 254         else
 255                 copy_from_user_overflow();
 256
 257         return ret;
 258 }
 259
 260 struct pt_regs;
 261 int fixup_exception(struct pt_regs *regs);
 262
 263 #endif /* __PARISC_UACCESS_H */