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/system.h>
   9 #include <asm/cache.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.
  63  */
  64
  65 struct exception_table_entry {
  66         unsigned long insn;  /* address of insn that is allowed to fault.   */
  67         long fixup;          /* fixup routine */
  68 };
  69
  70 #define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr )\
  71         ".section __ex_table,\"aw\"\n"                     \
  72         ASM_WORD_INSN #fault_addr ", " #except_addr "\n\t" \
  73         ".previous\n"
  74
  75 /*
  76  * The page fault handler stores, in a per-cpu area, the following information
  77  * if a fixup routine is available.
  78  */
  79 struct exception_data {
  80         unsigned long fault_ip;
  81         unsigned long fault_space;
  82         unsigned long fault_addr;
  83 };
  84
  85 #define __get_user(x,ptr)                               \
  86 ({                                                      \
  87         register long __gu_err __asm__ ("r8") = 0;      \
  88         register long __gu_val __asm__ ("r9") = 0;      \
  89                                                         \
  90         if (segment_eq(get_fs(),KERNEL_DS)) {           \
  91             switch (sizeof(*(ptr))) {                   \
  92             case 1: __get_kernel_asm("ldb",ptr); break; \
  93             case 2: __get_kernel_asm("ldh",ptr); break; \
  94             case 4: __get_kernel_asm("ldw",ptr); break; \
  95             case 8: LDD_KERNEL(ptr); break;             \
  96             default: __get_kernel_bad(); break;         \
  97             }                                           \
  98         }                                               \
  99         else {                                          \
 100             switch (sizeof(*(ptr))) {                   \
 101             case 1: __get_user_asm("ldb",ptr); break;   \
 102             case 2: __get_user_asm("ldh",ptr); break;   \
 103             case 4: __get_user_asm("ldw",ptr); break;   \
 104             case 8: LDD_USER(ptr);  break;              \
 105             default: __get_user_bad(); break;           \
 106             }                                           \
 107         }                                               \
 108                                                         \
 109         (x) = (__typeof__(*(ptr))) __gu_val;            \
 110         __gu_err;                                       \
 111 })
 112
 113 #define __get_kernel_asm(ldx,ptr)                       \
 114         __asm__("\n1:\t" ldx "\t0(%2),%0\n\t"           \
 115                 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_1)\
 116                 : "=r"(__gu_val), "=r"(__gu_err)        \
 117                 : "r"(ptr), "1"(__gu_err)               \
 118                 : "r1");
 119
 120 #define __get_user_asm(ldx,ptr)                         \
 121         __asm__("\n1:\t" ldx "\t0(%%sr3,%2),%0\n\t"     \
 122                 ASM_EXCEPTIONTABLE_ENTRY(1b,fixup_get_user_skip_1)\
 123                 : "=r"(__gu_val), "=r"(__gu_err)        \
 124                 : "r"(ptr), "1"(__gu_err)               \
 125                 : "r1");
 126
 127 #define __put_user(x,ptr)                                       \
 128 ({                                                              \
 129         register long __pu_err __asm__ ("r8") = 0;              \
 130         __typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x);       \
 131                                                                 \
 132         if (segment_eq(get_fs(),KERNEL_DS)) {                   \
 133             switch (sizeof(*(ptr))) {                           \
 134             case 1: __put_kernel_asm("stb",__x,ptr); break;     \
 135             case 2: __put_kernel_asm("sth",__x,ptr); break;     \
 136             case 4: __put_kernel_asm("stw",__x,ptr); break;     \
 137             case 8: STD_KERNEL(__x,ptr); break;                 \
 138             default: __put_kernel_bad(); break;                 \
 139             }                                                   \
 140         }                                                       \
 141         else {                                                  \
 142             switch (sizeof(*(ptr))) {                           \
 143             case 1: __put_user_asm("stb",__x,ptr); break;       \
 144             case 2: __put_user_asm("sth",__x,ptr); break;       \
 145             case 4: __put_user_asm("stw",__x,ptr); break;       \
 146             case 8: STD_USER(__x,ptr); break;                   \
 147             default: __put_user_bad(); break;                   \
 148             }                                                   \
 149         }                                                       \
 150                                                                 \
 151         __pu_err;                                               \
 152 })
 153
 154 /*
 155  * The "__put_user/kernel_asm()" macros tell gcc they read from memory
 156  * instead of writing. This is because they do not write to any memory
 157  * gcc knows about, so there are no aliasing issues. These macros must
 158  * also be aware that "fixup_put_user_skip_[12]" are executed in the
 159  * context of the fault, and any registers used there must be listed
 160  * as clobbers. In this case only "r1" is used by the current routines.
 161  * r8/r9 are already listed as err/val.
 162  */
 163
 164 #define __put_kernel_asm(stx,x,ptr)                         \
 165         __asm__ __volatile__ (                              \
 166                 "\n1:\t" stx "\t%2,0(%1)\n\t"               \
 167                 ASM_EXCEPTIONTABLE_ENTRY(1b,fixup_put_user_skip_1)\
 168                 : "=r"(__pu_err)                            \
 169                 : "r"(ptr), "r"(x), "0"(__pu_err)           \
 170                 : "r1")
 171
 172 #define __put_user_asm(stx,x,ptr)                           \
 173         __asm__ __volatile__ (                              \
 174                 "\n1:\t" stx "\t%2,0(%%sr3,%1)\n\t"         \
 175                 ASM_EXCEPTIONTABLE_ENTRY(1b,fixup_put_user_skip_1)\
 176                 : "=r"(__pu_err)                            \
 177                 : "r"(ptr), "r"(x), "0"(__pu_err)           \
 178                 : "r1")
 179
 180
 181 #if !defined(CONFIG_64BIT)
 182
 183 #define __put_kernel_asm64(__val,ptr) do {                  \
 184         u64 __val64 = (u64)(__val);                         \
 185         u32 hi = (__val64) >> 32;                           \
 186         u32 lo = (__val64) & 0xffffffff;                    \
 187         __asm__ __volatile__ (                              \
 188                 "\n1:\tstw %2,0(%1)"                        \
 189                 "\n2:\tstw %3,4(%1)\n\t"                    \
 190                 ASM_EXCEPTIONTABLE_ENTRY(1b,fixup_put_user_skip_2)\
 191                 ASM_EXCEPTIONTABLE_ENTRY(2b,fixup_put_user_skip_1)\
 192                 : "=r"(__pu_err)                            \
 193                 : "r"(ptr), "r"(hi), "r"(lo), "0"(__pu_err) \
 194                 : "r1");                                    \
 195 } while (0)
 196
 197 #define __put_user_asm64(__val,ptr) do {                    \
 198         u64 __val64 = (u64)(__val);                         \
 199         u32 hi = (__val64) >> 32;                           \
 200         u32 lo = (__val64) & 0xffffffff;                    \
 201         __asm__ __volatile__ (                              \
 202                 "\n1:\tstw %2,0(%%sr3,%1)"                  \
 203                 "\n2:\tstw %3,4(%%sr3,%1)\n\t"              \
 204                 ASM_EXCEPTIONTABLE_ENTRY(1b,fixup_put_user_skip_2)\
 205                 ASM_EXCEPTIONTABLE_ENTRY(2b,fixup_put_user_skip_1)\
 206                 : "=r"(__pu_err)                            \
 207                 : "r"(ptr), "r"(hi), "r"(lo), "0"(__pu_err) \
 208                 : "r1");                                    \
 209 } while (0)
 210
 211 #endif /* !defined(CONFIG_64BIT) */
 212
 213
 214 /*
 215  * Complex access routines -- external declarations
 216  */
 217
 218 extern unsigned long lcopy_to_user(void __user *, const void *, unsigned long);
 219 extern unsigned long lcopy_from_user(void *, const void __user *, unsigned long);
 220 extern unsigned long lcopy_in_user(void __user *, const void __user *, unsigned long);
 221 extern long lstrncpy_from_user(char *, const char __user *, long);
 222 extern unsigned lclear_user(void __user *,unsigned long);
 223 extern long lstrnlen_user(const char __user *,long);
 224
 225 /*
 226  * Complex access routines -- macros
 227  */
 228
 229 #define strncpy_from_user lstrncpy_from_user
 230 #define strnlen_user lstrnlen_user
 231 #define strlen_user(str) lstrnlen_user(str, 0x7fffffffL)
 232 #define clear_user lclear_user
 233 #define __clear_user lclear_user
 234
 235 unsigned long copy_to_user(void __user *dst, const void *src, unsigned long len);
 236 #define __copy_to_user copy_to_user
 237 unsigned long copy_from_user(void *dst, const void __user *src, unsigned long len);
 238 #define __copy_from_user copy_from_user
 239 unsigned long copy_in_user(void __user *dst, const void __user *src, unsigned long len);
 240 #define __copy_in_user copy_in_user
 241 #define __copy_to_user_inatomic __copy_to_user
 242 #define __copy_from_user_inatomic __copy_from_user
 243
 244 struct pt_regs;
 245 int fixup_exception(struct pt_regs *regs);
 246
 247 #endif /* __PARISC_UACCESS_H */