LXR linux/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
  31extern int __get_kernel_bad(void);
  32extern int __get_user_bad(void);
  33extern int __put_kernel_bad(void);
  34extern int __put_user_bad(void);
  35
  36static 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
  65struct 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 */
  79struct 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        __asm__ __volatile__ (                              \
 185                "\n1:\tstw %2,0(%1)"                        \
 186                "\n2:\tstw %R2,4(%1)\n\t"                   \
 187                ASM_EXCEPTIONTABLE_ENTRY(1b,fixup_put_user_skip_2)\
 188                ASM_EXCEPTIONTABLE_ENTRY(2b,fixup_put_user_skip_1)\
 189                : "=r"(__pu_err)                            \
 190                : "r"(ptr), "r"(__val), "0"(__pu_err) \
 191                : "r1");                                    \
 192} while (0)
 193
 194#define __put_user_asm64(__val,ptr) do {                    \
 195        __asm__ __volatile__ (                              \
 196                "\n1:\tstw %2,0(%%sr3,%1)"                  \
 197                "\n2:\tstw %R2,4(%%sr3,%1)\n\t"             \
 198                ASM_EXCEPTIONTABLE_ENTRY(1b,fixup_put_user_skip_2)\
 199                ASM_EXCEPTIONTABLE_ENTRY(2b,fixup_put_user_skip_1)\
 200                : "=r"(__pu_err)                            \
 201                : "r"(ptr), "r"(__val), "0"(__pu_err) \
 202                : "r1");                                    \
 203} while (0)
 204
 205#endif /* !defined(CONFIG_64BIT) */
 206
 207
 208/*
 209 * Complex access routines -- external declarations
 210 */
 211
 212extern unsigned long lcopy_to_user(void __user *, const void *, unsigned long);
 213extern unsigned long lcopy_from_user(void *, const void __user *, unsigned long);
 214extern unsigned long lcopy_in_user(void __user *, const void __user *, unsigned long);
 215extern long strncpy_from_user(char *, const char __user *, long);
 216extern unsigned lclear_user(void __user *,unsigned long);
 217extern long lstrnlen_user(const char __user *,long);
 218/*
 219 * Complex access routines -- macros
 220 */
 221#define user_addr_max() (~0UL)
 222
 223#define strnlen_user lstrnlen_user
 224#define strlen_user(str) lstrnlen_user(str, 0x7fffffffL)
 225#define clear_user lclear_user
 226#define __clear_user lclear_user
 227
 228unsigned long copy_to_user(void __user *dst, const void *src, unsigned long len);
 229#define __copy_to_user copy_to_user
 230unsigned long __copy_from_user(void *dst, const void __user *src, unsigned long len);
 231unsigned long copy_in_user(void __user *dst, const void __user *src, unsigned long len);
 232#define __copy_in_user copy_in_user
 233#define __copy_to_user_inatomic __copy_to_user
 234#define __copy_from_user_inatomic __copy_from_user
 235
 236extern void copy_from_user_overflow(void)
 237#ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
 238        __compiletime_error("copy_from_user() buffer size is not provably correct")
 239#else
 240        __compiletime_warning("copy_from_user() buffer size is not provably correct")
 241#endif
 242;
 243
 244static inline unsigned long __must_check copy_from_user(void *to,
 245                                          const void __user *from,
 246                                          unsigned long n)
 247{
 248        int sz = __compiletime_object_size(to);
 249        int ret = -EFAULT;
 250
 251        if (likely(sz == -1 || !__builtin_constant_p(n) || sz >= n))
 252                ret = __copy_from_user(to, from, n);
 253        else
 254                copy_from_user_overflow();
 255
 256        return ret;
 257}
 258
 259struct pt_regs;
 260int fixup_exception(struct pt_regs *regs);
 261
 262#endif /* __PARISC_UACCESS_H */
 263