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/system.h>
   9#include <asm/cache.h>
  10#include <asm/errno.h>
  11#include <asm-generic/uaccess-unaligned.h>
  12
  13#define VERIFY_READ 0
  14#define VERIFY_WRITE 1
  15
  16#define KERNEL_DS       ((mm_segment_t){0})
  17#define USER_DS         ((mm_segment_t){1})
  18
  19#define segment_eq(a,b) ((a).seg == (b).seg)
  20
  21#define get_ds()        (KERNEL_DS)
  22#define get_fs()        (current_thread_info()->addr_limit)
  23#define set_fs(x)       (current_thread_info()->addr_limit = (x))
  24
  25/*
  26 * Note that since kernel addresses are in a separate address space on
  27 * parisc, we don't need to do anything for access_ok().
  28 * We just let the page fault handler do the right thing. This also means
  29 * that put_user is the same as __put_user, etc.
  30 */
  31
  32extern int __get_kernel_bad(void);
  33extern int __get_user_bad(void);
  34extern int __put_kernel_bad(void);
  35extern int __put_user_bad(void);
  36
  37static inline long access_ok(int type, const void __user * addr,
  38                unsigned long size)
  39{
  40        return 1;
  41}
  42
  43#define put_user __put_user
  44#define get_user __get_user
  45
  46#if !defined(CONFIG_64BIT)
  47#define LDD_KERNEL(ptr)         __get_kernel_bad();
  48#define LDD_USER(ptr)           __get_user_bad();
  49#define STD_KERNEL(x, ptr)      __put_kernel_asm64(x,ptr)
  50#define STD_USER(x, ptr)        __put_user_asm64(x,ptr)
  51#define ASM_WORD_INSN           ".word\t"
  52#else
  53#define LDD_KERNEL(ptr)         __get_kernel_asm("ldd",ptr)
  54#define LDD_USER(ptr)           __get_user_asm("ldd",ptr)
  55#define STD_KERNEL(x, ptr)      __put_kernel_asm("std",x,ptr)
  56#define STD_USER(x, ptr)        __put_user_asm("std",x,ptr)
  57#define ASM_WORD_INSN           ".dword\t"
  58#endif
  59
  60/*
  61 * The exception table contains two values: the first is an address
  62 * for an instruction that is allowed to fault, and the second is
  63 * the address to the fixup routine. 
  64 */
  65
  66struct exception_table_entry {
  67        unsigned long insn;  /* address of insn that is allowed to fault.   */
  68        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 */
  80struct 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        u64 __val64 = (u64)(__val);                         \
 186        u32 hi = (__val64) >> 32;                           \
 187        u32 lo = (__val64) & 0xffffffff;                    \
 188        __asm__ __volatile__ (                              \
 189                "\n1:\tstw %2,0(%1)"                        \
 190                "\n2:\tstw %3,4(%1)\n\t"                    \
 191                ASM_EXCEPTIONTABLE_ENTRY(1b,fixup_put_user_skip_2)\
 192                ASM_EXCEPTIONTABLE_ENTRY(2b,fixup_put_user_skip_1)\
 193                : "=r"(__pu_err)                            \
 194                : "r"(ptr), "r"(hi), "r"(lo), "0"(__pu_err) \
 195                : "r1");                                    \
 196} while (0)
 197
 198#define __put_user_asm64(__val,ptr) do {                    \
 199        u64 __val64 = (u64)(__val);                         \
 200        u32 hi = (__val64) >> 32;                           \
 201        u32 lo = (__val64) & 0xffffffff;                    \
 202        __asm__ __volatile__ (                              \
 203                "\n1:\tstw %2,0(%%sr3,%1)"                  \
 204                "\n2:\tstw %3,4(%%sr3,%1)\n\t"              \
 205                ASM_EXCEPTIONTABLE_ENTRY(1b,fixup_put_user_skip_2)\
 206                ASM_EXCEPTIONTABLE_ENTRY(2b,fixup_put_user_skip_1)\
 207                : "=r"(__pu_err)                            \
 208                : "r"(ptr), "r"(hi), "r"(lo), "0"(__pu_err) \
 209                : "r1");                                    \
 210} while (0)
 211
 212#endif /* !defined(CONFIG_64BIT) */
 213
 214
 215/*
 216 * Complex access routines -- external declarations
 217 */
 218
 219extern unsigned long lcopy_to_user(void __user *, const void *, unsigned long);
 220extern unsigned long lcopy_from_user(void *, const void __user *, unsigned long);
 221extern unsigned long lcopy_in_user(void __user *, const void __user *, unsigned long);
 222extern long lstrncpy_from_user(char *, const char __user *, long);
 223extern unsigned lclear_user(void __user *,unsigned long);
 224extern long lstrnlen_user(const char __user *,long);
 225
 226/*
 227 * Complex access routines -- macros
 228 */
 229
 230#define strncpy_from_user lstrncpy_from_user
 231#define strnlen_user lstrnlen_user
 232#define strlen_user(str) lstrnlen_user(str, 0x7fffffffL)
 233#define clear_user lclear_user
 234#define __clear_user lclear_user
 235
 236unsigned long copy_to_user(void __user *dst, const void *src, unsigned long len);
 237#define __copy_to_user copy_to_user
 238unsigned long __copy_from_user(void *dst, const void __user *src, unsigned long len);
 239unsigned 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
 244extern void copy_from_user_overflow(void)
 245#ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
 246        __compiletime_error("copy_from_user() buffer size is not provably correct")
 247#else
 248        __compiletime_warning("copy_from_user() buffer size is not provably correct")
 249#endif
 250;
 251
 252static inline unsigned long __must_check copy_from_user(void *to,
 253                                          const void __user *from,
 254                                          unsigned long n)
 255{
 256        int sz = __compiletime_object_size(to);
 257        int ret = -EFAULT;
 258
 259        if (likely(sz == -1 || !__builtin_constant_p(n) || sz >= n))
 260                ret = __copy_from_user(to, from, n);
 261        else
 262                copy_from_user_overflow();
 263
 264        return ret;
 265}
 266
 267struct pt_regs;
 268int fixup_exception(struct pt_regs *regs);
 269
 270#endif /* __PARISC_UACCESS_H */
 271