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