linux/arch/sh/include/asm/uaccess.h
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   1#ifndef __ASM_SH_UACCESS_H
   2#define __ASM_SH_UACCESS_H
   3
   4#include <linux/errno.h>
   5#include <linux/sched.h>
   6#include <asm/segment.h>
   7
   8#define VERIFY_READ    0
   9#define VERIFY_WRITE   1
  10
  11#define __addr_ok(addr) \
  12        ((unsigned long __force)(addr) < current_thread_info()->addr_limit.seg)
  13
  14/*
  15 * __access_ok: Check if address with size is OK or not.
  16 *
  17 * Uhhuh, this needs 33-bit arithmetic. We have a carry..
  18 *
  19 * sum := addr + size;  carry? --> flag = true;
  20 * if (sum >= addr_limit) flag = true;
  21 */
  22#define __access_ok(addr, size)         \
  23        (__addr_ok((addr) + (size)))
  24#define access_ok(type, addr, size)     \
  25        (__chk_user_ptr(addr),          \
  26         __access_ok((unsigned long __force)(addr), (size)))
  27
  28#define user_addr_max() (current_thread_info()->addr_limit.seg)
  29
  30/*
  31 * Uh, these should become the main single-value transfer routines ...
  32 * They automatically use the right size if we just have the right
  33 * pointer type ...
  34 *
  35 * As SuperH uses the same address space for kernel and user data, we
  36 * can just do these as direct assignments.
  37 *
  38 * Careful to not
  39 * (a) re-use the arguments for side effects (sizeof is ok)
  40 * (b) require any knowledge of processes at this stage
  41 */
  42#define put_user(x,ptr)         __put_user_check((x), (ptr), sizeof(*(ptr)))
  43#define get_user(x,ptr)         __get_user_check((x), (ptr), sizeof(*(ptr)))
  44
  45/*
  46 * The "__xxx" versions do not do address space checking, useful when
  47 * doing multiple accesses to the same area (the user has to do the
  48 * checks by hand with "access_ok()")
  49 */
  50#define __put_user(x,ptr)       __put_user_nocheck((x), (ptr), sizeof(*(ptr)))
  51#define __get_user(x,ptr)       __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
  52
  53struct __large_struct { unsigned long buf[100]; };
  54#define __m(x) (*(struct __large_struct __user *)(x))
  55
  56#define __get_user_nocheck(x,ptr,size)                          \
  57({                                                              \
  58        long __gu_err;                                          \
  59        unsigned long __gu_val;                                 \
  60        const __typeof__(*(ptr)) __user *__gu_addr = (ptr);     \
  61        __chk_user_ptr(ptr);                                    \
  62        __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
  63        (x) = (__typeof__(*(ptr)))__gu_val;                     \
  64        __gu_err;                                               \
  65})
  66
  67#define __get_user_check(x,ptr,size)                                    \
  68({                                                                      \
  69        long __gu_err = -EFAULT;                                        \
  70        unsigned long __gu_val = 0;                                     \
  71        const __typeof__(*(ptr)) *__gu_addr = (ptr);                    \
  72        if (likely(access_ok(VERIFY_READ, __gu_addr, (size))))          \
  73                __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
  74        (x) = (__typeof__(*(ptr)))__gu_val;                             \
  75        __gu_err;                                                       \
  76})
  77
  78#define __put_user_nocheck(x,ptr,size)                          \
  79({                                                              \
  80        long __pu_err;                                          \
  81        __typeof__(*(ptr)) __user *__pu_addr = (ptr);           \
  82        __typeof__(*(ptr)) __pu_val = x;                        \
  83        __chk_user_ptr(ptr);                                    \
  84        __put_user_size(__pu_val, __pu_addr, (size), __pu_err); \
  85        __pu_err;                                               \
  86})
  87
  88#define __put_user_check(x,ptr,size)                            \
  89({                                                              \
  90        long __pu_err = -EFAULT;                                \
  91        __typeof__(*(ptr)) __user *__pu_addr = (ptr);           \
  92        __typeof__(*(ptr)) __pu_val = x;                        \
  93        if (likely(access_ok(VERIFY_WRITE, __pu_addr, size)))   \
  94                __put_user_size(__pu_val, __pu_addr, (size),    \
  95                                __pu_err);                      \
  96        __pu_err;                                               \
  97})
  98
  99#ifdef CONFIG_SUPERH32
 100# include <asm/uaccess_32.h>
 101#else
 102# include <asm/uaccess_64.h>
 103#endif
 104
 105extern long strncpy_from_user(char *dest, const char __user *src, long count);
 106
 107extern __must_check long strlen_user(const char __user *str);
 108extern __must_check long strnlen_user(const char __user *str, long n);
 109
 110/* Generic arbitrary sized copy.  */
 111/* Return the number of bytes NOT copied */
 112__kernel_size_t __copy_user(void *to, const void *from, __kernel_size_t n);
 113
 114static __always_inline unsigned long
 115__copy_from_user(void *to, const void __user *from, unsigned long n)
 116{
 117        return __copy_user(to, (__force void *)from, n);
 118}
 119
 120static __always_inline unsigned long __must_check
 121__copy_to_user(void __user *to, const void *from, unsigned long n)
 122{
 123        return __copy_user((__force void *)to, from, n);
 124}
 125
 126#define __copy_to_user_inatomic __copy_to_user
 127#define __copy_from_user_inatomic __copy_from_user
 128
 129/*
 130 * Clear the area and return remaining number of bytes
 131 * (on failure.  Usually it's 0.)
 132 */
 133__kernel_size_t __clear_user(void *addr, __kernel_size_t size);
 134
 135#define clear_user(addr,n)                                              \
 136({                                                                      \
 137        void __user * __cl_addr = (addr);                               \
 138        unsigned long __cl_size = (n);                                  \
 139                                                                        \
 140        if (__cl_size && access_ok(VERIFY_WRITE,                        \
 141                ((unsigned long)(__cl_addr)), __cl_size))               \
 142                __cl_size = __clear_user(__cl_addr, __cl_size);         \
 143                                                                        \
 144        __cl_size;                                                      \
 145})
 146
 147static inline unsigned long
 148copy_from_user(void *to, const void __user *from, unsigned long n)
 149{
 150        unsigned long __copy_from = (unsigned long) from;
 151        __kernel_size_t __copy_size = (__kernel_size_t) n;
 152
 153        if (__copy_size && __access_ok(__copy_from, __copy_size))
 154                return __copy_user(to, from, __copy_size);
 155
 156        return __copy_size;
 157}
 158
 159static inline unsigned long
 160copy_to_user(void __user *to, const void *from, unsigned long n)
 161{
 162        unsigned long __copy_to = (unsigned long) to;
 163        __kernel_size_t __copy_size = (__kernel_size_t) n;
 164
 165        if (__copy_size && __access_ok(__copy_to, __copy_size))
 166                return __copy_user(to, from, __copy_size);
 167
 168        return __copy_size;
 169}
 170
 171/*
 172 * The exception table consists of pairs of addresses: the first is the
 173 * address of an instruction that is allowed to fault, and the second is
 174 * the address at which the program should continue.  No registers are
 175 * modified, so it is entirely up to the continuation code to figure out
 176 * what to do.
 177 *
 178 * All the routines below use bits of fixup code that are out of line
 179 * with the main instruction path.  This means when everything is well,
 180 * we don't even have to jump over them.  Further, they do not intrude
 181 * on our cache or tlb entries.
 182 */
 183struct exception_table_entry {
 184        unsigned long insn, fixup;
 185};
 186
 187#if defined(CONFIG_SUPERH64) && defined(CONFIG_MMU)
 188#define ARCH_HAS_SEARCH_EXTABLE
 189#endif
 190
 191int fixup_exception(struct pt_regs *regs);
 192/* Returns 0 if exception not found and fixup.unit otherwise.  */
 193unsigned long search_exception_table(unsigned long addr);
 194const struct exception_table_entry *search_exception_tables(unsigned long addr);
 195
 196extern void *set_exception_table_vec(unsigned int vec, void *handler);
 197
 198static inline void *set_exception_table_evt(unsigned int evt, void *handler)
 199{
 200        return set_exception_table_vec(evt >> 5, handler);
 201}
 202
 203struct mem_access {
 204        unsigned long (*from)(void *dst, const void __user *src, unsigned long cnt);
 205        unsigned long (*to)(void __user *dst, const void *src, unsigned long cnt);
 206};
 207
 208int handle_unaligned_access(insn_size_t instruction, struct pt_regs *regs,
 209                            struct mem_access *ma, int, unsigned long address);
 210
 211#endif /* __ASM_SH_UACCESS_H */
 212