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/*
  29 * Uh, these should become the main single-value transfer routines ...
  30 * They automatically use the right size if we just have the right
  31 * pointer type ...
  32 *
  33 * As SuperH uses the same address space for kernel and user data, we
  34 * can just do these as direct assignments.
  35 *
  36 * Careful to not
  37 * (a) re-use the arguments for side effects (sizeof is ok)
  38 * (b) require any knowledge of processes at this stage
  39 */
  40#define put_user(x,ptr)         __put_user_check((x), (ptr), sizeof(*(ptr)))
  41#define get_user(x,ptr)         __get_user_check((x), (ptr), sizeof(*(ptr)))
  42
  43/*
  44 * The "__xxx" versions do not do address space checking, useful when
  45 * doing multiple accesses to the same area (the user has to do the
  46 * checks by hand with "access_ok()")
  47 */
  48#define __put_user(x,ptr)       __put_user_nocheck((x), (ptr), sizeof(*(ptr)))
  49#define __get_user(x,ptr)       __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
  50
  51struct __large_struct { unsigned long buf[100]; };
  52#define __m(x) (*(struct __large_struct __user *)(x))
  53
  54#define __get_user_nocheck(x,ptr,size)                          \
  55({                                                              \
  56        long __gu_err;                                          \
  57        unsigned long __gu_val;                                 \
  58        const __typeof__(*(ptr)) __user *__gu_addr = (ptr);     \
  59        __chk_user_ptr(ptr);                                    \
  60        __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
  61        (x) = (__typeof__(*(ptr)))__gu_val;                     \
  62        __gu_err;                                               \
  63})
  64
  65#define __get_user_check(x,ptr,size)                                    \
  66({                                                                      \
  67        long __gu_err = -EFAULT;                                        \
  68        unsigned long __gu_val = 0;                                     \
  69        const __typeof__(*(ptr)) *__gu_addr = (ptr);                    \
  70        if (likely(access_ok(VERIFY_READ, __gu_addr, (size))))          \
  71                __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
  72        (x) = (__typeof__(*(ptr)))__gu_val;                             \
  73        __gu_err;                                                       \
  74})
  75
  76#define __put_user_nocheck(x,ptr,size)                          \
  77({                                                              \
  78        long __pu_err;                                          \
  79        __typeof__(*(ptr)) __user *__pu_addr = (ptr);           \
  80        __typeof__(*(ptr)) __pu_val = x;                        \
  81        __chk_user_ptr(ptr);                                    \
  82        __put_user_size(__pu_val, __pu_addr, (size), __pu_err); \
  83        __pu_err;                                               \
  84})
  85
  86#define __put_user_check(x,ptr,size)                            \
  87({                                                              \
  88        long __pu_err = -EFAULT;                                \
  89        __typeof__(*(ptr)) __user *__pu_addr = (ptr);           \
  90        __typeof__(*(ptr)) __pu_val = x;                        \
  91        if (likely(access_ok(VERIFY_WRITE, __pu_addr, size)))   \
  92                __put_user_size(__pu_val, __pu_addr, (size),    \
  93                                __pu_err);                      \
  94        __pu_err;                                               \
  95})
  96
  97#ifdef CONFIG_SUPERH32
  98# include "uaccess_32.h"
  99#else
 100# include "uaccess_64.h"
 101#endif
 102
 103/* Generic arbitrary sized copy.  */
 104/* Return the number of bytes NOT copied */
 105__kernel_size_t __copy_user(void *to, const void *from, __kernel_size_t n);
 106
 107static __always_inline unsigned long
 108__copy_from_user(void *to, const void __user *from, unsigned long n)
 109{
 110        return __copy_user(to, (__force void *)from, n);
 111}
 112
 113static __always_inline unsigned long __must_check
 114__copy_to_user(void __user *to, const void *from, unsigned long n)
 115{
 116        return __copy_user((__force void *)to, from, n);
 117}
 118
 119#define __copy_to_user_inatomic __copy_to_user
 120#define __copy_from_user_inatomic __copy_from_user
 121
 122/*
 123 * Clear the area and return remaining number of bytes
 124 * (on failure.  Usually it's 0.)
 125 */
 126__kernel_size_t __clear_user(void *addr, __kernel_size_t size);
 127
 128#define clear_user(addr,n)                                              \
 129({                                                                      \
 130        void __user * __cl_addr = (addr);                               \
 131        unsigned long __cl_size = (n);                                  \
 132                                                                        \
 133        if (__cl_size && access_ok(VERIFY_WRITE,                        \
 134                ((unsigned long)(__cl_addr)), __cl_size))               \
 135                __cl_size = __clear_user(__cl_addr, __cl_size);         \
 136                                                                        \
 137        __cl_size;                                                      \
 138})
 139
 140/**
 141 * strncpy_from_user: - Copy a NUL terminated string from userspace.
 142 * @dst:   Destination address, in kernel space.  This buffer must be at
 143 *         least @count bytes long.
 144 * @src:   Source address, in user space.
 145 * @count: Maximum number of bytes to copy, including the trailing NUL.
 146 *
 147 * Copies a NUL-terminated string from userspace to kernel space.
 148 *
 149 * On success, returns the length of the string (not including the trailing
 150 * NUL).
 151 *
 152 * If access to userspace fails, returns -EFAULT (some data may have been
 153 * copied).
 154 *
 155 * If @count is smaller than the length of the string, copies @count bytes
 156 * and returns @count.
 157 */
 158#define strncpy_from_user(dest,src,count)                               \
 159({                                                                      \
 160        unsigned long __sfu_src = (unsigned long)(src);                 \
 161        int __sfu_count = (int)(count);                                 \
 162        long __sfu_res = -EFAULT;                                       \
 163                                                                        \
 164        if (__access_ok(__sfu_src, __sfu_count))                        \
 165                __sfu_res = __strncpy_from_user((unsigned long)(dest),  \
 166                                __sfu_src, __sfu_count);                \
 167                                                                        \
 168        __sfu_res;                                                      \
 169})
 170
 171static inline unsigned long
 172copy_from_user(void *to, const void __user *from, unsigned long n)
 173{
 174        unsigned long __copy_from = (unsigned long) from;
 175        __kernel_size_t __copy_size = (__kernel_size_t) n;
 176
 177        if (__copy_size && __access_ok(__copy_from, __copy_size))
 178                return __copy_user(to, from, __copy_size);
 179
 180        return __copy_size;
 181}
 182
 183static inline unsigned long
 184copy_to_user(void __user *to, const void *from, unsigned long n)
 185{
 186        unsigned long __copy_to = (unsigned long) to;
 187        __kernel_size_t __copy_size = (__kernel_size_t) n;
 188
 189        if (__copy_size && __access_ok(__copy_to, __copy_size))
 190                return __copy_user(to, from, __copy_size);
 191
 192        return __copy_size;
 193}
 194
 195/**
 196 * strnlen_user: - Get the size of a string in user space.
 197 * @s: The string to measure.
 198 * @n: The maximum valid length
 199 *
 200 * Context: User context only.  This function may sleep.
 201 *
 202 * Get the size of a NUL-terminated string in user space.
 203 *
 204 * Returns the size of the string INCLUDING the terminating NUL.
 205 * On exception, returns 0.
 206 * If the string is too long, returns a value greater than @n.
 207 */
 208static inline long strnlen_user(const char __user *s, long n)
 209{
 210        if (!__addr_ok(s))
 211                return 0;
 212        else
 213                return __strnlen_user(s, n);
 214}
 215
 216/**
 217 * strlen_user: - Get the size of a string in user space.
 218 * @str: The string to measure.
 219 *
 220 * Context: User context only.  This function may sleep.
 221 *
 222 * Get the size of a NUL-terminated string in user space.
 223 *
 224 * Returns the size of the string INCLUDING the terminating NUL.
 225 * On exception, returns 0.
 226 *
 227 * If there is a limit on the length of a valid string, you may wish to
 228 * consider using strnlen_user() instead.
 229 */
 230#define strlen_user(str)        strnlen_user(str, ~0UL >> 1)
 231
 232/*
 233 * The exception table consists of pairs of addresses: the first is the
 234 * address of an instruction that is allowed to fault, and the second is
 235 * the address at which the program should continue.  No registers are
 236 * modified, so it is entirely up to the continuation code to figure out
 237 * what to do.
 238 *
 239 * All the routines below use bits of fixup code that are out of line
 240 * with the main instruction path.  This means when everything is well,
 241 * we don't even have to jump over them.  Further, they do not intrude
 242 * on our cache or tlb entries.
 243 */
 244struct exception_table_entry {
 245        unsigned long insn, fixup;
 246};
 247
 248#if defined(CONFIG_SUPERH64) && defined(CONFIG_MMU)
 249#define ARCH_HAS_SEARCH_EXTABLE
 250#endif
 251
 252int fixup_exception(struct pt_regs *regs);
 253/* Returns 0 if exception not found and fixup.unit otherwise.  */
 254unsigned long search_exception_table(unsigned long addr);
 255const struct exception_table_entry *search_exception_tables(unsigned long addr);
 256
 257
 258#endif /* __ASM_SH_UACCESS_H */
 259