#ifndef __i386_UACCESS_H
#define __i386_UACCESS_H

/*
 * User space memory access functions
 */
#include <linux/config.h>
#include <linux/sched.h>
#include <linux/prefetch.h>
#include <asm/page.h>

#define VERIFY_READ 0
#define VERIFY_WRITE 1

/*
 * The fs value determines whether argument validity checking should be
 * performed or not.  If get_fs() == USER_DS, checking is performed, with
 * get_fs() == KERNEL_DS, checking is bypassed.
 *
 * For historical reasons, these macros are grossly misnamed.
 */

#define MAKE_MM_SEG(s)  ((mm_segment_t) { (s) })


#define KERNEL_DS       MAKE_MM_SEG(0xFFFFFFFF)
#define USER_DS         MAKE_MM_SEG(PAGE_OFFSET)

#define get_ds()        (KERNEL_DS)
#define get_fs()        (current->addr_limit)
#define set_fs(x)       (current->addr_limit = (x))

#define segment_eq(a,b) ((a).seg == (b).seg)

extern int __verify_write(const void *, unsigned long);

#define __addr_ok(addr) ((unsigned long)(addr) < (current->addr_limit.seg))

/*
 * Test whether a block of memory is a valid user space address.
 * Returns 0 if the range is valid, nonzero otherwise.
 *
 * This is equivalent to the following test:
 * (u33)addr + (u33)size >= (u33)current->addr_limit.seg
 *
 * This needs 33-bit arithmetic. We have a carry...
 */
#define __range_ok(addr,size) ({ \
        unsigned long flag,sum; \
        asm("addl %3,%1 ; sbbl %0,%0; cmpl %1,%4; sbbl $0,%0" \
                :"=&r" (flag), "=r" (sum) \
                :"1" (addr),"g" ((int)(size)),"g" (current->addr_limit.seg)); \
        flag; })

#ifdef CONFIG_X86_WP_WORKS_OK

/**
 * access_ok: - Checks if a user space pointer is valid
 * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE.  Note that
 *        %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
 *        to write to a block, it is always safe to read from it.
 * @addr: User space pointer to start of block to check
 * @size: Size of block to check
 *
 * Context: User context only.  This function may sleep.
 *
 * Checks if a pointer to a block of memory in user space is valid.
 *
 * Returns true (nonzero) if the memory block may be valid, false (zero)
 * if it is definitely invalid.
 *
 * Note that, depending on architecture, this function probably just
 * checks that the pointer is in the user space range - after calling
 * this function, memory access functions may still return -EFAULT.
 */
#define access_ok(type,addr,size) (__range_ok(addr,size) == 0)

#else

#define access_ok(type,addr,size) ( (__range_ok(addr,size) == 0) && \
                         ((type) == VERIFY_READ || boot_cpu_data.wp_works_ok || \
                         segment_eq(get_fs(),KERNEL_DS) || \
                          __verify_write((void *)(addr),(size))))

#endif

/**
 * verify_area: - Obsolete, use access_ok()
 * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE
 * @addr: User space pointer to start of block to check
 * @size: Size of block to check
 *
 * Context: User context only.  This function may sleep.
 *
 * This function has been replaced by access_ok().
 *
 * Checks if a pointer to a block of memory in user space is valid.
 *
 * Returns zero if the memory block may be valid, -EFAULT
 * if it is definitely invalid.
 *
 * See access_ok() for more details.
 */
static inline int verify_area(int type, const void * addr, unsigned long size)
{
        return access_ok(type,addr,size) ? 0 : -EFAULT;
}


/*
 * The exception table consists of pairs of addresses: the first is the
 * address of an instruction that is allowed to fault, and the second is
 * the address at which the program should continue.  No registers are
 * modified, so it is entirely up to the continuation code to figure out
 * what to do.
 *
 * All the routines below use bits of fixup code that are out of line
 * with the main instruction path.  This means when everything is well,
 * we don't even have to jump over them.  Further, they do not intrude
 * on our cache or tlb entries.
 */

struct exception_table_entry
{
        unsigned long insn, fixup;
};

/* Returns 0 if exception not found and fixup otherwise.  */
extern unsigned long search_exception_table(unsigned long);


/*
 * These are the main single-value transfer routines.  They automatically
 * use the right size if we just have the right pointer type.
 *
 * This gets kind of ugly. We want to return _two_ values in "get_user()"
 * and yet we don't want to do any pointers, because that is too much
 * of a performance impact. Thus we have a few rather ugly macros here,
 * and hide all the uglyness from the user.
 *
 * The "__xxx" versions of the user access functions are versions that
 * do not verify the address space, that must have been done previously
 * with a separate "access_ok()" call (this is used when we do multiple
 * accesses to the same area of user memory).
 */

extern void __get_user_1(void);
extern void __get_user_2(void);
extern void __get_user_4(void);

#define __get_user_x(size,ret,x,ptr) \
        __asm__ __volatile__("call __get_user_" #size \
                :"=a" (ret),"=d" (x) \
                :"0" (ptr))


/* Careful: we have to cast the result to the type of the pointer for sign reasons */
/**
 * get_user: - Get a simple variable from user space.
 * @x:   Variable to store result.
 * @ptr: Source address, in user space.
 *
 * Context: User context only.  This function may sleep.
 *
 * This macro copies a single simple variable from user space to kernel
 * space.  It supports simple types like char and int, but not larger
 * data types like structures or arrays.
 *
 * @ptr must have pointer-to-simple-variable type, and the result of
 * dereferencing @ptr must be assignable to @x without a cast.
 *
 * Returns zero on success, or -EFAULT on error.
 * On error, the variable @x is set to zero.
 */
#define get_user(x,ptr)                                                 \
({      int __ret_gu,__val_gu;                                          \
        switch(sizeof (*(ptr))) {                                       \
        case 1:  __get_user_x(1,__ret_gu,__val_gu,ptr); break;          \
        case 2:  __get_user_x(2,__ret_gu,__val_gu,ptr); break;          \
        case 4:  __get_user_x(4,__ret_gu,__val_gu,ptr); break;          \
        default: __get_user_x(X,__ret_gu,__val_gu,ptr); break;          \
        }                                                               \
        (x) = (__typeof__(*(ptr)))__val_gu;                             \
        __ret_gu;                                                       \
})

extern void __put_user_1(void);
extern void __put_user_2(void);
extern void __put_user_4(void);
extern void __put_user_8(void);

extern void __put_user_bad(void);


/**
 * put_user: - Write a simple value into user space.
 * @x:   Value to copy to user space.
 * @ptr: Destination address, in user space.
 *
 * Context: User context only.  This function may sleep.
 *
 * This macro copies a single simple value from kernel space to user
 * space.  It supports simple types like char and int, but not larger
 * data types like structures or arrays.
 *
 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 * to the result of dereferencing @ptr.
 *
 * Returns zero on success, or -EFAULT on error.
 */
#define put_user(x,ptr)                                                 \
  __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))


/**
 * __get_user: - Get a simple variable from user space, with less checking.
 * @x:   Variable to store result.
 * @ptr: Source address, in user space.
 *
 * Context: User context only.  This function may sleep.
 *
 * This macro copies a single simple variable from user space to kernel
 * space.  It supports simple types like char and int, but not larger
 * data types like structures or arrays.
 *
 * @ptr must have pointer-to-simple-variable type, and the result of
 * dereferencing @ptr must be assignable to @x without a cast.
 *
 * Caller must check the pointer with access_ok() before calling this
 * function.
 *
 * Returns zero on success, or -EFAULT on error.
 * On error, the variable @x is set to zero.
 */
#define __get_user(x,ptr) \
  __get_user_nocheck((x),(ptr),sizeof(*(ptr)))


/**
 * __put_user: - Write a simple value into user space, with less checking.
 * @x:   Value to copy to user space.
 * @ptr: Destination address, in user space.
 *
 * Context: User context only.  This function may sleep.
 *
 * This macro copies a single simple value from kernel space to user
 * space.  It supports simple types like char and int, but not larger
 * data types like structures or arrays.
 *
 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 * to the result of dereferencing @ptr.
 *
 * Caller must check the pointer with access_ok() before calling this
 * function.
 *
 * Returns zero on success, or -EFAULT on error.
 */
#define __put_user(x,ptr) \
  __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))

#define __put_user_nocheck(x,ptr,size)                  \
({                                                      \
        long __pu_err;                                  \
        __put_user_size((x),(ptr),(size),__pu_err);     \
        __pu_err;                                       \
})


#define __put_user_check(x,ptr,size)                    \
({                                                      \
        long __pu_err = -EFAULT;                                        \
        __typeof__(*(ptr)) *__pu_addr = (ptr);          \
        if (access_ok(VERIFY_WRITE,__pu_addr,size))     \
                __put_user_size((x),__pu_addr,(size),__pu_err); \
        __pu_err;                                       \
})                                                      

#define __put_user_u64(x, addr, err)                            \
        __asm__ __volatile__(                                   \
                "1:     movl %%eax,0(%2)\n"                     \
                "2:     movl %%edx,4(%2)\n"                     \
                "3:\n"                                          \
                ".section .fixup,\"ax\"\n"                      \
                "4:     movl %3,%0\n"                           \
                "       jmp 3b\n"                               \
                ".previous\n"                                   \
                ".section __ex_table,\"a\"\n"                   \
                "       .align 4\n"                             \
                "       .long 1b,4b\n"                          \
                "       .long 2b,4b\n"                          \
                ".previous"                                     \
                : "=r"(err)                                     \
                : "A" (x), "r" (addr), "i"(-EFAULT), "0"(err))

#define __put_user_size(x,ptr,size,retval)                              \
do {                                                                    \
        retval = 0;                                                     \
        switch (size) {                                                 \
          case 1: __put_user_asm(x,ptr,retval,"b","b","iq"); break;     \
          case 2: __put_user_asm(x,ptr,retval,"w","w","ir"); break;     \
          case 4: __put_user_asm(x,ptr,retval,"l","","ir"); break;      \
          case 8: __put_user_u64(x,ptr,retval); break;                  \
          default: __put_user_bad();                                    \
        }                                                               \
} while (0)

struct __large_struct { unsigned long buf[100]; };
#define __m(x) (*(struct __large_struct *)(x))

/*
 * Tell gcc we read from memory instead of writing: this is because
 * we do not write to any memory gcc knows about, so there are no
 * aliasing issues.
 */
#define __put_user_asm(x, addr, err, itype, rtype, ltype)       \
        __asm__ __volatile__(                                   \
                "1:     mov"itype" %"rtype"1,%2\n"              \
                "2:\n"                                          \
                ".section .fixup,\"ax\"\n"                      \
                "3:     movl %3,%0\n"                           \
                "       jmp 2b\n"                               \
                ".previous\n"                                   \
                ".section __ex_table,\"a\"\n"                   \
                "       .align 4\n"                             \
                "       .long 1b,3b\n"                          \
                ".previous"                                     \
                : "=r"(err)                                     \
                : ltype (x), "m"(__m(addr)), "i"(-EFAULT), "0"(err))


#define __get_user_nocheck(x,ptr,size)                          \
({                                                              \
        long __gu_err, __gu_val;                                \
        __get_user_size(__gu_val,(ptr),(size),__gu_err);        \
        (x) = (__typeof__(*(ptr)))__gu_val;                     \
        __gu_err;                                               \
})

extern long __get_user_bad(void);

#define __get_user_size(x,ptr,size,retval)                              \
do {                                                                    \
        retval = 0;                                                     \
        switch (size) {                                                 \
          case 1: __get_user_asm(x,ptr,retval,"b","b","=q"); break;     \
          case 2: __get_user_asm(x,ptr,retval,"w","w","=r"); break;     \
          case 4: __get_user_asm(x,ptr,retval,"l","","=r"); break;      \
          default: (x) = __get_user_bad();                              \
        }                                                               \
} while (0)

#define __get_user_asm(x, addr, err, itype, rtype, ltype)       \
        __asm__ __volatile__(                                   \
                "1:     mov"itype" %2,%"rtype"1\n"              \
                "2:\n"                                          \
                ".section .fixup,\"ax\"\n"                      \
                "3:     movl %3,%0\n"                           \
                "       xor"itype" %"rtype"1,%"rtype"1\n"       \
                "       jmp 2b\n"                               \
                ".previous\n"                                   \
                ".section __ex_table,\"a\"\n"                   \
                "       .align 4\n"                             \
                "       .long 1b,3b\n"                          \
                ".previous"                                     \
                : "=r"(err), ltype (x)                          \
                : "m"(__m(addr)), "i"(-EFAULT), "0"(err))


/*
 * Copy To/From Userspace
 */

/* Generic arbitrary sized copy.  */
#define __copy_user(to,from,size)                                       \
do {                                                                    \
        int __d0, __d1;                                                 \
        __asm__ __volatile__(                                           \
                "0:     rep; movsl\n"                                   \
                "       movl %3,%0\n"                                   \
                "1:     rep; movsb\n"                                   \
                "2:\n"                                                  \
                ".section .fixup,\"ax\"\n"                              \
                "3:     lea 0(%3,%0,4),%0\n"                            \
                "       jmp 2b\n"                                       \
                ".previous\n"                                           \
                ".section __ex_table,\"a\"\n"                           \
                "       .align 4\n"                                     \
                "       .long 0b,3b\n"                                  \
                "       .long 1b,2b\n"                                  \
                ".previous"                                             \
                : "=&c"(size), "=&D" (__d0), "=&S" (__d1)               \
                : "r"(size & 3), "0"(size / 4), "1"(to), "2"(from)      \
                : "memory");                                            \
} while (0)

#define __copy_user_zeroing(to,from,size)                               \
do {                                                                    \
        int __d0, __d1;                                                 \
        __asm__ __volatile__(                                           \
                "0:     rep; movsl\n"                                   \
                "       movl %3,%0\n"                                   \
                "1:     rep; movsb\n"                                   \
                "2:\n"                                                  \
                ".section .fixup,\"ax\"\n"                              \
                "3:     lea 0(%3,%0,4),%0\n"                            \
                "4:     pushl %0\n"                                     \
                "       pushl %%eax\n"                                  \
                "       xorl %%eax,%%eax\n"                             \
                "       rep; stosb\n"                                   \
                "       popl %%eax\n"                                   \
                "       popl %0\n"                                      \
                "       jmp 2b\n"                                       \
                ".previous\n"                                           \
                ".section __ex_table,\"a\"\n"                           \
                "       .align 4\n"                                     \
                "       .long 0b,3b\n"                                  \
                "       .long 1b,4b\n"                                  \
                ".previous"                                             \
                : "=&c"(size), "=&D" (__d0), "=&S" (__d1)               \
                : "r"(size & 3), "0"(size / 4), "1"(to), "2"(from)      \
                : "memory");                                            \
} while (0)

/* We let the __ versions of copy_from/to_user inline, because they're often
 * used in fast paths and have only a small space overhead.
 */
static inline unsigned long
__generic_copy_from_user_nocheck(void *to, const void *from, unsigned long n)
{
        __copy_user_zeroing(to,from,n);
        return n;
}

static inline unsigned long
__generic_copy_to_user_nocheck(void *to, const void *from, unsigned long n)
{
        __copy_user(to,from,n);
        return n;
}


/* Optimize just a little bit when we know the size of the move. */
#define __constant_copy_user(to, from, size)                    \
do {                                                            \
        int __d0, __d1;                                         \
        switch (size & 3) {                                     \
        default:                                                \
                __asm__ __volatile__(                           \
                        "0:     rep; movsl\n"                   \
                        "1:\n"                                  \
                        ".section .fixup,\"ax\"\n"              \
                        "2:     shl $2,%0\n"                    \
                        "       jmp 1b\n"                       \
                        ".previous\n"                           \
                        ".section __ex_table,\"a\"\n"           \
                        "       .align 4\n"                     \
                        "       .long 0b,2b\n"                  \
                        ".previous"                             \
                        : "=c"(size), "=&S" (__d0), "=&D" (__d1)\
                        : "1"(from), "2"(to), "0"(size/4)       \
                        : "memory");                            \
                break;                                          \
        case 1:                                                 \
                __asm__ __volatile__(                           \
                        "0:     rep; movsl\n"                   \
                        "1:     movsb\n"                        \
                        "2:\n"                                  \
                        ".section .fixup,\"ax\"\n"              \
                        "3:     shl $2,%0\n"                    \
                        "4:     incl %0\n"                      \
                        "       jmp 2b\n"                       \
                        ".previous\n"                           \
                        ".section __ex_table,\"a\"\n"           \
                        "       .align 4\n"                     \
                        "       .long 0b,3b\n"                  \
                        "       .long 1b,4b\n"                  \
                        ".previous"                             \
                        : "=c"(size), "=&S" (__d0), "=&D" (__d1)\
                        : "1"(from), "2"(to), "0"(size/4)       \
                        : "memory");                            \
                break;                                          \
        case 2:                                                 \
                __asm__ __volatile__(                           \
                        "0:     rep; movsl\n"                   \
                        "1:     movsw\n"                        \
                        "2:\n"                                  \
                        ".section .fixup,\"ax\"\n"              \
                        "3:     shl $2,%0\n"                    \
                        "4:     addl $2,%0\n"                   \
                        "       jmp 2b\n"                       \
                        ".previous\n"                           \
                        ".section __ex_table,\"a\"\n"           \
                        "       .align 4\n"                     \
                        "       .long 0b,3b\n"                  \
                        "       .long 1b,4b\n"                  \
                        ".previous"                             \
                        : "=c"(size), "=&S" (__d0), "=&D" (__d1)\
                        : "1"(from), "2"(to), "0"(size/4)       \
                        : "memory");                            \
                break;                                          \
        case 3:                                                 \
                __asm__ __volatile__(                           \
                        "0:     rep; movsl\n"                   \
                        "1:     movsw\n"                        \
                        "2:     movsb\n"                        \
                        "3:\n"                                  \
                        ".section .fixup,\"ax\"\n"              \
                        "4:     shl $2,%0\n"                    \
                        "5:     addl $2,%0\n"                   \
                        "6:     incl %0\n"                      \
                        "       jmp 3b\n"                       \
                        ".previous\n"                           \
                        ".section __ex_table,\"a\"\n"           \
                        "       .align 4\n"                     \
                        "       .long 0b,4b\n"                  \
                        "       .long 1b,5b\n"                  \
                        "       .long 2b,6b\n"                  \
                        ".previous"                             \
                        : "=c"(size), "=&S" (__d0), "=&D" (__d1)\
                        : "1"(from), "2"(to), "0"(size/4)       \
                        : "memory");                            \
                break;                                          \
        }                                                       \
} while (0)

/* Optimize just a little bit when we know the size of the move. */
#define __constant_copy_user_zeroing(to, from, size)            \
do {                                                            \
        int __d0, __d1;                                         \
        switch (size & 3) {                                     \
        default:                                                \
                __asm__ __volatile__(                           \
                        "0:     rep; movsl\n"                   \
                        "1:\n"                                  \
                        ".section .fixup,\"ax\"\n"              \
                        "2:     pushl %0\n"                     \
                        "       pushl %%eax\n"                  \
                        "       xorl %%eax,%%eax\n"             \
                        "       rep; stosl\n"                   \
                        "       popl %%eax\n"                   \
                        "       popl %0\n"                      \
                        "       shl $2,%0\n"                    \
                        "       jmp 1b\n"                       \
                        ".previous\n"                           \
                        ".section __ex_table,\"a\"\n"           \
                        "       .align 4\n"                     \
                        "       .long 0b,2b\n"                  \
                        ".previous"                             \
                        : "=c"(size), "=&S" (__d0), "=&D" (__d1)\
                        : "1"(from), "2"(to), "0"(size/4)       \
                        : "memory");                            \
                break;                                          \
        case 1:                                                 \
                __asm__ __volatile__(                           \
                        "0:     rep; movsl\n"                   \
                        "1:     movsb\n"                        \
                        "2:\n"                                  \
                        ".section .fixup,\"ax\"\n"              \
                        "3:     pushl %0\n"                     \
                        "       pushl %%eax\n"                  \
                        "       xorl %%eax,%%eax\n"             \
                        "       rep; stosl\n"                   \
                        "       stosb\n"                        \
                        "       popl %%eax\n"                   \
                        "       popl %0\n"                      \
                        "       shl $2,%0\n"                    \
                        "       incl %0\n"                      \
                        "       jmp 2b\n"                       \
                        "4:     pushl %%eax\n"                  \
                        "       xorl %%eax,%%eax\n"             \
                        "       stosb\n"                        \
                        "       popl %%eax\n"                   \
                        "       incl %0\n"                      \
                        "       jmp 2b\n"                       \
                        ".previous\n"                           \
                        ".section __ex_table,\"a\"\n"           \
                        "       .align 4\n"                     \
                        "       .long 0b,3b\n"                  \
                        "       .long 1b,4b\n"                  \
                        ".previous"                             \
                        : "=c"(size), "=&S" (__d0), "=&D" (__d1)\
                        : "1"(from), "2"(to), "0"(size/4)       \
                        : "memory");                            \
                break;                                          \
        case 2:                                                 \
                __asm__ __volatile__(                           \
                        "0:     rep; movsl\n"                   \
                        "1:     movsw\n"                        \
                        "2:\n"                                  \
                        ".section .fixup,\"ax\"\n"              \
                        "3:     pushl %0\n"                     \
                        "       pushl %%eax\n"                  \
                        "       xorl %%eax,%%eax\n"             \
                        "       rep; stosl\n"                   \
                        "       stosw\n"                        \
                        "       popl %%eax\n"                   \
                        "       popl %0\n"                      \
                        "       shl $2,%0\n"                    \
                        "       addl $2,%0\n"                   \
                        "       jmp 2b\n"                       \
                        "4:     pushl %%eax\n"                  \
                        "       xorl %%eax,%%eax\n"             \
                        "       stosw\n"                        \
                        "       popl %%eax\n"                   \
                        "       addl $2,%0\n"                   \
                        "       jmp 2b\n"                       \
                        ".previous\n"                           \
                        ".section __ex_table,\"a\"\n"           \
                        "       .align 4\n"                     \
                        "       .long 0b,3b\n"                  \
                        "       .long 1b,4b\n"                  \
                        ".previous"                             \
                        : "=c"(size), "=&S" (__d0), "=&D" (__d1)\
                        : "1"(from), "2"(to), "0"(size/4)       \
                        : "memory");                            \
                break;                                          \
        case 3:                                                 \
                __asm__ __volatile__(                           \
                        "0:     rep; movsl\n"                   \
                        "1:     movsw\n"                        \
                        "2:     movsb\n"                        \
                        "3:\n"                                  \
                        ".section .fixup,\"ax\"\n"              \
                        "4:     pushl %0\n"                     \
                        "       pushl %%eax\n"                  \
                        "       xorl %%eax,%%eax\n"             \
                        "       rep; stosl\n"                   \
                        "       stosw\n"                        \
                        "       stosb\n"                        \
                        "       popl %%eax\n"                   \
                        "       popl %0\n"                      \
                        "       shl $2,%0\n"                    \
                        "       addl $3,%0\n"                   \
                        "       jmp 2b\n"                       \
                        "5:     pushl %%eax\n"                  \
                        "       xorl %%eax,%%eax\n"             \
                        "       stosw\n"                        \
                        "       stosb\n"                        \
                        "       popl %%eax\n"                   \
                        "       addl $3,%0\n"                   \
                        "       jmp 2b\n"                       \
                        "6:     pushl %%eax\n"                  \
                        "       xorl %%eax,%%eax\n"             \
                        "       stosb\n"                        \
                        "       popl %%eax\n"                   \
                        "       incl %0\n"                      \
                        "       jmp 3b\n"                       \
                        ".previous\n"                           \
                        ".section __ex_table,\"a\"\n"           \
                        "       .align 4\n"                     \
                        "       .long 0b,4b\n"                  \
                        "       .long 1b,5b\n"                  \
                        "       .long 2b,6b\n"                  \
                        ".previous"                             \
                        : "=c"(size), "=&S" (__d0), "=&D" (__d1)\
                        : "1"(from), "2"(to), "0"(size/4)       \
                        : "memory");                            \
                break;                                          \
        }                                                       \
} while (0)

unsigned long __generic_copy_to_user(void *, const void *, unsigned long);
unsigned long __generic_copy_from_user(void *, const void *, unsigned long);

static inline unsigned long
__constant_copy_to_user(void *to, const void *from, unsigned long n)
{
        prefetch(from);
        if (access_ok(VERIFY_WRITE, to, n))
                __constant_copy_user(to,from,n);
        return n;
}

static inline unsigned long
__constant_copy_from_user(void *to, const void *from, unsigned long n)
{
        if (access_ok(VERIFY_READ, from, n))
                __constant_copy_user_zeroing(to,from,n);
        else
                memset(to, 0, n);
        return n;
}

static inline unsigned long
__constant_copy_to_user_nocheck(void *to, const void *from, unsigned long n)
{
        __constant_copy_user(to,from,n);
        return n;
}

static inline unsigned long
__constant_copy_from_user_nocheck(void *to, const void *from, unsigned long n)
{
        __constant_copy_user_zeroing(to,from,n);
        return n;
}

/**
 * copy_to_user: - Copy a block of data into user space.
 * @to:   Destination address, in user space.
 * @from: Source address, in kernel space.
 * @n:    Number of bytes to copy.
 *
 * Context: User context only.  This function may sleep.
 *
 * Copy data from kernel space to user space.
 *
 * Returns number of bytes that could not be copied.
 * On success, this will be zero.
 */
#define copy_to_user(to,from,n)                         \
        (__builtin_constant_p(n) ?                      \
         __constant_copy_to_user((to),(from),(n)) :     \
         __generic_copy_to_user((to),(from),(n)))

/**
 * copy_from_user: - Copy a block of data from user space.
 * @to:   Destination address, in kernel space.
 * @from: Source address, in user space.
 * @n:    Number of bytes to copy.
 *
 * Context: User context only.  This function may sleep.
 *
 * Copy data from user space to kernel space.
 *
 * Returns number of bytes that could not be copied.
 * On success, this will be zero.
 *
 * If some data could not be copied, this function will pad the copied
 * data to the requested size using zero bytes.
 */
#define copy_from_user(to,from,n)                       \
        (__builtin_constant_p(n) ?                      \
         __constant_copy_from_user((to),(from),(n)) :   \
         __generic_copy_from_user((to),(from),(n)))

/**
 * __copy_to_user: - Copy a block of data into user space, with less checking.
 * @to:   Destination address, in user space.
 * @from: Source address, in kernel space.
 * @n:    Number of bytes to copy.
 *
 * Context: User context only.  This function may sleep.
 *
 * Copy data from kernel space to user space.  Caller must check
 * the specified block with access_ok() before calling this function.
 *
 * Returns number of bytes that could not be copied.
 * On success, this will be zero.
 */
#define __copy_to_user(to,from,n)                       \
        (__builtin_constant_p(n) ?                      \
         __constant_copy_to_user_nocheck((to),(from),(n)) :     \
         __generic_copy_to_user_nocheck((to),(from),(n)))

/**
 * __copy_from_user: - Copy a block of data from user space, with less checking.
 * @to:   Destination address, in kernel space.
 * @from: Source address, in user space.
 * @n:    Number of bytes to copy.
 *
 * Context: User context only.  This function may sleep.
 *
 * Copy data from user space to kernel space.  Caller must check
 * the specified block with access_ok() before calling this function.
 *
 * Returns number of bytes that could not be copied.
 * On success, this will be zero.
 *
 * If some data could not be copied, this function will pad the copied
 * data to the requested size using zero bytes.
 */
#define __copy_from_user(to,from,n)                     \
        (__builtin_constant_p(n) ?                      \
         __constant_copy_from_user_nocheck((to),(from),(n)) :   \
         __generic_copy_from_user_nocheck((to),(from),(n)))

long strncpy_from_user(char *dst, const char *src, long count);
long __strncpy_from_user(char *dst, const char *src, long count);

/**
 * strlen_user: - Get the size of a string in user space.
 * @str: The string to measure.
 *
 * Context: User context only.  This function may sleep.
 *
 * Get the size of a NUL-terminated string in user space.
 *
 * Returns the size of the string INCLUDING the terminating NUL.
 * On exception, returns 0.
 *
 * If there is a limit on the length of a valid string, you may wish to
 * consider using strnlen_user() instead.
 */
#define strlen_user(str) strnlen_user(str, ~0UL >> 1)

long strnlen_user(const char *str, long n);
unsigned long clear_user(void *mem, unsigned long len);
unsigned long __clear_user(void *mem, unsigned long len);

#endif /* __i386_UACCESS_H */