root/arch/x86/include/asm/uaccess_64.h

INCLUDED FROM

DEFINITIONS

1. copy_user_generic
2. __copy_from_user_nocheck
3. __copy_from_user
4. __copy_to_user_nocheck
5. __copy_to_user
6. __copy_in_user
7. __copy_from_user_inatomic
8. __copy_to_user_inatomic
9. __copy_from_user_nocache
10. __copy_from_user_inatomic_nocache

#ifndef _ASM_X86_UACCESS_64_H
#define _ASM_X86_UACCESS_64_H

/*
 * User space memory access functions
 */
#include <linux/compiler.h>
#include <linux/errno.h>
#include <linux/lockdep.h>
#include <asm/alternative.h>
#include <asm/cpufeature.h>
#include <asm/page.h>

/*
 * Copy To/From Userspace
 */

/* Handles exceptions in both to and from, but doesn't do access_ok */
__must_check unsigned long
copy_user_enhanced_fast_string(void *to, const void *from, unsigned len);
__must_check unsigned long
copy_user_generic_string(void *to, const void *from, unsigned len);
__must_check unsigned long
copy_user_generic_unrolled(void *to, const void *from, unsigned len);

static __always_inline __must_check unsigned long
copy_user_generic(void *to, const void *from, unsigned len)
{
        unsigned ret;

        /*
         * If CPU has ERMS feature, use copy_user_enhanced_fast_string.
         * Otherwise, if CPU has rep_good feature, use copy_user_generic_string.
         * Otherwise, use copy_user_generic_unrolled.
         */
        alternative_call_2(copy_user_generic_unrolled,
                         copy_user_generic_string,
                         X86_FEATURE_REP_GOOD,
                         copy_user_enhanced_fast_string,
                         X86_FEATURE_ERMS,
                         ASM_OUTPUT2("=a" (ret), "=D" (to), "=S" (from),
                                     "=d" (len)),
                         "1" (to), "2" (from), "3" (len)
                         : "memory", "rcx", "r8", "r9", "r10", "r11");
        return ret;
}

__must_check unsigned long
copy_in_user(void __user *to, const void __user *from, unsigned len);

static __always_inline __must_check
int __copy_from_user_nocheck(void *dst, const void __user *src, unsigned size)
{
        int ret = 0;

        if (!__builtin_constant_p(size))
                return copy_user_generic(dst, (__force void *)src, size);
        switch (size) {
        case 1:__get_user_asm(*(u8 *)dst, (u8 __user *)src,
                              ret, "b", "b", "=q", 1);
                return ret;
        case 2:__get_user_asm(*(u16 *)dst, (u16 __user *)src,
                              ret, "w", "w", "=r", 2);
                return ret;
        case 4:__get_user_asm(*(u32 *)dst, (u32 __user *)src,
                              ret, "l", "k", "=r", 4);
                return ret;
        case 8:__get_user_asm(*(u64 *)dst, (u64 __user *)src,
                              ret, "q", "", "=r", 8);
                return ret;
        case 10:
                __get_user_asm(*(u64 *)dst, (u64 __user *)src,
                               ret, "q", "", "=r", 10);
                if (unlikely(ret))
                        return ret;
                __get_user_asm(*(u16 *)(8 + (char *)dst),
                               (u16 __user *)(8 + (char __user *)src),
                               ret, "w", "w", "=r", 2);
                return ret;
        case 16:
                __get_user_asm(*(u64 *)dst, (u64 __user *)src,
                               ret, "q", "", "=r", 16);
                if (unlikely(ret))
                        return ret;
                __get_user_asm(*(u64 *)(8 + (char *)dst),
                               (u64 __user *)(8 + (char __user *)src),
                               ret, "q", "", "=r", 8);
                return ret;
        default:
                return copy_user_generic(dst, (__force void *)src, size);
        }
}

static __always_inline __must_check
int __copy_from_user(void *dst, const void __user *src, unsigned size)
{
        might_fault();
        return __copy_from_user_nocheck(dst, src, size);
}

static __always_inline __must_check
int __copy_to_user_nocheck(void __user *dst, const void *src, unsigned size)
{
        int ret = 0;

        if (!__builtin_constant_p(size))
                return copy_user_generic((__force void *)dst, src, size);
        switch (size) {
        case 1:__put_user_asm(*(u8 *)src, (u8 __user *)dst,
                              ret, "b", "b", "iq", 1);
                return ret;
        case 2:__put_user_asm(*(u16 *)src, (u16 __user *)dst,
                              ret, "w", "w", "ir", 2);
                return ret;
        case 4:__put_user_asm(*(u32 *)src, (u32 __user *)dst,
                              ret, "l", "k", "ir", 4);
                return ret;
        case 8:__put_user_asm(*(u64 *)src, (u64 __user *)dst,
                              ret, "q", "", "er", 8);
                return ret;
        case 10:
                __put_user_asm(*(u64 *)src, (u64 __user *)dst,
                               ret, "q", "", "er", 10);
                if (unlikely(ret))
                        return ret;
                asm("":::"memory");
                __put_user_asm(4[(u16 *)src], 4 + (u16 __user *)dst,
                               ret, "w", "w", "ir", 2);
                return ret;
        case 16:
                __put_user_asm(*(u64 *)src, (u64 __user *)dst,
                               ret, "q", "", "er", 16);
                if (unlikely(ret))
                        return ret;
                asm("":::"memory");
                __put_user_asm(1[(u64 *)src], 1 + (u64 __user *)dst,
                               ret, "q", "", "er", 8);
                return ret;
        default:
                return copy_user_generic((__force void *)dst, src, size);
        }
}

static __always_inline __must_check
int __copy_to_user(void __user *dst, const void *src, unsigned size)
{
        might_fault();
        return __copy_to_user_nocheck(dst, src, size);
}

static __always_inline __must_check
int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
{
        int ret = 0;

        might_fault();
        if (!__builtin_constant_p(size))
                return copy_user_generic((__force void *)dst,
                                         (__force void *)src, size);
        switch (size) {
        case 1: {
                u8 tmp;
                __get_user_asm(tmp, (u8 __user *)src,
                               ret, "b", "b", "=q", 1);
                if (likely(!ret))
                        __put_user_asm(tmp, (u8 __user *)dst,
                                       ret, "b", "b", "iq", 1);
                return ret;
        }
        case 2: {
                u16 tmp;
                __get_user_asm(tmp, (u16 __user *)src,
                               ret, "w", "w", "=r", 2);
                if (likely(!ret))
                        __put_user_asm(tmp, (u16 __user *)dst,
                                       ret, "w", "w", "ir", 2);
                return ret;
        }

        case 4: {
                u32 tmp;
                __get_user_asm(tmp, (u32 __user *)src,
                               ret, "l", "k", "=r", 4);
                if (likely(!ret))
                        __put_user_asm(tmp, (u32 __user *)dst,
                                       ret, "l", "k", "ir", 4);
                return ret;
        }
        case 8: {
                u64 tmp;
                __get_user_asm(tmp, (u64 __user *)src,
                               ret, "q", "", "=r", 8);
                if (likely(!ret))
                        __put_user_asm(tmp, (u64 __user *)dst,
                                       ret, "q", "", "er", 8);
                return ret;
        }
        default:
                return copy_user_generic((__force void *)dst,
                                         (__force void *)src, size);
        }
}

static __must_check __always_inline int
__copy_from_user_inatomic(void *dst, const void __user *src, unsigned size)
{
        return __copy_from_user_nocheck(dst, src, size);
}

static __must_check __always_inline int
__copy_to_user_inatomic(void __user *dst, const void *src, unsigned size)
{
        return __copy_to_user_nocheck(dst, src, size);
}

extern long __copy_user_nocache(void *dst, const void __user *src,
                                unsigned size, int zerorest);

static inline int
__copy_from_user_nocache(void *dst, const void __user *src, unsigned size)
{
        might_fault();
        return __copy_user_nocache(dst, src, size, 1);
}

static inline int
__copy_from_user_inatomic_nocache(void *dst, const void __user *src,
                                  unsigned size)
{
        return __copy_user_nocache(dst, src, size, 0);
}

unsigned long
copy_user_handle_tail(char *to, char *from, unsigned len, unsigned zerorest);

#endif /* _ASM_X86_UACCESS_64_H */