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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_UACCESS_64_H
#define _ASM_X86_UACCESS_64_H
/*
* User space memory access functions
*/
#include <linux/compiler.h>
#include <linux/lockdep.h>
#include <linux/kasan-checks.h>
#include <asm/alternative.h>
#include <asm/cpufeatures.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;
}
static __always_inline __must_check unsigned long
copy_to_user_mcsafe(void *to, const void *from, unsigned len)
{
unsigned long ret;
__uaccess_begin();
/*
* Note, __memcpy_mcsafe() is explicitly used since it can
* handle exceptions / faults. memcpy_mcsafe() may fall back to
* memcpy() which lacks this handling.
*/
ret = __memcpy_mcsafe(to, from, len);
__uaccess_end();
return ret;
}
static __always_inline __must_check unsigned long
raw_copy_from_user(void *dst, const void __user *src, unsigned long size)
{
int ret = 0;
if (!__builtin_constant_p(size))
return copy_user_generic(dst, (__force void *)src, size);
switch (size) {
case 1:
__uaccess_begin_nospec();
__get_user_asm_nozero(*(u8 *)dst, (u8 __user *)src,
ret, "b", "b", "=q", 1);
__uaccess_end();
return ret;
case 2:
__uaccess_begin_nospec();
__get_user_asm_nozero(*(u16 *)dst, (u16 __user *)src,
ret, "w", "w", "=r", 2);
__uaccess_end();
return ret;
case 4:
__uaccess_begin_nospec();
__get_user_asm_nozero(*(u32 *)dst, (u32 __user *)src,
ret, "l", "k", "=r", 4);
__uaccess_end();
return ret;
case 8:
__uaccess_begin_nospec();
__get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src,
ret, "q", "", "=r", 8);
__uaccess_end();
return ret;
case 10:
__uaccess_begin_nospec();
__get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src,
ret, "q", "", "=r", 10);
if (likely(!ret))
__get_user_asm_nozero(*(u16 *)(8 + (char *)dst),
(u16 __user *)(8 + (char __user *)src),
ret, "w", "w", "=r", 2);
__uaccess_end();
return ret;
case 16:
__uaccess_begin_nospec();
__get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src,
ret, "q", "", "=r", 16);
if (likely(!ret))
__get_user_asm_nozero(*(u64 *)(8 + (char *)dst),
(u64 __user *)(8 + (char __user *)src),
ret, "q", "", "=r", 8);
__uaccess_end();
return ret;
default:
return copy_user_generic(dst, (__force void *)src, size);
}
}
static __always_inline __must_check unsigned long
raw_copy_to_user(void __user *dst, const void *src, unsigned long size)
{
int ret = 0;
if (!__builtin_constant_p(size))
return copy_user_generic((__force void *)dst, src, size);
switch (size) {
case 1:
__uaccess_begin();
__put_user_asm(*(u8 *)src, (u8 __user *)dst,
ret, "b", "b", "iq", 1);
__uaccess_end();
return ret;
case 2:
__uaccess_begin();
__put_user_asm(*(u16 *)src, (u16 __user *)dst,
ret, "w", "w", "ir", 2);
__uaccess_end();
return ret;
case 4:
__uaccess_begin();
__put_user_asm(*(u32 *)src, (u32 __user *)dst,
ret, "l", "k", "ir", 4);
__uaccess_end();
return ret;
case 8:
__uaccess_begin();
__put_user_asm(*(u64 *)src, (u64 __user *)dst,
ret, "q", "", "er", 8);
__uaccess_end();
return ret;
case 10:
__uaccess_begin();
__put_user_asm(*(u64 *)src, (u64 __user *)dst,
ret, "q", "", "er", 10);
if (likely(!ret)) {
asm("":::"memory");
__put_user_asm(4[(u16 *)src], 4 + (u16 __user *)dst,
ret, "w", "w", "ir", 2);
}
__uaccess_end();
return ret;
case 16:
__uaccess_begin();
__put_user_asm(*(u64 *)src, (u64 __user *)dst,
ret, "q", "", "er", 16);
if (likely(!ret)) {
asm("":::"memory");
__put_user_asm(1[(u64 *)src], 1 + (u64 __user *)dst,
ret, "q", "", "er", 8);
}
__uaccess_end();
return ret;
default:
return copy_user_generic((__force void *)dst, src, size);
}
}
static __always_inline __must_check
unsigned long raw_copy_in_user(void __user *dst, const void __user *src, unsigned long size)
{
return copy_user_generic((__force void *)dst,
(__force void *)src, size);
}
extern long __copy_user_nocache(void *dst, const void __user *src,
unsigned size, int zerorest);
extern long __copy_user_flushcache(void *dst, const void __user *src, unsigned size);
extern void memcpy_page_flushcache(char *to, struct page *page, size_t offset,
size_t len);
static inline int
__copy_from_user_inatomic_nocache(void *dst, const void __user *src,
unsigned size)
{
kasan_check_write(dst, size);
return __copy_user_nocache(dst, src, size, 0);
}
static inline int
__copy_from_user_flushcache(void *dst, const void __user *src, unsigned size)
{
kasan_check_write(dst, size);
return __copy_user_flushcache(dst, src, size);
}
unsigned long
mcsafe_handle_tail(char *to, char *from, unsigned len);
#endif /* _ASM_X86_UACCESS_64_H */
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