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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_GENERIC_UACCESS_H
#define __ASM_GENERIC_UACCESS_H
/*
* User space memory access functions, these should work
* on any machine that has kernel and user data in the same
* address space, e.g. all NOMMU machines.
*/
#include <linux/string.h>
#include <asm-generic/access_ok.h>
#ifdef CONFIG_UACCESS_MEMCPY
#include <asm/unaligned.h>
static __always_inline int
__get_user_fn(size_t size, const void __user *from, void *to)
{
BUILD_BUG_ON(!__builtin_constant_p(size));
switch (size) {
case 1:
*(u8 *)to = *((u8 __force *)from);
return 0;
case 2:
*(u16 *)to = get_unaligned((u16 __force *)from);
return 0;
case 4:
*(u32 *)to = get_unaligned((u32 __force *)from);
return 0;
case 8:
*(u64 *)to = get_unaligned((u64 __force *)from);
return 0;
default:
BUILD_BUG();
return 0;
}
}
#define __get_user_fn(sz, u, k) __get_user_fn(sz, u, k)
static __always_inline int
__put_user_fn(size_t size, void __user *to, void *from)
{
BUILD_BUG_ON(!__builtin_constant_p(size));
switch (size) {
case 1:
*(u8 __force *)to = *(u8 *)from;
return 0;
case 2:
put_unaligned(*(u16 *)from, (u16 __force *)to);
return 0;
case 4:
put_unaligned(*(u32 *)from, (u32 __force *)to);
return 0;
case 8:
put_unaligned(*(u64 *)from, (u64 __force *)to);
return 0;
default:
BUILD_BUG();
return 0;
}
}
#define __put_user_fn(sz, u, k) __put_user_fn(sz, u, k)
#define __get_kernel_nofault(dst, src, type, err_label) \
do { \
*((type *)dst) = get_unaligned((type *)(src)); \
if (0) /* make sure the label looks used to the compiler */ \
goto err_label; \
} while (0)
#define __put_kernel_nofault(dst, src, type, err_label) \
do { \
put_unaligned(*((type *)src), (type *)(dst)); \
if (0) /* make sure the label looks used to the compiler */ \
goto err_label; \
} while (0)
static inline __must_check unsigned long
raw_copy_from_user(void *to, const void __user * from, unsigned long n)
{
memcpy(to, (const void __force *)from, n);
return 0;
}
static inline __must_check unsigned long
raw_copy_to_user(void __user *to, const void *from, unsigned long n)
{
memcpy((void __force *)to, from, n);
return 0;
}
#define INLINE_COPY_FROM_USER
#define INLINE_COPY_TO_USER
#endif /* CONFIG_UACCESS_MEMCPY */
/*
* These are the main single-value transfer routines. They automatically
* use the right size if we just have the right pointer type.
* This version just falls back to copy_{from,to}_user, which should
* provide a fast-path for small values.
*/
#define __put_user(x, ptr) \
({ \
__typeof__(*(ptr)) __x = (x); \
int __pu_err = -EFAULT; \
__chk_user_ptr(ptr); \
switch (sizeof (*(ptr))) { \
case 1: \
case 2: \
case 4: \
case 8: \
__pu_err = __put_user_fn(sizeof (*(ptr)), \
ptr, &__x); \
break; \
default: \
__put_user_bad(); \
break; \
} \
__pu_err; \
})
#define put_user(x, ptr) \
({ \
void __user *__p = (ptr); \
might_fault(); \
access_ok(__p, sizeof(*ptr)) ? \
__put_user((x), ((__typeof__(*(ptr)) __user *)__p)) : \
-EFAULT; \
})
#ifndef __put_user_fn
static inline int __put_user_fn(size_t size, void __user *ptr, void *x)
{
return unlikely(raw_copy_to_user(ptr, x, size)) ? -EFAULT : 0;
}
#define __put_user_fn(sz, u, k) __put_user_fn(sz, u, k)
#endif
extern int __put_user_bad(void) __attribute__((noreturn));
#define __get_user(x, ptr) \
({ \
int __gu_err = -EFAULT; \
__chk_user_ptr(ptr); \
switch (sizeof(*(ptr))) { \
case 1: { \
unsigned char __x = 0; \
__gu_err = __get_user_fn(sizeof (*(ptr)), \
ptr, &__x); \
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
break; \
}; \
case 2: { \
unsigned short __x = 0; \
__gu_err = __get_user_fn(sizeof (*(ptr)), \
ptr, &__x); \
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
break; \
}; \
case 4: { \
unsigned int __x = 0; \
__gu_err = __get_user_fn(sizeof (*(ptr)), \
ptr, &__x); \
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
break; \
}; \
case 8: { \
unsigned long long __x = 0; \
__gu_err = __get_user_fn(sizeof (*(ptr)), \
ptr, &__x); \
(x) = *(__force __typeof__(*(ptr)) *) &__x; \
break; \
}; \
default: \
__get_user_bad(); \
break; \
} \
__gu_err; \
})
#define get_user(x, ptr) \
({ \
const void __user *__p = (ptr); \
might_fault(); \
access_ok(__p, sizeof(*ptr)) ? \
__get_user((x), (__typeof__(*(ptr)) __user *)__p) :\
((x) = (__typeof__(*(ptr)))0,-EFAULT); \
})
#ifndef __get_user_fn
static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)
{
return unlikely(raw_copy_from_user(x, ptr, size)) ? -EFAULT : 0;
}
#define __get_user_fn(sz, u, k) __get_user_fn(sz, u, k)
#endif
extern int __get_user_bad(void) __attribute__((noreturn));
/*
* Zero Userspace
*/
#ifndef __clear_user
static inline __must_check unsigned long
__clear_user(void __user *to, unsigned long n)
{
memset((void __force *)to, 0, n);
return 0;
}
#endif
static inline __must_check unsigned long
clear_user(void __user *to, unsigned long n)
{
might_fault();
if (!access_ok(to, n))
return n;
return __clear_user(to, n);
}
#include <asm/extable.h>
__must_check long strncpy_from_user(char *dst, const char __user *src,
long count);
__must_check long strnlen_user(const char __user *src, long n);
#endif /* __ASM_GENERIC_UACCESS_H */
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