280 lines
6.4 KiB
C
280 lines
6.4 KiB
C
/* 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>
|
|
|
|
#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)
|
|
|
|
#define HAVE_GET_KERNEL_NOFAULT 1
|
|
|
|
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 */
|
|
|
|
#ifdef CONFIG_SET_FS
|
|
#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
|
|
|
|
#ifndef KERNEL_DS
|
|
#define KERNEL_DS MAKE_MM_SEG(~0UL)
|
|
#endif
|
|
|
|
#ifndef USER_DS
|
|
#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
|
|
#endif
|
|
|
|
#ifndef get_fs
|
|
#define get_fs() (current_thread_info()->addr_limit)
|
|
|
|
static inline void set_fs(mm_segment_t fs)
|
|
{
|
|
current_thread_info()->addr_limit = fs;
|
|
}
|
|
#endif
|
|
|
|
#ifndef uaccess_kernel
|
|
#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
|
|
#endif
|
|
|
|
#ifndef user_addr_max
|
|
#define user_addr_max() (uaccess_kernel() ? ~0UL : TASK_SIZE)
|
|
#endif
|
|
|
|
#endif /* CONFIG_SET_FS */
|
|
|
|
#define access_ok(addr, size) __access_ok((unsigned long)(addr),(size))
|
|
|
|
/*
|
|
* The architecture should really override this if possible, at least
|
|
* doing a check on the get_fs()
|
|
*/
|
|
#ifndef __access_ok
|
|
static inline int __access_ok(unsigned long addr, unsigned long size)
|
|
{
|
|
return 1;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* 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 */
|