234 lines · 5.5 KB · C
RawDownload
/* 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 <linux/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 longraw_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 longraw_copy_to_user(void __user *to, const void *from, unsigned long n){	memcpy((void __force *)to, from, n);	return 0;}#define INLINE_COPY_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_fnstatic 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_userstatic 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 longclear_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 */