#ifndef __ASM_GENERIC_UACCESS_H#define __ASM_GENERIC_UACCESS_H /* * User space memory access functions, these should work * on a ny machine that has kernel and user data in the same * address space, e.g. all NOMMU machines. */#include <linux/sched.h>#include <linux/mm.h>#include <linux/string.h> #include <asm/segment.h> #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_ds()	(KERNEL_DS)#define get_fs()	(current_thread_info()->addr_limit) static inline void set_fs(mm_segment_t fs){	current_thread_info()->addr_limit = fs;}#endif #define segment_eq(a, b) ((a).seg == (b).seg) #define VERIFY_READ	0#define VERIFY_WRITE	1 #define access_ok(type, 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_okstatic inline int __access_ok(unsigned long addr, unsigned long size){	return 1;}#endif /* * The exception table consists of pairs of addresses: the first is the * address of an instruction that is allowed to fault, and the second is * the address at which the program should continue.  No registers are * modified, so it is entirely up to the continuation code to figure out * what to do. * * All the routines below use bits of fixup code that are out of line * with the main instruction path.  This means when everything is well, * we don't even have to jump over them.  Further, they do not intrude * on our cache or tlb entries. */ struct exception_table_entry{	unsigned long insn, fixup;}; /* Returns 0 if exception not found and fixup otherwise.  */extern unsigned long search_exception_table(unsigned long); /* * architectures with an MMU should override these two */#ifndef __copy_from_userstatic inline __must_check long __copy_from_user(void *to,		const void __user * from, unsigned long n){	if (__builtin_constant_p(n)) {		switch(n) {		case 1:			*(u8 *)to = *(u8 __force *)from;			return 0;		case 2:			*(u16 *)to = *(u16 __force *)from;			return 0;		case 4:			*(u32 *)to = *(u32 __force *)from;			return 0;#ifdef CONFIG_64BIT		case 8:			*(u64 *)to = *(u64 __force *)from;			return 0;#endif		default:			break;		}	} 	memcpy(to, (const void __force *)from, n);	return 0;}#endif #ifndef __copy_to_userstatic inline __must_check long __copy_to_user(void __user *to,		const void *from, unsigned long n){	if (__builtin_constant_p(n)) {		switch(n) {		case 1:			*(u8 __force *)to = *(u8 *)from;			return 0;		case 2:			*(u16 __force *)to = *(u16 *)from;			return 0;		case 4:			*(u32 __force *)to = *(u32 *)from;			return 0;#ifdef CONFIG_64BIT		case 8:			*(u64 __force *)to = *(u64 *)from;			return 0;#endif		default:			break;		}	} 	memcpy((void __force *)to, from, n);	return 0;}#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)					\({								\	might_sleep();						\	access_ok(VERIFY_WRITE, ptr, sizeof(*ptr)) ?		\		__put_user(x, ptr) :				\		-EFAULT;					\}) static inline int __put_user_fn(size_t size, void __user *ptr, void *x){	size = __copy_to_user(ptr, x, size);	return size ? -EFAULT : size;} 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;				\		__gu_err = __get_user_fn(sizeof (*(ptr)),	\					 ptr, &__x);		\		(x) = *(__force __typeof__(*(ptr)) *) &__x;	\		break;						\	};							\	case 2: {						\		unsigned short __x;				\		__gu_err = __get_user_fn(sizeof (*(ptr)),	\					 ptr, &__x);		\		(x) = *(__force __typeof__(*(ptr)) *) &__x;	\		break;						\	};							\	case 4: {						\		unsigned int __x;				\		__gu_err = __get_user_fn(sizeof (*(ptr)),	\					 ptr, &__x);		\		(x) = *(__force __typeof__(*(ptr)) *) &__x;	\		break;						\	};							\	case 8: {						\		unsigned long long __x;				\		__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)					\({								\	might_sleep();						\	access_ok(VERIFY_READ, ptr, sizeof(*ptr)) ?		\		__get_user(x, ptr) :				\		-EFAULT;					\}) static inline int __get_user_fn(size_t size, const void __user *ptr, void *x){	size = __copy_from_user(x, ptr, size);	return size ? -EFAULT : size;} extern int __get_user_bad(void) __attribute__((noreturn)); #ifndef __copy_from_user_inatomic#define __copy_from_user_inatomic __copy_from_user#endif #ifndef __copy_to_user_inatomic#define __copy_to_user_inatomic __copy_to_user#endif static inline long copy_from_user(void *to,		const void __user * from, unsigned long n){	might_sleep();	if (access_ok(VERIFY_READ, from, n))		return __copy_from_user(to, from, n);	else		return n;} static inline long copy_to_user(void __user *to,		const void *from, unsigned long n){	might_sleep();	if (access_ok(VERIFY_WRITE, to, n))		return __copy_to_user(to, from, n);	else		return n;} /* * Copy a null terminated string from userspace. */#ifndef __strncpy_from_userstatic inline long__strncpy_from_user(char *dst, const char __user *src, long count){	char *tmp;	strncpy(dst, (const char __force *)src, count);	for (tmp = dst; *tmp && count > 0; tmp++, count--)		;	return (tmp - dst);}#endif static inline longstrncpy_from_user(char *dst, const char __user *src, long count){	if (!access_ok(VERIFY_READ, src, 1))		return -EFAULT;	return __strncpy_from_user(dst, src, count);} /* * Return the size of a string (including the ending 0) * * Return 0 on exception, a value greater than N if too long */#ifndef __strnlen_user#define __strnlen_user(s, n) (strnlen((s), (n)) + 1)#endif /* * Unlike strnlen, strnlen_user includes the nul terminator in * its returned count. Callers should check for a returned value * greater than N as an indication the string is too long. */static inline long strnlen_user(const char __user *src, long n){	if (!access_ok(VERIFY_READ, src, 1))		return 0;	return __strnlen_user(src, n);} static inline long strlen_user(const char __user *src){	return strnlen_user(src, 32767);} /* * 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_sleep();	if (!access_ok(VERIFY_WRITE, to, n))		return n; 	return __clear_user(to, n);} #endif /* __ASM_GENERIC_UACCESS_H */