[deliverable/linux.git] / include / asm-s390 / uaccess.h

/*
 *  include/asm-s390/uaccess.h
 *
 *  S390 version
 *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
 *    Author(s): Hartmut Penner (hp@de.ibm.com),
 *               Martin Schwidefsky (schwidefsky@de.ibm.com)
 *
 *  Derived from "include/asm-i386/uaccess.h"
 */
#ifndef __S390_UACCESS_H
#define __S390_UACCESS_H

/*
 * User space memory access functions
 */
#include <linux/sched.h>
#include <linux/errno.h>

#define VERIFY_READ     0
#define VERIFY_WRITE    1


/*
 * The fs value determines whether argument validity checking should be
 * performed or not.  If get_fs() == USER_DS, checking is performed, with
 * get_fs() == KERNEL_DS, checking is bypassed.
 *
 * For historical reasons, these macros are grossly misnamed.
 */

#define MAKE_MM_SEG(a)  ((mm_segment_t) { (a) })


#define KERNEL_DS       MAKE_MM_SEG(0)
#define USER_DS         MAKE_MM_SEG(1)

#define get_ds()        (KERNEL_DS)
#define get_fs()        (current->thread.mm_segment)

#ifdef __s390x__
#define set_fs(x) \
({									\
	unsigned long __pto;						\
	current->thread.mm_segment = (x);				\
	__pto = current->thread.mm_segment.ar4 ?			\
		S390_lowcore.user_asce : S390_lowcore.kernel_asce;	\
	asm volatile ("lctlg 7,7,%0" : : "m" (__pto) );			\
})
#else
#define set_fs(x) \
({									\
	unsigned long __pto;						\
	current->thread.mm_segment = (x);				\
	__pto = current->thread.mm_segment.ar4 ?			\
		S390_lowcore.user_asce : S390_lowcore.kernel_asce;	\
	asm volatile ("lctl  7,7,%0" : : "m" (__pto) );			\
})
#endif

#define segment_eq(a,b) ((a).ar4 == (b).ar4)


static inline int __access_ok(const void __user *addr, unsigned long size)
{
	return 1;
}
#define access_ok(type,addr,size) __access_ok(addr,size)

/*
 * 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;
};

#ifndef __s390x__
#define __uaccess_fixup \
	".section .fixup,\"ax\"\n"	\
	"2: lhi    %0,%4\n"		\
	"   bras   1,3f\n"		\
	"   .long  1b\n"		\
	"3: l      1,0(1)\n"		\
	"   br     1\n"			\
	".previous\n"			\
	".section __ex_table,\"a\"\n"	\
	"   .align 4\n"			\
	"   .long  0b,2b\n"		\
	".previous"
#define __uaccess_clobber "cc", "1"
#else /* __s390x__ */
#define __uaccess_fixup \
	".section .fixup,\"ax\"\n"	\
	"2: lghi   %0,%4\n"		\
	"   jg     1b\n"		\
	".previous\n"			\
	".section __ex_table,\"a\"\n"	\
	"   .align 8\n"			\
	"   .quad  0b,2b\n"		\
	".previous"
#define __uaccess_clobber "cc"
#endif /* __s390x__ */

/*
 * These are the main single-value transfer routines.  They automatically
 * use the right size if we just have the right pointer type.
 */
#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
#define __put_user_asm(x, ptr, err) \
({								\
	err = 0;						\
	asm volatile(						\
		"0: mvcs  0(%1,%2),%3,%0\n"			\
		"1:\n"						\
		__uaccess_fixup					\
		: "+&d" (err)					\
		: "d" (sizeof(*(ptr))), "a" (ptr), "Q" (x),	\
		  "K" (-EFAULT)					\
		: __uaccess_clobber );				\
})
#else
#define __put_user_asm(x, ptr, err) \
({								\
	err = 0;						\
	asm volatile(						\
		"0: mvcs  0(%1,%2),0(%3),%0\n"			\
		"1:\n"						\
		__uaccess_fixup					\
		: "+&d" (err)					\
		: "d" (sizeof(*(ptr))), "a" (ptr), "a" (&(x)),	\
		  "K" (-EFAULT), "m" (x)			\
		: __uaccess_clobber );				\
})
#endif

#define __put_user(x, ptr) \
({								\
	__typeof__(*(ptr)) __x = (x);				\
	int __pu_err;						\
        __chk_user_ptr(ptr);                                    \
	switch (sizeof (*(ptr))) {				\
	case 1:							\
	case 2:							\
	case 4:							\
	case 8:							\
		__put_user_asm(__x, ptr, __pu_err);		\
		break;						\
	default:						\
		__put_user_bad();				\
		break;						\
	 }							\
	__pu_err;						\
})

#define put_user(x, ptr)					\
({								\
	might_sleep();						\
	__put_user(x, ptr);					\
})


extern int __put_user_bad(void) __attribute__((noreturn));

#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
#define __get_user_asm(x, ptr, err) \
({								\
	err = 0;						\
	asm volatile (						\
		"0: mvcp  %O1(%2,%R1),0(%3),%0\n"		\
		"1:\n"						\
		__uaccess_fixup					\
		: "+&d" (err), "=Q" (x)				\
		: "d" (sizeof(*(ptr))), "a" (ptr),		\
		  "K" (-EFAULT)					\
		: __uaccess_clobber );				\
})
#else
#define __get_user_asm(x, ptr, err) \
({								\
	err = 0;						\
	asm volatile (						\
		"0: mvcp  0(%2,%5),0(%3),%0\n"			\
		"1:\n"						\
		__uaccess_fixup					\
		: "+&d" (err), "=m" (x)				\
		: "d" (sizeof(*(ptr))), "a" (ptr),		\
		  "K" (-EFAULT), "a" (&(x))			\
		: __uaccess_clobber );				\
})
#endif

#define __get_user(x, ptr)					\
({								\
	int __gu_err;						\
        __chk_user_ptr(ptr);                                    \
	switch (sizeof(*(ptr))) {				\
	case 1: {						\
		unsigned char __x;				\
		__get_user_asm(__x, ptr, __gu_err);		\
		(x) = *(__typeof__(*(ptr)) *) &__x;		\
		break;						\
	};							\
	case 2: {						\
		unsigned short __x;				\
		__get_user_asm(__x, ptr, __gu_err);		\
		(x) = *(__typeof__(*(ptr)) *) &__x;		\
		break;						\
	};							\
	case 4: {						\
		unsigned int __x;				\
		__get_user_asm(__x, ptr, __gu_err);		\
		(x) = *(__typeof__(*(ptr)) *) &__x;		\
		break;						\
	};							\
	case 8: {						\
		unsigned long long __x;				\
		__get_user_asm(__x, ptr, __gu_err);		\
		(x) = *(__typeof__(*(ptr)) *) &__x;		\
		break;						\
	};							\
	default:						\
		__get_user_bad();				\
		break;						\
	}							\
	__gu_err;						\
})

#define get_user(x, ptr)					\
({								\
	might_sleep();						\
	__get_user(x, ptr);					\
})

extern int __get_user_bad(void) __attribute__((noreturn));

#define __put_user_unaligned __put_user
#define __get_user_unaligned __get_user

extern long __copy_to_user_asm(const void *from, long n, void __user *to);

/**
 * __copy_to_user: - Copy a block of data into user space, with less checking.
 * @to:   Destination address, in user space.
 * @from: Source address, in kernel space.
 * @n:    Number of bytes to copy.
 *
 * Context: User context only.  This function may sleep.
 *
 * Copy data from kernel space to user space.  Caller must check
 * the specified block with access_ok() before calling this function.
 *
 * Returns number of bytes that could not be copied.
 * On success, this will be zero.
 */
static inline unsigned long
__copy_to_user(void __user *to, const void *from, unsigned long n)
{
	return __copy_to_user_asm(from, n, to);
}

#define __copy_to_user_inatomic __copy_to_user
#define __copy_from_user_inatomic __copy_from_user

/**
 * copy_to_user: - Copy a block of data into user space.
 * @to:   Destination address, in user space.
 * @from: Source address, in kernel space.
 * @n:    Number of bytes to copy.
 *
 * Context: User context only.  This function may sleep.
 *
 * Copy data from kernel space to user space.
 *
 * Returns number of bytes that could not be copied.
 * On success, this will be zero.
 */
static inline unsigned long
copy_to_user(void __user *to, const void *from, unsigned long n)
{
	might_sleep();
	if (access_ok(VERIFY_WRITE, to, n))
		n = __copy_to_user(to, from, n);
	return n;
}

extern long __copy_from_user_asm(void *to, long n, const void __user *from);

/**
 * __copy_from_user: - Copy a block of data from user space, with less checking.
 * @to:   Destination address, in kernel space.
 * @from: Source address, in user space.
 * @n:    Number of bytes to copy.
 *
 * Context: User context only.  This function may sleep.
 *
 * Copy data from user space to kernel space.  Caller must check
 * the specified block with access_ok() before calling this function.
 *
 * Returns number of bytes that could not be copied.
 * On success, this will be zero.
 *
 * If some data could not be copied, this function will pad the copied
 * data to the requested size using zero bytes.
 */
static inline unsigned long
__copy_from_user(void *to, const void __user *from, unsigned long n)
{
	return __copy_from_user_asm(to, n, from);
}

/**
 * copy_from_user: - Copy a block of data from user space.
 * @to:   Destination address, in kernel space.
 * @from: Source address, in user space.
 * @n:    Number of bytes to copy.
 *
 * Context: User context only.  This function may sleep.
 *
 * Copy data from user space to kernel space.
 *
 * Returns number of bytes that could not be copied.
 * On success, this will be zero.
 *
 * If some data could not be copied, this function will pad the copied
 * data to the requested size using zero bytes.
 */
static inline unsigned long
copy_from_user(void *to, const void __user *from, unsigned long n)
{
	might_sleep();
	if (access_ok(VERIFY_READ, from, n))
		n = __copy_from_user(to, from, n);
	else
		memset(to, 0, n);
	return n;
}

extern unsigned long __copy_in_user_asm(const void __user *from, long n,
							void __user *to);

static inline unsigned long
__copy_in_user(void __user *to, const void __user *from, unsigned long n)
{
	return __copy_in_user_asm(from, n, to);
}

static inline unsigned long
copy_in_user(void __user *to, const void __user *from, unsigned long n)
{
	might_sleep();
	if (__access_ok(from,n) && __access_ok(to,n))
		n = __copy_in_user_asm(from, n, to);
	return n;
}

/*
 * Copy a null terminated string from userspace.
 */
extern long __strncpy_from_user_asm(long count, char *dst,
					const char __user *src);

static inline long
strncpy_from_user(char *dst, const char __user *src, long count)
{
        long res = -EFAULT;
        might_sleep();
        if (access_ok(VERIFY_READ, src, 1))
                res = __strncpy_from_user_asm(count, dst, src);
        return res;
}


extern long __strnlen_user_asm(long count, const char __user *src);

static inline unsigned long
strnlen_user(const char __user * src, unsigned long n)
{
	might_sleep();
	return __strnlen_user_asm(n, src);
}

/**
 * strlen_user: - Get the size of a string in user space.
 * @str: The string to measure.
 *
 * Context: User context only.  This function may sleep.
 *
 * Get the size of a NUL-terminated string in user space.
 *
 * Returns the size of the string INCLUDING the terminating NUL.
 * On exception, returns 0.
 *
 * If there is a limit on the length of a valid string, you may wish to
 * consider using strnlen_user() instead.
 */
#define strlen_user(str) strnlen_user(str, ~0UL)

/*
 * Zero Userspace
 */

extern long __clear_user_asm(void __user *to, long n);

static inline unsigned long
__clear_user(void __user *to, unsigned long n)
{
	return __clear_user_asm(to, n);
}

static inline unsigned long
clear_user(void __user *to, unsigned long n)
{
	might_sleep();
	if (access_ok(VERIFY_WRITE, to, n))
		n = __clear_user_asm(to, n);
	return n;
}

#endif /* __S390_UACCESS_H */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* include/asm-s390/uaccess.h
	3	*
	4	* S390 version
	5	* Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
	6	* Author(s): Hartmut Penner (hp@de.ibm.com),
	7	* Martin Schwidefsky (schwidefsky@de.ibm.com)
	8	*
	9	* Derived from "include/asm-i386/uaccess.h"
	10	*/
	11	#ifndef __S390_UACCESS_H
	12	#define __S390_UACCESS_H
	13
	14	/*
	15	* User space memory access functions
	16	*/
	17	#include <linux/sched.h>
	18	#include <linux/errno.h>
	19
	20	#define VERIFY_READ 0
	21	#define VERIFY_WRITE 1
	22
	23
	24	/*
	25	* The fs value determines whether argument validity checking should be
	26	* performed or not. If get_fs() == USER_DS, checking is performed, with
	27	* get_fs() == KERNEL_DS, checking is bypassed.
	28	*
	29	* For historical reasons, these macros are grossly misnamed.
	30	*/
	31
	32	#define MAKE_MM_SEG(a) ((mm_segment_t) { (a) })
	33
	34
	35	#define KERNEL_DS MAKE_MM_SEG(0)
	36	#define USER_DS MAKE_MM_SEG(1)
	37
	38	#define get_ds() (KERNEL_DS)
	39	#define get_fs() (current->thread.mm_segment)
	40
	41	#ifdef __s390x__
	42	#define set_fs(x) \
	43	({ \
	44	unsigned long __pto; \
	45	current->thread.mm_segment = (x); \
	46	__pto = current->thread.mm_segment.ar4 ? \
	47	S390_lowcore.user_asce : S390_lowcore.kernel_asce; \
	48	asm volatile ("lctlg 7,7,%0" : : "m" (__pto) ); \
	49	})
	50	#else
	51	#define set_fs(x) \
	52	({ \
	53	unsigned long __pto; \
	54	current->thread.mm_segment = (x); \
	55	__pto = current->thread.mm_segment.ar4 ? \
	56	S390_lowcore.user_asce : S390_lowcore.kernel_asce; \
	57	asm volatile ("lctl 7,7,%0" : : "m" (__pto) ); \
	58	})
	59	#endif
	60
	61	#define segment_eq(a,b) ((a).ar4 == (b).ar4)
	62
	63
793af244	64	static inline int __access_ok(const void __user *addr, unsigned long size)
a63a4931 MS	65	{
	66	return 1;
	67	}
1da177e4 LT	68	#define access_ok(type,addr,size) __access_ok(addr,size)
1da177e4 LT	69
1da177e4 LT	70	/*
	71	* The exception table consists of pairs of addresses: the first is the
	72	* address of an instruction that is allowed to fault, and the second is
	73	* the address at which the program should continue. No registers are
	74	* modified, so it is entirely up to the continuation code to figure out
	75	* what to do.
	76	*
	77	* All the routines below use bits of fixup code that are out of line
	78	* with the main instruction path. This means when everything is well,
	79	* we don't even have to jump over them. Further, they do not intrude
	80	* on our cache or tlb entries.
	81	*/
	82
	83	struct exception_table_entry
	84	{
	85	unsigned long insn, fixup;
	86	};
	87
	88	#ifndef __s390x__
	89	#define __uaccess_fixup \
	90	".section .fixup,\"ax\"\n" \
	91	"2: lhi %0,%4\n" \
	92	" bras 1,3f\n" \
	93	" .long 1b\n" \
	94	"3: l 1,0(1)\n" \
	95	" br 1\n" \
	96	".previous\n" \
	97	".section __ex_table,\"a\"\n" \
	98	" .align 4\n" \
	99	" .long 0b,2b\n" \
	100	".previous"
	101	#define __uaccess_clobber "cc", "1"
	102	#else /* __s390x__ */
	103	#define __uaccess_fixup \
	104	".section .fixup,\"ax\"\n" \
	105	"2: lghi %0,%4\n" \
	106	" jg 1b\n" \
	107	".previous\n" \
	108	".section __ex_table,\"a\"\n" \
	109	" .align 8\n" \
	110	" .quad 0b,2b\n" \
	111	".previous"
	112	#define __uaccess_clobber "cc"
	113	#endif /* __s390x__ */
	114
	115	/*
	116	* These are the main single-value transfer routines. They automatically
	117	* use the right size if we just have the right pointer type.
	118	*/
	119	#if __GNUC__ > 3 \|\| (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
	120	#define __put_user_asm(x, ptr, err) \
	121	({ \
	122	err = 0; \
	123	asm volatile( \
	124	"0: mvcs 0(%1,%2),%3,%0\n" \
	125	"1:\n" \
	126	__uaccess_fixup \
	127	: "+&d" (err) \
	128	: "d" (sizeof(*(ptr))), "a" (ptr), "Q" (x), \
	129	"K" (-EFAULT) \
	130	: __uaccess_clobber ); \
	131	})
	132	#else
	133	#define __put_user_asm(x, ptr, err) \
134	({ \
135	err = 0; \
136	asm volatile( \
137	"0: mvcs 0(%1,%2),0(%3),%0\n" \
138	"1:\n" \
139	__uaccess_fixup \
140	: "+&d" (err) \
141	: "d" (sizeof(*(ptr))), "a" (ptr), "a" (&(x)), \
142	"K" (-EFAULT), "m" (x) \
143	: __uaccess_clobber ); \
144	})
145	#endif
146
1da177e4 LT	147	#define __put_user(x, ptr) \
	148	({ \
	149	__typeof__(*(ptr)) __x = (x); \
	150	int __pu_err; \
17566c3c	151	__chk_user_ptr(ptr); \
1da177e4 LT	152	switch (sizeof (*(ptr))) { \
	153	case 1: \
	154	case 2: \
	155	case 4: \
	156	case 8: \
	157	__put_user_asm(__x, ptr, __pu_err); \
	158	break; \
	159	default: \
	160	__put_user_bad(); \
	161	break; \
	162	} \
	163	__pu_err; \
	164	})
1da177e4 LT	165
	166	#define put_user(x, ptr) \
	167	({ \
	168	might_sleep(); \
	169	__put_user(x, ptr); \
	170	})
	171
	172
	173	extern int __put_user_bad(void) __attribute__((noreturn));
	174
	175	#if __GNUC__ > 3 \|\| (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
	176	#define __get_user_asm(x, ptr, err) \
	177	({ \
	178	err = 0; \
	179	asm volatile ( \
	180	"0: mvcp %O1(%2,%R1),0(%3),%0\n" \
	181	"1:\n" \
	182	__uaccess_fixup \
	183	: "+&d" (err), "=Q" (x) \
	184	: "d" (sizeof(*(ptr))), "a" (ptr), \
	185	"K" (-EFAULT) \
	186	: __uaccess_clobber ); \
	187	})
	188	#else
	189	#define __get_user_asm(x, ptr, err) \
	190	({ \
	191	err = 0; \
	192	asm volatile ( \
	193	"0: mvcp 0(%2,%5),0(%3),%0\n" \
	194	"1:\n" \
	195	__uaccess_fixup \
	196	: "+&d" (err), "=m" (x) \
	197	: "d" (sizeof(*(ptr))), "a" (ptr), \
	198	"K" (-EFAULT), "a" (&(x)) \
	199	: __uaccess_clobber ); \
	200	})
	201	#endif
	202
1da177e4 LT	203	#define __get_user(x, ptr) \
1da177e4 LT	204	({ \
1da177e4	205	int __gu_err; \
17566c3c	206	__chk_user_ptr(ptr); \
1da177e4	207	switch (sizeof(*(ptr))) { \
1047aa77 MS	208	case 1: { \
	209	unsigned char __x; \
	210	__get_user_asm(__x, ptr, __gu_err); \
a63a4931	211	(x) = (__typeof__((ptr)) *) &__x; \
1047aa77 MS	212	break; \
	213	}; \
	214	case 2: { \
	215	unsigned short __x; \
	216	__get_user_asm(__x, ptr, __gu_err); \
a63a4931	217	(x) = (__typeof__((ptr)) *) &__x; \
1047aa77 MS	218	break; \
	219	}; \
	220	case 4: { \
	221	unsigned int __x; \
	222	__get_user_asm(__x, ptr, __gu_err); \
a63a4931	223	(x) = (__typeof__((ptr)) *) &__x; \
1047aa77 MS	224	break; \
	225	}; \
	226	case 8: { \
	227	unsigned long long __x; \
1da177e4	228	__get_user_asm(__x, ptr, __gu_err); \
a63a4931	229	(x) = (__typeof__((ptr)) *) &__x; \
1da177e4	230	break; \
1047aa77	231	}; \
1da177e4 LT	232	default: \
	233	__get_user_bad(); \
	234	break; \
	235	} \
1da177e4 LT	236	__gu_err; \
1da177e4 LT	237	})
1da177e4 LT	238
	239	#define get_user(x, ptr) \
	240	({ \
	241	might_sleep(); \
	242	__get_user(x, ptr); \
	243	})
	244
	245	extern int __get_user_bad(void) __attribute__((noreturn));
	246
	247	#define __put_user_unaligned __put_user
	248	#define __get_user_unaligned __get_user
	249
	250	extern long __copy_to_user_asm(const void from, long n, void __user to);
	251
	252	/**
	253	* __copy_to_user: - Copy a block of data into user space, with less checking.
	254	* @to: Destination address, in user space.
	255	* @from: Source address, in kernel space.
	256	* @n: Number of bytes to copy.
	257	*
	258	* Context: User context only. This function may sleep.
	259	*
	260	* Copy data from kernel space to user space. Caller must check
	261	* the specified block with access_ok() before calling this function.
	262	*
	263	* Returns number of bytes that could not be copied.
	264	* On success, this will be zero.
	265	*/
	266	static inline unsigned long
	267	__copy_to_user(void __user to, const void from, unsigned long n)
	268	{
	269	return __copy_to_user_asm(from, n, to);
	270	}
	271
	272	#define __copy_to_user_inatomic __copy_to_user
	273	#define __copy_from_user_inatomic __copy_from_user
	274
	275	/**
	276	* copy_to_user: - Copy a block of data into user space.
	277	* @to: Destination address, in user space.
	278	* @from: Source address, in kernel space.
	279	* @n: Number of bytes to copy.
	280	*
	281	* Context: User context only. This function may sleep.
	282	*
	283	* Copy data from kernel space to user space.
	284	*
	285	* Returns number of bytes that could not be copied.
	286	* On success, this will be zero.
	287	*/
	288	static inline unsigned long
	289	copy_to_user(void __user to, const void from, unsigned long n)
	290	{
	291	might_sleep();
	292	if (access_ok(VERIFY_WRITE, to, n))
	293	n = __copy_to_user(to, from, n);
	294	return n;
	295	}
	296
	297	extern long __copy_from_user_asm(void to, long n, const void __user from);
	298
	299	/**
	300	* __copy_from_user: - Copy a block of data from user space, with less checking.
	301	* @to: Destination address, in kernel space.
302	* @from: Source address, in user space.
303	* @n: Number of bytes to copy.
304	*
305	* Context: User context only. This function may sleep.
306	*
307	* Copy data from user space to kernel space. Caller must check
308	* the specified block with access_ok() before calling this function.
309	*
310	* Returns number of bytes that could not be copied.
311	* On success, this will be zero.
312	*
313	* If some data could not be copied, this function will pad the copied
314	* data to the requested size using zero bytes.
315	*/
316	static inline unsigned long
317	__copy_from_user(void to, const void __user from, unsigned long n)
318	{
319	return __copy_from_user_asm(to, n, from);
320	}
321
322	/**
323	* copy_from_user: - Copy a block of data from user space.
324	* @to: Destination address, in kernel space.
325	* @from: Source address, in user space.
326	* @n: Number of bytes to copy.
327	*
328	* Context: User context only. This function may sleep.
329	*
330	* Copy data from user space to kernel space.
331	*
332	* Returns number of bytes that could not be copied.
333	* On success, this will be zero.
334	*
335	* If some data could not be copied, this function will pad the copied
336	* data to the requested size using zero bytes.
337	*/
338	static inline unsigned long
339	copy_from_user(void to, const void __user from, unsigned long n)
340	{
341	might_sleep();
342	if (access_ok(VERIFY_READ, from, n))
343	n = __copy_from_user(to, from, n);
344	else
345	memset(to, 0, n);
346	return n;
347	}
348
349	extern unsigned long __copy_in_user_asm(const void __user *from, long n,
350	void __user *to);
351
352	static inline unsigned long
353	__copy_in_user(void __user to, const void __user from, unsigned long n)
354	{
355	return __copy_in_user_asm(from, n, to);
356	}
357
358	static inline unsigned long
359	copy_in_user(void __user to, const void __user from, unsigned long n)
360	{
361	might_sleep();
362	if (__access_ok(from,n) && __access_ok(to,n))
363	n = __copy_in_user_asm(from, n, to);
364	return n;
365	}
366
367	/*
368	* Copy a null terminated string from userspace.
369	*/
370	extern long __strncpy_from_user_asm(long count, char *dst,
371	const char __user *src);
372
373	static inline long
374	strncpy_from_user(char dst, const char __user src, long count)
375	{
376	long res = -EFAULT;
377	might_sleep();
378	if (access_ok(VERIFY_READ, src, 1))
379	res = __strncpy_from_user_asm(count, dst, src);
380	return res;
381	}
382
383
384	extern long __strnlen_user_asm(long count, const char __user *src);
385
386	static inline unsigned long
387	strnlen_user(const char __user * src, unsigned long n)
388	{
389	might_sleep();
390	return __strnlen_user_asm(n, src);
391	}
392
393	/**
394	* strlen_user: - Get the size of a string in user space.
395	* @str: The string to measure.
396	*
397	* Context: User context only. This function may sleep.
398	*
399	* Get the size of a NUL-terminated string in user space.
400	*
401	* Returns the size of the string INCLUDING the terminating NUL.
402	* On exception, returns 0.
403	*
404	* If there is a limit on the length of a valid string, you may wish to
405	* consider using strnlen_user() instead.
406	*/
407	#define strlen_user(str) strnlen_user(str, ~0UL)
408
409	/*
410	* Zero Userspace
411	*/
412
413	extern long __clear_user_asm(void __user *to, long n);
414
415	static inline unsigned long
416	__clear_user(void __user *to, unsigned long n)
417	{
418	return __clear_user_asm(to, n);
419	}
420
421	static inline unsigned long
422	clear_user(void __user *to, unsigned long n)
423	{
424	might_sleep();
425	if (access_ok(VERIFY_WRITE, to, n))
426	n = __clear_user_asm(to, n);
427	return n;
428	}
429
430	#endif /* __S390_UACCESS_H */