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

/*
 *  S390 version
 *    Copyright IBM Corp. 1999, 2000
 *    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>
#include <asm/ctl_reg.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)

#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;	\
	__ctl_load(__pto, 7, 7);					\
})

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

static inline int __range_ok(unsigned long addr, unsigned long size)
{
	return 1;
}

#define __access_ok(addr, size)				\
({							\
	__chk_user_ptr(addr);				\
	__range_ok((unsigned long)(addr), (size));	\
})

#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
{
	int insn, fixup;
};

static inline unsigned long extable_insn(const struct exception_table_entry *x)
{
	return (unsigned long)&x->insn + x->insn;
}

static inline unsigned long extable_fixup(const struct exception_table_entry *x)
{
	return (unsigned long)&x->fixup + x->fixup;
}

#define ARCH_HAS_SORT_EXTABLE
#define ARCH_HAS_SEARCH_EXTABLE

/**
 * __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 if pagefaults are
 *          enabled.
 *
 * 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.
 */
unsigned long __must_check __copy_from_user(void *to, const void __user *from,
					    unsigned long n);

/**
 * __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 if pagefaults are
 *          enabled.
 *
 * 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.
 */
unsigned long __must_check __copy_to_user(void __user *to, const void *from,
					  unsigned long n);

#define __copy_to_user_inatomic __copy_to_user
#define __copy_from_user_inatomic __copy_from_user

#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES

#define __put_get_user_asm(to, from, size, spec)		\
({								\
	register unsigned long __reg0 asm("0") = spec;		\
	int __rc;						\
								\
	asm volatile(						\
		"0:	mvcos	%1,%3,%2\n"			\
		"1:	xr	%0,%0\n"			\
		"2:\n"						\
		".pushsection .fixup, \"ax\"\n"			\
		"3:	lhi	%0,%5\n"			\
		"	jg	2b\n"				\
		".popsection\n"					\
		EX_TABLE(0b,3b) EX_TABLE(1b,3b)			\
		: "=d" (__rc), "=Q" (*(to))			\
		: "d" (size), "Q" (*(from)),			\
		  "d" (__reg0), "K" (-EFAULT)			\
		: "cc");					\
	__rc;							\
})

#define __put_user_fn(x, ptr, size) __put_get_user_asm(ptr, x, size, 0x810000UL)
#define __get_user_fn(x, ptr, size) __put_get_user_asm(x, ptr, size, 0x81UL)

#else /* CONFIG_HAVE_MARCH_Z10_FEATURES */

static inline int __put_user_fn(void *x, void __user *ptr, unsigned long size)
{
	size = __copy_to_user(ptr, x, size);
	return size ? -EFAULT : 0;
}

static inline int __get_user_fn(void *x, const void __user *ptr, unsigned long size)
{
	size = __copy_from_user(x, ptr, size);
	return size ? -EFAULT : 0;
}

#endif /* CONFIG_HAVE_MARCH_Z10_FEATURES */

/*
 * These are the main single-value transfer routines.  They automatically
 * use the right size if we just have the right pointer type.
 */
#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(&__x, ptr,		\
					 sizeof(*(ptr)));	\
		break;						\
	default:						\
		__put_user_bad();				\
		break;						\
	 }							\
	__pu_err;						\
})

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


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(&__x, ptr,		\
					 sizeof(*(ptr)));	\
		(x) = *(__force __typeof__(*(ptr)) *) &__x;	\
		break;						\
	};							\
	case 2: {						\
		unsigned short __x;				\
		__gu_err = __get_user_fn(&__x, ptr,		\
					 sizeof(*(ptr)));	\
		(x) = *(__force __typeof__(*(ptr)) *) &__x;	\
		break;						\
	};							\
	case 4: {						\
		unsigned int __x;				\
		__gu_err = __get_user_fn(&__x, ptr,		\
					 sizeof(*(ptr)));	\
		(x) = *(__force __typeof__(*(ptr)) *) &__x;	\
		break;						\
	};							\
	case 8: {						\
		unsigned long long __x;				\
		__gu_err = __get_user_fn(&__x, ptr,		\
					 sizeof(*(ptr)));	\
		(x) = *(__force __typeof__(*(ptr)) *) &__x;	\
		break;						\
	};							\
	default:						\
		__get_user_bad();				\
		break;						\
	}							\
	__gu_err;						\
})

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

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

#define __put_user_unaligned __put_user
#define __get_user_unaligned __get_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 if pagefaults are
 *          enabled.
 *
 * 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 __must_check
copy_to_user(void __user *to, const void *from, unsigned long n)
{
	might_fault();
	return __copy_to_user(to, from, n);
}

void copy_from_user_overflow(void)
#ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
__compiletime_warning("copy_from_user() buffer size is not provably correct")
#endif
;

/**
 * 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 if pagefaults are
 *          enabled.
 *
 * 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 __must_check
copy_from_user(void *to, const void __user *from, unsigned long n)
{
	unsigned int sz = __compiletime_object_size(to);

	might_fault();
	if (unlikely(sz != -1 && sz < n)) {
		copy_from_user_overflow();
		return n;
	}
	return __copy_from_user(to, from, n);
}

unsigned long __must_check
__copy_in_user(void __user *to, const void __user *from, unsigned long n);

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

/*
 * Copy a null terminated string from userspace.
 */

long __strncpy_from_user(char *dst, const char __user *src, long count);

static inline long __must_check
strncpy_from_user(char *dst, const char __user *src, long count)
{
	might_fault();
	return __strncpy_from_user(dst, src, count);
}

unsigned long __must_check __strnlen_user(const char __user *src, unsigned long count);

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

/**
 * strlen_user: - Get the size of a string in user space.
 * @str: The string to measure.
 *
 * Context: User context only. This function may sleep if pagefaults are
 *          enabled.
 *
 * 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
 */
unsigned long __must_check __clear_user(void __user *to, unsigned long size);

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

int copy_to_user_real(void __user *dest, void *src, unsigned long count);
void s390_kernel_write(void *dst, const void *src, size_t size);

#endif /* __S390_UACCESS_H */
Commit	Line	Data
1da177e4	1	/*
1da177e4	2	* S390 version
a53c8fab	3	* Copyright IBM Corp. 1999, 2000
1da177e4 LT	4	* Author(s): Hartmut Penner (hp@de.ibm.com),
	5	* Martin Schwidefsky (schwidefsky@de.ibm.com)
	6	*
	7	* Derived from "include/asm-i386/uaccess.h"
	8	*/
	9	#ifndef __S390_UACCESS_H
	10	#define __S390_UACCESS_H
	11
	12	/*
	13	* User space memory access functions
	14	*/
	15	#include <linux/sched.h>
	16	#include <linux/errno.h>
a0616cde	17	#include <asm/ctl_reg.h>
1da177e4 LT	18
	19	#define VERIFY_READ 0
	20	#define VERIFY_WRITE 1
	21
	22
	23	/*
	24	* The fs value determines whether argument validity checking should be
	25	* performed or not. If get_fs() == USER_DS, checking is performed, with
	26	* get_fs() == KERNEL_DS, checking is bypassed.
	27	*
	28	* For historical reasons, these macros are grossly misnamed.
	29	*/
	30
	31	#define MAKE_MM_SEG(a) ((mm_segment_t) { (a) })
	32
	33
	34	#define KERNEL_DS MAKE_MM_SEG(0)
	35	#define USER_DS MAKE_MM_SEG(1)
	36
	37	#define get_ds() (KERNEL_DS)
	38	#define get_fs() (current->thread.mm_segment)
	39
1da177e4 LT	40	#define set_fs(x) \
	41	({ \
	42	unsigned long __pto; \
	43	current->thread.mm_segment = (x); \
	44	__pto = current->thread.mm_segment.ar4 ? \
	45	S390_lowcore.user_asce : S390_lowcore.kernel_asce; \
94c12cc7	46	__ctl_load(__pto, 7, 7); \
1da177e4	47	})
1da177e4 LT	48
	49	#define segment_eq(a,b) ((a).ar4 == (b).ar4)
	50
491af990 HC	51	static inline int __range_ok(unsigned long addr, unsigned long size)
	52	{
	53	return 1;
	54	}
	55
	56	#define __access_ok(addr, size) \
	57	({ \
	58	__chk_user_ptr(addr); \
	59	__range_ok((unsigned long)(addr), (size)); \
7683f744	60	})
1da177e4	61
7683f744	62	#define access_ok(type, addr, size) __access_ok(addr, size)
1da177e4	63
1da177e4 LT	64	/*
	65	* The exception table consists of pairs of addresses: the first is the
	66	* address of an instruction that is allowed to fault, and the second is
	67	* the address at which the program should continue. No registers are
	68	* modified, so it is entirely up to the continuation code to figure out
	69	* what to do.
	70	*
	71	* All the routines below use bits of fixup code that are out of line
	72	* with the main instruction path. This means when everything is well,
	73	* we don't even have to jump over them. Further, they do not intrude
	74	* on our cache or tlb entries.
	75	*/
	76
	77	struct exception_table_entry
	78	{
eb608fb3	79	int insn, fixup;
1da177e4 LT	80	};
1da177e4 LT	81
eb608fb3 HC	82	static inline unsigned long extable_insn(const struct exception_table_entry *x)
	83	{
	84	return (unsigned long)&x->insn + x->insn;
	85	}
	86
	87	static inline unsigned long extable_fixup(const struct exception_table_entry *x)
	88	{
	89	return (unsigned long)&x->fixup + x->fixup;
	90	}
	91
	92	#define ARCH_HAS_SORT_EXTABLE
	93	#define ARCH_HAS_SEARCH_EXTABLE
	94
4f41c2b4 HC	95	/**
	96	* __copy_from_user: - Copy a block of data from user space, with less checking.
	97	* @to: Destination address, in kernel space.
	98	* @from: Source address, in user space.
	99	* @n: Number of bytes to copy.
	100	*
b3c395ef DH	101	* Context: User context only. This function may sleep if pagefaults are
b3c395ef DH	102	* enabled.
4f41c2b4 HC	103	*
	104	* Copy data from user space to kernel space. Caller must check
	105	* the specified block with access_ok() before calling this function.
	106	*
	107	* Returns number of bytes that could not be copied.
	108	* On success, this will be zero.
	109	*
	110	* If some data could not be copied, this function will pad the copied
	111	* data to the requested size using zero bytes.
	112	*/
211deca6 HC	113	unsigned long __must_check __copy_from_user(void to, const void __user from,
211deca6 HC	114	unsigned long n);
4f41c2b4 HC	115
	116	/**
	117	* __copy_to_user: - Copy a block of data into user space, with less checking.
	118	* @to: Destination address, in user space.
	119	* @from: Source address, in kernel space.
	120	* @n: Number of bytes to copy.
	121	*
b3c395ef DH	122	* Context: User context only. This function may sleep if pagefaults are
b3c395ef DH	123	* enabled.
4f41c2b4 HC	124	*
	125	* Copy data from kernel space to user space. Caller must check
	126	* the specified block with access_ok() before calling this function.
	127	*
	128	* Returns number of bytes that could not be copied.
	129	* On success, this will be zero.
	130	*/
	131	unsigned long __must_check __copy_to_user(void __user to, const void from,
	132	unsigned long n);
d02765d1	133
4f41c2b4 HC	134	#define __copy_to_user_inatomic __copy_to_user
4f41c2b4 HC	135	#define __copy_from_user_inatomic __copy_from_user
6c1e3e79	136
c9ca7841 HC	137	#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES
	138
	139	#define __put_get_user_asm(to, from, size, spec) \
	140	({ \
	141	register unsigned long __reg0 asm("0") = spec; \
	142	int __rc; \
	143	\
	144	asm volatile( \
	145	"0: mvcos %1,%3,%2\n" \
	146	"1: xr %0,%0\n" \
	147	"2:\n" \
	148	".pushsection .fixup, \"ax\"\n" \
	149	"3: lhi %0,%5\n" \
	150	" jg 2b\n" \
	151	".popsection\n" \
	152	EX_TABLE(0b,3b) EX_TABLE(1b,3b) \
	153	: "=d" (__rc), "=Q" (*(to)) \
	154	: "d" (size), "Q" (*(from)), \
	155	"d" (__reg0), "K" (-EFAULT) \
	156	: "cc"); \
	157	__rc; \
	158	})
	159
	160	#define __put_user_fn(x, ptr, size) __put_get_user_asm(ptr, x, size, 0x810000UL)
	161	#define __get_user_fn(x, ptr, size) __put_get_user_asm(x, ptr, size, 0x81UL)
	162
	163	#else /* CONFIG_HAVE_MARCH_Z10_FEATURES */
	164
211deca6	165	static inline int __put_user_fn(void x, void __user ptr, unsigned long size)
d02765d1	166	{
4f41c2b4 HC	167	size = __copy_to_user(ptr, x, size);
4f41c2b4 HC	168	return size ? -EFAULT : 0;
d02765d1 GS	169	}
d02765d1 GS	170
211deca6	171	static inline int __get_user_fn(void x, const void __user ptr, unsigned long size)
d02765d1	172	{
4f41c2b4 HC	173	size = __copy_from_user(x, ptr, size);
4f41c2b4 HC	174	return size ? -EFAULT : 0;
d02765d1	175	}
1da177e4	176
c9ca7841 HC	177	#endif /* CONFIG_HAVE_MARCH_Z10_FEATURES */
c9ca7841 HC	178
1da177e4 LT	179	/*
	180	* These are the main single-value transfer routines. They automatically
	181	* use the right size if we just have the right pointer type.
	182	*/
1da177e4 LT	183	#define __put_user(x, ptr) \
	184	({ \
	185	__typeof__(*(ptr)) __x = (x); \
d02765d1	186	int __pu_err = -EFAULT; \
17566c3c	187	__chk_user_ptr(ptr); \
1da177e4 LT	188	switch (sizeof (*(ptr))) { \
	189	case 1: \
	190	case 2: \
	191	case 4: \
	192	case 8: \
cfa785e6 HC	193	__pu_err = __put_user_fn(&__x, ptr, \
cfa785e6 HC	194	sizeof(*(ptr))); \
1da177e4 LT	195	break; \
	196	default: \
	197	__put_user_bad(); \
	198	break; \
	199	} \
	200	__pu_err; \
	201	})
1da177e4 LT	202
	203	#define put_user(x, ptr) \
	204	({ \
dab4079d	205	might_fault(); \
1da177e4 LT	206	__put_user(x, ptr); \
	207	})
	208
	209
4f41c2b4	210	int __put_user_bad(void) __attribute__((noreturn));
1da177e4	211
1da177e4 LT	212	#define __get_user(x, ptr) \
1da177e4 LT	213	({ \
d02765d1 GS	214	int __gu_err = -EFAULT; \
d02765d1 GS	215	__chk_user_ptr(ptr); \
1da177e4	216	switch (sizeof(*(ptr))) { \
1047aa77 MS	217	case 1: { \
1047aa77 MS	218	unsigned char __x; \
cfa785e6 HC	219	__gu_err = __get_user_fn(&__x, ptr, \
cfa785e6 HC	220	sizeof(*(ptr))); \
97fa5a66	221	(x) = (__force __typeof__((ptr)) *) &__x; \
1047aa77 MS	222	break; \
	223	}; \
	224	case 2: { \
	225	unsigned short __x; \
cfa785e6 HC	226	__gu_err = __get_user_fn(&__x, ptr, \
cfa785e6 HC	227	sizeof(*(ptr))); \
97fa5a66	228	(x) = (__force __typeof__((ptr)) *) &__x; \
1047aa77 MS	229	break; \
	230	}; \
	231	case 4: { \
	232	unsigned int __x; \
cfa785e6 HC	233	__gu_err = __get_user_fn(&__x, ptr, \
cfa785e6 HC	234	sizeof(*(ptr))); \
97fa5a66	235	(x) = (__force __typeof__((ptr)) *) &__x; \
1047aa77 MS	236	break; \
	237	}; \
	238	case 8: { \
	239	unsigned long long __x; \
cfa785e6 HC	240	__gu_err = __get_user_fn(&__x, ptr, \
cfa785e6 HC	241	sizeof(*(ptr))); \
97fa5a66	242	(x) = (__force __typeof__((ptr)) *) &__x; \
1da177e4	243	break; \
1047aa77	244	}; \
1da177e4 LT	245	default: \
	246	__get_user_bad(); \
	247	break; \
	248	} \
1da177e4 LT	249	__gu_err; \
1da177e4 LT	250	})
1da177e4 LT	251
	252	#define get_user(x, ptr) \
	253	({ \
dab4079d	254	might_fault(); \
1da177e4 LT	255	__get_user(x, ptr); \
	256	})
	257
4f41c2b4	258	int __get_user_bad(void) __attribute__((noreturn));
1da177e4 LT	259
	260	#define __put_user_unaligned __put_user
	261	#define __get_user_unaligned __get_user
	262
1da177e4 LT	263	/**
	264	* copy_to_user: - Copy a block of data into user space.
	265	* @to: Destination address, in user space.
	266	* @from: Source address, in kernel space.
	267	* @n: Number of bytes to copy.
	268	*
b3c395ef DH	269	* Context: User context only. This function may sleep if pagefaults are
b3c395ef DH	270	* enabled.
1da177e4 LT	271	*
	272	* Copy data from kernel space to user space.
	273	*
	274	* Returns number of bytes that could not be copied.
	275	* On success, this will be zero.
	276	*/
f7675ad7	277	static inline unsigned long __must_check
1da177e4 LT	278	copy_to_user(void __user to, const void from, unsigned long n)
1da177e4 LT	279	{
dab4079d	280	might_fault();
d12a2970	281	return __copy_to_user(to, from, n);
1da177e4 LT	282	}
1da177e4 LT	283
4f41c2b4	284	void copy_from_user_overflow(void)
1dcec254 HC	285	#ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
	286	__compiletime_warning("copy_from_user() buffer size is not provably correct")
	287	#endif
	288	;
	289
1da177e4 LT	290	/**
	291	* copy_from_user: - Copy a block of data from user space.
	292	* @to: Destination address, in kernel space.
	293	* @from: Source address, in user space.
	294	* @n: Number of bytes to copy.
	295	*
b3c395ef DH	296	* Context: User context only. This function may sleep if pagefaults are
b3c395ef DH	297	* enabled.
1da177e4 LT	298	*
	299	* Copy data from user space to kernel space.
	300	*
	301	* Returns number of bytes that could not be copied.
	302	* On success, this will be zero.
	303	*
	304	* If some data could not be copied, this function will pad the copied
	305	* data to the requested size using zero bytes.
	306	*/
f7675ad7	307	static inline unsigned long __must_check
1da177e4 LT	308	copy_from_user(void to, const void __user from, unsigned long n)
1da177e4 LT	309	{
1dcec254 HC	310	unsigned int sz = __compiletime_object_size(to);
1dcec254 HC	311
dab4079d	312	might_fault();
1dcec254 HC	313	if (unlikely(sz != -1 && sz < n)) {
	314	copy_from_user_overflow();
	315	return n;
	316	}
d12a2970	317	return __copy_from_user(to, from, n);
1da177e4 LT	318	}
1da177e4 LT	319
4f41c2b4 HC	320	unsigned long __must_check
4f41c2b4 HC	321	__copy_in_user(void __user to, const void __user from, unsigned long n);
1da177e4	322
f7675ad7	323	static inline unsigned long __must_check
1da177e4 LT	324	copy_in_user(void __user to, const void __user from, unsigned long n)
1da177e4 LT	325	{
dab4079d	326	might_fault();
d12a2970	327	return __copy_in_user(to, from, n);
1da177e4 LT	328	}
	329
	330	/*
	331	* Copy a null terminated string from userspace.
	332	*/
4f41c2b4 HC	333
	334	long __strncpy_from_user(char dst, const char __user src, long count);
	335
f7675ad7	336	static inline long __must_check
1da177e4 LT	337	strncpy_from_user(char dst, const char __user src, long count)
1da177e4 LT	338	{
dab4079d	339	might_fault();
4f41c2b4	340	return __strncpy_from_user(dst, src, count);
1da177e4 LT	341	}
1da177e4 LT	342
211deca6	343	unsigned long __must_check __strnlen_user(const char __user *src, unsigned long count);
4f41c2b4	344
211deca6	345	static inline unsigned long strnlen_user(const char __user *src, unsigned long n)
1da177e4	346	{
dab4079d	347	might_fault();
4f41c2b4	348	return __strnlen_user(src, n);
1da177e4 LT	349	}
	350
	351	/**
	352	* strlen_user: - Get the size of a string in user space.
	353	* @str: The string to measure.
	354	*
b3c395ef DH	355	* Context: User context only. This function may sleep if pagefaults are
b3c395ef DH	356	* enabled.
1da177e4 LT	357	*
	358	* Get the size of a NUL-terminated string in user space.
	359	*
	360	* Returns the size of the string INCLUDING the terminating NUL.
	361	* On exception, returns 0.
	362	*
	363	* If there is a limit on the length of a valid string, you may wish to
	364	* consider using strnlen_user() instead.
	365	*/
	366	#define strlen_user(str) strnlen_user(str, ~0UL)
	367
	368	/*
	369	* Zero Userspace
	370	*/
211deca6	371	unsigned long __must_check __clear_user(void __user *to, unsigned long size);
1da177e4	372
211deca6	373	static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
1da177e4	374	{
dab4079d	375	might_fault();
4f41c2b4	376	return __clear_user(to, n);
1da177e4 LT	377	}
1da177e4 LT	378
211deca6	379	int copy_to_user_real(void __user dest, void src, unsigned long count);
8a5d8473	380	void s390_kernel_write(void dst, const void src, size_t size);
a0616cde	381
1da177e4	382	#endif /* __S390_UACCESS_H */