[linux.git] / include / asm-powerpc / uaccess.h

#ifndef _ARCH_POWERPC_UACCESS_H
#define _ARCH_POWERPC_UACCESS_H

#ifdef __KERNEL__
#ifndef __ASSEMBLY__

#include <linux/sched.h>
#include <linux/errno.h>
#include <asm/processor.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.
 *
 * The fs/ds values are now the highest legal address in the "segment".
 * This simplifies the checking in the routines below.
 */

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

#define KERNEL_DS	MAKE_MM_SEG(~0UL)
#ifdef __powerpc64__
/* We use TASK_SIZE_USER64 as TASK_SIZE is not constant */
#define USER_DS		MAKE_MM_SEG(TASK_SIZE_USER64 - 1)
#else
#define USER_DS		MAKE_MM_SEG(TASK_SIZE - 1)
#endif

#define get_ds()	(KERNEL_DS)
#define get_fs()	(current->thread.fs)
#define set_fs(val)	(current->thread.fs = (val))

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

#ifdef __powerpc64__
/*
 * This check is sufficient because there is a large enough
 * gap between user addresses and the kernel addresses
 */
#define __access_ok(addr, size, segment)	\
	(((addr) <= (segment).seg) && ((size) <= (segment).seg))

#else

#define __access_ok(addr, size, segment)	\
	(((addr) <= (segment).seg) &&		\
	 (((size) == 0) || (((size) - 1) <= ((segment).seg - (addr)))))

#endif

#define access_ok(type, addr, size)		\
	(__chk_user_ptr(addr),			\
	 __access_ok((__force unsigned long)(addr), (size), get_fs()))

/*
 * 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;
	unsigned long fixup;
};

/*
 * These are the main single-value transfer routines.  They automatically
 * use the right size if we just have the right pointer type.
 *
 * This gets kind of ugly. We want to return _two_ values in "get_user()"
 * and yet we don't want to do any pointers, because that is too much
 * of a performance impact. Thus we have a few rather ugly macros here,
 * and hide all the ugliness from the user.
 *
 * The "__xxx" versions of the user access functions are versions that
 * do not verify the address space, that must have been done previously
 * with a separate "access_ok()" call (this is used when we do multiple
 * accesses to the same area of user memory).
 *
 * As we use the same address space for kernel and user data on the
 * PowerPC, we can just do these as direct assignments.  (Of course, the
 * exception handling means that it's no longer "just"...)
 *
 * The "user64" versions of the user access functions are versions that
 * allow access of 64-bit data. The "get_user" functions do not
 * properly handle 64-bit data because the value gets down cast to a long.
 * The "put_user" functions already handle 64-bit data properly but we add
 * "user64" versions for completeness
 */
#define get_user(x, ptr) \
	__get_user_check((x), (ptr), sizeof(*(ptr)))
#define put_user(x, ptr) \
	__put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))

#define __get_user(x, ptr) \
	__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
#define __put_user(x, ptr) \
	__put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
#ifndef __powerpc64__
#define __get_user64(x, ptr) \
	__get_user64_nocheck((x), (ptr), sizeof(*(ptr)))
#define __put_user64(x, ptr) __put_user(x, ptr)
#endif

#define __get_user_unaligned __get_user
#define __put_user_unaligned __put_user

extern long __put_user_bad(void);

/*
 * We don't tell gcc that we are accessing memory, but this is OK
 * because we do not write to any memory gcc knows about, so there
 * are no aliasing issues.
 */
#define __put_user_asm(x, addr, err, op)			\
	__asm__ __volatile__(					\
		"1:	" op " %1,0(%2)	# put_user\n"		\
		"2:\n"						\
		".section .fixup,\"ax\"\n"			\
		"3:	li %0,%3\n"				\
		"	b 2b\n"					\
		".previous\n"					\
		".section __ex_table,\"a\"\n"			\
		"	.balign %5\n"				\
			PPC_LONG "1b,3b\n"			\
		".previous"					\
		: "=r" (err)					\
		: "r" (x), "b" (addr), "i" (-EFAULT), "0" (err),\
		  "i"(sizeof(unsigned long)))

#ifdef __powerpc64__
#define __put_user_asm2(x, ptr, retval)				\
	  __put_user_asm(x, ptr, retval, "std")
#else /* __powerpc64__ */
#define __put_user_asm2(x, addr, err)				\
	__asm__ __volatile__(					\
		"1:	stw %1,0(%2)\n"				\
		"2:	stw %1+1,4(%2)\n"			\
		"3:\n"						\
		".section .fixup,\"ax\"\n"			\
		"4:	li %0,%3\n"				\
		"	b 3b\n"					\
		".previous\n"					\
		".section __ex_table,\"a\"\n"			\
		"	.balign %5\n"				\
			PPC_LONG "1b,4b\n"			\
			PPC_LONG "2b,4b\n"			\
		".previous"					\
		: "=r" (err)					\
		: "r" (x), "b" (addr), "i" (-EFAULT), "0" (err),\
		  "i"(sizeof(unsigned long)))
#endif /* __powerpc64__ */

#define __put_user_size(x, ptr, size, retval)			\
do {								\
	retval = 0;						\
	switch (size) {						\
	  case 1: __put_user_asm(x, ptr, retval, "stb"); break;	\
	  case 2: __put_user_asm(x, ptr, retval, "sth"); break;	\
	  case 4: __put_user_asm(x, ptr, retval, "stw"); break;	\
	  case 8: __put_user_asm2(x, ptr, retval); break;	\
	  default: __put_user_bad();				\
	}							\
} while (0)

#define __put_user_nocheck(x, ptr, size)			\
({								\
	long __pu_err;						\
	might_sleep();						\
	__chk_user_ptr(ptr);					\
	__put_user_size((x), (ptr), (size), __pu_err);		\
	__pu_err;						\
})

#define __put_user_check(x, ptr, size)					\
({									\
	long __pu_err = -EFAULT;					\
	__typeof__(*(ptr)) __user *__pu_addr = (ptr);			\
	might_sleep();							\
	if (access_ok(VERIFY_WRITE, __pu_addr, size))			\
		__put_user_size((x), __pu_addr, (size), __pu_err);	\
	__pu_err;							\
})

extern long __get_user_bad(void);

#define __get_user_asm(x, addr, err, op)		\
	__asm__ __volatile__(				\
		"1:	"op" %1,0(%2)	# get_user\n"	\
		"2:\n"					\
		".section .fixup,\"ax\"\n"		\
		"3:	li %0,%3\n"			\
		"	li %1,0\n"			\
		"	b 2b\n"				\
		".previous\n"				\
		".section __ex_table,\"a\"\n"		\
		"	.balign %5\n"			\
			PPC_LONG "1b,3b\n"		\
		".previous"				\
		: "=r" (err), "=r" (x)			\
		: "b" (addr), "i" (-EFAULT), "0" (err),	\
		  "i"(sizeof(unsigned long)))

#ifdef __powerpc64__
#define __get_user_asm2(x, addr, err)			\
	__get_user_asm(x, addr, err, "ld")
#else /* __powerpc64__ */
#define __get_user_asm2(x, addr, err)			\
	__asm__ __volatile__(				\
		"1:	lwz %1,0(%2)\n"			\
		"2:	lwz %1+1,4(%2)\n"		\
		"3:\n"					\
		".section .fixup,\"ax\"\n"		\
		"4:	li %0,%3\n"			\
		"	li %1,0\n"			\
		"	li %1+1,0\n"			\
		"	b 3b\n"				\
		".previous\n"				\
		".section __ex_table,\"a\"\n"		\
		"	.balign %5\n"			\
			PPC_LONG "1b,4b\n"		\
			PPC_LONG "2b,4b\n"		\
		".previous"				\
		: "=r" (err), "=&r" (x)			\
		: "b" (addr), "i" (-EFAULT), "0" (err),	\
		  "i"(sizeof(unsigned long)))
#endif /* __powerpc64__ */

#define __get_user_size(x, ptr, size, retval)			\
do {								\
	retval = 0;						\
	__chk_user_ptr(ptr);					\
	if (size > sizeof(x))					\
		(x) = __get_user_bad();				\
	switch (size) {						\
	case 1: __get_user_asm(x, ptr, retval, "lbz"); break;	\
	case 2: __get_user_asm(x, ptr, retval, "lhz"); break;	\
	case 4: __get_user_asm(x, ptr, retval, "lwz"); break;	\
	case 8: __get_user_asm2(x, ptr, retval);  break;	\
	default: (x) = __get_user_bad();			\
	}							\
} while (0)

#define __get_user_nocheck(x, ptr, size)			\
({								\
	long __gu_err;						\
	unsigned long __gu_val;					\
	__chk_user_ptr(ptr);					\
	might_sleep();						\
	__get_user_size(__gu_val, (ptr), (size), __gu_err);	\
	(x) = (__typeof__(*(ptr)))__gu_val;			\
	__gu_err;						\
})

#ifndef __powerpc64__
#define __get_user64_nocheck(x, ptr, size)			\
({								\
	long __gu_err;						\
	long long __gu_val;					\
	__chk_user_ptr(ptr);					\
	might_sleep();						\
	__get_user_size(__gu_val, (ptr), (size), __gu_err);	\
	(x) = (__typeof__(*(ptr)))__gu_val;			\
	__gu_err;						\
})
#endif /* __powerpc64__ */

#define __get_user_check(x, ptr, size)					\
({									\
	long __gu_err = -EFAULT;					\
	unsigned long  __gu_val = 0;					\
	const __typeof__(*(ptr)) __user *__gu_addr = (ptr);		\
	might_sleep();							\
	if (access_ok(VERIFY_READ, __gu_addr, (size)))			\
		__get_user_size(__gu_val, __gu_addr, (size), __gu_err);	\
	(x) = (__typeof__(*(ptr)))__gu_val;				\
	__gu_err;							\
})

/* more complex routines */

extern unsigned long __copy_tofrom_user(void __user *to,
		const void __user *from, unsigned long size);

#ifndef __powerpc64__

extern inline unsigned long copy_from_user(void *to,
		const void __user *from, unsigned long n)
{
	unsigned long over;

	if (access_ok(VERIFY_READ, from, n))
		return __copy_tofrom_user((__force void __user *)to, from, n);
	if ((unsigned long)from < TASK_SIZE) {
		over = (unsigned long)from + n - TASK_SIZE;
		return __copy_tofrom_user((__force void __user *)to, from,
				n - over) + over;
	}
	return n;
}

extern inline unsigned long copy_to_user(void __user *to,
		const void *from, unsigned long n)
{
	unsigned long over;

	if (access_ok(VERIFY_WRITE, to, n))
		return __copy_tofrom_user(to, (__force void __user *)from, n);
	if ((unsigned long)to < TASK_SIZE) {
		over = (unsigned long)to + n - TASK_SIZE;
		return __copy_tofrom_user(to, (__force void __user *)from,
				n - over) + over;
	}
	return n;
}

#else /* __powerpc64__ */

#define __copy_in_user(to, from, size) \
	__copy_tofrom_user((to), (from), (size))

extern unsigned long copy_from_user(void *to, const void __user *from,
				    unsigned long n);
extern unsigned long copy_to_user(void __user *to, const void *from,
				  unsigned long n);
extern unsigned long copy_in_user(void __user *to, const void __user *from,
				  unsigned long n);

#endif /* __powerpc64__ */

static inline unsigned long __copy_from_user_inatomic(void *to,
		const void __user *from, unsigned long n)
{
	if (__builtin_constant_p(n) && (n <= 8)) {
		unsigned long ret;

		switch (n) {
		case 1:
			__get_user_size(*(u8 *)to, from, 1, ret);
			break;
		case 2:
			__get_user_size(*(u16 *)to, from, 2, ret);
			break;
		case 4:
			__get_user_size(*(u32 *)to, from, 4, ret);
			break;
		case 8:
			__get_user_size(*(u64 *)to, from, 8, ret);
			break;
		}
		if (ret == 0)
			return 0;
	}
	return __copy_tofrom_user((__force void __user *)to, from, n);
}

static inline unsigned long __copy_to_user_inatomic(void __user *to,
		const void *from, unsigned long n)
{
	if (__builtin_constant_p(n) && (n <= 8)) {
		unsigned long ret;

		switch (n) {
		case 1:
			__put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret);
			break;
		case 2:
			__put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret);
			break;
		case 4:
			__put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret);
			break;
		case 8:
			__put_user_size(*(u64 *)from, (u64 __user *)to, 8, ret);
			break;
		}
		if (ret == 0)
			return 0;
	}
	return __copy_tofrom_user(to, (__force const void __user *)from, n);
}

static inline unsigned long __copy_from_user(void *to,
		const void __user *from, unsigned long size)
{
	might_sleep();
	return __copy_from_user_inatomic(to, from, size);
}

static inline unsigned long __copy_to_user(void __user *to,
		const void *from, unsigned long size)
{
	might_sleep();
	return __copy_to_user_inatomic(to, from, size);
}

extern unsigned long __clear_user(void __user *addr, unsigned long size);

static inline unsigned long clear_user(void __user *addr, unsigned long size)
{
	might_sleep();
	if (likely(access_ok(VERIFY_WRITE, addr, size)))
		return __clear_user(addr, size);
	if ((unsigned long)addr < TASK_SIZE) {
		unsigned long over = (unsigned long)addr + size - TASK_SIZE;
		return __clear_user(addr, size - over) + over;
	}
	return size;
}

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

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

/*
 * Return the size of a string (including the ending 0)
 *
 * Return 0 for error
 */
extern int __strnlen_user(const char __user *str, long len, unsigned long top);

/*
 * Returns the length of the string at str (including the null byte),
 * or 0 if we hit a page we can't access,
 * or something > len if we didn't find a null byte.
 *
 * The `top' parameter to __strnlen_user is to make sure that
 * we can never overflow from the user area into kernel space.
 */
static inline int strnlen_user(const char __user *str, long len)
{
	unsigned long top = current->thread.fs.seg;

	if ((unsigned long)str > top)
		return 0;
	return __strnlen_user(str, len, top);
}

#define strlen_user(str)	strnlen_user((str), 0x7ffffffe)

#endif  /* __ASSEMBLY__ */
#endif /* __KERNEL__ */

#endif	/* _ARCH_POWERPC_UACCESS_H */
Commit	Line	Data
2df5e8bc SR	1	#ifndef _ARCH_POWERPC_UACCESS_H
	2	#define _ARCH_POWERPC_UACCESS_H
	3
	4	#ifdef __KERNEL__
	5	#ifndef __ASSEMBLY__
	6
	7	#include <linux/sched.h>
	8	#include <linux/errno.h>
	9	#include <asm/processor.h>
	10
	11	#define VERIFY_READ 0
	12	#define VERIFY_WRITE 1
	13
	14	/*
	15	* The fs value determines whether argument validity checking should be
	16	* performed or not. If get_fs() == USER_DS, checking is performed, with
	17	* get_fs() == KERNEL_DS, checking is bypassed.
	18	*
	19	* For historical reasons, these macros are grossly misnamed.
	20	*
	21	* The fs/ds values are now the highest legal address in the "segment".
	22	* This simplifies the checking in the routines below.
	23	*/
	24
	25	#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
	26
5015b494	27	#define KERNEL_DS MAKE_MM_SEG(~0UL)
2df5e8bc	28	#ifdef __powerpc64__
5015b494 SR	29	/* We use TASK_SIZE_USER64 as TASK_SIZE is not constant */
5015b494 SR	30	#define USER_DS MAKE_MM_SEG(TASK_SIZE_USER64 - 1)
2df5e8bc	31	#else
2df5e8bc SR	32	#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
	33	#endif
	34
	35	#define get_ds() (KERNEL_DS)
	36	#define get_fs() (current->thread.fs)
	37	#define set_fs(val) (current->thread.fs = (val))
	38
	39	#define segment_eq(a, b) ((a).seg == (b).seg)
	40
	41	#ifdef __powerpc64__
	42	/*
5015b494 SR	43	* This check is sufficient because there is a large enough
5015b494 SR	44	* gap between user addresses and the kernel addresses
2df5e8bc SR	45	*/
2df5e8bc SR	46	#define __access_ok(addr, size, segment) \
5015b494	47	(((addr) <= (segment).seg) && ((size) <= (segment).seg))
2df5e8bc SR	48
	49	#else
	50
	51	#define __access_ok(addr, size, segment) \
	52	(((addr) <= (segment).seg) && \
	53	(((size) == 0) \|\| (((size) - 1) <= ((segment).seg - (addr)))))
	54
	55	#endif
	56
	57	#define access_ok(type, addr, size) \
	58	(__chk_user_ptr(addr), \
	59	__access_ok((__force unsigned long)(addr), (size), get_fs()))
	60
	61	/*
	62	* The exception table consists of pairs of addresses: the first is the
	63	* address of an instruction that is allowed to fault, and the second is
	64	* the address at which the program should continue. No registers are
	65	* modified, so it is entirely up to the continuation code to figure out
	66	* what to do.
	67	*
	68	* All the routines below use bits of fixup code that are out of line
	69	* with the main instruction path. This means when everything is well,
	70	* we don't even have to jump over them. Further, they do not intrude
	71	* on our cache or tlb entries.
	72	*/
	73
	74	struct exception_table_entry {
	75	unsigned long insn;
	76	unsigned long fixup;
	77	};
	78
	79	/*
	80	* These are the main single-value transfer routines. They automatically
	81	* use the right size if we just have the right pointer type.
	82	*
	83	* This gets kind of ugly. We want to return _two_ values in "get_user()"
	84	* and yet we don't want to do any pointers, because that is too much
	85	* of a performance impact. Thus we have a few rather ugly macros here,
	86	* and hide all the ugliness from the user.
	87	*
	88	* The "__xxx" versions of the user access functions are versions that
	89	* do not verify the address space, that must have been done previously
	90	* with a separate "access_ok()" call (this is used when we do multiple
	91	* accesses to the same area of user memory).
	92	*
	93	* As we use the same address space for kernel and user data on the
	94	* PowerPC, we can just do these as direct assignments. (Of course, the
	95	* exception handling means that it's no longer "just"...)
	96	*
	97	* The "user64" versions of the user access functions are versions that
	98	* allow access of 64-bit data. The "get_user" functions do not
	99	* properly handle 64-bit data because the value gets down cast to a long.
	100	* The "put_user" functions already handle 64-bit data properly but we add
	101	* "user64" versions for completeness
	102	*/
	103	#define get_user(x, ptr) \
	104	__get_user_check((x), (ptr), sizeof(*(ptr)))
	105	#define put_user(x, ptr) \
	106	__put_user_check((__typeof__((ptr)))(x), (ptr), sizeof((ptr)))
	107
	108	#define __get_user(x, ptr) \
	109	__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
	110	#define __put_user(x, ptr) \
	111	__put_user_nocheck((__typeof__((ptr)))(x), (ptr), sizeof((ptr)))
112	#ifndef __powerpc64__
113	#define __get_user64(x, ptr) \
114	__get_user64_nocheck((x), (ptr), sizeof(*(ptr)))
115	#define __put_user64(x, ptr) __put_user(x, ptr)
116	#endif
117
2df5e8bc SR	118	#define __get_user_unaligned __get_user
2df5e8bc SR	119	#define __put_user_unaligned __put_user
2df5e8bc SR	120
	121	extern long __put_user_bad(void);
	122
2df5e8bc SR	123	/*
	124	* We don't tell gcc that we are accessing memory, but this is OK
	125	* because we do not write to any memory gcc knows about, so there
	126	* are no aliasing issues.
	127	*/
	128	#define __put_user_asm(x, addr, err, op) \
	129	__asm__ __volatile__( \
	130	"1: " op " %1,0(%2) # put_user\n" \
	131	"2:\n" \
	132	".section .fixup,\"ax\"\n" \
	133	"3: li %0,%3\n" \
	134	" b 2b\n" \
	135	".previous\n" \
	136	".section __ex_table,\"a\"\n" \
3ddfbcf1 DG	137	" .balign %5\n" \
3ddfbcf1 DG	138	PPC_LONG "1b,3b\n" \
2df5e8bc SR	139	".previous" \
2df5e8bc SR	140	: "=r" (err) \
3ddfbcf1 DG	141	: "r" (x), "b" (addr), "i" (-EFAULT), "0" (err),\
3ddfbcf1 DG	142	"i"(sizeof(unsigned long)))
2df5e8bc	143
5015b494 SR	144	#ifdef __powerpc64__
	145	#define __put_user_asm2(x, ptr, retval) \
	146	__put_user_asm(x, ptr, retval, "std")
	147	#else /* __powerpc64__ */
2df5e8bc SR	148	#define __put_user_asm2(x, addr, err) \
	149	__asm__ __volatile__( \
	150	"1: stw %1,0(%2)\n" \
	151	"2: stw %1+1,4(%2)\n" \
	152	"3:\n" \
	153	".section .fixup,\"ax\"\n" \
	154	"4: li %0,%3\n" \
	155	" b 3b\n" \
	156	".previous\n" \
	157	".section __ex_table,\"a\"\n" \
3ddfbcf1 DG	158	" .balign %5\n" \
	159	PPC_LONG "1b,4b\n" \
	160	PPC_LONG "2b,4b\n" \
2df5e8bc SR	161	".previous" \
2df5e8bc SR	162	: "=r" (err) \
3ddfbcf1 DG	163	: "r" (x), "b" (addr), "i" (-EFAULT), "0" (err),\
3ddfbcf1 DG	164	"i"(sizeof(unsigned long)))
2df5e8bc SR	165	#endif /* __powerpc64__ */
	166
	167	#define __put_user_size(x, ptr, size, retval) \
	168	do { \
	169	retval = 0; \
	170	switch (size) { \
	171	case 1: __put_user_asm(x, ptr, retval, "stb"); break; \
	172	case 2: __put_user_asm(x, ptr, retval, "sth"); break; \
	173	case 4: __put_user_asm(x, ptr, retval, "stw"); break; \
	174	case 8: __put_user_asm2(x, ptr, retval); break; \
	175	default: __put_user_bad(); \
	176	} \
	177	} while (0)
	178
	179	#define __put_user_nocheck(x, ptr, size) \
	180	({ \
	181	long __pu_err; \
	182	might_sleep(); \
	183	__chk_user_ptr(ptr); \
	184	__put_user_size((x), (ptr), (size), __pu_err); \
	185	__pu_err; \
	186	})
	187
	188	#define __put_user_check(x, ptr, size) \
	189	({ \
	190	long __pu_err = -EFAULT; \
	191	__typeof__((ptr)) __user __pu_addr = (ptr); \
	192	might_sleep(); \
	193	if (access_ok(VERIFY_WRITE, __pu_addr, size)) \
	194	__put_user_size((x), __pu_addr, (size), __pu_err); \
	195	__pu_err; \
	196	})
	197
	198	extern long __get_user_bad(void);
	199
	200	#define __get_user_asm(x, addr, err, op) \
	201	__asm__ __volatile__( \
5015b494	202	"1: "op" %1,0(%2) # get_user\n" \
2df5e8bc SR	203	"2:\n" \
	204	".section .fixup,\"ax\"\n" \
	205	"3: li %0,%3\n" \
	206	" li %1,0\n" \
	207	" b 2b\n" \
	208	".previous\n" \
	209	".section __ex_table,\"a\"\n" \
3ddfbcf1 DG	210	" .balign %5\n" \
3ddfbcf1 DG	211	PPC_LONG "1b,3b\n" \
2df5e8bc SR	212	".previous" \
2df5e8bc SR	213	: "=r" (err), "=r" (x) \
3ddfbcf1 DG	214	: "b" (addr), "i" (-EFAULT), "0" (err), \
3ddfbcf1 DG	215	"i"(sizeof(unsigned long)))
2df5e8bc	216
5015b494 SR	217	#ifdef __powerpc64__
	218	#define __get_user_asm2(x, addr, err) \
	219	__get_user_asm(x, addr, err, "ld")
	220	#else /* __powerpc64__ */
	221	#define __get_user_asm2(x, addr, err) \
2df5e8bc SR	222	__asm__ __volatile__( \
	223	"1: lwz %1,0(%2)\n" \
	224	"2: lwz %1+1,4(%2)\n" \
	225	"3:\n" \
	226	".section .fixup,\"ax\"\n" \
	227	"4: li %0,%3\n" \
	228	" li %1,0\n" \
	229	" li %1+1,0\n" \
	230	" b 3b\n" \
	231	".previous\n" \
	232	".section __ex_table,\"a\"\n" \
3ddfbcf1 DG	233	" .balign %5\n" \
	234	PPC_LONG "1b,4b\n" \
	235	PPC_LONG "2b,4b\n" \
2df5e8bc SR	236	".previous" \
2df5e8bc SR	237	: "=r" (err), "=&r" (x) \
3ddfbcf1 DG	238	: "b" (addr), "i" (-EFAULT), "0" (err), \
3ddfbcf1 DG	239	"i"(sizeof(unsigned long)))
2df5e8bc SR	240	#endif /* __powerpc64__ */
	241
	242	#define __get_user_size(x, ptr, size, retval) \
	243	do { \
	244	retval = 0; \
	245	__chk_user_ptr(ptr); \
5015b494 SR	246	if (size > sizeof(x)) \
5015b494 SR	247	(x) = __get_user_bad(); \
2df5e8bc SR	248	switch (size) { \
	249	case 1: __get_user_asm(x, ptr, retval, "lbz"); break; \
	250	case 2: __get_user_asm(x, ptr, retval, "lhz"); break; \
	251	case 4: __get_user_asm(x, ptr, retval, "lwz"); break; \
	252	case 8: __get_user_asm2(x, ptr, retval); break; \
	253	default: (x) = __get_user_bad(); \
	254	} \
	255	} while (0)
	256
	257	#define __get_user_nocheck(x, ptr, size) \
	258	({ \
	259	long __gu_err; \
	260	unsigned long __gu_val; \
	261	__chk_user_ptr(ptr); \
	262	might_sleep(); \
	263	__get_user_size(__gu_val, (ptr), (size), __gu_err); \
	264	(x) = (__typeof__(*(ptr)))__gu_val; \
	265	__gu_err; \
	266	})
	267
	268	#ifndef __powerpc64__
	269	#define __get_user64_nocheck(x, ptr, size) \
	270	({ \
	271	long __gu_err; \
	272	long long __gu_val; \
	273	__chk_user_ptr(ptr); \
	274	might_sleep(); \
	275	__get_user_size(__gu_val, (ptr), (size), __gu_err); \
	276	(x) = (__typeof__(*(ptr)))__gu_val; \
	277	__gu_err; \
	278	})
	279	#endif /* __powerpc64__ */
	280
	281	#define __get_user_check(x, ptr, size) \
	282	({ \
	283	long __gu_err = -EFAULT; \
	284	unsigned long __gu_val = 0; \
	285	const __typeof__((ptr)) __user __gu_addr = (ptr); \
5015b494	286	might_sleep(); \
2df5e8bc SR	287	if (access_ok(VERIFY_READ, __gu_addr, (size))) \
	288	__get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
	289	(x) = (__typeof__(*(ptr)))__gu_val; \
	290	__gu_err; \
	291	})
	292
	293	/* more complex routines */
	294
	295	extern unsigned long __copy_tofrom_user(void __user *to,
	296	const void __user *from, unsigned long size);
	297
	298	#ifndef __powerpc64__
5015b494 SR	299
	300	extern inline unsigned long copy_from_user(void *to,
	301	const void __user *from, unsigned long n)
2df5e8bc SR	302	{
	303	unsigned long over;
	304
	305	if (access_ok(VERIFY_READ, from, n))
	306	return __copy_tofrom_user((__force void __user *)to, from, n);
	307	if ((unsigned long)from < TASK_SIZE) {
	308	over = (unsigned long)from + n - TASK_SIZE;
	309	return __copy_tofrom_user((__force void __user *)to, from,
	310	n - over) + over;
	311	}
	312	return n;
	313	}
	314
5015b494 SR	315	extern inline unsigned long copy_to_user(void __user *to,
5015b494 SR	316	const void *from, unsigned long n)
2df5e8bc SR	317	{
	318	unsigned long over;
	319
	320	if (access_ok(VERIFY_WRITE, to, n))
	321	return __copy_tofrom_user(to, (__force void __user *)from, n);
	322	if ((unsigned long)to < TASK_SIZE) {
	323	over = (unsigned long)to + n - TASK_SIZE;
	324	return __copy_tofrom_user(to, (__force void __user *)from,
	325	n - over) + over;
	326	}
	327	return n;
	328	}
	329
	330	#else /* __powerpc64__ */
	331
5015b494 SR	332	#define __copy_in_user(to, from, size) \
	333	__copy_tofrom_user((to), (from), (size))
	334
	335	extern unsigned long copy_from_user(void to, const void __user from,
	336	unsigned long n);
	337	extern unsigned long copy_to_user(void __user to, const void from,
	338	unsigned long n);
	339	extern unsigned long copy_in_user(void __user to, const void __user from,
	340	unsigned long n);
	341
48fe4871 SR	342	#endif /* __powerpc64__ */
48fe4871 SR	343
5015b494 SR	344	static inline unsigned long __copy_from_user_inatomic(void *to,
5015b494 SR	345	const void __user *from, unsigned long n)
2df5e8bc SR	346	{
	347	if (__builtin_constant_p(n) && (n <= 8)) {
	348	unsigned long ret;
	349
	350	switch (n) {
	351	case 1:
	352	__get_user_size((u8 )to, from, 1, ret);
	353	break;
	354	case 2:
	355	__get_user_size((u16 )to, from, 2, ret);
	356	break;
	357	case 4:
	358	__get_user_size((u32 )to, from, 4, ret);
	359	break;
	360	case 8:
	361	__get_user_size((u64 )to, from, 8, ret);
	362	break;
	363	}
48fe4871 SR	364	if (ret == 0)
48fe4871 SR	365	return 0;
2df5e8bc	366	}
48fe4871	367	return __copy_tofrom_user((__force void __user *)to, from, n);
2df5e8bc SR	368	}
2df5e8bc SR	369
5015b494 SR	370	static inline unsigned long __copy_to_user_inatomic(void __user *to,
5015b494 SR	371	const void *from, unsigned long n)
2df5e8bc SR	372	{
	373	if (__builtin_constant_p(n) && (n <= 8)) {
	374	unsigned long ret;
	375
	376	switch (n) {
	377	case 1:
	378	__put_user_size((u8 )from, (u8 __user *)to, 1, ret);
	379	break;
	380	case 2:
	381	__put_user_size((u16 )from, (u16 __user *)to, 2, ret);
	382	break;
	383	case 4:
	384	__put_user_size((u32 )from, (u32 __user *)to, 4, ret);
	385	break;
	386	case 8:
	387	__put_user_size((u64 )from, (u64 __user *)to, 8, ret);
	388	break;
	389	}
48fe4871 SR	390	if (ret == 0)
48fe4871 SR	391	return 0;
2df5e8bc	392	}
48fe4871	393	return __copy_tofrom_user(to, (__force const void __user *)from, n);
2df5e8bc SR	394	}
2df5e8bc SR	395
5015b494 SR	396	static inline unsigned long __copy_from_user(void *to,
5015b494 SR	397	const void __user *from, unsigned long size)
2df5e8bc SR	398	{
2df5e8bc SR	399	might_sleep();
2df5e8bc	400	return __copy_from_user_inatomic(to, from, size);
2df5e8bc SR	401	}
2df5e8bc SR	402
5015b494 SR	403	static inline unsigned long __copy_to_user(void __user *to,
5015b494 SR	404	const void *from, unsigned long size)
2df5e8bc SR	405	{
2df5e8bc SR	406	might_sleep();
2df5e8bc	407	return __copy_to_user_inatomic(to, from, size);
2df5e8bc SR	408	}
2df5e8bc SR	409
2df5e8bc SR	410	extern unsigned long __clear_user(void __user *addr, unsigned long size);
	411
	412	static inline unsigned long clear_user(void __user *addr, unsigned long size)
	413	{
	414	might_sleep();
	415	if (likely(access_ok(VERIFY_WRITE, addr, size)))
	416	return __clear_user(addr, size);
2df5e8bc SR	417	if ((unsigned long)addr < TASK_SIZE) {
	418	unsigned long over = (unsigned long)addr + size - TASK_SIZE;
	419	return __clear_user(addr, size - over) + over;
	420	}
2df5e8bc SR	421	return size;
	422	}
	423
	424	extern int __strncpy_from_user(char dst, const char __user src, long count);
	425
	426	static inline long strncpy_from_user(char dst, const char __user src,
	427	long count)
	428	{
	429	might_sleep();
	430	if (likely(access_ok(VERIFY_READ, src, 1)))
	431	return __strncpy_from_user(dst, src, count);
	432	return -EFAULT;
	433	}
	434
	435	/*
	436	* Return the size of a string (including the ending 0)
	437	*
	438	* Return 0 for error
	439	*/
2df5e8bc	440	extern int __strnlen_user(const char __user *str, long len, unsigned long top);
2df5e8bc SR	441
	442	/*
	443	* Returns the length of the string at str (including the null byte),
	444	* or 0 if we hit a page we can't access,
	445	* or something > len if we didn't find a null byte.
	446	*
	447	* The `top' parameter to __strnlen_user is to make sure that
	448	* we can never overflow from the user area into kernel space.
	449	*/
	450	static inline int strnlen_user(const char __user *str, long len)
	451	{
2df5e8bc SR	452	unsigned long top = current->thread.fs.seg;
	453
	454	if ((unsigned long)str > top)
	455	return 0;
	456	return __strnlen_user(str, len, top);
2df5e8bc SR	457	}
	458
	459	#define strlen_user(str) strnlen_user((str), 0x7ffffffe)
	460
	461	#endif /* __ASSEMBLY__ */
	462	#endif /* __KERNEL__ */
	463
	464	#endif /* _ARCH_POWERPC_UACCESS_H */