[deliverable/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);

#ifdef __powerpc64__
#define __EX_TABLE_ALIGN	"3"
#define __EX_TABLE_TYPE		"llong"
#else
#define __EX_TABLE_ALIGN	"2"
#define __EX_TABLE_TYPE		"long"
#endif

/*
 * 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"			\
		"	.align " __EX_TABLE_ALIGN "\n"		\
		"	."__EX_TABLE_TYPE" 1b,3b\n"		\
		".previous"					\
		: "=r" (err)					\
		: "r" (x), "b" (addr), "i" (-EFAULT), "0" (err))

#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"			\
		"	.align " __EX_TABLE_ALIGN "\n"		\
		"	." __EX_TABLE_TYPE " 1b,4b\n"		\
		"	." __EX_TABLE_TYPE " 2b,4b\n"		\
		".previous"					\
		: "=r" (err)					\
		: "r" (x), "b" (addr), "i" (-EFAULT), "0" (err))
#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"		\
		"	.align "__EX_TABLE_ALIGN "\n"	\
		"	." __EX_TABLE_TYPE " 1b,3b\n"	\
		".previous"				\
		: "=r" (err), "=r" (x)			\
		: "b" (addr), "i" (-EFAULT), "0" (err))

#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"		\
		"	.align " __EX_TABLE_ALIGN "\n"	\
		"	." __EX_TABLE_TYPE " 1b,4b\n"	\
		"	." __EX_TABLE_TYPE " 2b,4b\n"	\
		".previous"				\
		: "=r" (err), "=&r" (x)			\
		: "b" (addr), "i" (-EFAULT), "0" (err))
#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
	123	#ifdef __powerpc64__
	124	#define __EX_TABLE_ALIGN "3"
	125	#define __EX_TABLE_TYPE "llong"
	126	#else
	127	#define __EX_TABLE_ALIGN "2"
	128	#define __EX_TABLE_TYPE "long"
	129	#endif
	130
	131	/*
	132	* We don't tell gcc that we are accessing memory, but this is OK
	133	* because we do not write to any memory gcc knows about, so there
	134	* are no aliasing issues.
	135	*/
	136	#define __put_user_asm(x, addr, err, op) \
	137	__asm__ __volatile__( \
	138	"1: " op " %1,0(%2) # put_user\n" \
	139	"2:\n" \
	140	".section .fixup,\"ax\"\n" \
	141	"3: li %0,%3\n" \
	142	" b 2b\n" \
	143	".previous\n" \
	144	".section __ex_table,\"a\"\n" \
	145	" .align " __EX_TABLE_ALIGN "\n" \
	146	" ."__EX_TABLE_TYPE" 1b,3b\n" \
	147	".previous" \
	148	: "=r" (err) \
	149	: "r" (x), "b" (addr), "i" (-EFAULT), "0" (err))
	150
5015b494 SR	151	#ifdef __powerpc64__
	152	#define __put_user_asm2(x, ptr, retval) \
	153	__put_user_asm(x, ptr, retval, "std")
	154	#else /* __powerpc64__ */
2df5e8bc SR	155	#define __put_user_asm2(x, addr, err) \
	156	__asm__ __volatile__( \
	157	"1: stw %1,0(%2)\n" \
	158	"2: stw %1+1,4(%2)\n" \
	159	"3:\n" \
	160	".section .fixup,\"ax\"\n" \
	161	"4: li %0,%3\n" \
	162	" b 3b\n" \
	163	".previous\n" \
	164	".section __ex_table,\"a\"\n" \
	165	" .align " __EX_TABLE_ALIGN "\n" \
	166	" ." __EX_TABLE_TYPE " 1b,4b\n" \
	167	" ." __EX_TABLE_TYPE " 2b,4b\n" \
	168	".previous" \
	169	: "=r" (err) \
	170	: "r" (x), "b" (addr), "i" (-EFAULT), "0" (err))
2df5e8bc SR	171	#endif /* __powerpc64__ */
	172
	173	#define __put_user_size(x, ptr, size, retval) \
	174	do { \
	175	retval = 0; \
	176	switch (size) { \
	177	case 1: __put_user_asm(x, ptr, retval, "stb"); break; \
	178	case 2: __put_user_asm(x, ptr, retval, "sth"); break; \
	179	case 4: __put_user_asm(x, ptr, retval, "stw"); break; \
	180	case 8: __put_user_asm2(x, ptr, retval); break; \
	181	default: __put_user_bad(); \
	182	} \
	183	} while (0)
	184
	185	#define __put_user_nocheck(x, ptr, size) \
	186	({ \
	187	long __pu_err; \
	188	might_sleep(); \
	189	__chk_user_ptr(ptr); \
	190	__put_user_size((x), (ptr), (size), __pu_err); \
	191	__pu_err; \
	192	})
	193
	194	#define __put_user_check(x, ptr, size) \
	195	({ \
	196	long __pu_err = -EFAULT; \
	197	__typeof__((ptr)) __user __pu_addr = (ptr); \
	198	might_sleep(); \
	199	if (access_ok(VERIFY_WRITE, __pu_addr, size)) \
	200	__put_user_size((x), __pu_addr, (size), __pu_err); \
	201	__pu_err; \
	202	})
	203
	204	extern long __get_user_bad(void);
	205
	206	#define __get_user_asm(x, addr, err, op) \
	207	__asm__ __volatile__( \
5015b494	208	"1: "op" %1,0(%2) # get_user\n" \
2df5e8bc SR	209	"2:\n" \
	210	".section .fixup,\"ax\"\n" \
	211	"3: li %0,%3\n" \
	212	" li %1,0\n" \
	213	" b 2b\n" \
	214	".previous\n" \
	215	".section __ex_table,\"a\"\n" \
	216	" .align "__EX_TABLE_ALIGN "\n" \
	217	" ." __EX_TABLE_TYPE " 1b,3b\n" \
	218	".previous" \
	219	: "=r" (err), "=r" (x) \
	220	: "b" (addr), "i" (-EFAULT), "0" (err))
	221
5015b494 SR	222	#ifdef __powerpc64__
	223	#define __get_user_asm2(x, addr, err) \
	224	__get_user_asm(x, addr, err, "ld")
	225	#else /* __powerpc64__ */
	226	#define __get_user_asm2(x, addr, err) \
2df5e8bc SR	227	__asm__ __volatile__( \
	228	"1: lwz %1,0(%2)\n" \
	229	"2: lwz %1+1,4(%2)\n" \
	230	"3:\n" \
	231	".section .fixup,\"ax\"\n" \
	232	"4: li %0,%3\n" \
	233	" li %1,0\n" \
	234	" li %1+1,0\n" \
	235	" b 3b\n" \
	236	".previous\n" \
	237	".section __ex_table,\"a\"\n" \
	238	" .align " __EX_TABLE_ALIGN "\n" \
	239	" ." __EX_TABLE_TYPE " 1b,4b\n" \
	240	" ." __EX_TABLE_TYPE " 2b,4b\n" \
	241	".previous" \
	242	: "=r" (err), "=&r" (x) \
	243	: "b" (addr), "i" (-EFAULT), "0" (err))
2df5e8bc SR	244	#endif /* __powerpc64__ */
	245
	246	#define __get_user_size(x, ptr, size, retval) \
	247	do { \
	248	retval = 0; \
	249	__chk_user_ptr(ptr); \
5015b494 SR	250	if (size > sizeof(x)) \
5015b494 SR	251	(x) = __get_user_bad(); \
2df5e8bc SR	252	switch (size) { \
	253	case 1: __get_user_asm(x, ptr, retval, "lbz"); break; \
	254	case 2: __get_user_asm(x, ptr, retval, "lhz"); break; \
	255	case 4: __get_user_asm(x, ptr, retval, "lwz"); break; \
	256	case 8: __get_user_asm2(x, ptr, retval); break; \
	257	default: (x) = __get_user_bad(); \
	258	} \
	259	} while (0)
	260
	261	#define __get_user_nocheck(x, ptr, size) \
	262	({ \
	263	long __gu_err; \
	264	unsigned long __gu_val; \
	265	__chk_user_ptr(ptr); \
	266	might_sleep(); \
	267	__get_user_size(__gu_val, (ptr), (size), __gu_err); \
	268	(x) = (__typeof__(*(ptr)))__gu_val; \
	269	__gu_err; \
	270	})
	271
	272	#ifndef __powerpc64__
	273	#define __get_user64_nocheck(x, ptr, size) \
	274	({ \
	275	long __gu_err; \
	276	long long __gu_val; \
	277	__chk_user_ptr(ptr); \
	278	might_sleep(); \
	279	__get_user_size(__gu_val, (ptr), (size), __gu_err); \
	280	(x) = (__typeof__(*(ptr)))__gu_val; \
	281	__gu_err; \
	282	})
	283	#endif /* __powerpc64__ */
	284
	285	#define __get_user_check(x, ptr, size) \
	286	({ \
	287	long __gu_err = -EFAULT; \
	288	unsigned long __gu_val = 0; \
	289	const __typeof__((ptr)) __user __gu_addr = (ptr); \
5015b494	290	might_sleep(); \
2df5e8bc SR	291	if (access_ok(VERIFY_READ, __gu_addr, (size))) \
	292	__get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
	293	(x) = (__typeof__(*(ptr)))__gu_val; \
	294	__gu_err; \
	295	})
	296
	297	/* more complex routines */
	298
	299	extern unsigned long __copy_tofrom_user(void __user *to,
	300	const void __user *from, unsigned long size);
	301
	302	#ifndef __powerpc64__
5015b494 SR	303
	304	extern inline unsigned long copy_from_user(void *to,
	305	const void __user *from, unsigned long n)
2df5e8bc SR	306	{
	307	unsigned long over;
	308
	309	if (access_ok(VERIFY_READ, from, n))
	310	return __copy_tofrom_user((__force void __user *)to, from, n);
	311	if ((unsigned long)from < TASK_SIZE) {
	312	over = (unsigned long)from + n - TASK_SIZE;
	313	return __copy_tofrom_user((__force void __user *)to, from,
	314	n - over) + over;
	315	}
	316	return n;
	317	}
	318
5015b494 SR	319	extern inline unsigned long copy_to_user(void __user *to,
5015b494 SR	320	const void *from, unsigned long n)
2df5e8bc SR	321	{
	322	unsigned long over;
	323
	324	if (access_ok(VERIFY_WRITE, to, n))
	325	return __copy_tofrom_user(to, (__force void __user *)from, n);
	326	if ((unsigned long)to < TASK_SIZE) {
	327	over = (unsigned long)to + n - TASK_SIZE;
	328	return __copy_tofrom_user(to, (__force void __user *)from,
	329	n - over) + over;
	330	}
	331	return n;
	332	}
	333
	334	#else /* __powerpc64__ */
	335
5015b494 SR	336	#define __copy_in_user(to, from, size) \
	337	__copy_tofrom_user((to), (from), (size))
	338
	339	extern unsigned long copy_from_user(void to, const void __user from,
	340	unsigned long n);
	341	extern unsigned long copy_to_user(void __user to, const void from,
	342	unsigned long n);
	343	extern unsigned long copy_in_user(void __user to, const void __user from,
	344	unsigned long n);
	345
48fe4871 SR	346	#endif /* __powerpc64__ */
48fe4871 SR	347
5015b494 SR	348	static inline unsigned long __copy_from_user_inatomic(void *to,
5015b494 SR	349	const void __user *from, unsigned long n)
2df5e8bc SR	350	{
	351	if (__builtin_constant_p(n) && (n <= 8)) {
	352	unsigned long ret;
	353
	354	switch (n) {
	355	case 1:
	356	__get_user_size((u8 )to, from, 1, ret);
	357	break;
	358	case 2:
	359	__get_user_size((u16 )to, from, 2, ret);
	360	break;
	361	case 4:
	362	__get_user_size((u32 )to, from, 4, ret);
	363	break;
	364	case 8:
	365	__get_user_size((u64 )to, from, 8, ret);
	366	break;
	367	}
48fe4871 SR	368	if (ret == 0)
48fe4871 SR	369	return 0;
2df5e8bc	370	}
48fe4871	371	return __copy_tofrom_user((__force void __user *)to, from, n);
2df5e8bc SR	372	}
2df5e8bc SR	373
5015b494 SR	374	static inline unsigned long __copy_to_user_inatomic(void __user *to,
5015b494 SR	375	const void *from, unsigned long n)
2df5e8bc SR	376	{
	377	if (__builtin_constant_p(n) && (n <= 8)) {
	378	unsigned long ret;
	379
	380	switch (n) {
	381	case 1:
	382	__put_user_size((u8 )from, (u8 __user *)to, 1, ret);
	383	break;
	384	case 2:
	385	__put_user_size((u16 )from, (u16 __user *)to, 2, ret);
	386	break;
	387	case 4:
	388	__put_user_size((u32 )from, (u32 __user *)to, 4, ret);
	389	break;
	390	case 8:
	391	__put_user_size((u64 )from, (u64 __user *)to, 8, ret);
	392	break;
	393	}
48fe4871 SR	394	if (ret == 0)
48fe4871 SR	395	return 0;
2df5e8bc	396	}
48fe4871	397	return __copy_tofrom_user(to, (__force const void __user *)from, n);
2df5e8bc SR	398	}
2df5e8bc SR	399
5015b494 SR	400	static inline unsigned long __copy_from_user(void *to,
5015b494 SR	401	const void __user *from, unsigned long size)
2df5e8bc SR	402	{
2df5e8bc SR	403	might_sleep();
2df5e8bc	404	return __copy_from_user_inatomic(to, from, size);
2df5e8bc SR	405	}
2df5e8bc SR	406
5015b494 SR	407	static inline unsigned long __copy_to_user(void __user *to,
5015b494 SR	408	const void *from, unsigned long size)
2df5e8bc SR	409	{
2df5e8bc SR	410	might_sleep();
2df5e8bc	411	return __copy_to_user_inatomic(to, from, size);
2df5e8bc SR	412	}
2df5e8bc SR	413
2df5e8bc SR	414	extern unsigned long __clear_user(void __user *addr, unsigned long size);
	415
	416	static inline unsigned long clear_user(void __user *addr, unsigned long size)
	417	{
	418	might_sleep();
	419	if (likely(access_ok(VERIFY_WRITE, addr, size)))
	420	return __clear_user(addr, size);
2df5e8bc SR	421	if ((unsigned long)addr < TASK_SIZE) {
	422	unsigned long over = (unsigned long)addr + size - TASK_SIZE;
	423	return __clear_user(addr, size - over) + over;
	424	}
2df5e8bc SR	425	return size;
	426	}
	427
	428	extern int __strncpy_from_user(char dst, const char __user src, long count);
	429
	430	static inline long strncpy_from_user(char dst, const char __user src,
	431	long count)
	432	{
	433	might_sleep();
	434	if (likely(access_ok(VERIFY_READ, src, 1)))
	435	return __strncpy_from_user(dst, src, count);
	436	return -EFAULT;
	437	}
	438
	439	/*
	440	* Return the size of a string (including the ending 0)
	441	*
	442	* Return 0 for error
	443	*/
2df5e8bc	444	extern int __strnlen_user(const char __user *str, long len, unsigned long top);
2df5e8bc SR	445
	446	/*
	447	* Returns the length of the string at str (including the null byte),
	448	* or 0 if we hit a page we can't access,
	449	* or something > len if we didn't find a null byte.
	450	*
	451	* The `top' parameter to __strnlen_user is to make sure that
	452	* we can never overflow from the user area into kernel space.
	453	*/
	454	static inline int strnlen_user(const char __user *str, long len)
	455	{
2df5e8bc SR	456	unsigned long top = current->thread.fs.seg;
	457
	458	if ((unsigned long)str > top)
	459	return 0;
	460	return __strnlen_user(str, len, top);
2df5e8bc SR	461	}
	462
	463	#define strlen_user(str) strnlen_user((str), 0x7ffffffe)
	464
	465	#endif /* __ASSEMBLY__ */
	466	#endif /* __KERNEL__ */
	467
	468	#endif /* _ARCH_POWERPC_UACCESS_H */