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							- /*
 
-  * This file is subject to the terms and conditions of the GNU General Public
 
-  * License.  See the file "COPYING" in the main directory of this archive
 
-  * for more details.
 
-  *
 
-  * Copyright (C) 1996, 1997, 1998, 1999, 2000, 03, 04 by Ralf Baechle
 
-  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 
-  * Copyright (C) 2007  Maciej W. Rozycki
 
-  */
 
- #ifndef _ASM_UACCESS_H
 
- #define _ASM_UACCESS_H
 
- #include <linux/kernel.h>
 
- #include <linux/errno.h>
 
- #include <linux/thread_info.h>
 
- /*
 
-  * 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.
 
-  */
 
- #ifdef CONFIG_32BIT
 
- #define __UA_LIMIT	0x80000000UL
 
- #define __UA_ADDR	".word"
 
- #define __UA_LA		"la"
 
- #define __UA_ADDU	"addu"
 
- #define __UA_t0		"$8"
 
- #define __UA_t1		"$9"
 
- #endif /* CONFIG_32BIT */
 
- #ifdef CONFIG_64BIT
 
- extern u64 __ua_limit;
 
- #define __UA_LIMIT	__ua_limit
 
- #define __UA_ADDR	".dword"
 
- #define __UA_LA		"dla"
 
- #define __UA_ADDU	"daddu"
 
- #define __UA_t0		"$12"
 
- #define __UA_t1		"$13"
 
- #endif /* CONFIG_64BIT */
 
- /*
 
-  * USER_DS is a bitmask that has the bits set that may not be set in a valid
 
-  * userspace address.  Note that we limit 32-bit userspace to 0x7fff8000 but
 
-  * the arithmetic we're doing only works if the limit is a power of two, so
 
-  * we use 0x80000000 here on 32-bit kernels.  If a process passes an invalid
 
-  * address in this range it's the process's problem, not ours :-)
 
-  */
 
- #define KERNEL_DS	((mm_segment_t) { 0UL })
 
- #define USER_DS		((mm_segment_t) { __UA_LIMIT })
 
- #define VERIFY_READ    0
 
- #define VERIFY_WRITE   1
 
- #define get_ds()	(KERNEL_DS)
 
- #define get_fs()	(current_thread_info()->addr_limit)
 
- #define set_fs(x)	(current_thread_info()->addr_limit = (x))
 
- #define segment_eq(a, b)	((a).seg == (b).seg)
 
- /*
 
-  * Is a address valid? This does a straighforward calculation rather
 
-  * than tests.
 
-  *
 
-  * Address valid if:
 
-  *  - "addr" doesn't have any high-bits set
 
-  *  - AND "size" doesn't have any high-bits set
 
-  *  - AND "addr+size" doesn't have any high-bits set
 
-  *  - OR we are in kernel mode.
 
-  *
 
-  * __ua_size() is a trick to avoid runtime checking of positive constant
 
-  * sizes; for those we already know at compile time that the size is ok.
 
-  */
 
- #define __ua_size(size)							\
 
- 	((__builtin_constant_p(size) && (signed long) (size) > 0) ? 0 : (size))
 
- /*
 
-  * access_ok: - Checks if a user space pointer is valid
 
-  * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE.  Note that
 
-  *        %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
 
-  *        to write to a block, it is always safe to read from it.
 
-  * @addr: User space pointer to start of block to check
 
-  * @size: Size of block to check
 
-  *
 
-  * Context: User context only.  This function may sleep.
 
-  *
 
-  * Checks if a pointer to a block of memory in user space is valid.
 
-  *
 
-  * Returns true (nonzero) if the memory block may be valid, false (zero)
 
-  * if it is definitely invalid.
 
-  *
 
-  * Note that, depending on architecture, this function probably just
 
-  * checks that the pointer is in the user space range - after calling
 
-  * this function, memory access functions may still return -EFAULT.
 
-  */
 
- #define __access_mask get_fs().seg
 
- #define __access_ok(addr, size, mask)					\
 
- ({									\
 
- 	unsigned long __addr = (unsigned long) (addr);			\
 
- 	unsigned long __size = size;					\
 
- 	unsigned long __mask = mask;					\
 
- 	unsigned long __ok;						\
 
- 									\
 
- 	__chk_user_ptr(addr);						\
 
- 	__ok = (signed long)(__mask & (__addr | (__addr + __size) |	\
 
- 		__ua_size(__size)));					\
 
- 	__ok == 0;							\
 
- })
 
- #define access_ok(type, addr, size)					\
 
- 	likely(__access_ok((addr), (size), __access_mask))
 
- /*
 
-  * put_user: - Write a simple value into user space.
 
-  * @x:   Value to copy to user space.
 
-  * @ptr: Destination address, in user space.
 
-  *
 
-  * Context: User context only.  This function may sleep.
 
-  *
 
-  * This macro copies a single simple value from kernel space to user
 
-  * space.  It supports simple types like char and int, but not larger
 
-  * data types like structures or arrays.
 
-  *
 
-  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 
-  * to the result of dereferencing @ptr.
 
-  *
 
-  * Returns zero on success, or -EFAULT on error.
 
-  */
 
- #define put_user(x,ptr)	\
 
- 	__put_user_check((x), (ptr), sizeof(*(ptr)))
 
- /*
 
-  * get_user: - Get a simple variable from user space.
 
-  * @x:   Variable to store result.
 
-  * @ptr: Source address, in user space.
 
-  *
 
-  * Context: User context only.  This function may sleep.
 
-  *
 
-  * This macro copies a single simple variable from user space to kernel
 
-  * space.  It supports simple types like char and int, but not larger
 
-  * data types like structures or arrays.
 
-  *
 
-  * @ptr must have pointer-to-simple-variable type, and the result of
 
-  * dereferencing @ptr must be assignable to @x without a cast.
 
-  *
 
-  * Returns zero on success, or -EFAULT on error.
 
-  * On error, the variable @x is set to zero.
 
-  */
 
- #define get_user(x,ptr) \
 
- 	__get_user_check((x), (ptr), sizeof(*(ptr)))
 
- /*
 
-  * __put_user: - Write a simple value into user space, with less checking.
 
-  * @x:   Value to copy to user space.
 
-  * @ptr: Destination address, in user space.
 
-  *
 
-  * Context: User context only.  This function may sleep.
 
-  *
 
-  * This macro copies a single simple value from kernel space to user
 
-  * space.  It supports simple types like char and int, but not larger
 
-  * data types like structures or arrays.
 
-  *
 
-  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 
-  * to the result of dereferencing @ptr.
 
-  *
 
-  * Caller must check the pointer with access_ok() before calling this
 
-  * function.
 
-  *
 
-  * Returns zero on success, or -EFAULT on error.
 
-  */
 
- #define __put_user(x,ptr) \
 
- 	__put_user_nocheck((x), (ptr), sizeof(*(ptr)))
 
- /*
 
-  * __get_user: - Get a simple variable from user space, with less checking.
 
-  * @x:   Variable to store result.
 
-  * @ptr: Source address, in user space.
 
-  *
 
-  * Context: User context only.  This function may sleep.
 
-  *
 
-  * This macro copies a single simple variable from user space to kernel
 
-  * space.  It supports simple types like char and int, but not larger
 
-  * data types like structures or arrays.
 
-  *
 
-  * @ptr must have pointer-to-simple-variable type, and the result of
 
 
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