xref: /freebsd/sys/compat/linuxkpi/common/include/linux/uaccess.h (revision c66ec88fed842fbaad62c30d510644ceb7bd2d71)
1 /*-
2  * Copyright (c) 2010 Isilon Systems, Inc.
3  * Copyright (c) 2010 iX Systems, Inc.
4  * Copyright (c) 2010 Panasas, Inc.
5  * Copyright (c) 2013-2016 Mellanox Technologies, Ltd.
6  * Copyright (c) 2015 François Tigeot
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice unmodified, this list of conditions, and the following
14  *    disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  *
30  * $FreeBSD$
31  */
32 
33 #ifndef	_LINUX_UACCESS_H_
34 #define	_LINUX_UACCESS_H_
35 
36 #include <sys/param.h>
37 #include <sys/lock.h>
38 #include <sys/proc.h>
39 
40 #include <vm/vm.h>
41 #include <vm/vm_extern.h>
42 
43 #include <linux/compiler.h>
44 
45 #define	VERIFY_READ	VM_PROT_READ
46 #define	VERIFY_WRITE	VM_PROT_WRITE
47 
48 #define	__get_user(_x, _p) ({					\
49 	int __err;						\
50 	__typeof(*(_p)) __x;					\
51 	__err = linux_copyin((_p), &(__x), sizeof(*(_p)));	\
52 	(_x) = __x;						\
53 	__err;							\
54 })
55 
56 #define	__put_user(_x, _p) ({				\
57 	__typeof(*(_p)) __x = (_x);			\
58 	linux_copyout(&(__x), (_p), sizeof(*(_p)));	\
59 })
60 #define	get_user(_x, _p)	linux_copyin((_p), &(_x), sizeof(*(_p)))
61 #define	put_user(_x, _p)	__put_user(_x, _p)
62 #define	clear_user(...)		linux_clear_user(__VA_ARGS__)
63 
64 #if defined(LINUXKPI_VERSION) && LINUXKPI_VERSION >= 50000
65 #define	access_ok(a,b)		linux_access_ok(a,b)
66 #else
67 #define	access_ok(a,b,c)	linux_access_ok(b,c)
68 #endif
69 
70 extern int linux_copyin(const void *uaddr, void *kaddr, size_t len);
71 extern int linux_copyout(const void *kaddr, void *uaddr, size_t len);
72 extern size_t linux_clear_user(void *uaddr, size_t len);
73 extern int linux_access_ok(const void *uaddr, size_t len);
74 
75 /*
76  * NOTE: Each pagefault_disable() call must have a corresponding
77  * pagefault_enable() call in the same scope. The former creates a new
78  * block and defines a temporary variable, and the latter uses the
79  * temporary variable and closes the block. Failure to balance the
80  * calls will result in a compile-time error.
81  */
82 #define	pagefault_disable(void) do {		\
83 	int __saved_pflags =			\
84 	    vm_fault_disable_pagefaults()
85 
86 #define	pagefault_enable(void)				\
87 	vm_fault_enable_pagefaults(__saved_pflags);	\
88 } while (0)
89 
90 static inline bool
91 pagefault_disabled(void)
92 {
93 	return ((curthread->td_pflags & TDP_NOFAULTING) != 0);
94 }
95 
96 #endif					/* _LINUX_UACCESS_H_ */
97