1 /*
2  * Copyright (c) 2014-2019, Intel Corporation
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions are met:
6  *
7  *  * Redistributions of source code must retain the above copyright notice,
8  *    this list of conditions and the following disclaimer.
9  *  * Redistributions in binary form must reproduce the above copyright notice,
10  *    this list of conditions and the following disclaimer in the documentation
11  *    and/or other materials provided with the distribution.
12  *  * Neither the name of Intel Corporation nor the names of its contributors
13  *    may be used to endorse or promote products derived from this software
14  *    without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
20  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include "pt_asid.h"
30 
31 #include "intel-pt.h"
32 
33 #include <string.h>
34 
35 
36 int pt_asid_from_user(struct pt_asid *asid, const struct pt_asid *user)
37 {
38 	if (!asid)
39 		return -pte_internal;
40 
41 	pt_asid_init(asid);
42 
43 	if (user) {
44 		size_t size;
45 
46 		size = user->size;
47 
48 		/* Ignore fields in the user's asid we don't know. */
49 		if (sizeof(*asid) < size)
50 			size = sizeof(*asid);
51 
52 		/* Copy (portions of) the user's asid. */
53 		memcpy(asid, user, size);
54 
55 		/* We copied user's size - fix it. */
56 		asid->size = sizeof(*asid);
57 	}
58 
59 	return 0;
60 }
61 
62 int pt_asid_to_user(struct pt_asid *user, const struct pt_asid *asid,
63 		    size_t size)
64 {
65 	if (!user || !asid)
66 		return -pte_internal;
67 
68 	/* We need at least space for the size field. */
69 	if (size < sizeof(asid->size))
70 		return -pte_invalid;
71 
72 	/* Only provide the fields we actually have. */
73 	if (sizeof(*asid) < size)
74 		size = sizeof(*asid);
75 
76 	/* Copy (portions of) our asid to the user's. */
77 	memcpy(user, asid, size);
78 
79 	/* We copied our size - fix it. */
80 	user->size = size;
81 
82 	return 0;
83 }
84 
85 int pt_asid_match(const struct pt_asid *lhs, const struct pt_asid *rhs)
86 {
87 	uint64_t lcr3, rcr3, lvmcs, rvmcs;
88 
89 	if (!lhs || !rhs)
90 		return -pte_internal;
91 
92 	lcr3 = lhs->cr3;
93 	rcr3 = rhs->cr3;
94 
95 	if (lcr3 != rcr3 && lcr3 != pt_asid_no_cr3 && rcr3 != pt_asid_no_cr3)
96 		return 0;
97 
98 	lvmcs = lhs->vmcs;
99 	rvmcs = rhs->vmcs;
100 
101 	if (lvmcs != rvmcs && lvmcs != pt_asid_no_vmcs &&
102 	    rvmcs != pt_asid_no_vmcs)
103 		return 0;
104 
105 	return 1;
106 }
107