1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2023-2025 Ruslan Bukin <br@bsdpad.com>
5 *
6 * This work was supported by Innovate UK project 105694, "Digital Security
7 * by Design (DSbD) Technology Platform Prototype".
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, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 #include <sys/param.h>
32 #include <sys/kernel.h>
33 #include <sys/malloc.h>
34 #include <sys/mman.h>
35 #include <sys/mutex.h>
36 #include <sys/rwlock.h>
37 #include <sys/hwt.h>
38
39 #include <dev/hwt/hwt_owner.h>
40 #include <dev/hwt/hwt_ownerhash.h>
41
42 #define HWT_DEBUG
43 #undef HWT_DEBUG
44
45 #ifdef HWT_DEBUG
46 #define dprintf(fmt, ...) printf(fmt, ##__VA_ARGS__)
47 #else
48 #define dprintf(fmt, ...)
49 #endif
50
51 #define HWT_OWNERHASH_SIZE 1024
52
53 static MALLOC_DEFINE(M_HWT_OWNERHASH, "hwt_ohash", "Hardware Trace");
54
55 /*
56 * Hash function. Discard the lower 2 bits of the pointer since
57 * these are always zero for our uses. The hash multiplier is
58 * round((2^LONG_BIT) * ((sqrt(5)-1)/2)).
59 */
60
61 #define _HWT_HM 11400714819323198486u /* hash multiplier */
62 #define HWT_HASH_PTR(P, M) ((((unsigned long) (P) >> 2) * _HWT_HM) & (M))
63
64 static struct mtx hwt_ownerhash_mtx;
65 static u_long hwt_ownerhashmask;
LIST_HEAD(hwt_ownerhash,hwt_owner)66 static LIST_HEAD(hwt_ownerhash, hwt_owner) *hwt_ownerhash;
67
68 struct hwt_owner *
69 hwt_ownerhash_lookup(struct proc *p)
70 {
71 struct hwt_ownerhash *hoh;
72 struct hwt_owner *ho;
73 int hindex;
74
75 hindex = HWT_HASH_PTR(p, hwt_ownerhashmask);
76 hoh = &hwt_ownerhash[hindex];
77
78 HWT_OWNERHASH_LOCK();
79 LIST_FOREACH(ho, hoh, next) {
80 if (ho->p == p) {
81 HWT_OWNERHASH_UNLOCK();
82 return (ho);
83 }
84 }
85 HWT_OWNERHASH_UNLOCK();
86
87 return (NULL);
88 }
89
90 void
hwt_ownerhash_insert(struct hwt_owner * ho)91 hwt_ownerhash_insert(struct hwt_owner *ho)
92 {
93 struct hwt_ownerhash *hoh;
94 int hindex;
95
96 hindex = HWT_HASH_PTR(ho->p, hwt_ownerhashmask);
97 hoh = &hwt_ownerhash[hindex];
98
99 HWT_OWNERHASH_LOCK();
100 LIST_INSERT_HEAD(hoh, ho, next);
101 HWT_OWNERHASH_UNLOCK();
102 }
103
104 void
hwt_ownerhash_remove(struct hwt_owner * ho)105 hwt_ownerhash_remove(struct hwt_owner *ho)
106 {
107
108 /* Destroy hwt owner. */
109 HWT_OWNERHASH_LOCK();
110 LIST_REMOVE(ho, next);
111 HWT_OWNERHASH_UNLOCK();
112 }
113
114 void
hwt_ownerhash_load(void)115 hwt_ownerhash_load(void)
116 {
117
118 hwt_ownerhash = hashinit(HWT_OWNERHASH_SIZE, M_HWT_OWNERHASH,
119 &hwt_ownerhashmask);
120 mtx_init(&hwt_ownerhash_mtx, "hwt-owner-hash", "hwt-owner", MTX_DEF);
121 }
122
123 void
hwt_ownerhash_unload(void)124 hwt_ownerhash_unload(void)
125 {
126 struct hwt_ownerhash *hoh;
127 struct hwt_owner *ho, *tmp;
128
129 HWT_OWNERHASH_LOCK();
130 for (hoh = hwt_ownerhash;
131 hoh <= &hwt_ownerhash[hwt_ownerhashmask];
132 hoh++) {
133 LIST_FOREACH_SAFE(ho, hoh, next, tmp) {
134 /* TODO: module is in use ? */
135 }
136 }
137 HWT_OWNERHASH_UNLOCK();
138
139 mtx_destroy(&hwt_ownerhash_mtx);
140 hashdestroy(hwt_ownerhash, M_HWT_OWNERHASH, hwt_ownerhashmask);
141 }
142