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/refcount.h>
37 #include <sys/rwlock.h>
38 #include <sys/hwt.h>
39
40 #include <dev/hwt/hwt_hook.h>
41 #include <dev/hwt/hwt_context.h>
42 #include <dev/hwt/hwt_contexthash.h>
43 #include <dev/hwt/hwt_config.h>
44 #include <dev/hwt/hwt_cpu.h>
45 #include <dev/hwt/hwt_thread.h>
46 #include <dev/hwt/hwt_owner.h>
47 #include <dev/hwt/hwt_ownerhash.h>
48 #include <dev/hwt/hwt_backend.h>
49 #include <dev/hwt/hwt_vm.h>
50 #include <dev/hwt/hwt_record.h>
51
52 #define HWT_DEBUG
53 #undef HWT_DEBUG
54
55 #ifdef HWT_DEBUG
56 #define dprintf(fmt, ...) printf(fmt, ##__VA_ARGS__)
57 #else
58 #define dprintf(fmt, ...)
59 #endif
60
61 static MALLOC_DEFINE(M_HWT_OWNER, "hwt_owner", "Hardware Trace");
62
63 struct hwt_context *
hwt_owner_lookup_ctx(struct hwt_owner * ho,pid_t pid)64 hwt_owner_lookup_ctx(struct hwt_owner *ho, pid_t pid)
65 {
66 struct hwt_context *ctx;
67
68 mtx_lock(&ho->mtx);
69 LIST_FOREACH(ctx, &ho->hwts, next_hwts) {
70 if (ctx->pid == pid) {
71 mtx_unlock(&ho->mtx);
72 return (ctx);
73 }
74 }
75 mtx_unlock(&ho->mtx);
76
77 return (NULL);
78 }
79
80 #if 0
81 struct hwt_context *
82 hwt_owner_lookup_ctx_by_cpu(struct hwt_owner *ho, int cpu)
83 {
84 struct hwt_context *ctx;
85
86 mtx_lock(&ho->mtx);
87 LIST_FOREACH(ctx, &ho->hwts, next_hwts) {
88 if (ctx->cpu == cpu) {
89 mtx_unlock(&ho->mtx);
90 return (ctx);
91 }
92 }
93 mtx_unlock(&ho->mtx);
94
95 return (NULL);
96 }
97 #endif
98
99 struct hwt_owner *
hwt_owner_alloc(struct proc * p)100 hwt_owner_alloc(struct proc *p)
101 {
102 struct hwt_owner *ho;
103
104 ho = malloc(sizeof(struct hwt_owner), M_HWT_OWNER,
105 M_WAITOK | M_ZERO);
106 ho->p = p;
107
108 LIST_INIT(&ho->hwts);
109 mtx_init(&ho->mtx, "hwts", NULL, MTX_DEF);
110
111 return (ho);
112 }
113
114 void
hwt_owner_shutdown(struct hwt_owner * ho)115 hwt_owner_shutdown(struct hwt_owner *ho)
116 {
117 struct hwt_context *ctx;
118
119 dprintf("%s: stopping hwt owner\n", __func__);
120
121 while (1) {
122 mtx_lock(&ho->mtx);
123 ctx = LIST_FIRST(&ho->hwts);
124 if (ctx)
125 LIST_REMOVE(ctx, next_hwts);
126 mtx_unlock(&ho->mtx);
127
128 if (ctx == NULL)
129 break;
130
131 if (ctx->mode == HWT_MODE_THREAD)
132 hwt_contexthash_remove(ctx);
133
134 /*
135 * A hook could be still dealing with this ctx right here.
136 */
137
138 HWT_CTX_LOCK(ctx);
139 ctx->state = 0;
140 HWT_CTX_UNLOCK(ctx);
141
142 /* Ensure hooks invocation is now completed. */
143 while (refcount_load(&ctx->refcnt) > 0)
144 continue;
145
146 /*
147 * Note that a thread could be still sleeping on msleep(9).
148 */
149
150 hwt_backend_deinit(ctx);
151 hwt_record_free_all(ctx);
152 hwt_ctx_free(ctx);
153 }
154
155 hwt_ownerhash_remove(ho);
156 free(ho, M_HWT_OWNER);
157 }
158