1 /* $NetBSD: db_syncobj.c,v 1.3 2023/10/15 10:27:25 riastradh Exp $ */
2
3 /*-
4 * Copyright (c) 2023 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE 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 #define __MUTEX_PRIVATE
30 #define __RWLOCK_PRIVATE
31
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: db_syncobj.c,v 1.3 2023/10/15 10:27:25 riastradh Exp $");
34
35 #include <sys/types.h>
36
37 #include <sys/mutex.h>
38 #include <sys/null.h>
39 #include <sys/rwlock.h>
40 #include <sys/syncobj.h>
41
42 #include <ddb/ddb.h>
43
44 struct lwp *
db_syncobj_owner(const struct syncobj * sobj,wchan_t wchan)45 db_syncobj_owner(const struct syncobj *sobj, wchan_t wchan)
46 {
47 db_expr_t mutex_syncobj_;
48 db_expr_t rw_syncobj_;
49
50 if (db_value_of_name("mutex_syncobj", &mutex_syncobj_) &&
51 (db_expr_t)(uintptr_t)sobj == mutex_syncobj_) {
52 volatile const struct kmutex *mtx = wchan;
53 uintptr_t owner;
54
55 db_read_bytes((db_addr_t)&mtx->mtx_owner, sizeof(owner),
56 (char *)&owner);
57 return (struct lwp *)(owner & MUTEX_THREAD);
58
59 } else if (db_value_of_name("rw_syncobj", &rw_syncobj_) &&
60 (db_expr_t)(uintptr_t)sobj == rw_syncobj_) {
61 volatile const struct krwlock *rw = wchan;
62 uintptr_t owner;
63
64 db_read_bytes((db_addr_t)&rw->rw_owner, sizeof(owner),
65 (char *)&owner);
66 if (owner & RW_WRITE_LOCKED)
67 return (struct lwp *)(owner & RW_THREAD);
68 return NULL;
69
70 } else {
71 return NULL;
72 }
73 }
74