check_internal_locks.d revision 293493 
1#!/usr/sbin/dtrace -qs
2
3/*-
4 * Copyright (c) 2008-2012 Alexander Leidinger <netchild@FreeBSD.org>
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 *    in this position and unchanged.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * $FreeBSD: stable/10/sys/compat/linux/check_internal_locks.d 293493 2016-01-09 15:16:13Z dchagin $
29 */
30
31/**
32 * Check if the internal locks are correctly acquired/released:
33 *  - no recursive locking (mtx locks, write locks)
34 *  - no unlocking of already unlocked one
35 *
36 * Print stacktrace if a lock is longer locked than about 10sec or more.
37 */
38
39#pragma D option dynvarsize=32m
40#pragma D option specsize=32m
41
42BEGIN
43{
44	check["futex_mtx"] = 0;
45}
46
47linuxulator*:locks:futex_mtx:locked
48/check[probefunc] > 0/
49{
50	printf("ERROR: recursive lock of %s (%p),", probefunc, arg0);
51	printf("       or missing SDT probe in kernel. Stack trace follows:");
52	stack();
53}
54
55linuxulator*:locks:futex_mtx:locked
56{
57	++check[probefunc];
58	@stats[probefunc] = count();
59
60	ts[probefunc] = timestamp;
61	spec[probefunc] = speculation();
62}
63
64linuxulator*:locks:futex_mtx:unlock
65/check[probefunc] == 0/
66{
67	printf("ERROR: unlock attemt of unlocked %s (%p),", probefunc, arg0);
68	printf("       missing SDT probe in kernel, or dtrace program started");
69	printf("       while the %s was already held (race condition).", probefunc);
70	printf("       Stack trace follows:");
71	stack();
72}
73
74linuxulator*:locks:futex_mtx:unlock
75{
76	discard(spec[probefunc]);
77	spec[probefunc] = 0;
78	--check[probefunc];
79}
80
81/* Timeout handling */
82
83tick-10s
84/spec["futex_mtx"] != 0 && timestamp - ts["futex_mtx"] >= 9999999000/
85{
86	commit(spec["futex_mtx"]);
87	spec["futex_mtx"] = 0;
88}
89
90
91/* Statistics */
92
93END
94{
95        printf("Number of locks per type:");
96	printa(@stats);
97}
98