1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
|
#!/usr/sbin/dtrace -qs
/*-
* Copyright (c) 2008-2012 Alexander Leidinger <netchild@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer
* in this position and unchanged.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
/**
* Check if the internal locks are correctly acquired/released:
* - no recursive locking (mtx locks, write locks)
* - no unlocking of already unlocked one
*
* Print stacktrace if a lock is longer locked than about 10sec or more.
*/
#pragma D option dynvarsize=32m
#pragma D option specsize=32m
BEGIN
{
check["futex_mtx"] = 0;
}
linuxulator*:locks:futex_mtx:locked
/check[probefunc] > 0/
{
printf("ERROR: recursive lock of %s (%p),", probefunc, arg0);
printf(" or missing SDT probe in kernel. Stack trace follows:");
stack();
}
linuxulator*:locks:futex_mtx:locked
{
++check[probefunc];
@stats[probefunc] = count();
ts[probefunc] = timestamp;
spec[probefunc] = speculation();
}
linuxulator*:locks:futex_mtx:unlock
/check[probefunc] == 0/
{
printf("ERROR: unlock attempt of unlocked %s (%p),", probefunc, arg0);
printf(" missing SDT probe in kernel, or dtrace program started");
printf(" while the %s was already held (race condition).", probefunc);
printf(" Stack trace follows:");
stack();
}
linuxulator*:locks:futex_mtx:unlock
{
discard(spec[probefunc]);
spec[probefunc] = 0;
--check[probefunc];
}
/* Timeout handling */
tick-10s
/spec["futex_mtx"] != 0 && timestamp - ts["futex_mtx"] >= 9999999000/
{
commit(spec["futex_mtx"]);
spec["futex_mtx"] = 0;
}
/* Statistics */
END
{
printf("Number of locks per type:");
printa(@stats);
}
|
