1// SPDX-License-Identifier: GPL-2.0-only
2/// Find missing unlocks.  This semantic match considers the specific case
3/// where the unlock is missing from an if branch, and there is a lock
4/// before the if and an unlock after the if.  False positives are due to
5/// cases where the if branch represents a case where the function is
6/// supposed to exit with the lock held, or where there is some preceding
7/// function call that releases the lock.
8///
9// Confidence: Moderate
10// Copyright: (C) 2010-2012 Nicolas Palix.
11// Copyright: (C) 2010-2012 Julia Lawall, INRIA/LIP6.
12// Copyright: (C) 2010-2012 Gilles Muller, INRIA/LiP6.
13// URL: https://coccinelle.gitlabpages.inria.fr/website
14// Comments:
15// Options: --no-includes --include-headers
16
17virtual context
18virtual org
19virtual report
20
21@prelocked@
22position p1,p;
23expression E1;
24@@
25
26(
27mutex_lock@p1
28|
29mutex_trylock@p1
30|
31spin_lock@p1
32|
33spin_trylock@p1
34|
35read_lock@p1
36|
37read_trylock@p1
38|
39write_lock@p1
40|
41write_trylock@p1
42|
43read_lock_irq@p1
44|
45write_lock_irq@p1
46|
47read_lock_irqsave@p1
48|
49write_lock_irqsave@p1
50|
51spin_lock_irq@p1
52|
53spin_lock_irqsave@p1
54) (E1@p,...);
55
56@looped@
57position r;
58@@
59
60for(...;...;...) { <+... return@r ...; ...+> }
61
62@err exists@
63expression E1;
64position prelocked.p;
65position up != prelocked.p1;
66position r!=looped.r;
67identifier lock,unlock;
68@@
69
70*lock(E1@p,...);
71... when != E1
72    when any
73if (...) {
74  ... when != E1
75*  return@r ...;
76}
77... when != E1
78    when any
79*unlock@up(E1,...);
80
81@script:python depends on org@
82p << prelocked.p1;
83lock << err.lock;
84unlock << err.unlock;
85p2 << err.r;
86@@
87
88cocci.print_main(lock,p)
89cocci.print_secs(unlock,p2)
90
91@script:python depends on report@
92p << prelocked.p1;
93lock << err.lock;
94unlock << err.unlock;
95p2 << err.r;
96@@
97
98msg = "preceding lock on line %s" % (p[0].line)
99coccilib.report.print_report(p2[0],msg)
100