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