linux-kernel - [PATCH] Coccinelle: misc: Improve the script for more accurate results

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Date:   Thu, 13 Oct 2016 15:58:10 +0530
From:   Vaishali Thakkar <vaishali.thakkar@...cle.com>
To:     mmarek@...e.com
Cc:     Julia.Lawall@...6.fr, Gilles.Muller@...6.fr, nicolas.palix@...g.fr,
        cocci@...teme.lip6.fr, linux-kernel@...r.kernel.org,
        Vaishali Thakkar <vaishali.thakkar@...cle.com>
Subject: [PATCH] Coccinelle: misc: Improve the script for more accurate results

Currently because of the left associativity of the operators,
pattern IRQF_ONESHOT | flags does not match with the pattern
when we have more than one flag after the disjunction. This
eventually results in giving false positives by the script.
The patch eliminates these FPs by improving the rule.

Also, add a new rule to eliminate the false positives given by
the new line issue.

Misc:

1. Add support for the context, org and report mode in the case
   of devm_request_threaded_irq
2. To be consistent with other scripts, change the confidence
   level to 'Moderate'

Signed-off-by: Vaishali Thakkar <vaishali.thakkar@...cle.com>
---
 scripts/coccinelle/misc/irqf_oneshot.cocci | 41 +++++++++++++++++++++++++-----
 1 file changed, 34 insertions(+), 7 deletions(-)

diff --git a/scripts/coccinelle/misc/irqf_oneshot.cocci b/scripts/coccinelle/misc/irqf_oneshot.cocci
index b421150..76fd0a2 100644
--- a/scripts/coccinelle/misc/irqf_oneshot.cocci
+++ b/scripts/coccinelle/misc/irqf_oneshot.cocci
@@ -5,7 +5,7 @@
 /// So pass the IRQF_ONESHOT flag in this case.
 ///
 //
-// Confidence: Good
+// Confidence: Moderate
 // Comments:
 // Options: --no-includes
 
@@ -18,13 +18,12 @@ virtual report
 expression dev;
 expression irq;
 expression thread_fn;
-expression flags;
 position p;
 @@
 (
 request_threaded_irq@p(irq, NULL, thread_fn,
 (
-flags | IRQF_ONESHOT
+IRQF_ONESHOT | ...
 |
 IRQF_ONESHOT
 )
@@ -32,20 +31,40 @@ IRQF_ONESHOT
 |
 devm_request_threaded_irq@p(dev, irq, NULL, thread_fn,
 (
-flags | IRQF_ONESHOT
+IRQF_ONESHOT | ...
 |
 IRQF_ONESHOT
 )
 , ...)
 )
 
-@...ends on patch@
+@r2@
 expression dev;
 expression irq;
 expression thread_fn;
 expression flags;
+expression ret;
 position p != r1.p;
 @@
+flags = IRQF_ONESHOT | ...;
+(
+ret = request_threaded_irq@p(irq, NULL, thread_fn, flags, ...);
+|
+ret = devm_request_threaded_irq@p(dev, irq, NULL, thread_fn, flags, ...);
+|
+return request_threaded_irq@p(irq, NULL, thread_fn, flags, ...);
+|
+return devm_request_threaded_irq@p(dev, irq, NULL, thread_fn, flags, ...);
+)
+
+@...ends on patch@
+expression dev;
+expression irq;
+expression thread_fn;
+expression flags;
+position p != {r1.p,r2.p};
+@@
+
 (
 request_threaded_irq@p(irq, NULL, thread_fn,
 (
@@ -69,15 +88,23 @@ devm_request_threaded_irq@p(dev, irq, NULL, thread_fn,
 )
 
 @depends on context@
-position p != r1.p;
+position p != {r1.p,r2.p};
 @@
+(
 *request_threaded_irq@p(...)
+|
+*devm_request_threaded_irq@p(...)
+)
 
 @match depends on report || org@
 expression irq;
-position p != r1.p;
+position p != {r1.p,r2.p};
 @@
+(
 request_threaded_irq@p(irq, NULL, ...)
+|
+devm_request_threaded_irq@p(dev, irq, NULL, ...)
+)
 
 @script:python depends on org@
 p << match.p;
-- 
2.1.4