From: Andrzej Hajda <a.hajda@samsung.com>
To: Julia.Lawall@lip6.fr
Cc: Andrzej Hajda <a.hajda@samsung.com>,
Gilles.Muller@lip6.fr, nicolas.palix@imag.fr, mmarek@suse.com,
cocci@systeme.lip6.fr, joe@perches.com,
linux-kernel@vger.kernel.org, b.zolnierkie@samsung.com
Subject: [PATCH] coccinelle: tests: unsigned value cannot be lesser than zero
Date: Tue, 15 Sep 2015 11:27:12 +0200 [thread overview]
Message-ID: <1442309232-5902-1-git-send-email-a.hajda@samsung.com> (raw)
Code comparing unsigned variables with zero using operators < or >= does not
make sense. It is always false or true, respectively. However, its presence
often indicates bugs in the code.
gcc can detect it also using -Wtype-limits switch, but it warns also in correct
cases, making too much noise.
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
---
Hi Julia,
This test finds 93 issues in kernel code (with --all-includes) which could
be corrected. Some of them are harmless, just unnecessary code, but there
are also serious bugs, like:
u32 irq = platform_get_irq(...)
if (irq < 0)
...
unsigned int target = cpumask_any_but(cpu_online_mask, cpu);
if (target < 0)
...
Regards
Andrzej
---
.../tests/unsigned_lesser_than_zero.cocci | 37 ++++++++++++++++++++++
1 file changed, 37 insertions(+)
create mode 100644 scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci
diff --git a/scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci b/scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci
new file mode 100644
index 0000000..6a90510
--- /dev/null
+++ b/scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci
@@ -0,0 +1,37 @@
+/// Unsigned variables cannot be lesser than zero. Presence of such checks
+/// can indicate incorrect variable type or just unnecessary code.
+///
+// Confidence: High
+// Copyright: (C) 2015 Andrzej Hajda, Samsung Electronics Co., Ltd. GPLv2.
+// URL: http://coccinelle.lip6.fr/
+// Options: --include-headers
+
+virtual context
+virtual org
+virtual report
+
+@r depends on context || org || report@
+position p;
+typedef u8, u16, u32, u64;
+{unsigned char, unsigned short int, unsigned int, unsigned long, unsigned long long, size_t, u8, u16, u32, u64} v;
+@@
+
+(
+*v@p < 0
+|
+*v@p >= 0
+)
+
+@script:python depends on org@
+p << r.p;
+@@
+
+msg = "WARNING: Unsigned value cannot be lesser than zero"
+coccilib.org.print_todo(p[0], msg)
+
+@script:python depends on report@
+p << r.p;
+@@
+
+msg = "WARNING: Unsigned value cannot be lesser than zero"
+coccilib.report.print_report(p[0], msg)
--
1.9.1
next reply other threads:[~2015-09-15 9:27 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-15 9:27 Andrzej Hajda [this message]
2015-09-15 13:01 ` [PATCH] coccinelle: tests: unsigned value cannot be lesser than zero SF Markus Elfring
2015-09-15 13:07 ` Julia Lawall
2015-09-15 13:16 ` SF Markus Elfring
2015-09-15 13:31 ` Julia Lawall
2015-09-15 13:51 ` Andrzej Hajda
2015-09-15 13:57 ` Julia Lawall
2015-09-16 9:11 ` Andrzej Hajda
2015-09-16 9:25 ` Julia Lawall
2015-09-16 13:22 ` [PATCH v2] " Andrzej Hajda
2015-09-16 13:33 ` Julia Lawall
2015-09-16 18:56 ` SF Markus Elfring
2015-09-15 13:42 ` [PATCH] " Andrzej Hajda
2015-09-15 14:36 ` SF Markus Elfring
2015-09-15 14:43 ` [Cocci] " Julia Lawall
2015-09-15 14:53 ` SF Markus Elfring
2015-09-18 5:35 ` Julia Lawall
2015-09-21 10:37 ` [PATCH v3] " Andrzej Hajda
2015-09-21 13:02 ` SF Markus Elfring
2015-09-21 13:34 ` Andrzej Hajda
2015-09-21 14:06 ` SF Markus Elfring
2015-09-22 15:27 ` SF Markus Elfring
2015-09-23 7:34 ` Andrzej Hajda
2015-09-23 15:17 ` SF Markus Elfring
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