From: Joe Perches <joe@perches.com>
Date: Wed, 20 Mar 2013 04:07:45 +0000 (+1100)
Subject: checkpatch: add check for reuse of krealloc arg
X-Git-Tag: next-20130320~2^2~277
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=8aa4e94a607468e60b6b3fb91a4754b83ea6c796;p=karo-tx-linux.git

checkpatch: add check for reuse of krealloc arg

On Thu, 2013-03-14 at 13:30 +0000, David Woodhouse wrote:
> If krealloc() returns NULL, it *doesn't* free the original. So any code
> of the form 'foo = krealloc(foo, …);' is almost certainly a bug.

So add a check for it to checkpatch.

Signed-off-by: Joe Perches <joe@perches.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index b28cc384a5bc..7ef2b4bd0145 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3476,6 +3476,13 @@ sub process {
 			     "unnecessary cast may hide bugs, see http://c-faq.com/malloc/mallocnocast.html\n" . $herecurr);
 		}
 
+# check for krealloc arg reuse
+		if ($^V && $^V ge 5.10.0 &&
+		    $line =~ /\b($Lval)\s*\=\s*(?:$balanced_parens)?\s*krealloc\s*\(\s*\1\s*,/) {
+			WARN("KREALLOC_ARG_REUSE",
+			     "Reusing the krealloc arg is almost always a bug\n" . $herecurr);
+		}
+
 # check for alloc argument mismatch
 		if ($line =~ /\b(kcalloc|kmalloc_array)\s*\(\s*sizeof\b/) {
 			WARN("ALLOC_ARRAY_ARGS",