checkpatch: fix krealloc reuse test

The current krealloc test does not function correctly when the temporary
pointer return name contains the original pointer name.

Fix that by maximally matching the return pointer name and the original
pointer name and doing a separate comparison of the both names.

Link: http://lkml.kernel.org/r/e617ecb8c019a9c4c56540a1bec16c8aed43a4e4.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Manish Narani <manish.narani@xilinx.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 4523dd6..d43a446 100755 (executable)
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -6167,7 +6167,8 @@ sub process {
 
 # check for krealloc arg reuse
                if ($perl_version_ok &&
-                   $line =~ /\b($Lval)\s*\=\s*(?:$balanced_parens)?\s*krealloc\s*\(\s*\1\s*,/) {
+                   $line =~ /\b($Lval)\s*\=\s*(?:$balanced_parens)?\s*krealloc\s*\(\s*($Lval)\s*,/ &&
+                   $1 eq $3) {
                        WARN("KREALLOC_ARG_REUSE",
                             "Reusing the krealloc arg is almost always a bug\n" . $herecurr);
                }