[dm-devel] [PATCH 8/10] drivers/md: introduce missing kfree

[Julia Lawall]

From: Julia Lawall <julia at diku.dk>

Error handling code following a kmalloc should free the allocated data.

The semantic match that finds the problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r exists@
local idexpression x;
statement S;
expression E;
identifier f,f1,l;
position p1,p2;
expression *ptr != NULL;
@@

x at p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
...
if (x == NULL) S
<... when != x
     when != if (...) { <+...x...+> }
(
x->f1 = E
|
 (x->f1 == NULL || ...)
|
 f(...,x->f1,...)
)
...>
(
 return \(0\|<+...x...+>\|ptr\);
|
 return at p2 ...;
)

@script:python@
p1 << r.p1;
p2 << r.p2;
@@

print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line)
// </smpl>

Signed-off-by: Julia Lawall <julia at diku.dk>
---
 drivers/md/dm-exception-store.c     |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/md/dm-exception-store.c b/drivers/md/dm-exception-store.c
index 3710ff8..ee68d17 100644
--- a/drivers/md/dm-exception-store.c
+++ b/drivers/md/dm-exception-store.c
@@ -217,7 +217,8 @@ int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
 		type = get_type("N");
 	else {
 		ti->error = "Persistent flag is not P or N";
-		return -EINVAL;
+		r = -EINVAL;
+		goto bad_type;
 	}
 
 	if (!type) {