[PATCH v2 4/8] drivers/media/dvb-frontends/s921.c: Removes useless kfree()

From: Peter Senna Tschudin
Date: Wed Sep 12 2012 - 08:58:36 EST


From: Peter Senna Tschudin <peter.senna@xxxxxxxxx>

Remove useless kfree() and clean up code related to the removal.

The semantic patch that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
position p1,p2;
expression x;
@@

if (x@p1 == NULL) { ... kfree@p2(x); ... return ...; }

@unchanged exists@
position r.p1,r.p2;
expression e <= r.x,x,e1;
iterator I;
statement S;
@@

if (x@p1 == NULL) { ... when != I(x,...) S
when != e = e1
when != e += e1
when != e -= e1
when != ++e
when != --e
when != e++
when != e--
when != &e
kfree@p2(x); ... return ...; }

@ok depends on unchanged exists@
position any r.p1;
position r.p2;
expression x;
@@

... when != true x@p1 == NULL
kfree@p2(x);

@depends on !ok && unchanged@
position r.p2;
expression x;
@@

*kfree@p2(x);
// </smpl>

Signed-off-by: Peter Senna Tschudin <peter.senna@xxxxxxxxx>

---
drivers/media/dvb-frontends/s921.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/drivers/media/dvb-frontends/s921.c b/drivers/media/dvb-frontends/s921.c
index cd2288c..a271ac3 100644
--- a/drivers/media/dvb-frontends/s921.c
+++ b/drivers/media/dvb-frontends/s921.c
@@ -487,9 +487,9 @@ struct dvb_frontend *s921_attach(const struct s921_config *config,
kzalloc(sizeof(struct s921_state), GFP_KERNEL);

dprintk("\n");
- if (state == NULL) {
+ if (!state) {
rc("Unable to kzalloc\n");
- goto rcor;
+ return NULL;
}

/* setup the state */
@@ -502,11 +502,6 @@ struct dvb_frontend *s921_attach(const struct s921_config *config,
state->frontend.demodulator_priv = state;

return &state->frontend;
-
-rcor:
- kfree(state);
-
- return NULL;
}
EXPORT_SYMBOL(s921_attach);


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