[PATCH 4/5] drivers/net: Drop unnecessary NULL test

From: Julia Lawall
Date: Sun Jul 12 2009 - 16:14:50 EST


From: Julia Lawall <julia@xxxxxxx>

The result of container_of should not be NULL. In particular, in this case
the argument to the enclosing function has passed though INIT_WORK, which
dereferences it, implying that its container cannot be NULL.

A simplified version of the semantic patch that makes this change is as
follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
identifier fn,work,x,fld;
type T;
expression E1,E2;
statement S;
@@

static fn(struct work_struct *work) {
... when != work = E1
x = container_of(work,T,fld)
... when != x = E2
- if (x == NULL) S
...
}
// </smpl>

Signed-off-by: Julia Lawall <julia@xxxxxxx>

---
drivers/net/wireless/ipw2x00/ipw2200.c | 3 ---
1 files changed, 0 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/ipw2x00/ipw2200.c b/drivers/net/wireless/ipw2x00/ipw2200.c
index d726b3c..2dc1cdb 100644
--- a/drivers/net/wireless/ipw2x00/ipw2200.c
+++ b/drivers/net/wireless/ipw2x00/ipw2200.c
@@ -7250,9 +7250,6 @@ static void ipw_bg_qos_activate(struct work_struct *work)
struct ipw_priv *priv =
container_of(work, struct ipw_priv, qos_activate);

- if (priv == NULL)
- return;
-
mutex_lock(&priv->mutex);

if (priv->status & STATUS_ASSOCIATED)
--
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