Feb 11 2011

drivers/w1/masters/omap_hdq.c: add missing clk_put 

Author: Julia Lawall <julia@diku.dk>

This code makes two calls to clk_get, then test both return values and
fails if either failed.

The problem is that in the first inner if, where the first call to
clk_get has failed, it don't know if the second call has failed as well.
So it don't know whether clk_get should be called on the result of the
second call.  Of course, it would be possible to test that value again.
A simpler solution is just to test the result of calling clk_get
directly after each call.

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

// 
@r@
position p1,p2;
expression e;
statement S;
@@

e = clk_get@p1(...)
...
if@p2 (IS_ERR(e)) S

@@
expression e;
statement S;
identifier l;
position r.p1, p2 != r.p2;
@@

*e = clk_get@p1(...)
... when != clk_put(e)
*if@p2 (...)
{
  ... when != clk_put(e)
* return ...;
}// 

Signed-off-by: Julia Lawall 
Cc: Evgeniy Polyakov 
Acked-by: Tony Lindgren 
Acked-by: Amit Kucheria 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 

---
 drivers/w1/masters/omap_hdq.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)
 
diff --git a/drivers/w1/masters/omap_hdq.c b/drivers/w1/masters/omap_hdq.c
index 3a7e9ff..38e96ab 100644
--- a/drivers/w1/masters/omap_hdq.c
+++ b/drivers/w1/masters/omap_hdq.c
@@ -593,19 +593,17 @@ static int __devinit omap_hdq_probe(struct platform_device *pdev)
 
 	/* get interface & functional clock objects */
 	hdq_data->hdq_ick = clk_get(&pdev->dev, "ick");
-	hdq_data->hdq_fck = clk_get(&pdev->dev, "fck");
+	if (IS_ERR(hdq_data->hdq_ick)) {
+		dev_dbg(&pdev->dev, "Can't get HDQ ick clock object\n");
+		ret = PTR_ERR(hdq_data->hdq_ick);
+		goto err_ick;
+	}
 
-	if (IS_ERR(hdq_data->hdq_ick) || IS_ERR(hdq_data->hdq_fck)) {
-		dev_dbg(&pdev->dev, "Can't get HDQ clock objects\n");
-		if (IS_ERR(hdq_data->hdq_ick)) {
-			ret = PTR_ERR(hdq_data->hdq_ick);
-			goto err_clk;
-		}
-		if (IS_ERR(hdq_data->hdq_fck)) {
-			ret = PTR_ERR(hdq_data->hdq_fck);
-			clk_put(hdq_data->hdq_ick);
-			goto err_clk;
-		}
+	hdq_data->hdq_fck = clk_get(&pdev->dev, "fck");
+	if (IS_ERR(hdq_data->hdq_fck)) {
+		dev_dbg(&pdev->dev, "Can't get HDQ fck clock object\n");
+		ret = PTR_ERR(hdq_data->hdq_fck);
+		goto err_fck;
 	}
 
 	hdq_data->hdq_usecount = 0;
@@ -665,10 +663,12 @@ err_fnclk:
 	clk_disable(hdq_data->hdq_ick);
 
 err_intfclk:
-	clk_put(hdq_data->hdq_ick);
 	clk_put(hdq_data->hdq_fck);
 
-err_clk:
+err_fck:
+	clk_put(hdq_data->hdq_ick);
+
+err_ick:
 	iounmap(hdq_data->hdq_base);
 
 err_ioremap:

qlambert