Re: [PATCH 3/4] sound/soc/mxs/mxs-saif.c: add missing kfree

[Julia Lawall <julia@diku.dk>]

From: Julia Lawall <julia@diku.dk>

Move the test on pdev->id before the kzalloc to avoid requiring kfree when
the test fails.  This fix was suggested by Wolfram Sang.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier x;
expression E1!=0,E2,E3,E4;
statement S;
iterator I;
@@

(
if (...) { ... when != kfree(x)
               when != x = E3
               when != E3 = x
*  return ...;
 }
... when != x = E2
    when != I(...,x,...) S
if (...) { ... when != x = E4
 kfree(x); ... return ...; }
)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>

---
diff --git a/sound/soc/mxs/mxs-saif.c b/sound/soc/mxs/mxs-saif.c
index 0b3adae..e9a90e4 100644
--- a/sound/soc/mxs/mxs-saif.c
+++ b/sound/soc/mxs/mxs-saif.c
@@ -519,12 +519,11 @@ static int mxs_saif_probe(struct platform_device *pdev)
 	struct mxs_saif *saif;
 	int ret = 0;
 
+	if (pdev->id >= ARRAY_SIZE(mxs_saif))
+		return -EINVAL;
 	saif = kzalloc(sizeof(*saif), GFP_KERNEL);
 	if (!saif)
 		return -ENOMEM;
-
-	if (pdev->id >= ARRAY_SIZE(mxs_saif))
-		return -EINVAL;
 	mxs_saif[pdev->id] = saif;
 
 	saif->clk = clk_get(&pdev->dev, NULL);