mfd: Fix davinci memory leak

Author: Julia Lawall <julia@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/)

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

x@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@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)
// 

Signed-off-by: Julia Lawall 
Signed-off-by: Samuel Ortiz

---
 drivers/mfd/davinci_voicecodec.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
 
diff --git a/drivers/mfd/davinci_voicecodec.c b/drivers/mfd/davinci_voicecodec.c
index 3e75f02..33c923d 100644
--- a/drivers/mfd/davinci_voicecodec.c
+++ b/drivers/mfd/davinci_voicecodec.c
@@ -94,7 +94,8 @@ static int __init davinci_vc_probe(struct platform_device *pdev)
 	res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
 	if (!res) {
 		dev_err(&pdev->dev, "no DMA resource\n");
-		return -ENXIO;
+		ret = -ENXIO;
+		goto fail4;
 	}
 
 	davinci_vc->davinci_vcif.dma_tx_channel = res->start;
@@ -104,7 +105,8 @@ static int __init davinci_vc_probe(struct platform_device *pdev)
 	res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
 	if (!res) {
 		dev_err(&pdev->dev, "no DMA resource\n");
-		return -ENXIO;
+		ret = -ENXIO;
+		goto fail4;
 	}
 
 	davinci_vc->davinci_vcif.dma_rx_channel = res->start;

mfd: Fix davinci memory leak

qlambert

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