RE: [PATCH 1/3] sound/soc/mxs/mxs-saif.c: keep pointer to resourceso it can be freed

From: Julia Lawall
Date: Tue Oct 18 2011 - 09:18:10 EST


From: Julia Lawall <julia@xxxxxxx>

Add a new variable for storing resources accessed subsequent to the one
accessed using request_mem_region, so the one accessed using
request_mem_region can be released if needed.

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

// <smpl>
@r@
expression E, E1;
identifier f;
statement S1,S2,S3;
@@

if (E == NULL)
{
... when != if (E == NULL || ...) S1 else S2
when != E = E1
*E->f
... when any
return ...;
}
else S3
// </smpl>

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

---
Not even compile tested.

sound/soc/mxs/mxs-saif.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/sound/soc/mxs/mxs-saif.c b/sound/soc/mxs/mxs-saif.c
index 401944c..76dc74d 100644
--- a/sound/soc/mxs/mxs-saif.c
+++ b/sound/soc/mxs/mxs-saif.c
@@ -617,7 +617,7 @@ static irqreturn_t mxs_saif_irq(int irq, void *dev_id)

static int mxs_saif_probe(struct platform_device *pdev)
{
- struct resource *res;
+ struct resource *iores, *dmares;
struct mxs_saif *saif;
struct mxs_saif_platform_data *pdata;
int ret = 0;
@@ -655,35 +655,36 @@ static int mxs_saif_probe(struct platform_device *pdev)
goto failed_clk;
}

- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!res) {
+ iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!iores) {
ret = -ENODEV;
dev_err(&pdev->dev, "failed to get io resource: %d\n",
ret);
goto failed_get_resource;
}

- if (!request_mem_region(res->start, resource_size(res), "mxs-saif")) {
+ if (!request_mem_region(iores->start, resource_size(iores),
+ "mxs-saif")) {
dev_err(&pdev->dev, "request_mem_region failed\n");
ret = -EBUSY;
goto failed_get_resource;
}

- saif->base = ioremap(res->start, resource_size(res));
+ saif->base = ioremap(iores->start, resource_size(iores));
if (!saif->base) {
dev_err(&pdev->dev, "ioremap failed\n");
ret = -ENODEV;
goto failed_ioremap;
}

- res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
- if (!res) {
+ dmares = platform_get_resource(pdev, IORESOURCE_DMA, 0);
+ if (!dmares) {
ret = -ENODEV;
dev_err(&pdev->dev, "failed to get dma resource: %d\n",
ret);
goto failed_ioremap;
}
- saif->dma_param.chan_num = res->start;
+ saif->dma_param.chan_num = dmares->start;

saif->irq = platform_get_irq(pdev, 0);
if (saif->irq < 0) {
@@ -742,7 +743,7 @@ failed_get_irq2:
failed_get_irq1:
iounmap(saif->base);
failed_ioremap:
- release_mem_region(res->start, resource_size(res));
+ release_mem_region(iores->start, resource_size(iores));
failed_get_resource:
clk_put(saif->clk);
failed_clk:
--
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