[PATCH] ARM: imx: clean up error handling

[PATCH] ARM: imx: clean up error handling

[Emil Goode]

If we fail to allocate struct platform_device pdev we
dereference it after the goto label err.

I have rearranged the error handling a bit to fix the issue
and also make it more clear.

Signed-off-by: Emil Goode <emilgoode@gmail.com>
---
 arch/arm/mach-imx/devices/platform-ipu-core.c |   22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/arch/arm/mach-imx/devices/platform-ipu-core.c b/arch/arm/mach-imx/devices/platform-ipu-core.c
index fc4dd7c..14d61d9 100644
--- a/arch/arm/mach-imx/devices/platform-ipu-core.c
+++ b/arch/arm/mach-imx/devices/platform-ipu-core.c
@@ -77,34 +77,38 @@ struct platform_device *__init imx_alloc_mx3_camera(
 
 	pdev = platform_device_alloc("mx3-camera", 0);
 	if (!pdev)
-		goto err;
+		return ERR_PTR(ret);
 
 	pdev->dev.dma_mask = kmalloc(sizeof(*pdev->dev.dma_mask), GFP_KERNEL);
 	if (!pdev->dev.dma_mask)
-		goto err;
+		goto put_pdev;
 
 	*pdev->dev.dma_mask = DMA_BIT_MASK(32);
 	pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
 
 	ret = platform_device_add_resources(pdev, res, ARRAY_SIZE(res));
 	if (ret)
-		goto err;
+		goto free_dma_mask;
 
 	if (pdata) {
 		struct mx3_camera_pdata *copied_pdata;
 
 		ret = platform_device_add_data(pdev, pdata, sizeof(*pdata));
-		if (ret) {
-err:
-			kfree(pdev->dev.dma_mask);
-			platform_device_put(pdev);
-			return ERR_PTR(-ENODEV);
-		}
+		if (ret)
+			goto free_dma_mask;
+
 		copied_pdata = dev_get_platdata(&pdev->dev);
 		copied_pdata->dma_dev = &imx_ipu_coredev->dev;
 	}
 
 	return pdev;
+
+free_dma_mask:
+	kfree(pdev->dev.dma_mask);
+put_pdev:
+	platform_device_put(pdev);
+
+	return ERR_PTR(ret);
 }
 
 struct platform_device *__init imx_add_mx3_sdc_fb(
-- 
1.7.10.4

[PATCH] ARM: imx: clean up error handling

[Dan Carpenter]

On Thu, May 15, 2014 at 09:24:30PM +0200, Emil Goode wrote:
> If we fail to allocate struct platform_device pdev we
> dereference it after the goto label err.
> 
> I have rearranged the error handling a bit to fix the issue
> and also make it more clear.
> 
> Signed-off-by: Emil Goode <emilgoode@gmail.com>
> ---
>  arch/arm/mach-imx/devices/platform-ipu-core.c |   22 +++++++++++++---------
>  1 file changed, 13 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/arm/mach-imx/devices/platform-ipu-core.c b/arch/arm/mach-imx/devices/platform-ipu-core.c
> index fc4dd7c..14d61d9 100644
> --- a/arch/arm/mach-imx/devices/platform-ipu-core.c
> +++ b/arch/arm/mach-imx/devices/platform-ipu-core.c
> @@ -77,34 +77,38 @@ struct platform_device *__init imx_alloc_mx3_camera(
>  
>  	pdev = platform_device_alloc("mx3-camera", 0);
>  	if (!pdev)
> -		goto err;
> +		return ERR_PTR(ret);

It's more readable to say "return ERR_PTR(-ENOMEM);".

This patch is great but the subject should say "fix" and not "clean up"
since it fixes a NULL dereference bug.  The people who call their
checkpatch.pl clean ups "fixes" are also doing it wrong but those are
newbies and not worth educating.

regards,
dan carpenter

[PATCH] ARM: imx: clean up error handling

[Emil Goode]

Hello Dan,

Thanks for the review and sorry for the late reply.

On Thu, May 15, 2014 at 11:32:13PM +0300, Dan Carpenter wrote:
> On Thu, May 15, 2014 at 09:24:30PM +0200, Emil Goode wrote:
> > If we fail to allocate struct platform_device pdev we
> > dereference it after the goto label err.
> > 
> > I have rearranged the error handling a bit to fix the issue
> > and also make it more clear.
> > 
> > Signed-off-by: Emil Goode <emilgoode@gmail.com>
> > ---
> >  arch/arm/mach-imx/devices/platform-ipu-core.c |   22 +++++++++++++---------
> >  1 file changed, 13 insertions(+), 9 deletions(-)
> > 
> > diff --git a/arch/arm/mach-imx/devices/platform-ipu-core.c b/arch/arm/mach-imx/devices/platform-ipu-core.c
> > index fc4dd7c..14d61d9 100644
> > --- a/arch/arm/mach-imx/devices/platform-ipu-core.c
> > +++ b/arch/arm/mach-imx/devices/platform-ipu-core.c
> > @@ -77,34 +77,38 @@ struct platform_device *__init imx_alloc_mx3_camera(
> >  
> >  	pdev = platform_device_alloc("mx3-camera", 0);
> >  	if (!pdev)
> > -		goto err;
> > +		return ERR_PTR(ret);
> 
> It's more readable to say "return ERR_PTR(-ENOMEM);".

I think so to, will change this one but still use the ret variable at the
bottom of the function.

> 
> This patch is great but the subject should say "fix" and not "clean up"
> since it fixes a NULL dereference bug.  The people who call their
> checkpatch.pl clean ups "fixes" are also doing it wrong but those are
> newbies and not worth educating.

I agree, it's a bug fix and not a clean up.

Will resend tomorrow.

Best regards,

Emil Goode

> 
> regards,
> dan carpenter
>