Re: [PATCH 07/38] usb: host: ehci-msm: fix handling platform_get_irq result

[Alan Stern <stern@rowland.harvard.edu>]

On Mon, 21 Sep 2015, Andrzej Hajda wrote:

> The function can return negative values.
> 
> The problem has been detected using proposed semantic patch
> scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci [1].
> 
> [1]: http://permalink.gmane.org/gmane.linux.kernel/2038576
> 
> Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
> ---
>  drivers/usb/host/ehci-msm.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/host/ehci-msm.c b/drivers/usb/host/ehci-msm.c
> index 275c92e..c4f84c8 100644
> --- a/drivers/usb/host/ehci-msm.c
> +++ b/drivers/usb/host/ehci-msm.c
> @@ -80,12 +80,12 @@ static int ehci_msm_probe(struct platform_device *pdev)
>  		return  -ENOMEM;
>  	}
>  
> -	hcd->irq = platform_get_irq(pdev, 0);
> -	if (hcd->irq < 0) {
> +	ret = platform_get_irq(pdev, 0);
> +	if (ret < 0) {
>  		dev_err(&pdev->dev, "Unable to get IRQ resource\n");
> -		ret = hcd->irq;
>  		goto put_hcd;
>  	}
> +	hcd->irq = ret;
>  
>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  	if (!res) {

Acked-by: Alan Stern <stern@rowland.harvard.edu>

You might consider extending the coccinelle script to look for even
worse problems.  ehci-mv.c doesn't test for negative return values at
all!

Alan Stern