Re: [PATCH 9/9] drivers/acpi: correct error-handling code

[Julia Lawall <julia@diku.dk>]

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On Wed, 29 Jul 2009, Zhang Rui wrote:

> On Tue, 2009-07-28 at 23:56 +0800, Julia Lawall wrote:
> > From: Julia Lawall <julia@diku.dk>
> > 
> > backlight_device_register may return an ERR_PTR value rather than a valid
> > pointer.
> > 
> > A simplified version of the semantic match that finds this problem is as
> > follows: (http://coccinelle.lip6.fr/)
> 
> > Signed-off-by: Julia Lawall <julia@diku.dk>
> > 
> > ---
> >  drivers/acpi/video.c                |    2 ++
> >  1 files changed, 2 insertions(+), 0 deletions(-)
> > 
> > diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
> > index 8851315..29788db 100644
> > --- a/drivers/acpi/video.c
> > +++ b/drivers/acpi/video.c
> > @@ -982,6 +982,8 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
> >  		sprintf(name, "acpi_video%d", count++);
> >  		device->backlight = backlight_device_register(name,
> >  			NULL, device, &acpi_backlight_ops);
> > +		if (IS_ERR(device->backlight))
> > +			return;
> 
> we should kfree(name) here.

Yes, good point.

thanks,
julia

> >  		device->backlight->props.max_brightness = device->brightness->count-3;
> >  		kfree(name);
> 
> how about this one?
> 
> ÿÿbacklight_device_register may return an ERR_PTR value rather than a valid
> pointer.
> 
> Signed-off-by: Zhang Rui <rui.zhang@intel.com>
> ---
>  drivers/acpi/video.c |    4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> Index: linux-2.6/drivers/acpi/video.c
> ===================================================================
> --- linux-2.6.orig/drivers/acpi/video.c
> +++ linux-2.6/drivers/acpi/video.c
> @@ -982,8 +982,10 @@ static void acpi_video_device_find_cap(s
>  		sprintf(name, "acpi_video%d", count++);
>  		device->backlight = backlight_device_register(name,
>  			NULL, device, &acpi_backlight_ops);
> -		device->backlight->props.max_brightness = device->brightness->count-3;
>  		kfree(name);
> +		if (IS_ERR(device->backlight))
> +			return;
> +		device->backlight->props.max_brightness = device->brightness->count-3;
>  
>  		result = sysfs_create_link(&device->backlight->dev.kobj,
>  					   &device->dev->dev.kobj, "device");
> 
> 
> 
>  
> 
>