Re: [Linux-fbdev-devel] [PATCH] drivers/video: Bad error test beforea dereference

[Nicolas Ferre]

Hi Andrew,

Nicolas Ferre :
> Julien Brunel :
> > The error test that follows the call to backlight_device_register
> > semms not to concern the right variable.
> >
> > A simplified version of the semantic match that finds this problem is
> > as follows: 
> > (http://www.emn.fr/x-info/coccinelle/)
> > // <smpl>
> > @def0@
> > expression x;
> > position p0;
> > @@
> > x@p0 = backlight_device_register(...)
> >
> > @protected@
> > expression def0.x,E;
> > position def0.p0;
> > position p;
> > statement S;
> > @@
> > x@p0
> > ... when != x = E
> > if (!IS_ERR(x) && ...) {<... x@p ...>} else S
> >
> > @unprotected@
> > expression def0.x;
> > identifier fld;
> > position def0.p0;
> > position p != protected.p;
> > @@
> > x@p0
> > ... when != x = E
> > * x@p->fld
> > // </smpl>
> >
> > Signed-off-by: Julien Brunel <brunel@xxxxxxx>
> > Signed-off-by: Julia Lawall <julia@xxxxxxx>
>
> Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>

I do not know if you noticed this little patch but
I think it will be good if we can queue it for -final.

Do you want me to reformulate the submission or the
original email ok for you ?

> > ---
> >  drivers/video/atmel_lcdfb.c |    2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff -u -p a/drivers/video/atmel_lcdfb.c b/drivers/video/atmel_lcdfb.c
> > --- a/drivers/video/atmel_lcdfb.c
> > +++ b/drivers/video/atmel_lcdfb.c
> > @@ -132,7 +132,7 @@ static void init_backlight(struct atmel_
> >  
> >  	bl = backlight_device_register("backlight", &sinfo->pdev->dev,
> >  			sinfo, &atmel_lcdc_bl_ops);
> > -	if (IS_ERR(sinfo->backlight)) {
> > +	if (IS_ERR(bl)) {
> >  		dev_err(&sinfo->pdev->dev, "error %ld on backlight register\n",
> >  				PTR_ERR(bl));
> >  		return;

Thanks, regards,
--
Nicolas Ferre

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