Re: [PATCH v2] coccinelle: api: check for propagation of error from platform_get_irq

[Sergei Shtylyov]

On 12/27/2015 01:32 AM, Julia Lawall wrote:

> > > The error return value of platform_get_irq seems to often get dropped.
> > >
> > > Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxx>
> > >
> > > ---
> > >
> > > v2: Check for the direct return case also.  Added some mailing lists of
> > > common offenders.
> > >
> > > diff --git a/scripts/coccinelle/api/platform_get_irq_return.cocci
> > > b/scripts/coccinelle/api/platform_get_irq_return.cocci
> > > new file mode 100644
> > > index 0000000..44680d0
> > > --- /dev/null
> > > +++ b/scripts/coccinelle/api/platform_get_irq_return.cocci
> > > @@ -0,0 +1,58 @@
> > > +/// Propagate the return value of platform_get_irq.
> > > +//# Sometimes the return value of platform_get_irq is tested using <= 0,
> > > but 0
> > > +//# might not be an appropriate return value in an error case.
> > > +///
> > > +// Confidence: Moderate
> > > +// Copyright: (C) 2015 Julia Lawall, Inria. GPLv2.
> > > +// URL: http://coccinelle.lip6.fr/
> > > +// Options: --no-includes --include-headers
> > > +
> > > +virtual context
> > > +virtual org
> > > +virtual report
> > > +
> > > +//
> > > ----------------------------------------------------------------------------
> > > +
> > > +@r depends on context || org || report@
> > > +constant C;
> > > +statement S;
> > > +expression e, ret;
> > > +position j0, j1;
> > > +@@
> > > +
> > > +* e@j0 = platform_get_irq(...);
> > > +(
> > > +if@j1 (...) {
> > > +  ...
> > > +  return -C;
> > > +} else S
> > > +|
> > > +if@j1 (...) {
> > > +  ...
> > > +  ret = -C;
> > > +  ...
> > > +  return ret;
> > > +} else S
> >
> >     Well, this seems to also cover the (e <= 0) checks which do make same sense
> > in the light of Linus considering IRQ0 invalid. So I'd be more specific about
> > the checks here -- 0 should indeed be overridden with something if it's
> > considered invalid.
>
> That's what the limitations section says (lines with #).  This doesn't

   Ah, failed to notice those, only saw after replying.

> make any changes, it only makes warnings, which should include the
> limitations information, so perhaps people can consider what it is that
> they really intend to do.
>
> If you think this is not a good idea, then I can make the test more
> specific.

   Well, looking again, the patch should be good. I just thought its goal was 
to fix the code as well...

> julia

MBR, Sergei

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