linux-kernel - Re: [PATCH] coccinelle: api: add kzfree script

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Message-ID: <alpine.DEB.2.21.2006041755360.2577@hadrien>
Date:   Thu, 4 Jun 2020 17:56:38 +0200 (CEST)
From:   Julia Lawall <julia.lawall@...ia.fr>
To:     Markus Elfring <Markus.Elfring@....de>
cc:     Denis Efremov <efremov@...ux.com>,
        Gilles Muller <Gilles.Muller@...6.fr>,
        Masahiro Yamada <yamada.masahiro@...ionext.com>,
        Michal Marek <michal.lkml@...kovi.net>,
        Nicolas Palix <nicolas.palix@...g.fr>,
        Coccinelle <cocci@...teme.lip6.fr>,
        kernel-janitors@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] coccinelle: api: add kzfree script



On Thu, 4 Jun 2020, Markus Elfring wrote:

> > Check for memset() with 0 followed by kfree().
>
> I suggest to simplify the SmPL code a bit like the following.
>
>
> > +virtual context
> > +virtual org
> > +virtual report
> > +virtual patch
>
> +virtual context, org, report, patch

This is pointless.

>
>
> …
> > +@@
> > +
> > +(
> > +* memset(E, 0, ...);
> > +|
> > +* memset(E, '\0', ...);
> > +)
> > +* kfree(E)@p;
>
> +@@
> +*memset(E, 0, ...);
> +*kfree(E)@p;
>
>
> How does the SmPL asterisk functionality fit to the operation
> modes “org” and “report”?

make coccicheck uses the option --no-show-diff for the org and report
modes.

>
> > +@@
> > +
> > +(
> > +- memset(E, 0, ...);
> > +|
> > +- memset(E, '\0', ...);
> > +)
> > +- kfree(E);
> > ++ kzfree(E);
>
> +@@
> +-memset(E, 0, ...);
> +-kfree
> ++kzfree
> +       (E);
>
> I got the impression that the specification of a SmPL disjunction
> could be omitted because of the technical detail that the isomorphism
> “zero_multiple_format” should handle such an use case already.
>
> Would you like to tolerate any extra source code between these function calls?

I already addressed these issues.

julia