From: Maria Neptune <maria.elysse.n@gmail.com>
To: Martin Galvan <omgalvan.86@gmail.com>
Cc: "Valdis Klētnieks" <valdis.kletnieks@vt.edu>,
kernelnewbies@kernelnewbies.org
Subject: Re: Try/catch for modules?
Date: Fri, 18 Oct 2019 11:48:48 -0400 [thread overview]
Message-ID: <CAG=DERm2JFuDXOLSCzHOruem38xCK=ziaxojYZfw==CGx=7ZyA@mail.gmail.com> (raw)
In-Reply-To: <CAN19L9EF01s_yGwzNLtLp+3HYUxrHrt65XPEd0utvonLZAY8=g@mail.gmail.com>
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Edsger Dijkstra will haunt is forever, it seems. Gotos are just a tool,
and this is one of the few places they're the best tool for the job. And
generally in-kernel the acceptable method is to not forget a null check, as
Valdis mentioned. It's cool to forget a null check on your own machine (who
among us hasn't?) but if you're contributing/shipping code you gotta know
that those pointers are good.
On Fri, Oct 18, 2019, 11:44 Martin Galvan <omgalvan.86@gmail.com> wrote:
> El jue., 17 oct. 2019 a las 19:13, Valdis Klētnieks
> (<valdis.kletnieks@vt.edu>) escribió:
> >
> > For starters, the *correct* in-kernel way to deal with this is:
> > if (!ptr) {
> > printk("You blew it!\n");
> > goto you_blew_it;
> > }
>
> goto statements are harmful. In any case, what I meant was to have
> some sort of safety net to prevent exceptions (i.e. if I screw up and
> forget a NULL check) from panicking the system.
>
> > Also, "current PID" and "my module" aren't two things that can
> correspond....
>
> I don't understand what you mean by that. Module code (e.g. an ioctl)
> runs as some process. In the case of an ioctl, I'd assume it's the
> same PID of the user process.
>
> _______________________________________________
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> Kernelnewbies@kernelnewbies.org
> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>
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next prev parent reply other threads:[~2019-10-18 15:50 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-17 13:37 Try/catch for modules? Martin Galvan
[not found] ` <CAG=DERmX7AU8YkEAYnPLfPKCLD=1OugmD95R9wZ3CepXvqzd2Q@mail.gmail.com>
2019-10-17 13:42 ` Maria Neptune
2019-10-17 13:51 ` Ruben Safir
2019-10-17 22:12 ` Valdis Klētnieks
2019-10-18 15:43 ` Martin Galvan
2019-10-18 15:47 ` Anuz Pratap Singh Tomar
2019-10-18 15:48 ` Maria Neptune [this message]
2019-10-18 16:04 ` Bernd Petrovitsch
2019-10-18 16:11 ` Martin Galvan
2019-10-18 16:18 ` Bernd Petrovitsch
2019-10-18 17:02 ` Ruben Safir
2019-10-18 17:05 ` Martin Galvan
2019-10-18 18:52 ` Ruben Safir
2019-10-18 18:53 ` Ruben Safir
2019-10-18 19:08 ` Ruben Safir
2019-10-18 21:53 ` Valdis Klētnieks
2019-10-18 22:09 ` Martin Galvan
2019-10-18 22:28 ` Greg KH
2019-10-18 18:48 ` Ruben Safir
2019-10-18 21:24 ` Rik van Riel
2019-10-18 21:32 ` Ruben Safir
2019-10-18 21:37 ` Ruben Safir
2019-10-18 22:59 ` Valdis Klētnieks
2019-10-19 7:46 ` Bjørn Mork
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