Re: [PATCH v2] Whine about suspicious return values from module's ->init() hook

[Rusty Russell <rusty@rustcorp.com.au>]

On Monday 11 February 2008 09:09:06 Alexey Dobriyan wrote:
> On Wed, Feb 06, 2008 at 05:55:26PM +1100, Rusty Russell wrote:
> > I think you misunderstand.  I proposed that we audit all the code before
> > such a change.  We shouldn't do *anything* until we can estimate the
> > impact this change will have.
>
> With such rate of changes, good luck doing that.

I'm not convinced that people are introducing bugs that fast :)

> > Our users deserve better than "I don't know if this will break anything
> > so I used WARN_ON".  They deserve "we have confidence that this change
> > won't break any existing code".
> >
> > Now, if an audit is impractical or unreliable, we are better off with a
> > WARN_ON.
>
> It's impractical as in it's extremely boring to read every modules init
> function and propagate return values in mind.

Sure, I'd start by writing some filters for all the easy cases.  It'd probably 
only take a day to do them all.

The thing is, every time I do an audit like this, I find all kinds of things 
to fix; it's not actually a useless exercise.

> > But it is still an admission of ignorance.
>
> I love BUG_ON and BUILD_BUG_ON very much but on such scale you can't
> just throw them in.
>
> Here goes version 2 with improved changelog. Let's put in -mm and see
> what happens, then put it in mainline and see what happens.

Sure, I've put it in my tree for the moment.

Thanks,
Rusty.