Re: [PATCH 4/7] signal/mips: Document a conflict with SI_USER with SIGFPE

From: Ralf Baechle
Date: Mon Aug 07 2017 - 15:55:43 EST


On Mon, Aug 07, 2017 at 10:41:39AM -0700, Linus Torvalds wrote:

> On Mon, Aug 7, 2017 at 9:18 AM, Maciej W. Rozycki <macro@xxxxxxxxxx> wrote:
> >
> > So what would be the right value of `si_code' to use here for such an
> > unexpected exception condition? I think `BUG()' would be too big a
> > hammer here. Or wouldn't it?
>
> Hell no. NEVER EVER BUG().
>
> The only case to use BUG() is if there is some core data structure
> (say, kernel stack) that is so corrupted that you know you cannot
> continue. That's the *only* valid use.
>
> If this is a "this condition cannot happen" issue, then just remove
> the damn conditional. It's pointless. Adding a BUG() to show "this
> cannot happen" is not acceptable.

I queued a patch to remove the code for 4.14.

Ralf