Re: [PATCH] arch: configuration, deleting 'CONFIG_BUG' since always need it.

Russell King - ARM Linux
2013-05-23T09:05:34Z

On Thu, May 23, 2013 at 10:40:29AM +0200, Geert Uytterhoeven wrote:
> On Thu, May 23, 2013 at 9:57 AM, Chen Gang <gang.chen-bOixZGp5f+dBDgjK7y7TUQ@public.gmane.org> wrote:
> > -config BUG
> > - bool "BUG() support" if EXPERT
> > - default y
> > - help
> > - Disabling this option eliminates support for BUG and WARN, reducing
> > - the size of your kernel image and potentially quietly ignoring
> > - numerous fatal conditions. You should only consider disabling this
> > - option for embedded systems with no facilities for reporting errors.
> > - Just say Y.
>
> ... It's about reducing memory size on devices where you can't show bug or
> warning messages.

And turning off CONFIG_BUG causes lots of warning messages at compile time
about functions which are returning nothing which shouldn't.

The problem is: trying to fix that _will_ mean the result is a larger
kernel than if you just do the usual arch-implemented thing of placing
an defined faulting instruction at the BUG() site - which defeats the
purpose of turning off CONFIG_BUG.

Therefore, it's better that CONFIG_BUG always be y and we stop kidding
ourselves that it's possible to turn this off and safely save space.