On Thu, May 23, 2013 at 11:05 AM, Russell King - ARM Linux
[off-list ref] wrote:

On Thu, May 23, 2013 at 10:40:29AM +0200, Geert Uytterhoeven wrote:

quoted

On Thu, May 23, 2013 at 9:57 AM, Chen Gang [off-list ref] wrote:

quoted

-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.

Is __builtin_unreachable() working well these days?

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds