On Mon, Nov 12, 2012 at 04:12:29PM +0100, Maarten Lankhorst wrote:
> Op 08-11-12 21:23, Sasha Levin schreef:
> > @@ -465,10 +465,8 @@ static void __init combiner_cascade_irq(unsigned int
> > combiner_nr, unsigned int i
> > else
> > max_nr = EXYNOS4_MAX_COMBINER_NR;
> >
> > - if (combiner_nr >= max_nr)
> > - BUG();
> > - if (irq_set_handler_data(irq, &combiner_data[combiner_nr]) != 0)
> > - BUG();
> > + BUG_ON(combiner_nr >= max_nr);
> > + BUG_ON(irq_set_handler_data(irq, &combiner_data[combiner_nr]) != 0);
>
> Is it really a good idea to put functions that perform work in a BUG_ON?
> I don't know, but for some reason it just feels wrong. I'd expect code to
> compile fine if BUG_ON was a noop, so doing verification calls only, not
> actual work..
Well, it is currently defined as:
include/asm-generic/bug.h:#define BUG_ON(condition) do { if
(unlikely(condition)) BUG(); } while(0)
include/asm-generic/bug.h:#define BUG_ON(condition) do { if (condition) ; }
while(0)
but as these can be overridden, I don't think relying on those
implementations is a good idea; to do so would be fragile. Eg, what if
the BUG_ON() implementation becomes just:
#define BUG_ON(x)
then the function call itself vanishes. So, only put the actual bug test
inside a BUG_ON(), not the functional part which must always be executed.
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