Re: [RFC] asm-generic: default BUG_ON(x) to "if(x) BUG()"

Willy Tarreau
2015-11-23T16:52:48Z

On Mon, Nov 23, 2015 at 04:37:50PM +0000, Russell King - ARM Linux wrote:
> On Mon, Nov 23, 2015 at 05:33:59PM +0100, Willy Tarreau wrote:
> > I think you could do better by simply calling panic("BUG!") instead as
> > BUG() does. It will avoid the printk() call and pushing the file/line
> > number onto the stack. It will also probably not inflate the rodata this
> > way.
>
> Does that not depend on the architectures BUG() implementation? If an
> architecture implements it as a signalling illegal instruction and a
> lookup table, changing it to be a panic() would probably be more code.

That's a very good point, I didn't think about it and yes I think you're
right then (eg: when CONFIG_DEBUG_BUGVERBOSE is not set, x86 and arm will
only emit a single instruction).

Best regards,
Willy