Re: BUG and WARN kernel log levels

[Joe Perches <joe@perches.com>]

On Mon, 2016-08-15 at 11:53 -0700, Kees Cook wrote:
> Hi,
> 
> So, I noticed that asm-gemeric/bug.h defines BUG() without a log level:
> 
> #ifndef HAVE_ARCH_BUG
> #define BUG() do { \
>        printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \
> 
> Seems like it should have one?
> 
> Also, I think we might want to examine WARN() a bit... it doesn't have
> a log level either, but only a fraction of callers set one:
> 
> $ git grep -E 'WARN(_TAINT|)(_RATELIMIT|_ONCE|)\([^\)]' | grep -v KERN_ | wc -l
> 2735
> 
> $ git grep -E 'WARN(_TAINT|)(_RATELIMIT|_ONCE|)\([^\)]' | grep KERN_ | wc -l
> 77
> 
> If I'm reading checkpatch.pl correctly, it doesn't warn about missing
> log levels on WARN calls, but I think it should.
> 
> How do you think is best to clean this up?
> 
> Mainly, I'd like to add a format string to BUG, or introduce a new
> BUGish call that takes a format...

I once suggested something similar awhile ago.
https://lkml.org/lkml/2008/7/8/261

I think it's best to remove any KERN_<LEVEL> from the use of
all the WARN variants and add it to the WARN definitions.

Same with BUG.