Re: [discuss] booting a kernel compiled with -mregparm=0

["H. Peter Anvin" <hpa@zytor.com>]

Andi Kleen wrote:
> 
> To be fair there isn't a nice library for it on x86-64.  There
> is libunwind on IA64, but afaik nobody ported it to x86-64 yet.
> 
> Just various projects have their own private unwind
> implementation. The kernel including KDB has always lived with
> imprecise backtraces and no argument printing. I don't think it has
> been a show stopper so far.  If you really want the arguments you can
> always use kgdb.
> 
> However I'm not sure we really want libunwind in the kernel anyways
> (not even in KDB ;-) If anything better something stripped down and 
> simple which libunwind isn't.
> 
> Unfortunately dwarf2 is not exactly a simple spec so implementing
> a new backtracer for the kernel is not a trivial task. 
> 

Seems like the unwinder should be running client-side, like it does on 
kgdb.  Or does kdb not have a client at all?  (If so, I have no sympathy 
for it.)

	-hpa