Re: [PATCH] powerpc/bug: Remove specific powerpc BUG_ON()

[Nicholas Piggin]

Excerpts from Segher Boessenkool's message of February 11, 2021 9:50 pm:
> On Thu, Feb 11, 2021 at 08:04:55PM +1000, Nicholas Piggin wrote:
>> It would be nice if we could have a __builtin_trap_if that gcc would use 
>> conditional traps with, (and which never assumes following code is 
>> unreachable even for constant true, so we can use it with WARN and put 
>> explicit unreachable for BUG).
> 
> It automatically does that with just __builtin_trap, see my other mail :-)

If that is generated without branches (or at least with no more
branches than existing asm implementation), then it could be usable 
without trashing CFAR.

Unfortunately I don't think we will be parsing the dwarf information
to get line numbers from it any time soon, so not a drop in replacement 
but maybe one day someone would find a solution.

Thanks,
Nick