On Fri Jun 23, 2023 at 11:20 PM AEST, Fabiano Rosas wrote: > Nicholas Piggin <[email protected]> writes: > > > From: BALATON Zoltan <[email protected]> > > > > All powerpc exception handlers share some code when handling machine > > check exceptions. Move this to a common function. > > > > Maybe Machine Check is simple enough, but this kind of sharing of code > has historically caused pain when people want to change something for > the modern cpus and end up affecting the old cpus by mistake. > > There is also the inverse scenario where someone has access to the old > HW and just want to make an one-off contribution, but the community gets > insecure about it because it could also affect the new cpus. > > Then comes the obvious "solution" which is to bring in an artificial > identifier (excp. model) to be able to have conditional code inside the > common function. And that causes problems because no one really knows > how it maps to actual hardware/ISA. > > No objection, just a little cautionary tale. =)
Thanks Fabiano, good point. I know you spent a lot of work on untangling this mess. I'll think a bit more about it. Seems we need to at least make a few fixes first before we can turn this on for upstream. Thanks, Nick
