On Thu, Jun 14, 2018 at 10:10 PM Siarhei Liakh <siarhei.li...@concurrent-rt.com> wrote: > > fpu__drop() has an explicit fwait which under some conditions can trigger > a fixable FPU exception while in kernel. Thus, we should attempt to fixup > the exception first, and only call notify_die() if the fixup failed just > like in do_general_protection(). The original call sequence incorrectly > triggers KDB entry on debug kernels under particular FPU-intensive > workloads. This issue had been privately observed, fixed, and tested > on 4.9.98, while this patch brings the fix to the upstream.
Reviewed-by: Andy Lutomirski <l...@kernel.org> With the caveat that you are perpetuating what is arguably a bug in some of the other entries: math_error() can now be called with IRQs off and return with IRQs on. If we actually start asserting good behavior in the entry code, we'll need to fix this. --Andy
