On Mon, 2018-03-26 at 15:01:03 UTC, Nicholas Piggin wrote: > System Reset, being an NMI, must return more carefully than other > interrupts. It has traditionally returned via the nromal return > from exception path, but that has a number of problems. > > - r13 does not get restored if returning to kernel. This is for > interrupts which may cause a context switch, which sreset will > never do. Interrupting OPAL (which uses a different r13) is one > place where this causes breakage. > > - It may cause several other problems returning to kernel with > preempt or TIF_EMULATE_STACK_STORE if it hits at the wrong time. > > It's safer just to have a simple restore and return, like machine > check which is the other NMI. > > Signed-off-by: Nicholas Piggin <npig...@gmail.com>
Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/15b4dd7981496f51c5f9262a5e0761 cheers
