[PATCH] lazy tlb: consolidate lazy tlb mm switching fix

[Nicholas Piggin]

On Fri Oct 13, 2023 at 11:12 PM AEST, Christophe Leroy wrote:
>
>
> Le 07/06/2023 à 02:56, Nicholas Piggin a écrit :
> > Fix an upstream powerpc bug that was discovered with a WARN_ON added in
> > "lazy tlb: consolidate lazy tlb mm switching":
> > 
> >     Switching mm and tinkering with current->active_mm should be done with
> >      irqs disabled. There is a path where exit_lazy_flush_tlb can be called
> >      with irqs enabled:
> > 
> >          exit_lazy_flush_tlb
> >          flush_type_needed
> >          __flush_all_mm
> >          tlb_finish_mmu
> >          exit_mmap
> > 
> >      Which results in the switching being incorrectly with irqs enabled.
> > 
> >      Link: https://lore.kernel.org/linuxppc-dev/87a5xcgopc.fsf@mail.lhotse/T/#m105488939d0cd9f980978ed2fdeeb89bf731e673
> >      Fixes: a665eec0a22e1 ("powerpc/64s/radix: Fix mm_cpumask trimming race vs k>
> > 
> > I will send that fix upstream, which will end up conflicting with these.
> > The resolution will be to take akpm's side of the merge (with this patch).
> > Or drop the patch when it conflicts and I'll resend it rebased on the fix.
>
> This seems to badly conflict at the moment, is it still applicable ?

Been away, will have to check where all this ended up.

Thanks,
Nick