On Fri, Aug 24, 2018 at 03:25:45PM -0400, jglisse@xxxxxxxxxx wrote: > From: Ralph Campbell <rcampbell@xxxxxxxxxx> > > In hmm_mirror_unregister(), mm->hmm is set to NULL and then > mmu_notifier_unregister_no_release() is called. That creates a small > window where mmu_notifier can call mmu_notifier_ops with mm->hmm equal > to NULL. Fix this by first unregistering mmu notifier callbacks and > then setting mm->hmm to NULL. > > Similarly in hmm_register(), set mm->hmm before registering mmu_notifier > callbacks so callback functions always see mm->hmm set. > > Signed-off-by: Ralph Campbell <rcampbell@xxxxxxxxxx> > Reviewed-by: John Hubbard <jhubbard@xxxxxxxxxx> > Reviewed-by: Jérôme Glisse <jglisse@xxxxxxxxxx> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx Reviewed-by: Balbir Singh <bsingharora@xxxxxxxxx>
