On Fri, 2010-08-27 at 21:47 -0500, Christoph Lameter wrote: > > I'd be much more comfortable if the following would be done > > A. Pin the anon_vma by either > I. Take a refcount on the anon vma My preemptible mmu patches do that.. > II. Take a lock in the anon vma (something that is not pointed to) > > B. Either > I. All values that have been used before the pinning are > verified after the pinning (and the lock is reacquired > if verification fails). > > II. Or all functions using page_lock_anon_vma() must securely > work in the case that the anon_vma was reused for > something else before the vma lock was acquired. Last time I looked they all work like that, they all use something akin to vma_address() which validates that the page we're interested in is indeed part of the vma we obtained from the rmap chain. Anyway, I'll try and refresh my preemptible mmu patch-set now that the merge window dust settled and post if again, hopefully we can stick it in -next. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href