Messages in this thread | | | Date | Sun, 18 Mar 2012 22:07:51 +0000 | From | Al Viro <> | Subject | Re: [rfc][patches] fix for munmap/truncate races |
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On Sun, Mar 18, 2012 at 10:06:10PM +0000, Al Viro wrote: > On Sun, Mar 18, 2012 at 03:01:08PM -0700, Linus Torvalds wrote: > > On Sun, Mar 18, 2012 at 12:07 PM, Al Viro <viro@zeniv.linux.org.uk> wrote: > > > - ? ? ? tlb_finish_mmu(&tlb, 0, end); > > > + ? ? ? tlb_finish_mmu(&tlb, 0, -1); > > > > Hmm. The fact that you drop the end pointer means that some > > architectures that optimize the TLB flushing for ranges now > > effectively can't do it any more. > > > > Now, I think it's only ia64 that really is affected, but it *might* matter. > > > > In particular, ia64 has some logic for "if you only flush one single > > region, you can optimize it", and the region sizes are in the > > terabytes. And I'm pretty sure you broke that - I'm just not entirely > > sure how much we care. > > Nope - ia64 check explicitly for precisely that case: [snip] ... and everything else doesn't look at start or end at all.
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