lkml.org 
[lkml]   [2010]   [Apr]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: Ugly rmap NULL ptr deref oopsie on hibernate (was Linux 2.6.34-rc3)
    From
    Date
    On Tue, 2010-04-06 at 08:55 -0700, Linus Torvalds wrote:
    > I do wonder if "page_lock_anon_vma()" should check the whole
    > "page_mapped()" case _after_ taking the anon_vma lock. Because if the race
    > happens, we're following a anon_vma list that has nothing to do with that
    > page (it's stilla _valid_ list, since we locked the anon_vma, but will it
    > be ok?)
    >
    > IOW, what is it that really keeps the anon_vma list reliable _and_
    > relevant wrt the page? We know we may get a stale anon_vma, are we ok if
    > that anon_vma list doesn't actually have anything to do with the page any
    > more?

    When doing the whole make i_mmap_lock/anon_vma->lock a mutex thing last
    week I ran into the same issue and its on my todo list to find out wth
    is happening there.

    So yes I think we should move that validation check inside
    page_lock_anon_vma().

    I'll cook up a patch once I'm done staring at the various funny arch
    mmu_gather implementations.


    \
     
     \ /
      Last update: 2010-04-07 10:41    [W:4.248 / U:0.072 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site