Messages in this thread | | | Date | Tue, 06 Apr 2010 10:34:21 -0400 | From | Rik van Riel <> | Subject | Re: Ugly rmap NULL ptr deref oopsie on hibernate (was Linux 2.6.34-rc3) |
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On 04/06/2010 06:09 AM, KOSAKI Motohiro wrote: >> (b) is also impossible. SLAB_DESTROY_BY_RCU delay the page for anon_vma >> freeing until next rcu period. It mean rcu_read_lock()+page_mapped() >> can see kfree()ed page. but it is safe. noone corrupt it. > > by the way: I haven't understand why rik's per process anon_vma concept > works correctly with ksm. ksm increase anon_vma->ksm_refcount. but it seems > not guranteed vma->anon_vma and page->anon_vma are the same.
KSM removes the page from its original anon_vma.
If the page gets reinstantiated (copy on write), it will be created in the vma->anon_vma.
Am I overlooking something?
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