Re: Ugly rmap NULL ptr deref oopsie on hibernate (was Linux 2.6.34-rc3)
From: Rik van Riel
Date: Tue Apr 06 2010 - 10:36:25 EST
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?
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/