Messages in this thread | | | Date | Wed, 22 Oct 2014 12:09:31 +0200 | From | Paolo Bonzini <> | Subject | Re: [PATCH 3/4] s390/mm: prevent and break zero page mappings in case of storage keys |
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On 10/22/2014 10:30 AM, Dominik Dingel wrote: > As use_skey is already the condition on which we call s390_enable_skey > we need to introduce a new flag for the mm->context on which we decide > if zero page mapping is allowed.
Can you explain better why "mm->context.use_skey = 1" cannot be done before the walk_page_range? Where does the walk or __s390_enable_skey or (after the next patch) ksm_madvise rely on "mm->context.forbids_zeropage && !mm->context.use_skey"?
The only reason I can think of, is that the next patch does not reset "mm->context.forbids_zeropage" to 0 if the ksm_madvise fails. Why doesn't it do that---or is it a bug?
Thanks, and sorry for the flurry of questions! :)
Paolo
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