Messages in this thread | | | Date | Sat, 27 Jan 2007 09:08:58 +0000 (GMT) | From | Hugh Dickins <> | Subject | Re: [PATCH] Don't allow the stack to grow into hugetlb reserved regions |
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On Fri, 26 Jan 2007, Ken Chen wrote: > On 1/26/07, Hugh Dickins <hugh@veritas.com> wrote: > > Less trivial (and I wonder whether you've come to this from an ia64 > > or a powerpc direction): I notice that ia64 has more stringent REGION > > checks in its ia64_do_page_fault, before calling expand_stack or > > expand_upwards. So on that path, the usual path, I think your > > new check in acct_stack_growth is unnecessary on ia64; > > I think you are correct. This appears to affect powerpc only. On ia64, > hugetlb lives in a completely different region and they can never step > into normal stack address space. And for x86, there isn't a thing called > "reserved address space" for hugetlb mapping.
Thanks, that's reassuring for the hugetlb case, and therefore Adam's patch should not be delayed. But it does leave open the question I was raising in the text you've snipped: if ia64 needs those stringent REGION checks in its ia64_do_page_fault path, don't we need to add them some(messy)how in the get_user_pages find_extend_vma path?
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