Messages in this thread | | | Date | Thu, 14 Dec 2017 17:10:38 +0300 | From | "Kirill A. Shutemov" <> | Subject | Re: [PATCH PTI v3 03/10] x86/pti/64: Fix ESPFIX64 user mapping |
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On Wed, Dec 13, 2017 at 09:01:50AM -0800, Andy Lutomirski wrote: > On Wed, Dec 13, 2017 at 5:12 AM, Kirill A. Shutemov > <kirill@shutemov.name> wrote: > > On Tue, Dec 12, 2017 at 07:56:38AM -0800, Andy Lutomirski wrote: > >> The ESPFIX64 user mapping belongs in pti.c just like all the other > >> user mappings. Move it there and make it work correctly while we're > >> at it. > >> > >> Signed-off-by: Andy Lutomirski <luto@kernel.org> > > > > Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > > > > BTW, why do we open-code p?d_alloc() in pti_user_pagetable_walk_*()? > > It seems unnecessary and potentially bogus: see smp_wmb() in __p?d_alloc() > > helpers. > > The helpers won't work -- we're allocating kernel-owned tables in the > usermode part of init_mm. The p?d_alloc() helpers allocate > user-accounted tables in the kernelmode part of the mm.
What's wrong to account them against init_mm?
-- Kirill A. Shutemov
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