Messages in this thread | | | Date | Wed, 11 Jan 2023 17:14:59 +0300 | From | "Kirill A. Shutemov" <> | Subject | Re: [PATCHv14 04/17] x86/mm: Handle LAM on context switch |
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On Wed, Jan 11, 2023 at 07:49:30AM -0600, Linus Torvalds wrote: > Sorry, I'm traveling, and right now only on mobile. So I'm reading patches > on my phone, and answering on it too, so html garbage.. > > On Wed, Jan 11, 2023, 07:24 Kirill A. Shutemov < > kirill.shutemov@linux.intel.com> wrote: > > > > > +static inline unsigned long mm_lam_cr3_mask(struct mm_struct *mm) > > +{ > > + return READ_ONCE(mm->context.lam_cr3_mask); > > +} > > > > I mentioned this before - in the original version this needed (but didn't > have, iirc) that READ_ONCE, but in the new non-thread situation I don't > think that's true. There should be no concurrent changes that can interfere > with the read, no?
It should be safe, yes.
It is reachable from iommu_sva_bind_device(), but it only called with mm == current->mm.
I will drop the READ_ONCE().
-- Kiryl Shutsemau / Kirill A. Shutemov
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