Messages in this thread | | | Date | Mon, 16 Aug 2021 19:03:54 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v28 16/32] x86/mm: Update maybe_mkwrite() for shadow stack |
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On Thu, Jul 22, 2021 at 01:52:03PM -0700, Yu-cheng Yu wrote: > diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c > index 3364fe62b903..ba449d12ec32 100644 > --- a/arch/x86/mm/pgtable.c > +++ b/arch/x86/mm/pgtable.c > @@ -610,6 +610,26 @@ int pmdp_clear_flush_young(struct vm_area_struct *vma, > } > #endif > > +pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) > +{ > + if (likely(vma->vm_flags & VM_WRITE)) > + pte = pte_mkwrite(pte); > + else if (likely(vma->vm_flags & VM_SHADOW_STACK)) > + pte = pte_mkwrite_shstk(pte); > + return pte; > +} > + > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE > +pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) > +{ > + if (likely(vma->vm_flags & VM_WRITE)) > + pmd = pmd_mkwrite(pmd); > + else if (likely(vma->vm_flags & VM_SHADOW_STACK)) > + pmd = pmd_mkwrite_shstk(pmd);
What are all those likely()ies here for?
-- Regards/Gruss, Boris.
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