On 8/16/2021 10:03 AM, Borislav Petkov wrote:

On Thu, Jul 22, 2021 at 01:52:03PM -0700, Yu-cheng Yu wrote:

quoted

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?

I will remove those.

Thanks,
Yu-cheng