1 files changed, 47 insertions, 3 deletions

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index ca1f1c2bb7be..091934e1d0d9 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -473,6 +473,19 @@ try_preserve_large_page(pte_t *kpte, unsigned long address,
         pgprot_val(req_prot) |= pgprot_val(cpa->mask_set);
 
         /*
+         * Set the PSE and GLOBAL flags only if the PRESENT flag is
+         * set otherwise pmd_present/pmd_huge will return true even on
+         * a non present pmd. The canon_pgprot will clear _PAGE_GLOBAL
+         * for the ancient hardware that doesn't support it.
+         */
+        if (pgprot_val(new_prot) & _PAGE_PRESENT)
+                pgprot_val(new_prot) |= _PAGE_PSE | _PAGE_GLOBAL;
+        else
+                pgprot_val(new_prot) &= ~(_PAGE_PSE | _PAGE_GLOBAL);
+
+        new_prot = canon_pgprot(new_prot);
+
+        /*
          * old_pte points to the large page base address. So we need
          * to add the offset of the virtual address:
          */
@@ -517,7 +530,7 @@ try_preserve_large_page(pte_t *kpte, unsigned long address,
                  * The address is aligned and the number of pages
                  * covers the full page.
                  */
-                new_pte = pfn_pte(pte_pfn(old_pte), canon_pgprot(new_prot));
+                new_pte = pfn_pte(pte_pfn(old_pte), new_prot);
                 __set_pmd_pte(kpte, address, new_pte);
                 cpa->flags |= CPA_FLUSHTLB;
                 do_split = 0;
@@ -561,16 +574,35 @@ int __split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase)
 #ifdef CONFIG_X86_64
         if (level == PG_LEVEL_1G) {
                 pfninc = PMD_PAGE_SIZE >> PAGE_SHIFT;
-                pgprot_val(ref_prot) |= _PAGE_PSE;
+                /*
+                 * Set the PSE flags only if the PRESENT flag is set
+                 * otherwise pmd_present/pmd_huge will return true
+                 * even on a non present pmd.
+                 */
+                if (pgprot_val(ref_prot) & _PAGE_PRESENT)
+                        pgprot_val(ref_prot) |= _PAGE_PSE;
+                else
+                        pgprot_val(ref_prot) &= ~_PAGE_PSE;
         }
 #endif
 
         /*
+         * Set the GLOBAL flags only if the PRESENT flag is set
+         * otherwise pmd/pte_present will return true even on a non
+         * present pmd/pte. The canon_pgprot will clear _PAGE_GLOBAL
+         * for the ancient hardware that doesn't support it.
+         */
+        if (pgprot_val(ref_prot) & _PAGE_PRESENT)
+                pgprot_val(ref_prot) |= _PAGE_GLOBAL;
+        else
+                pgprot_val(ref_prot) &= ~_PAGE_GLOBAL;
+
+        /*
          * Get the target pfn from the original entry:
          */
         pfn = pte_pfn(*kpte);
         for (i = 0; i < PTRS_PER_PTE; i++, pfn += pfninc)
-                set_pte(&pbase[i], pfn_pte(pfn, ref_prot));
+                set_pte(&pbase[i], pfn_pte(pfn, canon_pgprot(ref_prot)));
 
         if (pfn_range_is_mapped(PFN_DOWN(__pa(address)),
                                 PFN_DOWN(__pa(address)) + 1))
@@ -685,6 +717,18 @@ repeat:
                 new_prot = static_protections(new_prot, address, pfn);
 
                 /*
+                 * Set the GLOBAL flags only if the PRESENT flag is
+                 * set otherwise pte_present will return true even on
+                 * a non present pte. The canon_pgprot will clear
+                 * _PAGE_GLOBAL for the ancient hardware that doesn't
+                 * support it.
+                 */
+                if (pgprot_val(new_prot) & _PAGE_PRESENT)
+                        pgprot_val(new_prot) |= _PAGE_GLOBAL;
+                else
+                        pgprot_val(new_prot) &= ~_PAGE_GLOBAL;
+
+                /*
                  * We need to keep the pfn from the existing PTE,
                  * after all we're only going to change it's attributes
                  * not the memory it points to