Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: use the right protections for split-up pagetables
  x86, vmi: TSC going backwards check in vmi clocksource

1 files changed, 5 insertions, 10 deletions

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 8ca0d8566fc8..7be47d1a97e4 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -508,18 +508,13 @@ static int split_large_page(pte_t *kpte, unsigned long address)
 #endif
 
         /*
-         * Install the new, split up pagetable. Important details here:
+         * Install the new, split up pagetable.
          *
-         * On Intel the NX bit of all levels must be cleared to make a
-         * page executable. See section 4.13.2 of Intel 64 and IA-32
-         * Architectures Software Developer's Manual).
-         *
-         * Mark the entry present. The current mapping might be
-         * set to not present, which we preserved above.
+         * We use the standard kernel pagetable protections for the new
+         * pagetable protections, the actual ptes set above control the
+         * primary protection behavior:
          */
-        ref_prot = pte_pgprot(pte_mkexec(pte_clrhuge(*kpte)));
-        pgprot_val(ref_prot) |= _PAGE_PRESENT;
-        __set_pmd_pte(kpte, address, mk_pte(base, ref_prot));
+        __set_pmd_pte(kpte, address, mk_pte(base, __pgprot(_KERNPG_TABLE)));
         base = NULL;
 
 out_unlock: