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

2 files changed, 9 insertions, 11 deletions

diff --git a/arch/x86/kernel/vmiclock_32.c b/arch/x86/kernel/vmiclock_32.c
index c4c1f9e09402..bde106cae0a9 100644
--- a/arch/x86/kernel/vmiclock_32.c
+++ b/arch/x86/kernel/vmiclock_32.c
@@ -283,10 +283,13 @@ void __devinit vmi_time_ap_init(void)
 #endif
 
 /** vmi clocksource */
+static struct clocksource clocksource_vmi;
 
 static cycle_t read_real_cycles(void)
 {
-        return vmi_timer_ops.get_cycle_counter(VMI_CYCLES_REAL);
+        cycle_t ret = (cycle_t)vmi_timer_ops.get_cycle_counter(VMI_CYCLES_REAL);
+        return ret >= clocksource_vmi.cycle_last ?
+                ret : clocksource_vmi.cycle_last;
 }
 
 static struct clocksource clocksource_vmi = {
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: