Merge 4.9.122 into android-4.9

Changes in 4.9.122
	x86/speculation/l1tf: Exempt zeroed PTEs from inversion
	Linux 4.9.122

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Makefile

diff --git a/Makefile b/Makefile
index 0d51510..46ecbf7a 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 VERSION = 4
 PATCHLEVEL = 9
-SUBLEVEL = 121
+SUBLEVEL = 122
 EXTRAVERSION =
 NAME = Roaring Lionus
 

arch/x86/include/asm/pgtable-invert.h

diff --git a/arch/x86/include/asm/pgtable-invert.h b/arch/x86/include/asm/pgtable-invert.h
index 44b1203e..a0c1525 100644
--- a/arch/x86/include/asm/pgtable-invert.h
+++ b/arch/x86/include/asm/pgtable-invert.h
@@ -4,9 +4,18 @@
 
 #ifndef __ASSEMBLY__
 
+/*
+ * A clear pte value is special, and doesn't get inverted.
+ *
+ * Note that even users that only pass a pgprot_t (rather
+ * than a full pte) won't trigger the special zero case,
+ * because even PAGE_NONE has _PAGE_PROTNONE | _PAGE_ACCESSED
+ * set. So the all zero case really is limited to just the
+ * cleared page table entry case.
+ */
 static inline bool __pte_needs_invert(u64 val)
 {
-	return !(val & _PAGE_PRESENT);
+	return val && !(val & _PAGE_PRESENT);
 }
 
 /* Get a mask to xor with the page table entry to get the correct pfn. */