x86/speculation/l1tf: Invert all not present mappings
authorAndi Kleen <ak@linux.intel.com>
Tue, 7 Aug 2018 22:09:36 +0000 (15:09 -0700)
committerThomas Gleixner <tglx@linutronix.de>
Wed, 8 Aug 2018 07:23:43 +0000 (09:23 +0200)
For kernel mappings PAGE_PROTNONE is not necessarily set for a non present
mapping, but the inversion logic explicitely checks for !PRESENT and
PROT_NONE.

Remove the PROT_NONE check and make the inversion unconditional for all not
present mappings.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
arch/x86/include/asm/pgtable-invert.h

index 1775641..44b1203 100644 (file)
@@ -6,7 +6,7 @@
 
 static inline bool __pte_needs_invert(u64 val)
 {
-       return (val & (_PAGE_PRESENT|_PAGE_PROTNONE)) == _PAGE_PROTNONE;
+       return !(val & _PAGE_PRESENT);
 }
 
 /* Get a mask to xor with the page table entry to get the correct pfn. */