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Subject[PATCH 4.4 39/43] x86/speculation/l1tf: Invert all not present mappings
Date
4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andi Kleen <ak@linux.intel.com>

commit f22cc87f6c1f771b57c407555cfefd811cdd9507 upstream

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>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/include/asm/pgtable-invert.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/include/asm/pgtable-invert.h
+++ b/arch/x86/include/asm/pgtable-invert.h
@@ -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. */

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