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[PATCH 4.9 01/78] x86/speculation/l1tf: Fix up pte->pfn conversion for PAE

4.9-stable review patch.  If anyone has any objections, please let me know.


From: Michal Hocko <mhocko@xxxxxxx>

commit e14d7dfb41f5807a0c1c26a13f2b8ef16af24935 upstream.

Jan has noticed that pte_pfn and co. resp. pfn_pte are incorrect for
CONFIG_PAE because phys_addr_t is wider than unsigned long and so the
pte_val reps. shift left would get truncated. Fix this up by using proper

[Just one chunk, again, needed here.  Thanks to Ben and Guenter for
finding and fixing this. - gregkh]

Fixes: 6b28baca9b1f ("x86/speculation/l1tf: Protect PROT_NONE PTEs against speculation")
Reported-by: Jan Beulich <JBeulich@xxxxxxxx>
Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

 arch/x86/include/asm/pgtable.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -420,7 +420,7 @@ static inline pmd_t pfn_pmd(unsigned lon
 static inline pud_t pfn_pud(unsigned long page_nr, pgprot_t pgprot)
-	phys_addr_t pfn = page_nr << PAGE_SHIFT;
+	phys_addr_t pfn = (phys_addr_t)page_nr << PAGE_SHIFT;
 	pfn ^= protnone_mask(pgprot_val(pgprot));
 	return __pud(pfn | massage_pgprot(pgprot));