Fix lazy mode vmalloc synchronization for paravirt

Touching vmalloc memory in the middle of a lazy mode update can generate
a kernel PDE update, which must be flushed immediately.  The fix is to
leave lazy mode when doing a vmalloc sync.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/arch/i386/mm/fault.c b/arch/i386/mm/fault.c
index 01ffdd4964f0..fcb38e7f3543 100644
--- a/arch/i386/mm/fault.c
+++ b/arch/i386/mm/fault.c
@@ -249,9 +249,10 @@ static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address)
         pmd_k = pmd_offset(pud_k, address);
         if (!pmd_present(*pmd_k))
                 return NULL;
-        if (!pmd_present(*pmd))
+        if (!pmd_present(*pmd)) {
                 set_pmd(pmd, *pmd_k);
-        else
+                arch_flush_lazy_mmu_mode();
+        } else
                 BUG_ON(pmd_page(*pmd) != pmd_page(*pmd_k));
         return pmd_k;
 }