mm: disable preemption in apply_to_pte_range
Impact: bugfix
Lazy mmu mode needs preemption disabled, so if we're apply to
init_mm (which doesn't require any pte locks), then explicitly
disable preemption. (Do it unconditionally after checking we've
successfully done the allocation to simplify the error handling.)
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
diff --git a/mm/memory.c b/mm/memory.c
index baa999e..b80cc31 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1718,6 +1718,7 @@
BUG_ON(pmd_huge(*pmd));
+ preempt_disable();
arch_enter_lazy_mmu_mode();
token = pmd_pgtable(*pmd);
@@ -1729,6 +1730,7 @@
} while (pte++, addr += PAGE_SIZE, addr != end);
arch_leave_lazy_mmu_mode();
+ preempt_enable();
if (mm != &init_mm)
pte_unmap_unlock(pte-1, ptl);