Similar to commit<0dc294f7>, there should be a check for 'mm' to prevent Null
pointer dereference in case of 'mm' argument was legitimately passed.
Signed-off-by: Defang Bo <bodef...@126.com>
---
arch/powerpc/mm/nohash/tlb.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/powerpc/mm/nohash/tlb.c b/arch/powerpc/mm/nohash/tlb.c
index 5872f69..09796c9 100644
--- a/arch/powerpc/mm/nohash/tlb.c
+++ b/arch/powerpc/mm/nohash/tlb.c
@@ -268,6 +268,9 @@ void flush_tlb_mm(struct mm_struct *mm)
{
unsigned int pid;
+ if (unlikely(!mm))
+ return;
+
preempt_disable();
pid = mm->context.id;
if (unlikely(pid == MMU_NO_CONTEXT))
--
2.7.4
