powerpc/mm: Warn on flushing tlb page in kernel context
Function __flush_tlb_page() must only be called for user contexts, so
put in extra hardening to warn on calling it for kernel context.
Signed-off-by: Arseny Solokha <asolokha@kb.kras.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/mm/tlb_nohash.c b/arch/powerpc/mm/tlb_nohash.c
index ab0616b..cbd3d06 100644
--- a/arch/powerpc/mm/tlb_nohash.c
+++ b/arch/powerpc/mm/tlb_nohash.c
@@ -284,7 +284,11 @@
struct cpumask *cpu_mask;
unsigned int pid;
- if (unlikely(!mm))
+ /*
+ * This function as well as __local_flush_tlb_page() must only be called
+ * for user contexts.
+ */
+ if (unlikely(WARN_ON(!mm)))
return;
preempt_disable();