1 files changed, 9 insertions, 0 deletions

diff --git a/arch/arm/mm/fault-armv.c b/arch/arm/mm/fault-armv.c
index d0d17b6a3703..729602291958 100644
--- a/arch/arm/mm/fault-armv.c
+++ b/arch/arm/mm/fault-armv.c
@@ -23,6 +23,8 @@
 #include <asm/pgtable.h>
 #include <asm/tlbflush.h>
 
+#include "mm.h"
+
 static unsigned long shared_pte_mask = L_PTE_MT_BUFFERABLE;
 
 /*
@@ -151,7 +153,14 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
         if (!pfn_valid(pfn))
                 return;
 
+        /*
+         * The zero page is never written to, so never has any dirty
+         * cache lines, and therefore never needs to be flushed.
+         */
         page = pfn_to_page(pfn);
+        if (page == ZERO_PAGE(0))
+                return;
+
         mapping = page_mapping(page);
 #ifndef CONFIG_SMP
         if (test_and_clear_bit(PG_dcache_dirty, &page->flags))