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-rw-r--r--arch/arm/mm/fault-armv.c9
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))
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