[SPARC64]: Fix D-cache corruption in mremap
If we move a mapping from one virtual address to another,
and this changes the virtual color of the mapping to those
pages, we can see corrupt data due to D-cache aliasing.
Check for and deal with this by overriding the move_pte()
macro. Set things up so that other platforms can cleanly
override the move_pte() macro too.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/asm-mips/pgtable.h b/include/asm-mips/pgtable.h
index 702a28f..69cebbd 100644
--- a/include/asm-mips/pgtable.h
+++ b/include/asm-mips/pgtable.h
@@ -70,7 +70,15 @@
#define ZERO_PAGE(vaddr) \
(virt_to_page(empty_zero_page + (((unsigned long)(vaddr)) & zero_page_mask)))
-#define __HAVE_ARCH_MULTIPLE_ZERO_PAGE
+#define __HAVE_ARCH_MOVE_PTE
+#define move_pte(pte, prot, old_addr, new_addr) \
+({ \
+ pte_t newpte = (pte); \
+ if (pte_present(pte) && pfn_valid(pte_pfn(pte)) && \
+ pte_page(pte) == ZERO_PAGE(old_addr)) \
+ newpte = mk_pte(ZERO_PAGE(new_addr), (prot)); \
+ newpte; \
+})
extern void paging_init(void);