arm64: Do not synchronise I and D caches for special ptes

Special pte mappings are not intended to be executable and do not even
have an associated struct page. This patch ensures that we do not call
__sync_icache_dcache() on such ptes.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Steve Capper <Steve.Capper@arm.com>
Tested-by: Laura Abbott <lauraa@codeaurora.org>
Tested-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
Cc: <stable@vger.kernel.org>

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 2d3cede..72c9ac3 100644 (file)
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -199,7 +199,7 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
                              pte_t *ptep, pte_t pte)
 {
        if (pte_valid_user(pte)) {
-               if (pte_exec(pte))
+               if (!pte_special(pte) && pte_exec(pte))
                        __sync_icache_dcache(pte, addr);
                if (pte_dirty(pte) && pte_write(pte))
                        pte_val(pte) &= ~PTE_RDONLY;