[PATCH 3.12 006/182] arm64: Do not synchronise I and D caches for special ptes

Jiri Slaby
2014-05-13T10:40:26Z

From: Catalin Marinas <catalin.marinas@arm.com>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

commit 71fdb6bf61bf0692f004f9daf5650392c0cfe300 upstream.

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>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
arch/arm64/include/asm/pgtable.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 82d95a7e9466..62713586d6e3 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -168,7 +168,7 @@ 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 = pte_wrprotect(pte);
--
1.9.3