[3.8.y.z extended stable] Patch "arm64: Do not synchronise I and D caches for special ptes" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

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

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.22.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 8e00338e37c9b04e6aaf95d483e15a7f0cb1fafb Mon Sep 17 00:00:00 2001
From: Catalin Marinas <catalin.marinas at arm.com>
Date: Wed, 12 Mar 2014 16:28:09 +0000
Subject: arm64: Do not synchronise I and D caches for special ptes

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 at arm.com>
Reported-by: Steve Capper <Steve.Capper at arm.com>
Tested-by: Laura Abbott <lauraa at codeaurora.org>
Tested-by: Bharat Bhushan <Bharat.Bhushan at freescale.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 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 09a6b8f..1d7373a 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -161,7 +161,7 @@ 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);
--
1.9.1