[PATCH 3.13 044/151] arm64: Do not synchronise I and D caches for special ptes

Kamal Mostafa kamal at canonical.com
Fri May 2 15:37:12 UTC 2014 -stable review patch.  If anyone has any objections, please let me know.


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

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 a08be42..322fe5b 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);

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