From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932543AbcHNR7B (ORCPT ); Sun, 14 Aug 2016 13:59:01 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:54923 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932501AbcHNR65 (ORCPT ); Sun, 14 Aug 2016 13:58:57 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Russell King" , "Catalin Marinas" , "Steve Capper" , "Russell King" , "Will Deacon" Date: Sat, 13 Aug 2016 18:42:51 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 181/305] ARM: 8578/1: mm: ensure pmd_present only checks the valid bit In-Reply-To: X-SA-Exim-Connect-IP: 92.40.249.202 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.37-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Will Deacon commit 624531886987f0f1b5d01fb598034d039198e090 upstream. In a subsequent patch, pmd_mknotpresent will clear the valid bit of the pmd entry, resulting in a not-present entry from the hardware's perspective. Unfortunately, pmd_present simply checks for a non-zero pmd value and will therefore continue to return true even after a pmd_mknotpresent operation. Since pmd_mknotpresent is only used for managing huge entries, this is only an issue for the 3-level case. This patch fixes the 3-level pmd_present implementation to take into account the valid bit. For bisectability, the change is made before the fix to pmd_mknotpresent. [catalin.marinas@arm.com: comment update regarding pmd_mknotpresent patch] Fixes: 8d9625070073 ("ARM: mm: Transparent huge page support for LPAE systems.") Cc: Russell King Cc: Steve Capper Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Russell King Signed-off-by: Ben Hutchings --- arch/arm/include/asm/pgtable-2level.h | 1 + arch/arm/include/asm/pgtable-3level.h | 1 + arch/arm/include/asm/pgtable.h | 1 - 3 files changed, 2 insertions(+), 1 deletion(-) --- a/arch/arm/include/asm/pgtable-2level.h +++ b/arch/arm/include/asm/pgtable-2level.h @@ -163,6 +163,7 @@ static inline pmd_t *pmd_offset(pud_t *p #define pmd_large(pmd) (pmd_val(pmd) & 2) #define pmd_bad(pmd) (pmd_val(pmd) & 2) +#define pmd_present(pmd) (pmd_val(pmd)) #define copy_pmd(pmdpd,pmdps) \ do { \ --- a/arch/arm/include/asm/pgtable-3level.h +++ b/arch/arm/include/asm/pgtable-3level.h @@ -212,6 +212,7 @@ static inline pmd_t *pmd_offset(pud_t *p : !!(pmd_val(pmd) & (val))) #define pmd_isclear(pmd, val) (!(pmd_val(pmd) & (val))) +#define pmd_present(pmd) (pmd_isset((pmd), L_PMD_SECT_VALID)) #define pmd_young(pmd) (pmd_isset((pmd), PMD_SECT_AF)) #define __HAVE_ARCH_PMD_WRITE --- a/arch/arm/include/asm/pgtable.h +++ b/arch/arm/include/asm/pgtable.h @@ -182,7 +182,6 @@ extern pgd_t swapper_pg_dir[PTRS_PER_PGD #define pgd_offset_k(addr) pgd_offset(&init_mm, addr) #define pmd_none(pmd) (!pmd_val(pmd)) -#define pmd_present(pmd) (pmd_val(pmd)) static inline pte_t *pmd_page_vaddr(pmd_t pmd) {