From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756398Ab3ASBgv (ORCPT ); Fri, 18 Jan 2013 20:36:51 -0500 Received: from mail.kernel.org ([198.145.19.201]:56239 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755473Ab3ASBRp (ORCPT ); Fri, 18 Jan 2013 20:17:45 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Will Deacon , Catalin Marinas Subject: [ 04/33] arm64: mm: only wrprotect clean ptes if they are present Date: Fri, 18 Jan 2013 17:16:29 -0800 Message-Id: <20130119010347.330247690@linuxfoundation.org> X-Mailer: git-send-email 1.8.1.rc1.5.g7e0651a In-Reply-To: <20130119010345.885772698@linuxfoundation.org> References: <20130119010345.885772698@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Will Deacon commit 02522463c84748b3b8ad770f9424bcfa70a5b4c4 upstream. Marking non-present ptes as read-only can corrupt file ptes, breaking things like swap and file mappings. This patch ensures that we only manipulate user pte bits when the pte is marked present. Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman --- arch/arm64/include/asm/pgtable.h | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -132,9 +132,8 @@ extern struct page *empty_zero_page; #define pte_write(pte) (!(pte_val(pte) & PTE_RDONLY)) #define pte_exec(pte) (!(pte_val(pte) & PTE_UXN)) -#define pte_present_exec_user(pte) \ - ((pte_val(pte) & (PTE_VALID | PTE_USER | PTE_UXN)) == \ - (PTE_VALID | PTE_USER)) +#define pte_present_user(pte) \ + ((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER)) #define PTE_BIT_FUNC(fn,op) \ static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; } @@ -157,10 +156,13 @@ extern void __sync_icache_dcache(pte_t p static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte) { - if (pte_present_exec_user(pte)) - __sync_icache_dcache(pte, addr); - if (!pte_dirty(pte)) - pte = pte_wrprotect(pte); + if (pte_present_user(pte)) { + if (pte_exec(pte)) + __sync_icache_dcache(pte, addr); + if (!pte_dirty(pte)) + pte = pte_wrprotect(pte); + } + set_pte(ptep, pte); }