From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932903AbaEEMxh (ORCPT ); Mon, 5 May 2014 08:53:37 -0400 Received: from ip4-83-240-18-248.cust.nbox.cz ([83.240.18.248]:41000 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932286AbaEEMne (ORCPT ); Mon, 5 May 2014 08:43:34 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Sergey Dyasly , Russell King , Jiri Slaby Subject: [PATCH 3.12 14/50] ARM: 7840/1: LPAE: don't reject mapping /dev/mem above 4GB Date: Mon, 5 May 2014 14:42:56 +0200 Message-Id: <4aeced5ed3e351ffad601615a11305b6e2eb16e1.1399292849.git.jslaby@suse.cz> X-Mailer: git-send-email 1.9.2 In-Reply-To: <7d4f4737432af6216e86975e587331b9d8b08063.1399292849.git.jslaby@suse.cz> References: <7d4f4737432af6216e86975e587331b9d8b08063.1399292849.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sergey Dyasly 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 3159f372354e8e1f5dee714663d705dd2c7e0759 upstream. With LPAE enabled, physical address space is larger than 4GB. Allow mapping any part of it via /dev/mem by using PHYS_MASK to determine valid range. PHYS_MASK covers 40 bits with LPAE enabled and 32 bits otherwise. Reported-by: Vassili Karpov Signed-off-by: Sergey Dyasly Acked-by: Catalin Marinas Signed-off-by: Russell King Signed-off-by: Jiri Slaby --- arch/arm/mm/mmap.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c index 304661d21369..5e85ed371364 100644 --- a/arch/arm/mm/mmap.c +++ b/arch/arm/mm/mmap.c @@ -202,13 +202,11 @@ int valid_phys_addr_range(phys_addr_t addr, size_t size) } /* - * We don't use supersection mappings for mmap() on /dev/mem, which - * means that we can't map the memory area above the 4G barrier into - * userspace. + * Do not allow /dev/mem mappings beyond the supported physical range. */ int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) { - return !(pfn + (size >> PAGE_SHIFT) > 0x00100000); + return (pfn + (size >> PAGE_SHIFT)) <= (1 + (PHYS_MASK >> PAGE_SHIFT)); } #ifdef CONFIG_STRICT_DEVMEM -- 1.9.2