From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vassili Karpov , Sergey Dyasly , Catalin Marinas , Russell King , hujianyang Subject: [PATCH 3.10 07/48] ARM: 7840/1: LPAE: dont reject mapping /dev/mem above 4GB Date: Sun, 11 May 2014 21:19:41 +0200 Message-Id: <20140511191949.129664388@linuxfoundation.org> In-Reply-To: <20140511191948.079900414@linuxfoundation.org> References: <20140511191948.079900414@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sergey Dyasly 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 Cc: hujianyang Signed-off-by: Greg Kroah-Hartman --- arch/arm/mm/mmap.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) --- a/arch/arm/mm/mmap.c +++ b/arch/arm/mm/mmap.c @@ -204,13 +204,11 @@ int valid_phys_addr_range(phys_addr_t ad } /* - * 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