Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932296AbaJ2KAp (ORCPT ); Wed, 29 Oct 2014 06:00:45 -0400 Received: from terminus.zytor.com ([198.137.202.10]:59191 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932218AbaJ2KAm (ORCPT ); Wed, 29 Oct 2014 06:00:42 -0400 Date: Wed, 29 Oct 2014 03:00:30 -0700 From: tip-bot for Dexuan Cui Message-ID: Cc: hpa@zytor.com, haiyangz@microsoft.com, mingo@kernel.org, tglx@linutronix.de, decui@microsoft.com, linux-kernel@vger.kernel.org, kys@microsoft.com Reply-To: hpa@zytor.com, haiyangz@microsoft.com, mingo@kernel.org, tglx@linutronix.de, kys@microsoft.com, decui@microsoft.com, linux-kernel@vger.kernel.org In-Reply-To: <1414580017-27444-1-git-send-email-decui@microsoft.com> References: <1414580017-27444-1-git-send-email-decui@microsoft.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE Git-Commit-ID: d1cd1210834649ce1ca6bafe5ac25d2f40331343 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: d1cd1210834649ce1ca6bafe5ac25d2f40331343 Gitweb: http://git.kernel.org/tip/d1cd1210834649ce1ca6bafe5ac25d2f40331343 Author: Dexuan Cui AuthorDate: Wed, 29 Oct 2014 03:53:37 -0700 Committer: Thomas Gleixner CommitDate: Wed, 29 Oct 2014 10:57:21 +0100 x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE pte_pfn() returns a PFN of long (32 bits in 32-PAE), so "long << PAGE_SHIFT" will overflow for PFNs above 4GB. Due to this issue, some Linux 32-PAE distros, running as guests on Hyper-V, with 5GB memory assigned, can't load the netvsc driver successfully and hence the synthetic network device can't work (we can use the kernel parameter mem=3000M to work around the issue). Cast pte_pfn() to phys_addr_t before shifting. Fixes: "commit d76565344512: x86, mm: Create slow_virt_to_phys()" Signed-off-by: Dexuan Cui Cc: K. Y. Srinivasan Cc: Haiyang Zhang Cc: gregkh@linuxfoundation.org Cc: linux-mm@kvack.org Cc: olaf@aepfle.de Cc: apw@canonical.com Cc: jasowang@redhat.com Cc: dave.hansen@intel.com Cc: riel@redhat.com Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1414580017-27444-1-git-send-email-decui@microsoft.com Signed-off-by: Thomas Gleixner --- arch/x86/mm/pageattr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index ae242a7..36de293 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -409,7 +409,7 @@ phys_addr_t slow_virt_to_phys(void *__virt_addr) psize = page_level_size(level); pmask = page_level_mask(level); offset = virt_addr & ~pmask; - phys_addr = pte_pfn(*pte) << PAGE_SHIFT; + phys_addr = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT; return (phys_addr | offset); } EXPORT_SYMBOL_GPL(slow_virt_to_phys); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/