Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932374AbaJ2JqZ (ORCPT ); Wed, 29 Oct 2014 05:46:25 -0400 Received: from p3plsmtps2ded02.prod.phx3.secureserver.net ([208.109.80.59]:55593 "EHLO p3plsmtps2ded02.prod.phx3.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932077AbaJ2JqV (ORCPT ); Wed, 29 Oct 2014 05:46:21 -0400 x-originating-ip: 72.167.245.219 From: Dexuan Cui To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org, olaf@aepfle.de, apw@canonical.com, jasowang@redhat.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, dave.hansen@intel.com, riel@redhat.com Cc: kys@microsoft.com, haiyangz@microsoft.com Subject: [PATCH] x86, pageattr: fix slow_virt_to_phys() for X86_PAE Date: Wed, 29 Oct 2014 03:53:53 -0700 Message-Id: <1414580033-27484-1-git-send-email-decui@microsoft.com> X-Mailer: git-send-email 1.7.4.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org pte_pfn() returns a PFN of long (32 bits in 32-PAE), then "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). Cc: K. Y. Srinivasan Cc: Haiyang Zhang Signed-off-by: Dexuan Cui --- 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); -- 1.9.1 -- 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/