From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qc0-f174.google.com (mail-qc0-f174.google.com [209.85.216.174]) by kanga.kvack.org (Postfix) with ESMTP id 0405F900021 for ; Wed, 29 Oct 2014 05:51:06 -0400 (EDT) Received: by mail-qc0-f174.google.com with SMTP id r5so2018807qcx.33 for ; Wed, 29 Oct 2014 02:51:06 -0700 (PDT) Received: from na01-bn1-obe.outbound.protection.outlook.com (mail-bn1on0143.outbound.protection.outlook.com. [157.56.110.143]) by mx.google.com with ESMTPS id y9si6641852qab.10.2014.10.29.02.51.06 for (version=TLSv1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 29 Oct 2014 02:51:06 -0700 (PDT) From: Dexuan Cui Subject: RE: [PATCH] x86, pageattr: fix slow_virt_to_phys() for X86_PAE Date: Wed, 29 Oct 2014 09:50:23 +0000 Message-ID: References: <1414580033-27484-1-git-send-email-decui@microsoft.com> In-Reply-To: <1414580033-27484-1-git-send-email-decui@microsoft.com> Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: 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: KY Srinivasan , Haiyang Zhang > -----Original Message----- > From: owner-linux-mm@kvack.org [mailto:owner-linux-mm@kvack.org] On > Behalf Of Dexuan Cui > Sent: Wednesday, October 29, 2014 18:54 PM > 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: KY Srinivasan; Haiyang Zhang > Subject: [PATCH] x86, pageattr: fix slow_virt_to_phys() for X86_PAE >=20 > pte_pfn() returns a PFN of long (32 bits in 32-PAE), then > "long << PAGE_SHIFT" will overflow for PFNs above 4GB. >=20 > 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=3D3000M to work around the issue). >=20 > 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(-) >=20 > 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 =3D page_level_size(level); > pmask =3D page_level_mask(level); > offset =3D virt_addr & ~pmask; > - phys_addr =3D pte_pfn(*pte) << PAGE_SHIFT; > + phys_addr =3D (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT; > return (phys_addr | offset); > } > EXPORT_SYMBOL_GPL(slow_virt_to_phys); Sorry for sending the same patch twice due to my silly typing! Thanks, -- Dexuan -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org