From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f182.google.com (mail-pd0-f182.google.com [209.85.192.182]) by kanga.kvack.org (Postfix) with ESMTP id ECE8E900021 for ; Wed, 29 Oct 2014 05:46:22 -0400 (EDT) Received: by mail-pd0-f182.google.com with SMTP id fp1so2613964pdb.41 for ; Wed, 29 Oct 2014 02:46:22 -0700 (PDT) Received: from p3plsmtps2ded02.prod.phx3.secureserver.net (p3plsmtps2ded02.prod.phx3.secureserver.net. [208.109.80.59]) by mx.google.com with ESMTP id a10si131836pat.135.2014.10.29.02.46.21 for ; Wed, 29 Oct 2014 02:46:22 -0700 (PDT) From: Dexuan Cui 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> 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: kys@microsoft.com, haiyangz@microsoft.com 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, 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