From patchwork Wed Mar 5 11:25:16 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bharat Bhushan X-Patchwork-Id: 3773311 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 44AB2BF13A for ; Wed, 5 Mar 2014 11:29:48 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 6065320256 for ; Wed, 5 Mar 2014 11:29:47 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 73CC720251 for ; Wed, 5 Mar 2014 11:29:46 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WLA0y-0006US-CS; Wed, 05 Mar 2014 11:29:32 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1WLA0r-0005Up-E2; Wed, 05 Mar 2014 11:29:25 +0000 Received: from va3ehsobe003.messaging.microsoft.com ([216.32.180.13] helo=va3outboundpool.messaging.microsoft.com) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WLA0o-0005TJ-QS for linux-arm-kernel@lists.infradead.org; Wed, 05 Mar 2014 11:29:23 +0000 Received: from mail143-va3-R.bigfish.com (10.7.14.228) by VA3EHSOBE007.bigfish.com (10.7.40.11) with Microsoft SMTP Server id 14.1.225.22; Wed, 5 Mar 2014 11:29:00 +0000 Received: from mail143-va3 (localhost [127.0.0.1]) by mail143-va3-R.bigfish.com (Postfix) with ESMTP id 6D6B11A0041; Wed, 5 Mar 2014 11:29:00 +0000 (UTC) X-Forefront-Antispam-Report: CIP:70.37.183.190; KIP:(null); UIP:(null); IPV:NLI; H:mail.freescale.net; RD:none; EFVD:NLI X-SpamScore: 3 X-BigFish: VS3(zzzz1f42h2148h208ch1ee6h1de0h1fdah2073h2146h1202h1e76h2189h1d1ah1d2ah1fc6h1082kzdchz1de098h8275bh1de097hz2dh2a8h839he5bhf0ah107ah1288h12a5h12a9h12bdh12e5h137ah139eh13b6h1441h1504h1537h162dh1631h1758h1898h18e1h1946h19b5h1ad9h1b0ah1b2fh2222h224fh1fb3h1d0ch1d2eh1d3fh1dc1h1dfeh1dffh1e1dh1e23h1fe8h1ff5h2218h2216h226dh22d0h24afh2327h2336h2438h2461h2487h24d7h2516h2545h255eh25cch25f6h1155h) Received: from mail143-va3 (localhost.localdomain [127.0.0.1]) by mail143-va3 (MessageSwitch) id 1394018938865148_6330; Wed, 5 Mar 2014 11:28:58 +0000 (UTC) Received: from VA3EHSMHS033.bigfish.com (unknown [10.7.14.238]) by mail143-va3.bigfish.com (Postfix) with ESMTP id CD8B41C00BF; Wed, 5 Mar 2014 11:28:58 +0000 (UTC) Received: from mail.freescale.net (70.37.183.190) by VA3EHSMHS033.bigfish.com (10.7.99.43) with Microsoft SMTP Server (TLS) id 14.16.227.3; Wed, 5 Mar 2014 11:28:58 +0000 Received: from az84smr01.freescale.net (10.64.34.197) by 039-SN1MMR1-005.039d.mgd.msft.net (10.84.1.17) with Microsoft SMTP Server (TLS) id 14.3.158.2; Wed, 5 Mar 2014 11:28:46 +0000 Received: from freescale.com ([10.232.15.72]) by az84smr01.freescale.net (8.14.3/8.14.0) with SMTP id s25BSfwK017328; Wed, 5 Mar 2014 04:28:44 -0700 Received: by freescale.com (sSMTP sendmail emulation); Wed, 05 Mar 2014 16:55:17 +0530 From: Bharat Bhushan To: , , Subject: [PATCH v2] ARM64: Kernel managed pages are only flushed Date: Wed, 5 Mar 2014 16:55:16 +0530 Message-ID: <1394018716-17075-1-git-send-email-Bharat.Bhushan@freescale.com> X-Mailer: git-send-email 1.7.0.4 MIME-Version: 1.0 X-OriginatorOrg: freescale.com X-FOPE-CONNECTOR: Id%0$Dn%*$RO%0$TLS%0$FQDN%$TlsDn% X-FOPE-CONNECTOR: Id%0$Dn%FREESCALE.MAIL.ONMICROSOFT.COM$RO%1$TLS%0$FQDN%$TlsDn% X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140305_062922_891868_F289201B X-CRM114-Status: GOOD ( 11.14 ) X-Spam-Score: -1.3 (-) Cc: Bharat Bhushan X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD,UNPARSEABLE_RELAY,UNRESOLVED_TEMPLATE autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Kernel can only access pages which maps to managed memory. So flush only valid kernel pages. I observed kernel crash direct assigning a device using VFIO and found that it was caused because of accessing invalid page Signed-off-by: Bharat Bhushan --- v1->v2 Getting pfn usin pte_pfn() in pfn_valid. arch/arm64/mm/flush.c | 13 ++++++++++++- 1 files changed, 12 insertions(+), 1 deletions(-) diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c index e4193e3..319826a 100644 --- a/arch/arm64/mm/flush.c +++ b/arch/arm64/mm/flush.c @@ -72,7 +72,18 @@ void copy_to_user_page(struct vm_area_struct *vma, struct page *page, void __sync_icache_dcache(pte_t pte, unsigned long addr) { - struct page *page = pte_page(pte); + struct page *page; + +#ifdef CONFIG_HAVE_ARCH_PFN_VALID + /* + * We can only access pages that the kernel maps + * as memory. Bail out for unmapped ones. + */ + if (!pfn_valid(pte_pfn(pte))) + return; + +#endif + page = pte_page(pte); /* no flushing needed for anonymous pages */ if (!page_mapping(page))