From patchwork Wed Mar 5 11:20:46 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bharat Bhushan X-Patchwork-Id: 3773221 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id B21689F1EE for ; Wed, 5 Mar 2014 11:24:49 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id CE8DD20256 for ; Wed, 5 Mar 2014 11:24:48 +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 E36452024C for ; Wed, 5 Mar 2014 11:24:47 +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 1WL9wJ-0004wy-D8; Wed, 05 Mar 2014 11:24:43 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1WL9wG-0005HN-Qb; Wed, 05 Mar 2014 11:24:40 +0000 Received: from tx2ehsobe001.messaging.microsoft.com ([65.55.88.11] helo=tx2outboundpool.messaging.microsoft.com) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WL9wF-0005H2-9K for linux-arm-kernel@lists.infradead.org; Wed, 05 Mar 2014 11:24:39 +0000 Received: from mail31-tx2-R.bigfish.com (10.9.14.251) by TX2EHSOBE001.bigfish.com (10.9.40.21) with Microsoft SMTP Server id 14.1.225.22; Wed, 5 Mar 2014 11:24:18 +0000 Received: from mail31-tx2 (localhost [127.0.0.1]) by mail31-tx2-R.bigfish.com (Postfix) with ESMTP id F253D180313; Wed, 5 Mar 2014 11:24:17 +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 mail31-tx2 (localhost.localdomain [127.0.0.1]) by mail31-tx2 (MessageSwitch) id 139401865781430_26353; Wed, 5 Mar 2014 11:24:17 +0000 (UTC) Received: from TX2EHSMHS014.bigfish.com (unknown [10.9.14.229]) by mail31-tx2.bigfish.com (Postfix) with ESMTP id 0C8B8F40054; Wed, 5 Mar 2014 11:24:17 +0000 (UTC) Received: from mail.freescale.net (70.37.183.190) by TX2EHSMHS014.bigfish.com (10.9.99.114) with Microsoft SMTP Server (TLS) id 14.16.227.3; Wed, 5 Mar 2014 11:24:17 +0000 Received: from az84smr01.freescale.net (10.64.34.197) by 039-SN1MMR1-004.039d.mgd.msft.net (10.84.1.14) with Microsoft SMTP Server (TLS) id 14.3.158.2; Wed, 5 Mar 2014 11:24:16 +0000 Received: from freescale.com ([10.232.15.72]) by az84smr01.freescale.net (8.14.3/8.14.0) with SMTP id s25BOCjd013294; Wed, 5 Mar 2014 04:24:13 -0700 Received: by freescale.com (sSMTP sendmail emulation); Wed, 05 Mar 2014 16:50:48 +0530 From: Bharat Bhushan To: , , Subject: [PATCH] ARM64: Kernel managed pages are only flushed Date: Wed, 5 Mar 2014 16:50:46 +0530 Message-ID: <1394018446-16738-1-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_062439_393537_EA822266 X-CRM114-Status: GOOD ( 11.34 ) X-Spam-Score: -2.9 (--) 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 --- 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..2b4e8b0 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(pfn)) + return; + +#endif + page = pte_page(pte); /* no flushing needed for anonymous pages */ if (!page_mapping(page))