From patchwork Wed May 29 09:04:05 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?SsO8cmdlbiBHcm/Dnw==?= X-Patchwork-Id: 10966521 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DE0FA15E6 for ; Wed, 29 May 2019 09:06:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D08AD284F5 for ; Wed, 29 May 2019 09:06:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C36E6288E5; Wed, 29 May 2019 09:06:11 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id DC4B1284F5 for ; Wed, 29 May 2019 09:06:10 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hVuVL-0005VS-7G; Wed, 29 May 2019 09:04:15 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hVuVK-0005V3-1F for xen-devel@lists.xenproject.org; Wed, 29 May 2019 09:04:14 +0000 X-Inumbo-ID: b92adda4-81f0-11e9-bf40-5f5954cf2a33 Received: from mx1.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id b92adda4-81f0-11e9-bf40-5f5954cf2a33; Wed, 29 May 2019 09:04:11 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 8C518AD5E; Wed, 29 May 2019 09:04:10 +0000 (UTC) From: Juergen Gross To: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org Date: Wed, 29 May 2019 11:04:05 +0200 Message-Id: <20190529090407.1225-2-jgross@suse.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20190529090407.1225-1-jgross@suse.com> References: <20190529090407.1225-1-jgross@suse.com> Subject: [Xen-devel] [PATCH v2 1/3] xen/swiotlb: fix condition for calling xen_destroy_contiguous_region() X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Juergen Gross , Stefano Stabellini , Konrad Rzeszutek Wilk , stable@vger.kernel.org, xen-devel@lists.xenproject.org, Boris Ostrovsky MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP The condition in xen_swiotlb_free_coherent() for deciding whether to call xen_destroy_contiguous_region() is wrong: in case the region to be freed is not contiguous calling xen_destroy_contiguous_region() is the wrong thing to do: it would result in inconsistent mappings of multiple PFNs to the same MFN. This will lead to various strange crashes or data corruption. Instead of calling xen_destroy_contiguous_region() in that case a warning should be issued as that situation should never occur. Cc: stable@vger.kernel.org Signed-off-by: Juergen Gross Reviewed-by: Boris Ostrovsky Reviewed-by: Jan Beulich --- V2: always issue a warning in case xen_destroy_contiguous_region() isn't called (Jan Beulich) --- drivers/xen/swiotlb-xen.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 5dcb06fe9667..1caadca124b3 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -360,8 +360,8 @@ xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr, /* Convert the size to actually allocated. */ size = 1UL << (order + XEN_PAGE_SHIFT); - if (((dev_addr + size - 1 <= dma_mask)) || - range_straddles_page_boundary(phys, size)) + if (!WARN_ON((dev_addr + size - 1 > dma_mask) || + range_straddles_page_boundary(phys, size))) xen_destroy_contiguous_region(phys, order); xen_free_coherent_pages(hwdev, size, vaddr, (dma_addr_t)phys, attrs);