From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D28CC282DA for ; Sun, 3 Feb 2019 14:27:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5641A2082C for ; Sun, 3 Feb 2019 14:27:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730765AbfBCO1p (ORCPT ); Sun, 3 Feb 2019 09:27:45 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:55526 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730079AbfBCOUn (ORCPT ); Sun, 3 Feb 2019 09:20:43 -0500 Received: from cable-78.29.236.164.coditel.net ([78.29.236.164] helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gqIdW-0006Lc-Gy; Sun, 03 Feb 2019 14:20:42 +0000 Received: from ben by deadeye with local (Exim 4.92-RC4) (envelope-from ) id 1gqI9Y-0006yP-Gh; Sun, 03 Feb 2019 14:49:44 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Boris Ostrovsky" , "Christoph Helwig" , "Joe Jin" , "Konrad Rzeszutek Wilk" , "Dongli Zhang" , "John Sobecki" Date: Sun, 03 Feb 2019 14:45:08 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 104/305] xen-swiotlb: use actually allocated size on check physical continuous In-Reply-To: X-SA-Exim-Connect-IP: 78.29.236.164 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.63-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Joe Jin commit 7250f422da0480d8512b756640f131b9b893ccda upstream. xen_swiotlb_{alloc,free}_coherent() allocate/free memory based on the order of the pages and not size argument (bytes). This is inconsistent with range_straddles_page_boundary and memset which use the 'size' value, which may lead to not exchanging memory with Xen (range_straddles_page_boundary() returned true). And then the call to xen_swiotlb_free_coherent() would actually try to exchange the memory with Xen, leading to the kernel hitting an BUG (as the hypercall returned an error). This patch fixes it by making the 'size' variable be of the same size as the amount of memory allocated. Signed-off-by: Joe Jin Cc: Konrad Rzeszutek Wilk Cc: Boris Ostrovsky Cc: Christoph Helwig Cc: Dongli Zhang Cc: John Sobecki Signed-off-by: Konrad Rzeszutek Wilk [bwh: Backported to 3.16: - Use PAGE_SHIFT instead of XEN_PAGE_SHIFT - Adjust context] Signed-off-by: Ben Hutchings --- drivers/xen/swiotlb-xen.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -311,6 +311,9 @@ xen_swiotlb_alloc_coherent(struct device */ flags &= ~(__GFP_DMA | __GFP_HIGHMEM); + /* Convert the size to actually allocated. */ + size = 1UL << (order + PAGE_SHIFT); + if (dma_alloc_from_coherent(hwdev, size, dma_handle, &ret)) return ret; @@ -366,6 +369,9 @@ xen_swiotlb_free_coherent(struct device * physical address */ phys = xen_bus_to_phys(dev_addr); + /* Convert the size to actually allocated. */ + size = 1UL << (order + PAGE_SHIFT); + if (((dev_addr + size - 1 <= dma_mask)) || range_straddles_page_boundary(phys, size)) xen_destroy_contiguous_region(phys, order);