From patchwork Mon Feb 22 12:13:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 386223 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 128E4C4332D for ; Mon, 22 Feb 2021 12:16:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C629C64F12 for ; Mon, 22 Feb 2021 12:16:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230314AbhBVMQM (ORCPT ); Mon, 22 Feb 2021 07:16:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:44826 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230357AbhBVMPO (ORCPT ); Mon, 22 Feb 2021 07:15:14 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id D4B1C64E41; Mon, 22 Feb 2021 12:14:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1613996080; bh=D8+nZ2fey+DhdbVVhKbwY5/ZqYS8vfRCe1+7dyAFP1k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vAK93XjIYx9vIss/DtWjF+gyDto6rBMkUi650Y47AQ8A286XUtKchvKNPMKR1mYn2 GLfv/gd7E82ZfuNWkNq7Qd1EsxayxotMdX5MHol4UgLLdugCz6wqDIkKPKjy8MJUDV AqKl15jLj+leN4P8LoNEMRirrQLXz+iU0fqUxcpU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jan Beulich , Juergen Gross Subject: [PATCH 5.10 21/29] xen-blkback: dont "handle" error by BUG() Date: Mon, 22 Feb 2021 13:13:15 +0100 Message-Id: <20210222121024.219839467@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210222121019.444399883@linuxfoundation.org> References: <20210222121019.444399883@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jan Beulich commit 5a264285ed1cd32e26d9de4f3c8c6855e467fd63 upstream. In particular -ENOMEM may come back here, from set_foreign_p2m_mapping(). Don't make problems worse, the more that handling elsewhere (together with map's status fields now indicating whether a mapping wasn't even attempted, and hence has to be considered failed) doesn't require this odd way of dealing with errors. This is part of XSA-362. Signed-off-by: Jan Beulich Cc: stable@vger.kernel.org Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman --- drivers/block/xen-blkback/blkback.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) --- a/drivers/block/xen-blkback/blkback.c +++ b/drivers/block/xen-blkback/blkback.c @@ -811,10 +811,8 @@ again: break; } - if (segs_to_map) { + if (segs_to_map) ret = gnttab_map_refs(map, NULL, pages_to_gnt, segs_to_map); - BUG_ON(ret); - } /* * Now swizzle the MFN in our domain with the MFN from the other domain @@ -830,7 +828,7 @@ again: gnttab_page_cache_put(&ring->free_pages, &pages[seg_idx]->page, 1); pages[seg_idx]->handle = BLKBACK_INVALID_HANDLE; - ret |= 1; + ret |= !ret; goto next; } pages[seg_idx]->handle = map[new_map_idx].handle;