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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 F2933C433DF for ; Tue, 7 Jul 2020 09:35:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CCB38206DF for ; Tue, 7 Jul 2020 09:35:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728025AbgGGJfU (ORCPT ); Tue, 7 Jul 2020 05:35:20 -0400 Received: from mx2.suse.de ([195.135.220.15]:46668 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727058AbgGGJfU (ORCPT ); Tue, 7 Jul 2020 05:35:20 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 7046AAC52; Tue, 7 Jul 2020 09:35:19 +0000 (UTC) Subject: Re: [PATCH v2 1/3] xen/privcmd: Corrected error handling path To: Souptick Joarder , boris.ostrovsky@oracle.com, sstabellini@kernel.org Cc: xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, John Hubbard , Paul Durrant References: <1594059372-15563-1-git-send-email-jrdr.linux@gmail.com> <1594059372-15563-2-git-send-email-jrdr.linux@gmail.com> From: =?UTF-8?B?SsO8cmdlbiBHcm/Dnw==?= Message-ID: <4bafb184-6f07-2582-3d0f-86fb53dd30dc@suse.com> Date: Tue, 7 Jul 2020 11:35:18 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <1594059372-15563-2-git-send-email-jrdr.linux@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06.07.20 20:16, Souptick Joarder wrote: > Previously, if lock_pages() end up partially mapping pages, it used > to return -ERRNO due to which unlock_pages() have to go through > each pages[i] till *nr_pages* to validate them. This can be avoided > by passing correct number of partially mapped pages & -ERRNO separately, > while returning from lock_pages() due to error. > > With this fix unlock_pages() doesn't need to validate pages[i] till > *nr_pages* for error scenario and few condition checks can be ignored. > > Signed-off-by: Souptick Joarder > Cc: John Hubbard > Cc: Boris Ostrovsky > Cc: Paul Durrant > --- > drivers/xen/privcmd.c | 31 +++++++++++++++---------------- > 1 file changed, 15 insertions(+), 16 deletions(-) > > diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c > index a250d11..33677ea 100644 > --- a/drivers/xen/privcmd.c > +++ b/drivers/xen/privcmd.c > @@ -580,13 +580,13 @@ static long privcmd_ioctl_mmap_batch( > > static int lock_pages( > struct privcmd_dm_op_buf kbufs[], unsigned int num, > - struct page *pages[], unsigned int nr_pages) > + struct page *pages[], unsigned int nr_pages, unsigned int *pinned) > { > unsigned int i; > + int page_count = 0; Initial value shouldn't be needed, and ... > > for (i = 0; i < num; i++) { > unsigned int requested; > - int pinned; ... you could move the declaration here. With that done you can add my Reviewed-by: Juergen Gross Juergen