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=-19.4 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, USER_AGENT_GIT autolearn=unavailable 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 01D99C07E9B for ; Fri, 9 Jul 2021 13:18:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DEA41613BC for ; Fri, 9 Jul 2021 13:18:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231854AbhGINVO (ORCPT ); Fri, 9 Jul 2021 09:21:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:51244 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231815AbhGINVL (ORCPT ); Fri, 9 Jul 2021 09:21:11 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2DC9F61357; Fri, 9 Jul 2021 13:18:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1625836707; bh=denMVhT9adw/N1SJptjRT5U9cniFnK/UQPmn521OKI0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=m4K+ZcXKWN0s2JepltFx4QOSLb578aeQexpCoXn8X8JL1/BRylq8dIoGjhY4zVQmQ sQD5I6utF5yHl4VOuqpNtwuvoWrHfTytTaM4qLVtumDwlm3sdLyjCoBrp6NdKTJ95v M7JlBM48P6zJyF+2pAdL0h7aWqXvKUp9PLK/IO+U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Julien Grall , Juergen Gross , Boris Ostrovsky Subject: [PATCH 4.4 3/4] xen/events: reset active flag for lateeoi events later Date: Fri, 9 Jul 2021 15:18:15 +0200 Message-Id: <20210709131535.098023418@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210709131529.395072769@linuxfoundation.org> References: <20210709131529.395072769@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Juergen Gross commit 3de218ff39b9e3f0d453fe3154f12a174de44b25 upstream. In order to avoid a race condition for user events when changing cpu affinity reset the active flag only when EOI-ing the event. This is working fine as all user events are lateeoi events. Note that lateeoi_ack_mask_dynirq() is not modified as there is no explicit call to xen_irq_lateeoi() expected later. Cc: stable@vger.kernel.org Reported-by: Julien Grall Fixes: b6622798bc50b62 ("xen/events: avoid handling the same event on two cpus at the same time") Tested-by: Julien Grall Signed-off-by: Juergen Gross Reviewed-by: Boris Ostrovsky Link: https://lore.kernel.org/r/20210623130913.9405-1-jgross@suse.com Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman --- drivers/xen/events/events_base.c | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-) --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -533,6 +533,9 @@ static void xen_irq_lateeoi_locked(struc } info->eoi_time = 0; + + /* is_active hasn't been reset yet, do it now. */ + smp_store_release(&info->is_active, 0); do_unmask(info, EVT_MASK_REASON_EOI_PENDING); } @@ -1777,10 +1780,22 @@ static void lateeoi_ack_dynirq(struct ir struct irq_info *info = info_for_irq(data->irq); evtchn_port_t evtchn = info ? info->evtchn : 0; - if (VALID_EVTCHN(evtchn)) { - do_mask(info, EVT_MASK_REASON_EOI_PENDING); - ack_dynirq(data); - } + if (!VALID_EVTCHN(evtchn)) + return; + + do_mask(info, EVT_MASK_REASON_EOI_PENDING); + + if (unlikely(irqd_is_setaffinity_pending(data)) && + likely(!irqd_irq_disabled(data))) { + do_mask(info, EVT_MASK_REASON_TEMPORARY); + + clear_evtchn(evtchn); + + irq_move_masked_irq(data); + + do_unmask(info, EVT_MASK_REASON_TEMPORARY); + } else + clear_evtchn(evtchn); } static void lateeoi_mask_ack_dynirq(struct irq_data *data)