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=-5.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 A2941C432C1 for ; Mon, 23 Sep 2019 21:50:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6462E2053B for ; Mon, 23 Sep 2019 21:50:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569275430; bh=uL09dUji+FB48rz9m57c3BRbd3Wt0dZwJd5rB9ibLic=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=LJvRlM4/NgKuFf4j28t9ejjZp8kwpLeplLTVXGjMRLgKvpIGyueb2zgJNV8pQCKSp RqWGmfBlSKb/1xW4JCfHlhnZjsJJtrq8c4izrvnF4wQ40jXOVS0u+ZAg+w9zT87kpi pV1nGwH6JMLOuCuXOZZZBOawRb5b/bdjVwn242j4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2503114AbfIWVua (ORCPT ); Mon, 23 Sep 2019 17:50:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:56856 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389663AbfIWVu3 (ORCPT ); Mon, 23 Sep 2019 17:50:29 -0400 Received: from localhost (unknown [69.71.4.100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B5D582053B; Mon, 23 Sep 2019 21:50:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569275429; bh=uL09dUji+FB48rz9m57c3BRbd3Wt0dZwJd5rB9ibLic=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=wQAK9extFxsky3WJhZyrFpApddpIWJSDKhmyYWWV6+15ZCgPPzWv7mE5+IFSI+VoZ Ltf3YyzbrmEZh0g+GRx4zagN7417PeHvk74Ld1OayLuPk338bCicV8JE1XYAjpfYPS mNIb7MBvoT6XspTuHBwoUia14v1GXp7vk1Wi7++0= Date: Mon, 23 Sep 2019 16:50:27 -0500 From: Bjorn Helgaas To: Benjamin Herrenschmidt Cc: "linux-pci@vger.kernel.org" Subject: Re: [RFC/PATCH] PCI: Protect pci_reassign_bridge_resources() against concurrent addition/removal Message-ID: <20190923215027.GA11938@google.com> References: <02ca29627597445442bb14c069678e549429dace.camel@kernel.crashing.org> <20190821130827.GF14450@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190821130827.GF14450@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Wed, Aug 21, 2019 at 08:08:27AM -0500, Bjorn Helgaas wrote: > On Mon, Jun 24, 2019 at 02:32:19PM +1000, Benjamin Herrenschmidt wrote: > > pci_reassign_bridge_resources() can be called by pci_resize_resource() > > at runtime. > > > > It will walk the PCI tree up and down, and isn't currently protected > > against any changes or hotplug operation. > > > > Signed-off-by: Benjamin Herrenschmidt > > Applied to pci/resource for v5.4, thanks! Dropped for now per Dan's bug report: https://lore.kernel.org/r/20190904100303.GD7007@mwanda > > --- > > > > --- a/drivers/pci/setup-bus.c > > +++ b/drivers/pci/setup-bus.c > > @@ -2104,6 +2104,8 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type) > > unsigned int i; > > int ret; > > > > + down_read(&pci_bus_sem); > > + > > /* Walk to the root hub, releasing bridge BARs when possible */ > > next = bridge; > > do { > > @@ -2160,6 +2162,7 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type) > > } > > > > free_list(&saved); > > + up_read(&pci_bus_sem); > > return 0; > > > > cleanup: > > @@ -2188,6 +2191,7 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type) > > pci_setup_bridge(bridge->subordinate); > > } > > free_list(&saved); > > + up_read(&pci_bus_sem); > > > > return ret; > > } > >