From patchwork Mon Feb 3 23:15:50 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 3572621 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: patchwork-linux-pci@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 77B17C02DC for ; Mon, 3 Feb 2014 23:29:34 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 3913120176 for ; Mon, 3 Feb 2014 23:29:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5CC7A20179 for ; Mon, 3 Feb 2014 23:29:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753956AbaBCX3J (ORCPT ); Mon, 3 Feb 2014 18:29:09 -0500 Received: from v094114.home.net.pl ([79.96.170.134]:52429 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753832AbaBCX2c (ORCPT ); Mon, 3 Feb 2014 18:28:32 -0500 Received: from afcm78.neoplus.adsl.tpnet.pl [95.49.64.78] (HELO vostro.rjw.lan) by serwer1319399.home.pl [79.96.170.134] with SMTP (IdeaSmtpServer v0.80) id c53c20e8755dd7e5; Tue, 4 Feb 2014 00:28:29 +0100 From: "Rafael J. Wysocki" To: ACPI Devel Maling List Cc: Mika Westerberg , Bjorn Helgaas , Aaron Lu , Linux Kernel Mailing List , Linux PCI Subject: [PATCH 2/24][Resend] ACPI / hotplug / PCI: Move PCI rescan-remove locking to hotplug_event() Date: Tue, 04 Feb 2014 00:15:50 +0100 Message-ID: <3356372.HPHJPAeHZz@vostro.rjw.lan> User-Agent: KMail/4.11.4 (Linux/3.13.0+; KDE/4.11.4; x86_64; ; ) In-Reply-To: <7532948.aJNUotNMpR@vostro.rjw.lan> References: <2217793.001RY6hKlo@vostro.rjw.lan> <20140203104408.GQ18029@intel.com> <7532948.aJNUotNMpR@vostro.rjw.lan> MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Spam-Status: No, score=-7.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Rafael J. Wysocki Commit 9217a984671e (ACPI / hotplug / PCI: Use global PCI rescan-remove locking) modified ACPIPHP to protect its PCI device removal and addition code paths from races against sysfs-driven rescan and remove operations with the help of PCI rescan-remove locking. However, it overlooked the fact that hotplug_event_work() is not the only caller of hotplug_event() which may also be called by dock_hotplug_event() and that code path is missing the PCI rescan-remove locking. This means that, although the PCI rescan-remove lock is held as appropriate during the handling of events originating from handle_hotplug_event(), the ACPIPHP's operations resulting from dock events may still suffer the race conditions that commit 9217a984671e was supposed to eliminate. To address that problem, move the PCI rescan-remove locking from hotplug_event_work() to hotplug_event() so that it is used regardless of the way that function is invoked. Revamps: 9217a984671e (ACPI / hotplug / PCI: Use global PCI rescan-remove locking) Signed-off-by: Rafael J. Wysocki Tested-by: Mika Westerberg --- drivers/pci/hotplug/acpiphp_glue.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Index: linux-pm/drivers/pci/hotplug/acpiphp_glue.c =================================================================== --- linux-pm.orig/drivers/pci/hotplug/acpiphp_glue.c +++ linux-pm/drivers/pci/hotplug/acpiphp_glue.c @@ -852,6 +852,7 @@ static void hotplug_event(acpi_handle ha mutex_unlock(&acpiphp_context_lock); + pci_lock_rescan_remove(); acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer); switch (type) { @@ -905,6 +906,7 @@ static void hotplug_event(acpi_handle ha break; } + pci_unlock_rescan_remove(); if (bridge) put_bridge(bridge); } @@ -915,11 +917,9 @@ static void hotplug_event_work(void *dat acpi_handle handle = context->handle; acpi_scan_lock_acquire(); - pci_lock_rescan_remove(); hotplug_event(handle, type, context); - pci_unlock_rescan_remove(); acpi_scan_lock_release(); acpi_evaluate_hotplug_ost(handle, type, ACPI_OST_SC_SUCCESS, NULL); put_bridge(context->func.parent);