From patchwork Sun Feb 2 00:22:06 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: 3565471 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: patchwork-linux-pci@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id A63FE9F464 for ; Sun, 2 Feb 2014 00:18:36 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D50B520279 for ; Sun, 2 Feb 2014 00:18:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0E6F92026C for ; Sun, 2 Feb 2014 00:18:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754925AbaBBAS0 (ORCPT ); Sat, 1 Feb 2014 19:18:26 -0500 Received: from v094114.home.net.pl ([79.96.170.134]:51000 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754909AbaBBAS0 (ORCPT ); Sat, 1 Feb 2014 19:18:26 -0500 Received: from aept186.neoplus.adsl.tpnet.pl [79.191.149.186] (HELO vostro.rjw.lan) by serwer1319399.home.pl [79.96.170.134] with SMTP (IdeaSmtpServer v0.80) id fb106c12deb2556b; Sun, 2 Feb 2014 01:18:21 +0100 From: "Rafael J. Wysocki" To: ACPI Devel Maling List Cc: Bjorn Helgaas , Aaron Lu , Linux Kernel Mailing List , Linux PCI , Mika Westerberg Subject: [PATCH v2 2/13] ACPI / hotplug / PCI: Move PCI rescan-remove locking to hotplug_event() Date: Sun, 02 Feb 2014 01:22:06 +0100 Message-ID: <3266705.b26GDtjItd@vostro.rjw.lan> User-Agent: KMail/4.11.4 (Linux/3.13.0+; KDE/4.11.4; x86_64; ; ) In-Reply-To: <1935791.liE9ZlzmO9@vostro.rjw.lan> References: <2217793.001RY6hKlo@vostro.rjw.lan> <1935791.liE9ZlzmO9@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 --- 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);