From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754957AbaBBASa (ORCPT ); Sat, 1 Feb 2014 19:18:30 -0500 Received: from v094114.home.net.pl ([79.96.170.134]:52975 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754922AbaBBAS1 (ORCPT ); Sat, 1 Feb 2014 19:18:27 -0500 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 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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(-) 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);