Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757422Ab3CZXuE (ORCPT ); Tue, 26 Mar 2013 19:50:04 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:52383 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754237Ab3CZWnj (ORCPT ); Tue, 26 Mar 2013 18:43:39 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Veaceslav Falico , Neil Horman , "David S. Miller" Subject: [ 05/98] netconsole: dont call __netpoll_cleanup() while atomic Date: Tue, 26 Mar 2013 15:41:54 -0700 Message-Id: <20130326224242.996778945@linuxfoundation.org> X-Mailer: git-send-email 1.8.1.rc1.5.g7e0651a In-Reply-To: <20130326224242.449070940@linuxfoundation.org> References: <20130326224242.449070940@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2041 Lines: 64 3.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Veaceslav Falico [ Upstream commit 3f315bef23075ea8a98a6fe4221a83b83456d970 ] __netpoll_cleanup() is called in netconsole_netdev_event() while holding a spinlock. Release/acquire the spinlock before/after it and restart the loop. Also, disable the netconsole completely, because we won't have chance after the restart of the loop, and might end up in a situation where nt->enabled == 1 and nt->np.dev == NULL. Signed-off-by: Veaceslav Falico Acked-by: Neil Horman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/netconsole.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) --- a/drivers/net/netconsole.c +++ b/drivers/net/netconsole.c @@ -630,6 +630,7 @@ static int netconsole_netdev_event(struc goto done; spin_lock_irqsave(&target_list_lock, flags); +restart: list_for_each_entry(nt, &target_list, list) { netconsole_target_get(nt); if (nt->np.dev == dev) { @@ -642,15 +643,17 @@ static int netconsole_netdev_event(struc case NETDEV_UNREGISTER: /* * rtnl_lock already held + * we might sleep in __netpoll_cleanup() */ - if (nt->np.dev) { - __netpoll_cleanup(&nt->np); - dev_put(nt->np.dev); - nt->np.dev = NULL; - } + spin_unlock_irqrestore(&target_list_lock, flags); + __netpoll_cleanup(&nt->np); + spin_lock_irqsave(&target_list_lock, flags); + dev_put(nt->np.dev); + nt->np.dev = NULL; nt->enabled = 0; stopped = true; - break; + netconsole_target_put(nt); + goto restart; } } netconsole_target_put(nt); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/