From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nikolay Aleksandrov Subject: Re: [PATCH net 2/3] bonding: Fix initialize after use for 3ad machine state spinlock Date: Mon, 18 Feb 2013 22:51:20 +0100 Message-ID: <5122A258.9000707@redhat.com> References: <1361210344-14907-1-git-send-email-nikolay@redhat.com> <1361210344-14907-2-git-send-email-nikolay@redhat.com> <21258.1361223190@death.nxdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, davem@davemloft.net, andy@greyhouse.net To: Jay Vosburgh Return-path: Received: from mx1.redhat.com ([209.132.183.28]:44724 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756399Ab3BRVvo (ORCPT ); Mon, 18 Feb 2013 16:51:44 -0500 In-Reply-To: <21258.1361223190@death.nxdomain> Sender: netdev-owner@vger.kernel.org List-ID: On 18/02/13 22:33, Jay Vosburgh wrote: > Nikolay Aleksandrov wrote: > >> The 3ad machine state spinlock can be used before it is inititialized >> while doing bond_enslave() (and the port is being initialized) since >> port->slave is set before the lock is prepared, thus causing soft >> lock-ups and a multitude of other nasty bugs. > > Does this change cause the "uninitialized port" warnings in > bond_3ad_state_machine_handler and bond_3ad_rx_indication to > intermittently print during the enslavement process? If so (and it > looks to me like it will), I think the warnings should be removed, since > after this change, port->slave being NULL isn't really an error > condition that needs a warning to the log. > This change couldn't cause that, it only initializes the spin lock before the slave is set, currently after the first patch of this series this is no longer a requirement as far as I can tell the only code that can access the lock before the slave is set was that one, but it still is a bug that can manifest later. I don't think it has anything to do with the warnings, the only change is that the spin lock is initialized prior to setting the slave to the port. Am I missing something here ? >> Signed-off-by: Nikolay Aleksandrov >> --- >> drivers/net/bonding/bond_3ad.c | 9 ++++----- >> 1 file changed, 4 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c >> index 1720742..96d471e 100644 >> --- a/drivers/net/bonding/bond_3ad.c >> +++ b/drivers/net/bonding/bond_3ad.c >> @@ -389,13 +389,13 @@ static u8 __get_duplex(struct port *port) >> >> /** >> * __initialize_port_locks - initialize a port's STATE machine spinlock >> - * @port: the port we're looking at >> + * @port: the slave of the port we're looking at >> * >> */ >> -static inline void __initialize_port_locks(struct port *port) >> +static inline void __initialize_port_locks(struct slave *port) >> { >> // make sure it isn't called twice >> - spin_lock_init(&(SLAVE_AD_INFO(port->slave).state_machine_lock)); >> + spin_lock_init(&(SLAVE_AD_INFO(port).state_machine_lock)); > > Change the name of the variable here, too, not just the type. > This is confusing. > > -J Thanks, I saw that after posting, I have prepared this change already. > >> } >> >> //conversions >> @@ -1910,6 +1910,7 @@ int bond_3ad_bind_slave(struct slave *slave) >> >> ad_initialize_port(port, bond->params.lacp_fast); >> >> + __initialize_port_locks(slave); >> port->slave = slave; >> port->actor_port_number = SLAVE_AD_INFO(slave).id; >> // key is determined according to the link speed, duplex and user key(which is yet not supported) >> @@ -1932,8 +1933,6 @@ int bond_3ad_bind_slave(struct slave *slave) >> port->next_port_in_aggregator = NULL; >> >> __disable_port(port); >> - __initialize_port_locks(port); >> - >> >> // aggregator initialization >> aggregator = &(SLAVE_AD_INFO(slave).aggregator); >> -- >> 1.7.11.7 >> > > --- > -Jay Vosburgh, IBM Linux Technology Center, fubar@us.ibm.com >