(Adding netdev@...) On Wed, Oct 29, 2014 at 9:16 AM, Peter Zijlstra <[email protected]> wrote: > > Dave, this relies on bits currently in tip/sched/core, if you're ok I'll > merge it through that tree. > > --- > Subject: netdev: Fix sleeping inside wait event > From: Peter Zijlstra <[email protected]> > Date: Wed Oct 29 17:04:56 CET 2014 > > rtnl_lock_unregistering() takes rtnl_lock() -- a mutex -- inside a > wait loop. The wait loop relies on current->state to function, but so > does mutex_lock(), nesting them makes for the inner to destroy the > outer state. >
While you are on it, please fix rtnl_lock_unregistering_all() too? Thanks! > Fix this using the new wait_woken() bits. > > Cc: Oleg Nesterov <[email protected]> > Cc: Eric Biederman <[email protected]> > Cc: David Miller <[email protected]> > Reported-by: Fengguang Wu <[email protected]> > Signed-off-by: Peter Zijlstra (Intel) <[email protected]> > --- > net/core/dev.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > --- a/net/core/dev.c > +++ b/net/core/dev.c > @@ -7196,11 +7196,10 @@ static void __net_exit rtnl_lock_unregis > */ > struct net *net; > bool unregistering; > - DEFINE_WAIT(wait); > + DEFINE_WAIT_FUNC(wait, woken_wake_function); > > + add_wait_queue(&netdev_unregistering_wq, &wait); > for (;;) { > - prepare_to_wait(&netdev_unregistering_wq, &wait, > - TASK_UNINTERRUPTIBLE); > unregistering = false; > rtnl_lock(); > list_for_each_entry(net, net_list, exit_list) { > @@ -7212,9 +7211,10 @@ static void __net_exit rtnl_lock_unregis > if (!unregistering) > break; > __rtnl_unlock(); > - schedule(); > + > + wait_woken(&wait, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); > } > - finish_wait(&netdev_unregistering_wq, &wait); > + remove_wait_queue(&netdev_unregistering_wq, &wait); > } > > static void __net_exit default_device_exit_batch(struct list_head *net_list) > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
