Re: [PATCH 1/1] ipvs: kernel oops - do_ip_vs_get_ctl

[Hans Schillstrom <hans.schillstrom@ericsson.com>]

On Wednesday 25 April 2012 11:06:01 Jesper Dangaard Brouer wrote:
> Hi Hans,
> 
> Thank you for your work.
> Just some whitespace nitpicks below.

OK thanks I forgott to run checkpatch ...
I'll send a new patch  

> I have not been able to reproduce the bug in:
>   https://bugzilla.redhat.com/show_bug.cgi?id=806704
> 
> Can you recommend a (better) way to reproduce this bug?
> I just want to be able to verify that this fixes the bug in question.

I think you need two threads or procs.
Start a modprobe in thread one then issue a ipvs ioctl in the other.
The timing is not that easy here :-)

> 
> 
> On Wed, 2012-04-25 at 09:44 +0200, Hans Schillstrom wrote:
> > Change order of init so netns init is ready
> > when register ioctl and netlink.
> > 
> > Reported-by: "Ryan O'Hara" <rohara@redhat.com>
> > Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
> > ---
> >  include/net/ip_vs.h             |    2 +
> >  net/netfilter/ipvs/ip_vs_core.c |    9 ++++++
> >  net/netfilter/ipvs/ip_vs_ctl.c  |   52 ++++++++++++++++++++++----------------
> >  3 files changed, 41 insertions(+), 22 deletions(-)
> > 
> > diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
> > index f967395..93b81aa 100644
> > --- a/include/net/ip_vs.h
> > +++ b/include/net/ip_vs.h
> > @@ -1201,6 +1201,8 @@ ip_vs_lookup_real_service(struct net *net, int af, __u16 protocol,
> >  
> >  extern int ip_vs_use_count_inc(void);
> >  extern void ip_vs_use_count_dec(void);
> > +extern int ip_vs_register_nl_ioctl(void);
> > +extern void ip_vs_unregister_nl_ioctl(void);
> >  extern int ip_vs_control_init(void);
> >  extern void ip_vs_control_cleanup(void);
> >  extern struct ip_vs_dest *
> > diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c
> > index d8b1d30..c8f36b9 100644
> > --- a/net/netfilter/ipvs/ip_vs_core.c
> > +++ b/net/netfilter/ipvs/ip_vs_core.c
> > @@ -1995,10 +1995,18 @@ static int __init ip_vs_init(void)
> >  		goto cleanup_dev;
> >  	}
> >  
> > +	ret = ip_vs_register_nl_ioctl();
> > +	if (ret < 0) {
> > +		pr_err("can't register netlink/ioctl.\n");
> > +		goto cleanup_hooks;
> > +	}
> > +
> >  	pr_info("ipvs loaded.\n");
> >  
> >  	return ret;
> >  
> > +cleanup_hooks:
> > +	nf_unregister_hooks(ip_vs_ops, ARRAY_SIZE(ip_vs_ops));
> >  cleanup_dev:
> >  	unregister_pernet_device(&ipvs_core_dev_ops);
> >  cleanup_sub:
> > @@ -2014,6 +2022,7 @@ exit:
> >  
> >  static void __exit ip_vs_cleanup(void)
> >  {
> > +	ip_vs_unregister_nl_ioctl();
> >  	nf_unregister_hooks(ip_vs_ops, ARRAY_SIZE(ip_vs_ops));
> >  	unregister_pernet_device(&ipvs_core_dev_ops);
> >  	unregister_pernet_subsys(&ipvs_core_ops);	/* free ip_vs struct */
> > diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
> > index 7131417..efaf484 100644
> > --- a/net/netfilter/ipvs/ip_vs_ctl.c
> > +++ b/net/netfilter/ipvs/ip_vs_ctl.c
> > @@ -3750,21 +3750,10 @@ void __net_exit ip_vs_control_net_cleanup(struct net *net)
> >  	free_percpu(ipvs->tot_stats.cpustats);
> >  }
> >  
> > -int __init ip_vs_control_init(void)
> > +int ip_vs_register_nl_ioctl(void)
> >  {
> > -	int idx;
> >  	int ret;
> >  
> > -	EnterFunction(2);
> > -
> > -	/* Initialize svc_table, ip_vs_svc_fwm_table, rs_table */
> > -	for(idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++)  {
> > -		INIT_LIST_HEAD(&ip_vs_svc_table[idx]);
> > -		INIT_LIST_HEAD(&ip_vs_svc_fwm_table[idx]);
> > -	}
> > -
> > -	smp_wmb();	/* Do we really need it now ? */
> > -
> >  	ret = nf_register_sockopt(&ip_vs_sockopts);
> >  	if (ret) {
> >  		pr_err("cannot register sockopt.\n");
> > @@ -3776,28 +3765,47 @@ int __init ip_vs_control_init(void)
> >  		pr_err("cannot register Generic Netlink interface.\n");
> >  		goto err_genl;
> >  	}
> > -
> > -	ret = register_netdevice_notifier(&ip_vs_dst_notifier);
> > -	if (ret < 0)
> > -		goto err_notf;
> > -
> > -	LeaveFunction(2);
> >  	return 0;
> >  
> > -err_notf:
> > -	ip_vs_genl_unregister();
> >  err_genl:
> >  	nf_unregister_sockopt(&ip_vs_sockopts);
> >  err_sock:
> >  	return ret;
> >  }
> >  
> > +void ip_vs_unregister_nl_ioctl(void) 
> 
> There is a extra trailing whitespace behind
> ip_vs_unregister_nl_ioctl(void)
> 
> 
> > +{
> > +	ip_vs_genl_unregister();
> > +	nf_unregister_sockopt(&ip_vs_sockopts);
> > +}
> > +
> > +int __init ip_vs_control_init(void)
> > +{
> > +	int idx;
> > +	int ret;
> > +
> > +	EnterFunction(2);
> > +
> > +	/* Initialize svc_table, ip_vs_svc_fwm_table, rs_table */
> > +	for(idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++)  {
> 
> The for loop is funny spaced...
> 
> 
> > +		INIT_LIST_HEAD(&ip_vs_svc_table[idx]);
> > +		INIT_LIST_HEAD(&ip_vs_svc_fwm_table[idx]);
> > +	}
> > +
> > +	smp_wmb();	/* Do we really need it now ? */
> > +
> > +	ret = register_netdevice_notifier(&ip_vs_dst_notifier);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	LeaveFunction(2);
> > +	return 0;
> > +}
> > +
> >  
> >  void ip_vs_control_cleanup(void)
> >  {
> >  	EnterFunction(2);
> >  	unregister_netdevice_notifier(&ip_vs_dst_notifier);
> > -	ip_vs_genl_unregister();
> > -	nf_unregister_sockopt(&ip_vs_sockopts);
> >  	LeaveFunction(2);
> >  }
> 

-- 
Regards
Hans Schillstrom <hans.schillstrom@ericsson.com>