Commit 1901066a authored by Stanislav Fomichev's avatar Stanislav Fomichev Committed by Jakub Kicinski
Browse files

netdevsim: add dummy device notifiers 



In order to exercise and verify notifiers' locking assumptions,
register dummy notifiers (via register_netdevice_notifier_dev_net).
Share notifier event handler that enforces the assumptions with
lock_debug.c (rename and export rtnl_net_debug_event as
netdev_debug_event). Add ops lock asserts to netdev_debug_event.

Signed-off-by: default avatarStanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250401163452.622454-6-sdf@fomichev.me


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent b912d599

drivers/net/netdevsim/netdev.c

+13 −0
Original line number Diff line number Diff line
@@ -939,6 +939,7 @@ static int nsim_init_netdevsim(struct netdevsim *ns) 
	ns->netdev->netdev_ops = &nsim_netdev_ops;

	ns->netdev->stat_ops = &nsim_stat_ops;

	ns->netdev->queue_mgmt_ops = &nsim_queue_mgmt_ops;

	netdev_lockdep_set_classes(ns->netdev);



	err = nsim_udp_tunnels_info_create(ns->nsim_dev, ns->netdev);

	if (err)
@@ -960,6 +961,14 @@ static int nsim_init_netdevsim(struct netdevsim *ns) 
	if (err)

		goto err_ipsec_teardown;

	rtnl_unlock();



	if (IS_ENABLED(CONFIG_DEBUG_NET)) {

		ns->nb.notifier_call = netdev_debug_event;

		if (register_netdevice_notifier_dev_net(ns->netdev, &ns->nb,

							&ns->nn))

			ns->nb.notifier_call = NULL;

	}



	return 0;



err_ipsec_teardown:
@@ -1043,6 +1052,10 @@ void nsim_destroy(struct netdevsim *ns) 
	debugfs_remove(ns->qr_dfs);

	debugfs_remove(ns->pp_dfs);



	if (ns->nb.notifier_call)

		unregister_netdevice_notifier_dev_net(ns->netdev, &ns->nb,

						      &ns->nn);



	rtnl_lock();

	peer = rtnl_dereference(ns->peer);

	if (peer)

drivers/net/netdevsim/netdevsim.h

+3 −0
Original line number Diff line number Diff line
@@ -144,6 +144,9 @@ struct netdevsim { 


	struct nsim_ethtool ethtool;

	struct netdevsim __rcu *peer;



	struct notifier_block nb;

	struct netdev_net_notifier nn;

};



struct netdevsim *

include/net/netdev_lock.h

+3 −0
Original line number Diff line number Diff line
@@ -98,4 +98,7 @@ static inline int netdev_lock_cmp_fn(const struct lockdep_map *a, 
				  &qdisc_xmit_lock_key);	\

}



int netdev_debug_event(struct notifier_block *nb, unsigned long event,

		       void *ptr);



#endif

net/core/lock_debug.c

+9 −5
Original line number Diff line number Diff line
@@ -6,10 +6,11 @@ 
#include <linux/notifier.h>

#include <linux/rtnetlink.h>

#include <net/net_namespace.h>

#include <net/netdev_lock.h>

#include <net/netns/generic.h>



static int rtnl_net_debug_event(struct notifier_block *nb,

				unsigned long event, void *ptr)

int netdev_debug_event(struct notifier_block *nb, unsigned long event,

		       void *ptr)

{

	struct net_device *dev = netdev_notifier_info_to_dev(ptr);

	struct net *net = dev_net(dev);
@@ -17,11 +18,13 @@ static int rtnl_net_debug_event(struct notifier_block *nb, 


	/* Keep enum and don't add default to trigger -Werror=switch */

	switch (cmd) {

	case NETDEV_REGISTER:

	case NETDEV_UP:

		netdev_ops_assert_locked(dev);

		fallthrough;

	case NETDEV_DOWN:

	case NETDEV_REBOOT:

	case NETDEV_CHANGE:

	case NETDEV_REGISTER:

	case NETDEV_UNREGISTER:

	case NETDEV_CHANGEMTU:

	case NETDEV_CHANGEADDR:
@@ -66,6 +69,7 @@ static int rtnl_net_debug_event(struct notifier_block *nb, 


	return NOTIFY_DONE;

}

EXPORT_SYMBOL_NS_GPL(netdev_debug_event, "NETDEV_INTERNAL");



static int rtnl_net_debug_net_id;
@@ -74,7 +78,7 @@ static int __net_init rtnl_net_debug_net_init(struct net *net) 
	struct notifier_block *nb;



	nb = net_generic(net, rtnl_net_debug_net_id);

	nb->notifier_call = rtnl_net_debug_event;

	nb->notifier_call = netdev_debug_event;



	return register_netdevice_notifier_net(net, nb);

}
@@ -95,7 +99,7 @@ static struct pernet_operations rtnl_net_debug_net_ops __net_initdata = { 
};



static struct notifier_block rtnl_net_debug_block = {

	.notifier_call = rtnl_net_debug_event,

	.notifier_call = netdev_debug_event,

};



static int __init rtnl_net_debug_init(void)