Commit 9b96309c authored by Pravin B Shelar's avatar Pravin B Shelar Committed by David S. Miller
Browse files

genl: Fix genl dumpit() locking. 



In case of genl-family with parallel ops off, dumpif() callback
is expected to run under genl_lock, But commit def31174
(genl: Allow concurrent genl callbacks.) changed this behaviour
where only first dumpit() op was called under genl-lock.
For subsequent dump, only nlk->cb_lock was taken.
Following patch fixes it by defining locked dumpit() and done()
callback which takes care of genl-locking.

CC: Jesse Gross <jesse@nicira.com>
CC: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarPravin B Shelar <pshelar@nicira.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a3097bda

net/netlink/genetlink.c

+46 −5
Original line number Diff line number Diff line
@@ -544,6 +544,30 @@ void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, 
}

EXPORT_SYMBOL(genlmsg_put);



static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb)

{

	struct genl_ops *ops = cb->data;

	int rc;



	genl_lock();

	rc = ops->dumpit(skb, cb);

	genl_unlock();

	return rc;

}



static int genl_lock_done(struct netlink_callback *cb)

{

	struct genl_ops *ops = cb->data;

	int rc = 0;



	if (ops->done) {

		genl_lock();

		rc = ops->done(cb);

		genl_unlock();

	}

	return rc;

}



static int genl_family_rcv_msg(struct genl_family *family,

			       struct sk_buff *skb,

			       struct nlmsghdr *nlh)
@@ -572,15 +596,32 @@ static int genl_family_rcv_msg(struct genl_family *family, 
		return -EPERM;



	if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) {

		int rc;



		if (ops->dumpit == NULL)

			return -EOPNOTSUPP;



		if (!family->parallel_ops) {

			struct netlink_dump_control c = {

				.data = ops,

				.dump = genl_lock_dumpit,

				.done = genl_lock_done,

			};



			genl_unlock();

			rc = netlink_dump_start(net->genl_sock, skb, nlh, &c);

			genl_lock();



		} else {

			struct netlink_dump_control c = {

				.dump = ops->dumpit,

				.done = ops->done,

			};



		if (ops->dumpit == NULL)

			return -EOPNOTSUPP;

			rc = netlink_dump_start(net->genl_sock, skb, nlh, &c);

		}



		return netlink_dump_start(net->genl_sock, skb, nlh, &c);

		return rc;

	}



	if (ops->doit == NULL)

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