Commit 7b1871af authored by Matt Johnston's avatar Matt Johnston Committed by David S. Miller
Browse files

mctp: Warn if pointer is set for a wrong dev type 

Should not occur but is a sanity check.

May help tracking down Trinity reported issue
https://lore.kernel.org/lkml/20210913030701.GA5926@xsang-OptiPlex-9020/



Signed-off-by: default avatarMatt Johnston <matt@codeconstruct.com.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6183569d

net/mctp/device.c

+24 −7
Original line number Diff line number Diff line
@@ -337,12 +337,26 @@ static int mctp_set_link_af(struct net_device *dev, const struct nlattr *attr, 
	return 0;

}



/* Matches netdev types that should have MCTP handling */

static bool mctp_known(struct net_device *dev)

{

	/* only register specific types (inc. NONE for TUN devices) */

	return dev->type == ARPHRD_MCTP ||

		   dev->type == ARPHRD_LOOPBACK ||

		   dev->type == ARPHRD_NONE;

}



static void mctp_unregister(struct net_device *dev)

{

	struct mctp_dev *mdev;



	mdev = mctp_dev_get_rtnl(dev);



	if (mctp_known(dev) != (bool)mdev) {

		// Sanity check, should match what was set in mctp_register

		netdev_warn(dev, "%s: mdev pointer %d but type (%d) match is %d",

			    __func__, (bool)mdev, mctp_known(dev), dev->type);

		return;

	}

	if (!mdev)

		return;
@@ -360,16 +374,19 @@ static int mctp_register(struct net_device *dev) 
	struct mctp_dev *mdev;



	/* Already registered? */

	if (rtnl_dereference(dev->mctp_ptr))

		return 0;

	mdev = rtnl_dereference(dev->mctp_ptr);



	/* only register specific types (inc. NONE for TUN devices) */

	if (!(dev->type == ARPHRD_MCTP ||

	      dev->type == ARPHRD_LOOPBACK ||

	      dev->type == ARPHRD_NONE)) {

	if (mdev) {

		if (!mctp_known(dev))

			netdev_warn(dev, "%s: mctp_dev set for unknown type %d",

				    __func__, dev->type);

		return 0;

	}



	/* only register specific types */

	if (!mctp_known(dev))

		return 0;



	mdev = mctp_add_dev(dev);

	if (IS_ERR(mdev))

		return PTR_ERR(mdev);