From 7b1871af75f30d9d88184fff42698718fa157dcf Mon Sep 17 00:00:00 2001 From: Matt Johnston Date: Wed, 29 Sep 2021 15:26:14 +0800 Subject: 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: Matt Johnston Signed-off-by: David S. Miller --- net/mctp/device.c | 31 ++++++++++++++++++++++++------- 1 file changed, 24 insertions(+), 7 deletions(-) (limited to 'net/mctp/device.c') diff --git a/net/mctp/device.c b/net/mctp/device.c index f556c6d01abc..3827d62f52c9 100644 --- a/net/mctp/device.c +++ b/net/mctp/device.c @@ -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); -- cgit v1.2.3