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| author | Matt Johnston <matt@codeconstruct.com.au> | 2021-09-29 15:26:14 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-09-29 11:00:12 +0100 |
| commit | 7b1871af75f30d9d88184fff42698718fa157dcf (patch) | |
| tree | ec5be2baead105d91fee958dd53ac4bae57ae5b6 /net/mctp | |
| parent | 6183569db80eedc648b584a658e6b898d43650cb (diff) | |
| download | lwn-7b1871af75f30d9d88184fff42698718fa157dcf.tar.gz lwn-7b1871af75f30d9d88184fff42698718fa157dcf.zip | |
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 <matt@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mctp')
| -rw-r--r-- | net/mctp/device.c | 31 |
1 files changed, 24 insertions, 7 deletions
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); |