[net,0/2] Subject: [PATCH net 0/2] net: fix lockdep false positive splat

Message

Taehee Yoo April 25, 2021, 3:52 p.m. UTC

This patchset is to fix lockdep false positive splat in multicast part of
the bridge.

When mdb or multicast config is changed, it acquires multicast_lock,
which is a per-interface(bridge) lock.
So, spin_lock_nested() should be used instead of spin_lock() because
interfaces can be recursive.
The spin_lock_nested() needs 'subclass' parameter.

The first patch adds a new helper function, which returns the nest_level
variable under RCU. The nest_level variable can be used as 'subclass'
parameter of spin_lock_nested().
The second patch fix lockdep false positive splat in the bridge multicast
part by using netdev_get_nest_level_rcu().

Taehee Yoo (2):
  net: core: make bond_get_lowest_level_rcu() generic
  net: bridge: fix lockdep multicast_lock false positive splat

 drivers/net/bonding/bond_main.c |  45 +---------
 include/linux/netdevice.h       |   1 +
 net/bridge/br_mdb.c             |  12 +--
 net/bridge/br_multicast.c       | 146 ++++++++++++++++++++------------
 net/bridge/br_multicast_eht.c   |  18 ++--
 net/bridge/br_private.h         |  48 +++++++++++
 net/core/dev.c                  |  44 ++++++++++
 7 files changed, 204 insertions(+), 110 deletions(-)