RDMA/bnxt_re: Serialize dcb_wq access against async notifier

bnxt_re_async_notifier() runs in NAPI/softirq context via bnxt_en's
RCU-protected ULP ops dispatch, never under rtnl_lock, so it isn't
serialized against bnxt_re_uninit_dcb_wq() destroying rdev->dcb_wq.
A concurrent notifier call can queue_work() on a workqueue that is
being, or has just been, destroyed.

Add a spinlock scoped to dcb_wq: the notifier takes it before
checking dcb_wq and queuing work, and bnxt_re_uninit_dcb_wq() takes
it to atomically clear dcb_wq before destroying it. Initialize the
lock at rdev allocation so it is valid on every teardown path,
including bnxt_re_dev_init()'s early failure labels.

Fixes: 51dc5312dcd9 ("RDMA/bnxt_re: Add support to handle DCB_CONFIG_CHANGE event")
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

0 files changed, 0 insertions, 0 deletions