RDMA/cm: Fix ordering of xa_alloc_cyclic() in ib_create_cm_id()
xa_alloc_cyclic() is a SMP release to be paired with some later acquire during xa_load() as part of cm_acquire_id(). As such, xa_alloc_cyclic() must be done after the cm_id is fully initialized, in particular, it absolutely must be after the refcount_set(), otherwise the refcount_inc() in cm_acquire_id() may not see the set. As there are several cases where a reader will be able to use the id.local_id after cm_acquire_id in the IB_CM_IDLE state there needs to be an unfortunate split into a NULL allocate and a finalizing xa_store. Fixes: a977049d ("[PATCH] IB: Add the kernel CM implementation") Link: https://lore.kernel.org/r/20200310092545.251365-2-leon@kernel.org Signed-off-by:Leon Romanovsky <leonro@mellanox.com> Signed-off-by:
Jason Gunthorpe <jgg@mellanox.com>
parent
9e57a9aa
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