[PATCH rdma-rc 1/3] RDMA/core: Wait for RCU callbacks before unloading ib_core

[Leon Romanovsky]

From: Leon Romanovsky <leonro@xxxxxxxxxx>

put_gid_ndev() is queued with call_rcu() and implemented in ib_core.
Stopping the workqueues does not drain callbacks already queued, so RCU
could invoke it after the module code has been unloaded.

synchronize_rcu() does not wait for callbacks. Wait for them after all
producers have stopped.

Fixes: 943bd984b108 ("RDMA/core: Allow detaching gid attribute netdevice for RoCE")
Reported-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Closes: https://lore.kernel.org/linux-rdma/20260708092316.Qb39F_B0@xxxxxxxxxxxxx/
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>
---
 drivers/infiniband/core/device.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index b8193e077a74..d954eda63134 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -3150,6 +3150,7 @@ static void __exit ib_core_cleanup(void)
 	/* Make sure that any pending umem accounting work is done. */
 	destroy_workqueue(ib_wq);
 	destroy_workqueue(ib_unreg_wq);
+	rcu_barrier();
 	WARN_ON(!xa_empty(&clients));
 	WARN_ON(!xa_empty(&devices));
 }

-- 
2.54.0