cnic: Don't take rcu_read_lock in cnic_rcv_netevent() (20f30c2d) · Commits · 戴 / test

Because the called function, such as bnx2fc_indicate_netevent(), can sleep, we cannot take rcu_lock(). To prevent the rcu protected ulp_ops from going away, we use the cnic_lock mutex and set the ULP_F_CALL_PENDING flag. The code already waits for ULP_F_CALL_PENDING flag to clear in cnic_unregister_device(). Signed-off-by:

Michael Chan <mchan@broadcom.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/cnic.c

+11 −4

Original line number	Diff line number	Diff line
		@@ -5624,20 +5624,27 @@ static void cnic_rcv_netevent(struct cnic_local *cp, unsigned long event,
		{
		int if_type;

		rcu_read_lock();
		for (if_type = 0; if_type < MAX_CNIC_ULP_TYPE; if_type++) {
		struct cnic_ulp_ops *ulp_ops;
		void *ctx;

		ulp_ops = rcu_dereference(cp->ulp_ops[if_type]);
		if (!ulp_ops \|\| !ulp_ops->indicate_netevent)
		mutex_lock(&cnic_lock);
		ulp_ops = rcu_dereference_protected(cp->ulp_ops[if_type],
		lockdep_is_held(&cnic_lock));
		if (!ulp_ops \|\| !ulp_ops->indicate_netevent) {
		mutex_unlock(&cnic_lock);
		continue;
		}

		ctx = cp->ulp_handle[if_type];

		set_bit(ULP_F_CALL_PENDING, &cp->ulp_flags[if_type]);
		mutex_unlock(&cnic_lock);

		ulp_ops->indicate_netevent(ctx, event, vlan_id);

		clear_bit(ULP_F_CALL_PENDING, &cp->ulp_flags[if_type]);
		}
		rcu_read_unlock();
		}

		/* netdev event handler */

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