From 20f30c2d5ea44925cb83b0fdae78b8600a76b66e Mon Sep 17 00:00:00 2001 From: Michael Chan Date: Mon, 2 Jun 2014 23:08:46 -0700 Subject: [PATCH] cnic: Don't take rcu_read_lock in cnic_rcv_netevent() 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 Signed-off-by: David S. Miller --- drivers/net/ethernet/broadcom/cnic.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/broadcom/cnic.c b/drivers/net/ethernet/broadcom/cnic.c index 09f3fefcbf9c..a0aae722ffcf 100644 --- a/drivers/net/ethernet/broadcom/cnic.c +++ b/drivers/net/ethernet/broadcom/cnic.c @@ -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 */ -- 2.30.2