netdev - [PATCH v2 net] ixgbevf: fix invalid uses of napi_hash

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Date:   Wed, 16 Nov 2016 07:26:50 -0800
From:   Eric Dumazet <eric.dumazet@...il.com>
To:     David Miller <davem@...emloft.net>
Cc:     netdev <netdev@...r.kernel.org>,
        Jeff Kirsher <jeffrey.t.kirsher@...el.com>
Subject: [PATCH v2 net] ixgbevf: fix invalid uses of napi_hash_del()

From: Eric Dumazet <edumazet@...gle.com>

Calling napi_hash_del() before netif_napi_del() is dangerous
if a synchronize_rcu() is not enforced before NAPI struct freeing.

Lets leave this detail to core networking stack to get it right.

Signed-off-by: Eric Dumazet <edumazet@...gle.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@...el.com>
---
 drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c |    6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index 7eaac3234049..bf4d7efc7dbd 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -2511,9 +2511,6 @@ static int ixgbevf_alloc_q_vectors(struct ixgbevf_adapter *adapter)
 	while (q_idx) {
 		q_idx--;
 		q_vector = adapter->q_vector[q_idx];
-#ifdef CONFIG_NET_RX_BUSY_POLL
-		napi_hash_del(&q_vector->napi);
-#endif
 		netif_napi_del(&q_vector->napi);
 		kfree(q_vector);
 		adapter->q_vector[q_idx] = NULL;
@@ -2537,9 +2534,6 @@ static void ixgbevf_free_q_vectors(struct ixgbevf_adapter *adapter)
 		struct ixgbevf_q_vector *q_vector = adapter->q_vector[q_idx];
 
 		adapter->q_vector[q_idx] = NULL;
-#ifdef CONFIG_NET_RX_BUSY_POLL
-		napi_hash_del(&q_vector->napi);
-#endif
 		netif_napi_del(&q_vector->napi);
 		kfree(q_vector);
 	}