From: Ganji Aravind Date: Tue, 18 Aug 2020 15:40:58 +0000 (+0530) Subject: cxgb4: Fix race between loopback and normal Tx path X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=c650e04898072e4b579cbf8d9dd5b86bcdbe9b00;p=linux.git cxgb4: Fix race between loopback and normal Tx path Even after Tx queues are marked stopped, there exists a small window where the current packet in the normal Tx path is still being sent out and loopback selftest ends up corrupting the same Tx ring. So, ensure selftest takes the Tx lock to synchronize access the Tx ring. Fixes: 7235ffae3d2c ("cxgb4: add loopback ethtool self-test") Signed-off-by: Ganji Aravind Reviewed-by: Jesse Brandeburg Signed-off-by: David S. Miller --- diff --git a/drivers/net/ethernet/chelsio/cxgb4/sge.c b/drivers/net/ethernet/chelsio/cxgb4/sge.c index 7c9fe4bc235bb..869431a1eedd4 100644 --- a/drivers/net/ethernet/chelsio/cxgb4/sge.c +++ b/drivers/net/ethernet/chelsio/cxgb4/sge.c @@ -2561,11 +2561,14 @@ int cxgb4_selftest_lb_pkt(struct net_device *netdev) lb->loopback = 1; q = &adap->sge.ethtxq[pi->first_qset]; + __netif_tx_lock(q->txq, smp_processor_id()); reclaim_completed_tx(adap, &q->q, -1, true); credits = txq_avail(&q->q) - ndesc; - if (unlikely(credits < 0)) + if (unlikely(credits < 0)) { + __netif_tx_unlock(q->txq); return -ENOMEM; + } wr = (void *)&q->q.desc[q->q.pidx]; memset(wr, 0, sizeof(struct tx_desc)); @@ -2598,6 +2601,7 @@ int cxgb4_selftest_lb_pkt(struct net_device *netdev) init_completion(&lb->completion); txq_advance(&q->q, ndesc); cxgb4_ring_tx_db(adap, &q->q, ndesc); + __netif_tx_unlock(q->txq); /* wait for the pkt to return */ ret = wait_for_completion_timeout(&lb->completion, 10 * HZ);