svn commit: r320626 - head/sys/dev/ena

[Zbigniew Bodek]

Author: zbb
Date: Tue Jul  4 00:00:42 2017
New Revision: 320626
URL: https://svnweb.freebsd.org/changeset/base/320626

Log:
  Acquire locks before calling drbr_flush()
  
  It is required to hold lock that is associated with buffer ring before
  flushing drbr.
  
  Submitted by:   Michal Krawczyk <mk at semihalf.com>
  Obtained from:  Semihalf
  Sponsored by:   Amazon.com Inc.

Modified:
  head/sys/dev/ena/ena.c

Modified: head/sys/dev/ena/ena.c
==============================================================================
--- head/sys/dev/ena/ena.c	Mon Jul  3 23:59:11 2017	(r320625)
+++ head/sys/dev/ena/ena.c	Tue Jul  4 00:00:42 2017	(r320626)
@@ -642,7 +642,9 @@ ena_setup_tx_resources(struct ena_adapter *adapter, in
 	tx_ring->next_to_clean = 0;
 
 	/* Make sure that drbr is empty */
+	ENA_RING_MTX_LOCK(tx_ring);
 	drbr_flush(adapter->ifp, tx_ring->br);
+	ENA_RING_MTX_UNLOCK(tx_ring);
 
 	/* ... and create the buffer DMA maps */
 	for (i = 0; i < tx_ring->ring_size; i++) {
@@ -709,11 +711,11 @@ ena_free_tx_resources(struct ena_adapter *adapter, int
 
 	taskqueue_free(tx_ring->enqueue_tq);
 
+	ENA_RING_MTX_LOCK(tx_ring);
 	/* Flush buffer ring, */
 	drbr_flush(adapter->ifp, tx_ring->br);
 
 	/* Free buffer DMA maps, */
-	ENA_RING_MTX_LOCK(tx_ring);
 	for (int i = 0; i < tx_ring->ring_size; i++) {
 		m_freem(tx_ring->tx_buffer_info[i].mbuf);
 		tx_ring->tx_buffer_info[i].mbuf = NULL;