RE: [PATCH] xen-netback: fix memory leaks on XenBus disconnect
From: Paul Durrant <hidden>
Date: 2017-01-13 09:01:45
Also in:
lkml
-----Original Message----- From: Igor Druzhinin [mailto:igor.druzhinin@citrix.com] Sent: 12 January 2017 17:52 To: Wei Liu <redacted>; xen-devel@lists.xenproject.org; Paul Durrant [off-list ref] Cc: netdev@vger.kernel.org; linux-kernel@vger.kernel.org; Igor Druzhinin [off-list ref] Subject: [PATCH] xen-netback: fix memory leaks on XenBus disconnect Eliminate memory leaks introduced several years ago by cleaning the queue resources which are allocated on XenBus connection event. Namely, queue structure array and pages used for IO rings. vif->lock is used to protect statistics gathering agents from using the queue structure during cleaning. Signed-off-by: Igor Druzhinin <redacted>
Reviewed-by: Paul Durrant <redacted> ...although I was involved with discussions concerning this, so Wei should probably look it over too.
quoted hunk ↗ jump to hunk
--- drivers/net/xen-netback/interface.c | 6 ++++-- drivers/net/xen-netback/xenbus.c | 13 +++++++++++++ 2 files changed, 17 insertions(+), 2 deletions(-)diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c index e30ffd2..5795213 100644--- a/drivers/net/xen-netback/interface.c +++ b/drivers/net/xen-netback/interface.c@@ -221,18 +221,18 @@ static struct net_device_stats*xenvif_get_stats(struct net_device *dev) { struct xenvif *vif = netdev_priv(dev); struct xenvif_queue *queue = NULL; - unsigned int num_queues = vif->num_queues; unsigned long rx_bytes = 0; unsigned long rx_packets = 0; unsigned long tx_bytes = 0; unsigned long tx_packets = 0; unsigned int index; + spin_lock(&vif->lock); if (vif->queues == NULL) goto out; /* Aggregate tx and rx stats from each queue */ - for (index = 0; index < num_queues; ++index) { + for (index = 0; index < vif->num_queues; ++index) { queue = &vif->queues[index]; rx_bytes += queue->stats.rx_bytes; rx_packets += queue->stats.rx_packets;@@ -241,6 +241,8 @@ static struct net_device_stats*xenvif_get_stats(struct net_device *dev) } out: + spin_unlock(&vif->lock); + vif->dev->stats.rx_bytes = rx_bytes; vif->dev->stats.rx_packets = rx_packets; vif->dev->stats.tx_bytes = tx_bytes;diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index 3124eae..85b742e 100644--- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c@@ -493,11 +493,22 @@ static int backend_create_xenvif(structbackend_info *be) static void backend_disconnect(struct backend_info *be) { if (be->vif) { + unsigned int queue_index; + xen_unregister_watchers(be->vif); #ifdef CONFIG_DEBUG_FS xenvif_debugfs_delif(be->vif); #endif /* CONFIG_DEBUG_FS */ xenvif_disconnect_data(be->vif); + for (queue_index = 0; queue_index < be->vif-quoted
num_queues; ++queue_index)+ xenvif_deinit_queue(&be->vif-quoted
queues[queue_index]);+ + spin_lock(&be->vif->lock); + vfree(be->vif->queues); + be->vif->num_queues = 0; + be->vif->queues = NULL; + spin_unlock(&be->vif->lock); + xenvif_disconnect_ctrl(be->vif); } }@@ -1034,6 +1045,8 @@ static void connect(struct backend_info *be) err: if (be->vif->num_queues > 0) xenvif_disconnect_data(be->vif); /* Clean up existingqueues */ + for (queue_index = 0; queue_index < be->vif->num_queues; ++queue_index) + xenvif_deinit_queue(&be->vif->queues[queue_index]); vfree(be->vif->queues); be->vif->queues = NULL; be->vif->num_queues = 0; -- 1.8.3.1