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| author | David S. Miller <davem@davemloft.net> | 2017-03-03 09:36:15 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-03-03 09:36:15 -0800 |
| commit | 2ddbcea75a36dac2ff62ee33a0a8df37e994201e (patch) | |
| tree | dda0845041f4823dd34c32ae1e974aeff896055d | |
| parent | f7bb3d86a64775e0a7636d211dbd80cbeea6e618 (diff) | |
| parent | a254d8f9a8a928772ef4608342125ccb35b79d5d (diff) | |
| download | lwn-2ddbcea75a36dac2ff62ee33a0a8df37e994201e.tar.gz lwn-2ddbcea75a36dac2ff62ee33a0a8df37e994201e.zip | |
Merge branch 'xen-netback-fixes'
Paul Durrant says:
====================
xen-netback: update memory leak fix to avoid BUG
Commit 9a6cdf52b85e "xen-netback: fix memory leaks on XenBus disconnect"
added missing code to fix a memory leak by calling vfree() in the
appropriate place.
Unfortunately subsequent commit f16f1df65f1c "xen-netback: protect
resource cleaning on XenBus disconnect" then wrapped this call to vfree()
in a spin lock, leading to a BUG due to incorrect context.
Patch #1 makes the existing code more readable
Patch #2 fixes the problem
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/xen-netback/xenbus.c | 31 |
1 files changed, 19 insertions, 12 deletions
diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index bb854f92f5a5..d2d7cd9145b1 100644 --- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c @@ -492,24 +492,31 @@ static int backend_create_xenvif(struct backend_info *be) static void backend_disconnect(struct backend_info *be) { - if (be->vif) { + struct xenvif *vif = be->vif; + + if (vif) { unsigned int queue_index; + struct xenvif_queue *queues; - xen_unregister_watchers(be->vif); + xen_unregister_watchers(vif); #ifdef CONFIG_DEBUG_FS - xenvif_debugfs_delif(be->vif); + xenvif_debugfs_delif(vif); #endif /* CONFIG_DEBUG_FS */ - xenvif_disconnect_data(be->vif); - for (queue_index = 0; queue_index < be->vif->num_queues; ++queue_index) - xenvif_deinit_queue(&be->vif->queues[queue_index]); + xenvif_disconnect_data(vif); + for (queue_index = 0; + queue_index < vif->num_queues; + ++queue_index) + xenvif_deinit_queue(&vif->queues[queue_index]); + + spin_lock(&vif->lock); + queues = vif->queues; + vif->num_queues = 0; + vif->queues = NULL; + spin_unlock(&vif->lock); - spin_lock(&be->vif->lock); - vfree(be->vif->queues); - be->vif->num_queues = 0; - be->vif->queues = NULL; - spin_unlock(&be->vif->lock); + vfree(queues); - xenvif_disconnect_ctrl(be->vif); + xenvif_disconnect_ctrl(vif); } } |