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authorPaul Durrant <Paul.Durrant@citrix.com>2017-03-02 12:54:26 +0000
committerDavid S. Miller <davem@davemloft.net>2017-03-03 09:36:15 -0800
commita254d8f9a8a928772ef4608342125ccb35b79d5d (patch)
treedda0845041f4823dd34c32ae1e974aeff896055d
parentd67ce7da3b1eda838db7bdca86d7ec28ef37068e (diff)
xen-netback: don't vfree() queues under spinlock
This leads to a BUG of the following form: [ 174.512861] switch: port 2(vif3.0) entered disabled state [ 174.522735] BUG: sleeping function called from invalid context at /home/build/linux-linus/mm/vmalloc.c:1441 [ 174.523451] in_atomic(): 1, irqs_disabled(): 0, pid: 28, name: xenwatch [ 174.524131] CPU: 1 PID: 28 Comm: xenwatch Tainted: G W 4.10.0upstream-11073-g4977ab6-dirty #1 [ 174.524819] Hardware name: MSI MS-7680/H61M-P23 (MS-7680), BIOS V17.0 03/14/2011 [ 174.525517] Call Trace: [ 174.526217] show_stack+0x23/0x60 [ 174.526899] dump_stack+0x5b/0x88 [ 174.527562] ___might_sleep+0xde/0x130 [ 174.528208] __might_sleep+0x35/0xa0 [ 174.528840] ? _raw_spin_unlock_irqrestore+0x13/0x20 [ 174.529463] ? __wake_up+0x40/0x50 [ 174.530089] remove_vm_area+0x20/0x90 [ 174.530724] __vunmap+0x1d/0xc0 [ 174.531346] ? delete_object_full+0x13/0x20 [ 174.531973] vfree+0x40/0x80 [ 174.532594] set_backend_state+0x18a/0xa90 [ 174.533221] ? dwc_scan_descriptors+0x24d/0x430 [ 174.533850] ? kfree+0x5b/0xc0 [ 174.534476] ? xenbus_read+0x3d/0x50 [ 174.535101] ? xenbus_read+0x3d/0x50 [ 174.535718] ? xenbus_gather+0x31/0x90 [ 174.536332] ? ___might_sleep+0xf6/0x130 [ 174.536945] frontend_changed+0x6b/0xd0 [ 174.537565] xenbus_otherend_changed+0x7d/0x80 [ 174.538185] frontend_changed+0x12/0x20 [ 174.538803] xenwatch_thread+0x74/0x110 [ 174.539417] ? woken_wake_function+0x20/0x20 [ 174.540049] kthread+0xe5/0x120 [ 174.540663] ? xenbus_printf+0x50/0x50 [ 174.541278] ? __kthread_init_worker+0x40/0x40 [ 174.541898] ret_from_fork+0x21/0x2c [ 174.548635] switch: port 2(vif3.0) entered disabled state This patch defers the vfree() until after the spinlock is released. Reported-by: Juergen Gross <jgross@suse.com> Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/xen-netback/xenbus.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
index d82ddc9..d2d7cd9 100644
--- a/drivers/net/xen-netback/xenbus.c
+++ b/drivers/net/xen-netback/xenbus.c
@@ -496,6 +496,7 @@ static void backend_disconnect(struct backend_info *be)
if (vif) {
unsigned int queue_index;
+ struct xenvif_queue *queues;
xen_unregister_watchers(vif);
#ifdef CONFIG_DEBUG_FS
@@ -508,11 +509,13 @@ static void backend_disconnect(struct backend_info *be)
xenvif_deinit_queue(&vif->queues[queue_index]);
spin_lock(&vif->lock);
- vfree(vif->queues);
+ queues = vif->queues;
vif->num_queues = 0;
vif->queues = NULL;
spin_unlock(&vif->lock);
+ vfree(queues);
+
xenvif_disconnect_ctrl(vif);
}
}