Re: [PATCH] virtio-serial-bus: fix memory leak while attach virtio-serial-bus

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Dec 03, 2019 at 08:53:42AM +0800, pannengyuan wrote:
> 
> 
> On 2019/12/2 21:58, Laurent Vivier wrote:
> > On 02/12/2019 12:15, pannengyuan@huawei.com wrote:
> >> From: PanNengyuan <pannengyuan@huawei.com>
> >>
> >> ivqs/ovqs/c_ivq/c_ovq is forgot to cleanup in
> >> virtio_serial_device_unrealize, the memory leak stack is as bellow:
> >>
> >> Direct leak of 1290240 byte(s) in 180 object(s) allocated from:
> >>     #0 0x7fc9bfc27560 in calloc (/usr/lib64/libasan.so.3+0xc7560)
> >>     #1 0x7fc9bed6f015 in g_malloc0 (/usr/lib64/libglib-2.0.so.0+0x50015)
> >>     #2 0x5650e02b83e7 in virtio_add_queue /mnt/sdb/qemu-4.2.0-rc0/hw/virtio/virtio.c:2327
> >>     #3 0x5650e02847b5 in virtio_serial_device_realize /mnt/sdb/qemu-4.2.0-rc0/hw/char/virtio-serial-bus.c:1089
> >>     #4 0x5650e02b56a7 in virtio_device_realize /mnt/sdb/qemu-4.2.0-rc0/hw/virtio/virtio.c:3504
> >>     #5 0x5650e03bf031 in device_set_realized /mnt/sdb/qemu-4.2.0-rc0/hw/core/qdev.c:876
> >>     #6 0x5650e0531efd in property_set_bool /mnt/sdb/qemu-4.2.0-rc0/qom/object.c:2080
> >>     #7 0x5650e053650e in object_property_set_qobject /mnt/sdb/qemu-4.2.0-rc0/qom/qom-qobject.c:26
> >>     #8 0x5650e0533e14 in object_property_set_bool /mnt/sdb/qemu-4.2.0-rc0/qom/object.c:1338
> >>     #9 0x5650e04c0e37 in virtio_pci_realize /mnt/sdb/qemu-4.2.0-rc0/hw/virtio/virtio-pci.c:1801
> >>
> >> Reported-by: Euler Robot <euler.robot@huawei.com>
> >> Signed-off-by: PanNengyuan <pannengyuan@huawei.com>
> >> ---
> >>  hw/char/virtio-serial-bus.c | 6 ++++++
> >>  1 file changed, 6 insertions(+)
> >>
> >> diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c
> >> index 3325904..da9019a 100644
> >> --- a/hw/char/virtio-serial-bus.c
> >> +++ b/hw/char/virtio-serial-bus.c
> >> @@ -1126,9 +1126,15 @@ static void virtio_serial_device_unrealize(DeviceState *dev, Error **errp)
> >>  {
> >>      VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> >>      VirtIOSerial *vser = VIRTIO_SERIAL(dev);
> >> +    int i;
> >>  
> >>      QLIST_REMOVE(vser, next);
> >>  
> >> +    for (i = 0; i <= vser->bus.max_nr_ports; i++) {
> >> +        virtio_del_queue(vdev, 2 * i);
> >> +        virtio_del_queue(vdev, 2 * i + 1);
> >> +    }
> >> +
> > 
> > According to virtio_serial_device_realize() and the number of
> > virtio_add_queue(), I think you have more queues to delete:
> > 
> >   4 + 2 * vser->bus.max_nr_ports
> > 
> > (for vser->ivqs[0], vser->ovqs[0], vser->c_ivq, vser->c_ovq,
> > vser->ivqs[i], vser->ovqs[i]).
> > 
> > Thanks,
> > Laurent
> > 
> > 
> Thanks, but I think the queues is correct, the queues in
> virtio_serial_device_realize is as follow:
> 
> // here is 2
> vser->ivqs[0] = virtio_add_queue(vdev, 128, handle_input);
> vser->ovqs[0] = virtio_add_queue(vdev, 128, handle_output);
> 
> // here is 2
> vser->c_ivq = virtio_add_queue(vdev, 32, control_in);
> vser->c_ovq = virtio_add_queue(vdev, 32, control_out);
> 
> // here 2 * (max_nr_ports - 1)  ----- i is from 1 to max_nr_ports - 1
> for (i = 1; i < vser->bus.max_nr_ports; i++) {
>     vser->ivqs[i] = virtio_add_queue(vdev, 128, handle_input);
>     vser->ovqs[i] = virtio_add_queue(vdev, 128, handle_output);
> }
> 
> so the total queues number is:  2 * (vser->bus.max_nr_ports + 1)

Rather than worry about this, I posted a patch adding virtio_delete_queue.
How about reusing that, and just using ivqs/ovqs pointers?

-- 
MST