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

[Laurent Vivier]

On 03/12/2019 01:53, pannengyuan wrote:
> 
> 
> On 2019/12/2 21:58, Laurent Vivier wrote:
>> On 02/12/2019 12:15, address@hidden wrote:
>>> From: PanNengyuan <address@hidden>
>>>
>>> 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 <address@hidden>
>>> Signed-off-by: PanNengyuan <address@hidden>
>>> ---
>>>  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)
> 

Yes, you're right. A comment in the code would have helped or written
clearly like:

for (i = 0; i < 2 * (vser->bus.max_nr_ports + 1); i++) {
    virtio_del_queue(vdev, i);
}

Thanks,
Laurent