Re: [Qemu-devel] [PATCH 1/1] virtio-serial-bus: send_control_msg should not deal with cpkts

[Markus Armbruster]

Amit Shah <address@hidden> writes:

> Stuff the cpkt before calling send_control_msg().  it should not be
> concerned about contents, just send across the buffer.
>
> A few code refactorings recently have made mkaing this change easier
> than earlier.
>
> Coverity and clang have flagged this code several times in the past
> (cpkt->id not set before send_control_event() passed it on to
> send_control_msg()).  This will finally eliminate the false-positive.
>
> CC: Markus Armbruster <address@hidden>
> Signed-off-by: Amit Shah <address@hidden>

Patch makes sense to me, and the Coverity defect report is gone.
However, it now worries find_port_by_id() in remove_port() could return
a null pointer, which is then dereferenced.  No idea why it didn't
report that before.  Obvious suppressor:

    diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c
    index 47d0481..7ff7505 100644
    --- a/hw/virtio-serial-bus.c
    +++ b/hw/virtio-serial-bus.c
    @@ -826,6 +826,7 @@ static void remove_port(VirtIOSerial *vser, uint32_t 
port_id)
         vser->ports_map[i] &= ~(1U << (port_id % 32));

         port = find_port_by_id(vser, port_id);
    +    assert(port);
         /* Flush out any unconsumed buffers first */
         discard_vq_data(port->ovq, &port->vser->vdev);

Reviewed-by: Markus Armbruster <address@hidden>