On (Sat) May 15 2010 [11:45:53], Julia Lawall wrote: > From: Julia Lawall <julia@xxxxxxx> > > In each case, the first argument to send_control_msg or __send_control_msg, > respectively, has either not been successfully allocated or has been freed > at the point of the call. In the first case, the first argument, port, is > only used to access the portdev and id fields, in order to call > __send_control_msg. Thus it seems possible instead to call > __send_control_msg directly. In the second case, the call to > __send_control_msg is moved up to a place where it seems like the first > argument, portdev, has been initialized sufficiently to make the call to > __send_control_msg meaningful. > > This has only been compile tested. > > A simplified version of the semantic match that finds this problem is as > follows: (http://coccinelle.lip6.fr/) > > // <smpl> > @free@ > expression E; > position p; > @@ > kfree@p(E) > > @@ > expression free.E, subE<=free.E, E1; > position free.p; > @@ > > kfree@p(E) > ... > ( > subE = E1 > | > * E > ) > // </smpl> > > Signed-off-by: Julia Lawall <julia@xxxxxxx> Acked-by: Amit Shah <amit.shah@xxxxxxxxxx> Thanks, Julia. Rusty, please pick this patch. Thanks. > > --- > drivers/char/virtio_console.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c > index 458d907..8c99bf1 100644 > --- a/drivers/char/virtio_console.c > +++ b/drivers/char/virtio_console.c > @@ -1090,7 +1090,7 @@ free_port: > kfree(port); > fail: > /* The host might want to notify management sw about port add failure */ > - send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 0); > + __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0); > return err; > } > > @@ -1559,6 +1559,9 @@ static int __devinit virtcons_probe(struct virtio_device *vdev) > return 0; > > free_vqs: > + /* The host might want to notify mgmt sw about device add failure */ > + __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID, > + VIRTIO_CONSOLE_DEVICE_READY, 0); > vdev->config->del_vqs(vdev); > kfree(portdev->in_vqs); > kfree(portdev->out_vqs); > @@ -1567,9 +1570,6 @@ free_chrdev: > free: > kfree(portdev); > fail: > - /* The host might want to notify mgmt sw about device add failure */ > - __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID, > - VIRTIO_CONSOLE_DEVICE_READY, 0); > return err; > } > Amit -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
