On Mon 02 Mar 09:44 PST 2020, Mathieu Poirier wrote:
> Hi Nikita,
>
> On Fri, 28 Feb 2020 at 04:07, <nikita.shubin@xxxxxxxxxxx> wrote:
> >
> > From: Nikita Shubin <NShubin@xxxxxxxxxx>
> >
> > .kick method not set in rproc_ops will result in:
> >
> > 8<--- cut here ---
> > Unable to handle kernel NULL pointer dereference
> >
> > in rproc_virtio_notify, after firmware loading.
>
> There wasn't any kernel stack trace? What platform was this observed
> on? I'm afraid we won't be able to move forward with this patch
> without one, or more information on what is happening.
>
> >
> > refuse to register an rproc-induced virtio device if no kick method was
> > defined for rproc.
> >
> > Signed-off-by: Nikita Shubin <NShubin@xxxxxxxxxx>
> > ---
Nikita, please include "v2" in the subject and add here (below the ---)
short summary of what changes since v1.
> > drivers/remoteproc/remoteproc_virtio.c | 7 +++++++
> > 1 file changed, 7 insertions(+)
> >
> > diff --git a/drivers/remoteproc/remoteproc_virtio.c b/drivers/remoteproc/remoteproc_virtio.c
> > index 8c07cb2ca8ba..31a62a0b470e 100644
> > --- a/drivers/remoteproc/remoteproc_virtio.c
> > +++ b/drivers/remoteproc/remoteproc_virtio.c
> > @@ -334,6 +334,13 @@ int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
> > struct rproc_mem_entry *mem;
> > int ret;
> >
> > + if (rproc->ops->kick == NULL) {
> > + ret = -EINVAL;
> > + dev_err(dev, ".kick method not defined for %s",
> > + rproc->name);
> > + goto out;
> > + }
>
> I think it would be better to use WARN_ONCE() in rproc_virtio_notify()
> than prevent a virtio device from being added. But again I will need
> more information on this case to know for sure.
>
I reviewed v1 and afaict there's no way rproc->ops->kick would change
and that things wouldn't work without a kick.
So I requested that it should be checked during initialization instead.
Please let me know if I missed some case.
Regards,
Bjorn
> Thanks,
> Mathieu
>
> > +
> > /* Try to find dedicated vdev buffer carveout */
> > mem = rproc_find_carveout_by_name(rproc, "vdev%dbuffer", rvdev->index);
> > if (mem) {
> > --
> > 2.24.1
> >
