Re: [PATCH] rpmsg: virtio_rpmsg_bus: replace "%p" with "%pK"

From: Bjorn Andersson
Date: Tue Aug 27 2019 - 01:10:13 EST


On Fri 09 Aug 13:25 PDT 2019, Suman Anna wrote:

> Hi Bjorn,
>

Hi Suman

> On 10/23/18 8:19 PM, Suman Anna wrote:
> > The virtio_rpmsg_bus driver uses the "%p" format-specifier for
> > printing the vring buffer address. This prints only a hashed
> > pointer even for previliged users. Use "%pK" instead so that
> > the address can be printed during debug using kptr_restrict
> > sysctl.
>
> Seems to have been lost among the patches, can you pick up this trivial
> patch for 5.4? Should apply cleanly on the latest HEAD as well.
>

I share Andrew's question regarding what benefit you have from knowing
this value. Should we not just remove the va from the print? Or do you
actually have a use case for it?

Regards,
Bjorn

> regards
> Suman
>
> >
> > Signed-off-by: Suman Anna <s-anna@xxxxxx>
> > ---
> > drivers/rpmsg/virtio_rpmsg_bus.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c
> > index f29dee731026..1345f373a1a0 100644
> > --- a/drivers/rpmsg/virtio_rpmsg_bus.c
> > +++ b/drivers/rpmsg/virtio_rpmsg_bus.c
> > @@ -950,7 +950,7 @@ static int rpmsg_probe(struct virtio_device *vdev)
> > goto vqs_del;
> > }
> >
> > - dev_dbg(&vdev->dev, "buffers: va %p, dma %pad\n",
> > + dev_dbg(&vdev->dev, "buffers: va %pK, dma %pad\n",
> > bufs_va, &vrp->bufs_dma);
> >
> > /* half of the buffers is dedicated for RX */
> >
>