Re: [PATCH] Drivers: hv: vmbus: finally fix hv_need_to_signal_on_read()

From: gregkh@xxxxxxxxxxxxxxxxxxx
Date: Thu Jan 26 2017 - 02:16:47 EST


On Thu, Jan 26, 2017 at 06:10:19AM +0000, Dexuan Cui wrote:
> > From: Stephen Hemminger [mailto:stephen@xxxxxxxxxxxxxxxxxx]
> > Sent: Wednesday, January 25, 2017 00:08
> > To: Dexuan Cui <decui@xxxxxxxxxxxxx>
> > Cc: gregkh@xxxxxxxxxxxxxxxxxxx; driverdev-devel@xxxxxxxxxxxxxxxxxxxxxx; KY
> > Srinivasan <kys@xxxxxxxxxxxxx>; Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>;
> > Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>; olaf@xxxxxxxxx; Rolf
> > Neugebauer <rolf.neugebauer@xxxxxxxxxx>; jasowang@xxxxxxxxxx; linux-
> > kernel@xxxxxxxxxxxxxxx; apw@xxxxxxxxxxxxx
> > Subject: Re: [PATCH] Drivers: hv: vmbus: finally fix hv_need_to_signal_on_read()
> >
> > On Tue, 24 Jan 2017 06:54:46 +0000
> > Dexuan Cui <decui@xxxxxxxxxxxxx> wrote:
> >
> > > +static inline void
> > > +init_cached_read_index(struct vmbus_channel *channel)
> > > +{
> > > + struct hv_ring_buffer_info *rbi = &channel->inbound;
> > > +
> > > + rbi->cached_read_index = rbi->ring_buffer->read_index;
> > > +}
> >
> > Looks good thanks. This should go in right away. Which versions are impacted?
> > Should it also go to stable?
>
> Yes, it needs to go to stable.
> I have Cc-ed <stable@xxxxxxxxxxxxxxx> in the patch's changelog, so it should be
> included in the stable tree automatically.
>
> As I checked against the kernels listed on the homapage of www.kernel.org, the
> below versions are impacted:
> v3.16.39
> v3.18.47
> v4.1.38
> v4.8.17
> v4.9.5
> v4.10-rc5
>
> It's interesting v4.4.44 is not impacted, but actually it needs both the 2 patches:
> i.e. this patch, and the previous one:
> Commit a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in hv_need_to_signal_on_read()")

That patch does not apply to the 4.4-stable tree, which is why it was
not included there. If you feel it should be included, please provide a
backport and send it to the stable@xxxxxxxxxxxxxxx mailing list.

thanks,

greg k-h