> -----Original Message----- > From: Jan Beulich <jbeulich@xxxxxxxx> > Sent: 29 November 2019 16:01 > To: Durrant, Paul <pdurrant@xxxxxxxxxx> > Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx; linux-block@xxxxxxxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; Stefano Stabellini <sstabellini@xxxxxxxxxx>; Boris > Ostrovsky <boris.ostrovsky@xxxxxxxxxx>; Juergen Gross <jgross@xxxxxxxx> > Subject: Re: [PATCH v2 1/2] xen/xenbus: reference count registered modules > > On 29.11.2019 14:43, Paul Durrant wrote: > > To prevent a module being removed whilst attached to a frontend, and > > Why only frontend? > True. Originally this was only intended for backends, but I guess this should now be 'otherend' or some equivalent form of words. > > hence xenbus calling into potentially invalid text, take a reference on > > the module before calling the probe() method (dropping it if > unsuccessful) > > and drop the reference after returning from the remove() method. > > > > NOTE: This allows the ad-hoc reference counting in xen-netback to be > > removed. This will be done in a subsequent patch. > > > > Suggested-by: Jan Beulich <jbeulich@xxxxxxxx> > > Signed-off-by: Paul Durrant <pdurrant@xxxxxxxxxx> > > > > --- a/drivers/xen/xenbus/xenbus_probe.c > > +++ b/drivers/xen/xenbus/xenbus_probe.c > > @@ -232,9 +232,11 @@ int xenbus_dev_probe(struct device *_dev) > > return err; > > } > > > > + __module_get(drv->driver.owner); > > I guess you really want try_module_get() and deal with it returning > false. > Perhaps, yes. Paul > Jan
