On Wed, 2016-11-23 at 11:33 -0500, Dawid Zamirski wrote:
> On Wed, 2016-11-23 at 11:00 -0500, Dawid Zamirski wrote:
> > On Wed, 2016-11-23 at 08:55 -0500, John Ferlan wrote:
> > > [...]
> > > > +
> > > > +static vboxDriverPtr
> > > > +vboxGetDriverConnection(void)
> > > > +{
> > > > + virMutexLock(&vbox_driver_lock);
> > > > +
> > > > + if (vbox_driver) {
> > > > + virObjectRef(vbox_driver);
> > > > + } else {
> > > > + vbox_driver = vboxDriverObjNew();
> > > > +
> > > > + if (!vbox_driver) {
> > > > + virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
> > > > + _("Failed to create vbox driver
> > > > object."));
> > > > + return NULL;
> > > > + }
> > > > + }
> > > > +
> > > > + if (vboxSdkInitialize() < 0 || vboxExtractVersion() < 0) {
> > >
> > > In this path should vboxSdkUninitialize be called (since it
> > > wouldn't
> > > be
> > > called in the destroy path)?
> >
> > If vboxSdkUnintialize fails, VBoxSVC is not started so it does not
> > need
> > to be unintialized - which is in line with the sample code included
> > SDK
> > where it returns with EXIT_FAILUE in main if pfnClientInifialize
> > fails.
> > However, if vboxExtractVersion fails (unlikely) we might want to
> > call
> > gVBoxAPI.UPFN.Unintialize(vbox_driver) directly (not via
> > vboxSdkUninitialize as it checks connectionCount > 0 which on
> > failure
> > would be 0). I've just tested both cases with
> > gVBoxAPI.UPFN.Unintialize
> > in the failure path, and calling it does not do any harm in both
> > cases,
> > so I guess it would be a good idea to put it there.
> >
>
> Actually, I was wrong in that it's safe to call
> gVBoxAPI.UPFN.Unintialize when vboxSdkInitialize fails - I got
> segfault
> when attempting to connect twice in VBOX_RELEASE(data->vboxObject).
> It's safe to do this though:
>
> if (vboxSdkInitialize() < 0) {
> virObjectUnref(vbox_driver);
> virMutexUnlock(&vbox_driver_lock);
>
> return NULL;
> }
>
> if (vboxExtractVersion() < 0) {
> gVBoxAPI.UPFN.Uninitialize(vbox_driver);
> virObjectUnref(vbox_driver);
> virMutexUnlock(&vbox_driver_lock);
>
> return NULL;
> }
>
> i.e do not uninitalize on initialize failure, but do unintialize on
> vboxExractVersion failure.
>
Sigh, it segfaults even in this case as well... :-( Calling
VBOX_RELEASE(data->vboxObj) more than once will trigger a segfault on
that call in both cases. The only way to address this would be to
change _pfnUnitilize in src/vbox/vbox_tmpl.c to check:
if (data->vboxObj)
VBOX_RELEASE(data->vboxObj);
if (data->vboxSession)
VBOX_RELEASE(data->vboxSession);
if (data->vboxClient)
VBOX_RELEASE(data->vboxClient);
only then it's safe to do this in src/vbox/vbox_common.c
if (vboxSdkInitialize() < 0 || vboxExtractVersion() < 0) {
gVBoxAPI.UPFN.Uninitialize(vbox_driver);
virObjectUnref(vbox_driver);
virMutexUnlock(&vbox_driver_lock);
return NULL;
}
I can send v3 with those changes applied if needed.
Regards,
Dawid
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