linux-kernel - Re: [Pv-drivers] [PATCH 05/12] VMCI: event handling implementation.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <2950075.FZEQUln4vx@dtor-d630.eng.vmware.com>
Date:	Tue, 30 Oct 2012 08:59:39 -0700
From:	Dmitry Torokhov <dtor@...are.com>
To:	Greg KH <gregkh@...uxfoundation.org>
Cc:	George Zhang <georgezhang@...are.com>, pv-drivers@...are.com,
	linux-kernel@...r.kernel.org,
	virtualization@...ts.linux-foundation.org
Subject: Re: [Pv-drivers] [PATCH 05/12] VMCI: event handling implementation.

On Tuesday, October 30, 2012 08:50:41 AM Greg KH wrote:
> On Mon, Oct 29, 2012 at 10:01:52PM -0700, Dmitry Torokhov wrote:
> > On Mon, Oct 29, 2012 at 07:26:05PM -0700, Greg KH wrote:
> > > On Mon, Oct 29, 2012 at 06:04:27PM -0700, George Zhang wrote:
> > > > +static void event_signal_destroy(struct kref *kref)
> > > > +{
> > > > +	struct vmci_subscription *entry =
> > > > +			container_of(kref, struct vmci_subscription, kref);
> > > > +
> > > > +	complete(&entry->done);
> > > > +}
> > > 
> > > Didn't you just leak memory here?  What frees the structure up?
> > 
> > event_unregister_subscription() waits for that completion and frees the
> > structure. We want event_unregister_subscription() to wait until all
> > fired callbacks completed before unregister is complete.
> 
> So all calls to this can just sit and spin waiting for others to clean
> up?  Odd, but ok.

Not all as there is logically only one owner of the subscription so
naturally it waits until all notification callbacks are done.

Frankly we have a change that gets rid of delayed ecvent callbacks
and so the refcounting is no longer needed at all.

Thanks,
Dmitry

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/