linux-kernel - Re: [BUGFIX] PM: Fix active child counting when disabled and forbidden

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] [day] [month] [year] [list]

Message-ID: <4327787.yACWT6Q3EK@vostro.rjw.lan>
Date:	Fri, 16 Nov 2012 11:10:59 +0100
From:	"Rafael J. Wysocki" <rjw@...k.pl>
To:	Huang Ying <ying.huang@...el.com>
Cc:	Alan Stern <stern@...land.harvard.edu>,
	linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org
Subject: Re: [BUGFIX] PM: Fix active child counting when disabled and forbidden

On Friday, November 16, 2012 09:27:05 AM Huang Ying wrote:
> On Fri, 2012-11-16 at 02:29 +0100, Rafael J. Wysocki wrote:
> > On Friday, November 16, 2012 08:54:56 AM Huang Ying wrote:
> > > On Fri, 2012-11-16 at 01:55 +0100, Rafael J. Wysocki wrote:
> > > > On Friday, November 16, 2012 01:44:00 AM Rafael J. Wysocki wrote:
> > > > > On Friday, November 16, 2012 08:36:14 AM Huang Ying wrote:
> > > > > > On Thu, 2012-11-15 at 10:51 +0100, Rafael J. Wysocki wrote:
> > > > 
> > > > [...]
> > > > 
> > > > > > 
> > > > > > For this situation, if user "echo auto > .../power/control" for the
> > > > > > device, the runtime PM callbacks of device will be called.  I think that
> > > > > > is not intended.  So I think it is better to use some kind of flag or
> > > > > > state for that.
> > > > > 
> > > > > I'm not sure what situation exactly you have in mind.  Care to give an
> > > > > exact scenario?
> > > > 
> > > > Ah, I see.  When we've just called drv->remove(), there is a window in
> > > > which user space may cause the driver's runtime PM callbacks to be
> > > > executed by changing its attribute to "auto".
> > > > 
> > > > So perhaps we should check pci_dev->driver rather than pci_dev->dev.driver
> > > > in the runtime PM callbacks?  With a few more changes that should allow us
> > > > to close that race.
> > > 
> > > Yes.  And I think, with pci_dev->driver (after some changes suggested by
> > > Alan), we need not to use pm_runtime_get/put_skip_callbacks().
> > 
> > Good.  Can you please prepare a patch, then? :-)
> 
> Sure.

Cool, thanks!

Rafael


-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
--
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/