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: <201005281726.00855.oneukum@suse.de>
Date:	Fri, 28 May 2010 17:26:00 +0200
From:	Oliver Neukum <oneukum@...e.de>
To:	Matthias Fuchs <matthias.fuchs@....eu>
Cc:	netdev@...r.kernel.org, Socketcan-core@...ts.berlios.de,
	linux-usb@...r.kernel.org
Subject: Re: [PATCH v3] can: Add driver for esd CAN-USB/2 device

Am Freitag, 28. Mai 2010 16:19:33 schrieb Matthias Fuchs:
> On Wednesday 26 May 2010 15:47, Oliver Neukum wrote:
> > Am Mittwoch, 26. Mai 2010 11:14:03 schrieb Matthias Fuchs:
> > > +       netdev->trans_start = jiffies;
> > > +
> > > +       /* Slow down tx path */
> > > +       if (atomic_read(&priv->active_tx_jobs) >= MAX_TX_URBS)
> > > +               netif_stop_queue(netdev);
> > 
> > Where is the queue started again?
> > 
> > 	Regards
> > 		Oliver
> 
> This is done in the ack-patch for sent messages:
> 
> static void esd_usb2_tx_done_msg(struct esd_usb2_net_priv *priv,
> 				 struct esd_usb2_msg *msg)
> {
> ...
> 	atomic_dec(&priv->active_tx_jobs);
> 
> 	netif_wake_queue(netdev);
> }

Oh, I see. I am afraid this is a race. You have no guarantee that
esd_usb2_tx_done_msg() runs after you stop the queue. If you do
it that way you must stop the queue before you submit the URB
due to which you want to stop it (and do the error handling)

	Regards
		Oliver
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Powered by blists - more mailing lists