netdev - Re: net_rx_action/NAPI oops [PATCH]

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: <20071127140904.20c4cba8@freepuppy.rosehill>
Date:	Tue, 27 Nov 2007 14:09:04 -0800
From:	Stephen Hemminger <shemminger@...ux-foundation.org>
To:	Robert Olsson <Robert.Olsson@...a.slu.se>
Cc:	David Miller <davem@...emloft.net>, netdev@...r.kernel.org,
	Robert.Olsson@...a.slu.se, Auke Kok <sofar@...-projects.org>
Subject: Re: net_rx_action/NAPI oops [PATCH]

On Tue, 27 Nov 2007 19:52:24 +0100
Robert Olsson <Robert.Olsson@...a.slu.se> wrote:

> 
> Hello!
> 
> I've discovered a bug while testing the new multiQ NAPI code. In hi-load 
> situations when we take down an interface we get a kernel panic. The
> oops is below.
> 
> From what I see this happens when driver does napi_disable() and clears
> NAPI_STATE_SCHED. In net_rx_action there is a check for work == weight 
> a sort indirect test but that's now not enough to cover the load situation. 
> where we have NAPI_STATE_SCHED cleared by e1000_down in my case and still 
> full quota. Latest git but I'll guess the is the same in all later kernels.
> There might be different solutions... one variant is below:

It is considered a driver bug in 2.6.24 to call netif_rx_complete (clear NAPI_STATE_SCHED)
and do a full quota. That bug already had to be fixed in other drivers,
look like e1000 has same problem.


-- 
Stephen Hemminger <shemminger@...ux-foundation.org>
-
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