netdev - Re: [PATCHv2 net-next] xen-netback: fix race between napi

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20140515180739.GF10525@zion.uk.xensource.com>
Date:	Thu, 15 May 2014 19:07:39 +0100
From:	Wei Liu <wei.liu2@...rix.com>
To:	David Vrabel <david.vrabel@...rix.com>
CC:	<netdev@...r.kernel.org>, <xen-devel@...ts.xenproject.org>,
	Ian Campbell <ian.campbell@...rix.com>,
	Wei Liu <wei.liu2@...rix.com>
Subject: Re: [PATCHv2 net-next] xen-netback: fix race between napi_complete()
 and interrupt handler

On Thu, May 15, 2014 at 06:17:08PM +0100, David Vrabel wrote:
> When the NAPI budget was not all used, xenvif_poll() would call
> napi_complete() /after/ enabling the interrupt.  This resulted in a
> race between the napi_complete() and the napi_schedule() in the
> interrupt handler.  The use of local_irq_save/restore() avoided by
> race iff the handler is running on the same CPU but not if it was
> running on a different CPU.
> 
> Fix this properly by calling napi_complete() before reenabling
> interrupts (in the xenvif_napi_schedule_or_enable_irq() call).
> 
> Signed-off-by: David Vrabel <david.vrabel@...rix.com>

Acked-by: Wei Liu <wei.liu2@...rix.com>
--
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