linux-kernel - Re: [PATCH 2.6.20.3] Flush writes to MSI-X table

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: <20070323210729.GC12182@suse.de>
Date:	Fri, 23 Mar 2007 14:07:29 -0700
From:	Greg KH <gregkh@...e.de>
To:	Mitch Williams <mitch.a.williams@...el.com>
Cc:	linux-kernel@...r.kernel.org, mingo@...hat.com,
	auke-jan.h.kok@...el.com, john.ronciak@...el.com,
	jesse.brandeburg@...el.com
Subject: Re: [PATCH 2.6.20.3] Flush writes to MSI-X table

On Thu, Mar 22, 2007 at 02:08:19PM -0700, Mitch Williams wrote:
> Because both MSI-X interrupt messages and MSI-X table writes are posted,
> it's possible for them to cross while in-flight.  This results in
> interrupts being received long after the kernel thinks they're disabled,
> and in interrupts being sent to stale vectors after rebalancing.
> 
> This patch performs a read flush after writes to the MSI-X table for
> enable/disable and rebalancing operations.  Because this is an expensive
> operation, we do not perform the read flush after mask/unmask
> operations.  Hardware which supports MSI-X typically also supports some
> sort of interrupt moderation, so a read-flush is not necessary for
> mask/unmask operations.
> 
> This patch has been validated with (unreleased) network hardware which
> uses MSI-X.

Is this needed for any hardware that is public today?

Also, it seems a bit too big of a patch for -stable right now,
especially as the mainline patch will not make it into 2.6.22 at the
earliest.

thanks,

greg k-h
-
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/