linux-kernel - Re: Serious problem with ticket spinlocks on ia64

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: <201008272241.15735.ptesarik@suse.cz>
Date:	Fri, 27 Aug 2010 22:41:14 +0200
From:	Petr Tesarik <ptesarik@...e.cz>
To:	"Luck, Tony" <tony.luck@...el.com>
Cc:	"linux-ia64@...r.kernel.org" <linux-ia64@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Hedi Berriche <hedi@....com>
Subject: Re: Serious problem with ticket spinlocks on ia64

On Friday 27 of August 2010 22:29:41 Luck, Tony wrote:
> > If this is a memory ordering problem (and that seems quite plausible)
> > then a liberal sprinkling of "ia64_mf()" calls throughout the spinlock
> > routines would probably make it go away.
>
> I think I take this back ... if it were a memory ordering problem, then
> it could show up any time - not just at wrap-around.

Well, I wasn't originally sure if it only happens at wrap-around. OTOH I've 
now modified my tests, so that they would also catch any other badness, and I 
still only got another two failures after wrap-around.

>From looking at the traces, I'm afraid this smells like another Itanium 
erratum. I'm now trying to write a minimal test case...

Petr Tesarik
--
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/