linux-kernel - Re: [Bisected] 3.7-rc1 can't resume (still present in 3.9)

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: <1682771.1PVxk2VyJS@vostro.rjw.lan>
Date:	Thu, 02 May 2013 02:45:43 +0200
From:	"Rafael J. Wysocki" <rjw@...k.pl>
To:	"H. Peter Anvin" <hpa@...or.com>,
	Jonas Heinrich <onny@...ject-insanity.org>
Cc:	len.brown@...el.com, pavel@....cz, tglx@...utronix.de,
	mingo@...hat.com, x86@...nel.org, linux-kernel@...r.kernel.org,
	linux-pm@...r.kernel.org,
	Jarkko Sakkinen <jarkko.sakkinen@...el.com>
Subject: Re: [Bisected] 3.7-rc1 can't resume (still present in 3.9)

On Wednesday, May 01, 2013 11:55:10 AM H. Peter Anvin wrote:
> On 05/01/2013 11:51 AM, Jonas Heinrich wrote:
> > Well, you could give me instructions on how to debug this (I'll do 
> > everything ;)) or I could ship you the Thinkpad T43. I guess this
> > would worth the effort since this bug is somehow critical.
> > 
> > Best regards, Jonas
> 
> I'll put together a debug patch unless I can trick Rafael into doing
> it first...

I'm afraid that code has changed quite a bit since I looked at it last time.
[Jarkko Sakkinen seems to have worked on it lately, CCed.]

Jonas, I wonder what happens if you drop the first hunk of the patch (it just
uses a different register, which shouldn't matter)?  Does it still help then?

If so, there are still a few things you can do to it, e.g:
(1) drop the

-       btl     $WAKEUP_BEHAVIOR_RESTORE_CR4, %edi
-       jnc     1f

lines,
(2) drop the

-       btl     $WAKEUP_BEHAVIOR_RESTORE_EFER, %edi
-       jnc     1f

lines,
(3) drop the

+       jecxz   1f

line,
(4) drop the

+       movl    %eax, %ecx
+       orl     %edx, %ecx
+       jz      1f

lines and see what the minimal patch needed for things to work again is.

Thanks,
Rafael


-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
--
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/