linux-kernel - Re: [BUG] 2.6.21-rc1,2,3 regressions on my system that I found so far

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: <200703180045.18490.maximlevitsky@gmail.com>
Date:	Sun, 18 Mar 2007 00:45:18 +0200
From:	Maxim <maximlevitsky@...il.com>
To:	Len Brown <lenb@...nel.org>
Cc:	tglx@...utronix.de, linux-kernel@...r.kernel.org,
	Ingo Molnar <mingo@...e.hu>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Adrian Bunk <bunk@...sta.de>,
	Arjan van de Ven <arjan@...radead.org>
Subject: Re: [BUG] 2.6.21-rc1,2,3 regressions on my system that I found so far

On Saturday 17 March 2007 03:32:53 Len Brown wrote:
> On Friday 16 March 2007 19:44, Thomas Gleixner wrote:
> > Maxim,
> > 
> > On Fri, 2007-03-16 at 12:30 +0200, Maxim Levitsky wrote:
> > > 3) Sometimes I get this (once in three boots or so)
> > > 
> > > [   36.217405] ENABLING IO-APIC IRQs
> > > [   36.217587] ..TIMER: vector=0x31 apic1=0 pin1=2 apic2=-1 pin2=-1
> > > [   36.433917] APIC timer disabled due to verification failure.
> > > 
> > > And NO_HZ is disabled due to that (I get 1000/s timer's interrupts)
> > > I haven't investigated that yet.
> > > It looks like another new test that my hardware fails to perform... 
> > 
> > Yes, this is probably caused by SMM code trying to emulate a PS/2
> > keyboard from a (maybe connected or not) USB keyboard. Unfortunately we
> > have no way to disable this BIOS misfeature in the early boot process. 
> > Arjan, Len ?????
> 
> Nope.  By definition, SMM is invisible to the OS -- we don't even
> get a bit that said it occurred (though we'd like one -- it would
> be really helpful to diagnose issues like this one)
> 
> So go into BIOS SETUP and see if there is a USB Legacy Emulation
> feature that you can disable.  Sometimes there is not, but disabling
> onboard USB altogether may help at least prove the issue is in that area.
> 
> > I built in this test to rule out bogus LAPIC timer calibration values
> > which are sometimes off by factor 2-10.
> > 
> > But I also built in a calibration against the PM-Timer, which turned out
> > to be quite reliable and I think the additional verification step is
> > only necessary for sytems without PM-Timer.
> > 
> > That was a bit over cautious from my side. I send a patch to avoid this
> > when PM-Timer is available in a separate mail.
> 
> PM-Timer was invented to work-around the issue that the TSC became unreliable
> in the face of power management on laptops.  In particular, to be able
> to time duration of OS idle where TSC stopped.
> 
> While it is not fine grain, and it is not low-latency, is should
> be very reliable.  My understanding is that it is implemented as
> a simple divider right off the system 14MHz clock -- the signal
> which most motherboard clocks are PLL multiplied up from --
> including the 100MHz front-side bus which drives the LAPIC timer.
> 
> But that said, I don't understand why calibrating the LAPIC timer
> using the PM-timer is going to be more reliable -- exactly how
> and why did the previous calibration scheme fail?
> Maybe I could follow the new logic in apic.c if I saw the "apic=debug"
> output for this box.
> 
> cheers,
> -Len
> 
> 
> 

Hi,

	Yes, usb emulation is enabled, but I need it. I will test without usb emulation, but since it shows only sometimes, 
	I don't know yet whenever usb legacy affects it.

	Regards, 
		Maxim Levitsky
-
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/