linux-kernel - Re: PROBLEM: modprobe hang at startup (3.8.x, 3.9.x, IBM x3550)

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] [day] [month] [year] [list]

Message-ID: <20130517121819.GA3165@pyro.melbourne.osa>
Date:	Fri, 17 May 2013 22:18:19 +1000
From:	Robert Norris <robn@...ra.com>
To:	Jean Delvare <khali@...ux-fr.org>
Cc:	Daniel Kurtz <djkurtz@...omium.org>, linux-kernel@...r.kernel.org,
	Linux I2C <linux-i2c@...r.kernel.org>
Subject: Re: PROBLEM: modprobe hang at startup (3.8.x, 3.9.x, IBM x3550)

On Fri, May 17, 2013 at 10:36:22AM +0200, Jean Delvare wrote:
> IPMI is still likely to access the SMBus controller. If there's a BMC
> in the machine, it can also access the SMBus slave with its own
> controller. It would be good to rule this out by disabling IPMI
> completely, removing the BMC from the machine if it has one, and
> checking if it makes the issue go away or not.

This ended up being easier than I thought. The BMC can't be physically
removed, but there is a jumper on the board to disable it. We flipped it
and got a message during POST about it not being present. Additionally
all IPMI functions did nothing (hung, but interruptable) which is what
you'd expect. I think it really is disabled.

In this state, I re-ran the previous tests, with identical results. That
is:

- "modprobe i2c_i801" succeeds
- "modprobe i2c_i801 disable_features=0x10" succeeds
- With interrupts disabled, "modprobe ics932s401"
- With interrupts enabled, "modprobe ics932s401" hangs
- With interrupts enabled, "i2cget 4 0x50 0x00" hangs

I'll leave the BMC disabled for now in case that's important for further
testing. If you need other tests run with the BMC enabled, I'll use a
differen machine.

Cheers,
Rob.
--
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/