linux-kernel - Re: [tpmdd-devel] [PATCH 1/2] tpm: Apply an adapterlimit for retransmission.

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: <20170222140134.GA23586@lunn.ch>
Date:   Wed, 22 Feb 2017 15:01:34 +0100
From:   Andrew Lunn <andrew@...n.ch>
To:     Enric Balletbo i Serra <enric.balletbo@...labora.com>
Cc:     Peter Huewe <peterhuewe@....de>,
        Marcel Selhorst <tpmdd@...horst.net>, apronin@...gle.com,
        tpmdd-devel@...ts.sourceforge.net, linux-kernel@...r.kernel.org,
        Wolfram Sang <wsa@...-dreams.de>
Subject: Re: [tpmdd-devel] [PATCH 1/2] tpm: Apply an adapterlimit for
 retransmission.

On Wed, Feb 22, 2017 at 12:16:08PM +0100, Enric Balletbo i Serra wrote:
> Hi Andrew,
> 
> Removing Bryan Freed from the loop as seems his email is not valid anymore. I already CC'ied Andrey which is doing the TPM bit in chromeos kernel.
> 
> On 21/02/17 17:29, Andrew Lunn wrote:
> > On Tue, Feb 21, 2017 at 03:44:59PM +0100, Enric Balletbo i Serra wrote:
> >> From: Bryan Freed <bfreed@...omium.org>
> >>
> >> When the I2C Infineon part is attached to an I2C adapter that imposes
> >> a size limitation, large requests will fail -EINVAL.
> >> Retry them with size backoff without re-issuing the 0x05 command
> >> as this appears to occasionally put the TPM in a bad state.
> > 
> > Hi Enric
> > 
> > Rather than trying small and smaller transfers, would it not be better
> > to get the i2c core to expose the quirk info about transfer limits?
> > 
> 
> Sounds a good idea to me, I guess the quirk info can be accessed with
> 
>   tpm_dev.client->adapter->quirks->max_read_len
> 
> so I think we don't need to touch the i2c core. I'll propose a second version of the patch.

Hi Enric

You should probably ask Wolfram Sang <wsa@...-dreams.de>, the i2c
subsystem maintainer. He may prefer adding an API call.

	  Andrew