linux-kernel - RE: [PATCH 4/4] driver: provide sysfs interfaces to access SMX parameter

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: <9E0BE1322F2F2246BD820DA9FC397ADE9AD2A2@SHSMSX102.ccr.corp.intel.com>
Date:	Sat, 11 May 2013 00:01:38 +0000
From:	"Ren, Qiaowei" <qiaowei.ren@...el.com>
To:	Matthew Garrett <matthew.garrett@...ula.com>
CC:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"platform-driver-x86@...r.kernel.org" 
	<platform-driver-x86@...r.kernel.org>,
	"Wei, Gang" <gang.wei@...el.com>
Subject: RE: [PATCH 4/4] driver: provide sysfs interfaces to access SMX
 parameter

On 2013-05-10, Matthew Garrett wrote:
> On Fri, 2013-05-10 at 07:05 +0000, Ren, Qiaowei wrote:
>> On 2013-05-08, Matthew Garrett wrote:
>>> On Tue, 2013-05-07 at 22:55 +0800, Qiaowei Ren wrote:
>>> 
>>>> +What:		/sys/devices/platform/intel_txt/parameter/acm_max_size
>>>> +Date:		May 2013
>>>> +KernelVersion:	3.9
>>>> +Contact:	"Qiaowei Ren" <qiaowei.ren@...el.com>
>>>> +Description:	The "acm_max_size" property will show max size of
>>>> +		authenticated code execution area.
>>> 
>>> What would userspace use this for?
>> 
>> These sysfs files are just export SMX & TXT related information to userspace.
> So that other developers (or OSV & ISV) can be able to develop txt
> related applications or tools based on these information.
> 
> If they're only using it for debugging purposes then sysfs probably
> isn't the right place. Is there any reason tools would need to know this during normal usage?

Unlike tboot log, these properties are not used for debugging purposes.
They are used to report attributes, options and limitations of SMX operation. Software may use them to identify operations limits or additional options.

Thanks,
Qiaowei