Re: [PATCH 01/15] taint: add module firmware crash taint support

Randy Dunlap
2020-05-10T02:20:02Z

On 5/9/20 9:46 AM, Luis Chamberlain wrote:
> On Sat, May 09, 2020 at 11:18:29AM -0400, Rafael Aquini wrote:
>> We are still missing the documentation bits for this
>> new flag, though.
>
> Ah yeah sorry about that.
>
>> How about having a blurb similar to:
>>
>> diff --git a/Documentation/admin-guide/tainted-kernels.rst b/Documentation/admin-guide/tainted-kernels.rst
>> index 71e9184a9079..5c6a9e2478b0 100644
>> --- a/Documentation/admin-guide/tainted-kernels.rst
>> +++ b/Documentation/admin-guide/tainted-kernels.rst
>> @@ -100,6 +100,7 @@ Bit Log Number Reason that got the kernel tainted
>> 15 _/K 32768 kernel has been live patched
>> 16 _/X 65536 auxiliary taint, defined for and used by distros
>> 17 _/T 131072 kernel was built with the struct randomization plugin
>> + 18 _/Q 262144 driver firmware crash annotation
>> === === ====== ========================================================
>>
>> Note: The character ``_`` is representing a blank in this table to make reading
>> @@ -162,3 +163,7 @@ More detailed explanation for tainting
>> produce extremely unusual kernel structure layouts (even performance
>> pathological ones), which is important to know when debugging. Set at
>> build time.
>> +
>> + 18) ``Q`` Device drivers might annotate the kernel with this taint, in cases
>> + their firmware might have crashed leaving the driver in a crippled and
>> + potentially useless state.
>
> Sure, I'll modify it a bit to add the use case to help with support
> issues, ie, to help rule out firmware issues.

Please also update tools/debugging/kernel-chktaint.

> I'm starting to think that to make this even more usesul later we may
> want to add a uevent to add_taint() so that userspace can decide to look
> into this, ignore it, or report something to the user, say on their
> desktop.

thanks.
--
~Randy