Re: [PATCH v1] mei: Don't encourage to use kernel internal types in user code

From: Andy Shevchenko
Date: Mon Mar 02 2020 - 10:58:20 EST


+Cc: Christoph.

On Sat, Feb 29, 2020 at 04:28:11PM +0000, Winkler, Tomas wrote:
> > uuid_le is internal kernel type which shall not be exposed to the user in the first
> > place.
> Why, these types are exported via include/uapi/linux/uuid.h

Which is wrong from the day 1.

The uuid_t type is being provided by libuuid in the user space, there is no
(more) kernel exported equivalent. Same should be done to the uuid_le.

We already discussed this couple of years ago.

> In order to mitigate the (wrong) distribution of the use of that type,
> > switch MEI AMT sample to plain unsigned char array.
>
> There was a change to guid_t from uuild_le, anyhow there is much more code
> except this sample that uses those types.

I guess you misunderstood the point. The types are for kernel use and keeping them
exported in a condition like it's now (quoter baked due to drop of uuid_be part
completely and uuid_le partially) is wrong.

There is *no* ABI change. And basically libuuid or another one should provide
type and infrastructure for this.

> Nack so far.

If you would like to bear the legacy type, why not to move this UUID UAPI parts
directly to MEI?

--
With Best Regards,
Andy Shevchenko