Re: [PATCH v1 1/1] sysctl: introduce uuid_le and uuid_be

From: Andy Shevchenko
Date: Tue May 24 2016 - 16:24:22 EST


On Tue, 2016-05-24 at 13:15 -0700, Andrew Morton wrote:
> On Tue, 24 May 2016 20:27:27 +0300 Andy Shevchenko <andriy.shevchenko@
> linux.intel.com> wrote:
>
> > By default the sysctl interface returns random UUID in big endian
> > format.
> > Sometimes it's not suitable, e.g. using generated UUID for EFI
> > variable name.
> > Provide uuid_le and uuid_be to comprehence that interface.
> >
> > ...
> >
> > Âdrivers/char/random.cÂÂÂÂÂÂÂ| 44
> > +++++++++++++++++++++++++++++++++++++++++
> > Âinclude/uapi/linux/sysctl.h |ÂÂ4 +++-
> > Âkernel/sysctl_binary.cÂÂÂÂÂÂ| 48
> > ++++++++++++++++++++++++++++++++++++++++++++
>
> Why does the kernel need to do this?ÂÂIf userspace wants a random uuid
> then it can grab a random number and cook up the UUID itself.

Good question. I dunno why we have uuid in the first place there. At
some point I noticed people who recommend to use that file to get a
random UUID(s), but apparently they don't aware that endianess matters.Â

P.S. I thought to send this as RFC, but decided to drop the notation in
last minute. So, it's okay to drop it.

--
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy