Re: Linux 4.4.256

Greg Kroah-Hartman
2021-02-06T13:20:46Z

On Sat, Feb 06, 2021 at 02:11:13PM +0100, Willy Tarreau wrote:
> On Sat, Feb 06, 2021 at 02:00:27PM +0100, Greg Kroah-Hartman wrote:
> > I think Sasha's patch here:
> > https://lore.kernel.org/r/20210205174702.1904681-1-sashal@kernel.org
> > is looking like the solution.
>
> It might cause trouble to those forcing SUBLEVEL to a given version such
> as .0 to avoid exposing the exact stable version. I guess we should
> instead try to integrate a test on the value itself and cap it at 255.

That's the main goal of the upstream submission that checks the value
before capping it:
https://lore.kernel.org/r/20210206035033.2036180-2-sashal@kernel.org

> Something like this looks more robust to me, it will use SUBLEVEL for
> values 0 to 255 and 255 for any larger value:
>
> - expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
> + expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 255 \* (0$(SUBLEVEL) > 255) + 0$(SUBLEVEL) * (0$(SUBLEVEL \<= 255)); \

I think you just rewrote the above linked patch :)

thanks,

greg k-h