Re: Regression: can't apply frequency offsets above 1000ppm.

[Thomas Gleixner <tglx@linutronix.de>]

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On Tue, 1 Sep 2015, John Stultz wrote:
> On Tue, Sep 1, 2015 at 1:25 PM, Thomas Gleixner <tglx@linutronix.de> wrote:
> > On Tue, 1 Sep 2015, Nuno Gonçalves wrote:
> >
> >> There is a regression on the clock system since v3.16-rc5-111-g4396e05
> >> [1],
> >
> >> [1] http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=4396e058c52e167729729cf64ea3dfa229637086
> >
> > That commit has absolutely nothing to do with NTP. I fear your bisect
> > went down the wrong road somewhere.
> >
> >> where the clock doesn't apply frequency offsets above about
> >> 1000ppm [2].
> >
> > This looks pretty familiar.
> >
> > The issue was introduced with commit 5e5aeb4367b (time: adjtimex:
> > Validate the ADJ_FREQUENCY values). That patch was tagged for stable,
> > so it got backported.
> >
> > The fix is in commit 29183a70b0b82 (ntp: Fixup adjtimex freq
> > validation on 32-bit systems). That commit was tagged for stable as
> > well, but with the extra '#3.19+' limitation.
> >
> > So in the worst case 5e5aeb4367b hit a stable tree < 3.19, but
> > 29183a70b0b82 did not.
> 
> Hrm. So that would be problematic, and I'll have to follow up that
> both changes got backported together.
> 
> But I don't think that's the issue here, since the problem supposedly
> continues w/ 4.2...

Duh, missed that part.

Thanks,

	tglx