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

From: Thomas Gleixner
Date: Tue Sep 01 2015 - 16:26:16 EST

On Tue, 1 Sep 2015, Nuno GonÃalves wrote:

> There is a regression on the clock system since v3.16-rc5-111-g4396e05
> [1],

> [1]

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.