ptp: only allow phase values lower than 1 period

The way we define the phase (the difference between the time of the
signal's rising edge, and the closest integer multiple of the period),
it doesn't make sense to have a phase value equal or larger than 1
period.

So deny these settings coming from the user.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Vladimir Oltean 2020-08-05 03:10:47 +03:00 committed by David S. Miller
parent 4c900a6b4e
commit c29f9aa350

View File

@ -218,6 +218,19 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
break;
}
}
if (perout->flags & PTP_PEROUT_PHASE) {
/*
* The phase should be specified modulo the
* period, therefore anything equal or larger
* than 1 period is invalid.
*/
if (perout->phase.sec > perout->period.sec ||
(perout->phase.sec == perout->period.sec &&
perout->phase.nsec >= perout->period.nsec)) {
err = -ERANGE;
break;
}
}
} else if (cmd == PTP_PEROUT_REQUEST) {
req.perout.flags &= PTP_PEROUT_V1_VALID_FLAGS;
req.perout.rsv[0] = 0;