| Message ID | 20200805001047.1372299-1-olteanv@gmail.com |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | [v3,net-next] ptp: only allow phase values lower than 1 period | expand |
On Wed, Aug 05, 2020 at 03:10:47AM +0300, Vladimir Oltean wrote: > 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>
> -----Original Message----- > From: Richard Cochran <richardcochran@gmail.com> > Sent: Tuesday, August 04, 2020 7:06 PM > To: Vladimir Oltean <olteanv@gmail.com> > Cc: kuba@kernel.org; davem@davemloft.net; netdev@vger.kernel.org; Keller, > Jacob E <jacob.e.keller@intel.com> > Subject: Re: [PATCH v3 net-next] ptp: only allow phase values lower than 1 > period > > On Wed, Aug 05, 2020 at 03:10:47AM +0300, Vladimir Oltean wrote: > > 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> Thanks!
From: Vladimir Oltean <olteanv@gmail.com> Date: Wed, 5 Aug 2020 03:10:47 +0300 > 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> Applied, thank you.
diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c index e0e6f85966e1..af3bc65c4595 100644 --- a/drivers/ptp/ptp_chardev.c +++ b/drivers/ptp/ptp_chardev.c @@ -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;
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> --- Changes in v3: Adjust the comments to cover the equality case. Changes in v2: Be sure to also deny the case where the period is equal to the phase. This represents a 360 degree offset, which is equivalent to a phase of zero, so it should be rejected on the grounds of having a modulo equivalent as well. drivers/ptp/ptp_chardev.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)