@@ -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(+)