diff options
| author | Vladimir Oltean <olteanv@gmail.com> | 2020-08-05 03:10:47 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-08-05 12:06:44 -0700 |
| commit | c29f9aa35016729fc0cf72994e8b57f33466b64c (patch) | |
| tree | 282a9f364a184ad6e776861d7bba5b3594a87687 /drivers | |
| parent | 4c900a6b4e057fc9623240682988e203ae98ca94 (diff) | |
| download | lwn-c29f9aa35016729fc0cf72994e8b57f33466b64c.tar.gz lwn-c29f9aa35016729fc0cf72994e8b57f33466b64c.zip | |
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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/ptp/ptp_chardev.c | 13 |
1 files changed, 13 insertions, 0 deletions
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; |