Re: Q: sys_futex() && timespec_valid()

[Ulrich Drepper]

----- "Thomas Gleixner" <tglx@xxxxxxxxxxxxx> wrote:
> tv->sec < 0 is definitely an invalid value for both CLOCK_REALTIME
> and CLOCK_MONOTONIC.

CLOCK_MONOTONIC is different but it's wrong for CLOCK_REALTIME.  Why would it be invalid?  Because times before Epoch will not be used?  By that logic you would have to declare all values before Linus' first running kernel as invalid.  None of this makes sense.

The tv_sec in timespec is of type time_t and for absolute time values the same semantics as for naked time_t values applies.  The absolute time is

  epoch + tv_sec + tv_nsec / 1000000000

If tv_sec is negative these are values before epoch.

If there are other interfaces with absolute timeouts they certainly should be changed as well.

-- 
â Ulrich Drepper â Red Hat, Inc. â 444 Castro St â Mountain View, CA â
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/