On Thu, Oct 15, 2020 at 04:13:42PM +0200, Thomas Gleixner wrote:
> On Thu, Oct 15 2020 at 14:26, Dmitry Safonov wrote:
>
> > On 10/15/20 8:29 AM, Andrei Vagin wrote:
> >> For all commands except FUTEX_WAIT, timeout is interpreted as an
> >> absolute value. This absolute value is inside the task's time namespace
> >> and has to be converted to the host's time.
> >>
> >> Cc: <stable@xxxxxxxxxxxxxxx>
> >> Fixes: 5a590f35add9 ("posix-clocks: Wire up clock_gettime() with timens offsets")
> >> Reported-by: Hans van der Laan <j.h.vanderlaan@xxxxxxxxxxxxxxxxxx>
> >> Signed-off-by: Andrei Vagin <avagin@xxxxxxxxx>[..]
> >> @@ -3797,6 +3798,8 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
> >> t = timespec64_to_ktime(ts);
> >> if (cmd == FUTEX_WAIT)
> >> t = ktime_add_safe(ktime_get(), t);
> >> + else if (!(cmd & FUTEX_CLOCK_REALTIME))
> >> + t = timens_ktime_to_host(CLOCK_MONOTONIC, t);
> >
> > Err, it probably should be
> > : else if (!(op & FUTEX_CLOCK_REALTIME))
Dmitry, thank you for catching this.
>
> Duh, you are right. I stared at it for a while and did not spot it.
>
> > And there's also
> > : SYSCALL_DEFINE6(futex_time32, ...)
> > which wants to be patched.
>
> Indeed. I zapped the commits.
I sent a new version. This time, I extended the test to check
FUTEX_CLOCK_REALTIME and I compiled and run the compat version.
Everything works as it should be.
Thanks,
Andrei
