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@vger.kernel.org Fixes: 5a590f35add9 ("posix-clocks: Wire up clock_gettime() with timens offsets") Reported-by: Hans van der Laan j.h.vanderlaan@student.utwente.nl Signed-off-by: Andrei Vagin avagin@gmail.com[..] @@ -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