1
0
Fork 0

futex: Do not apply time namespace adjustment on FUTEX_LOCK_PI

commit cdf78db407 upstream.

FUTEX_LOCK_PI does not require to have the FUTEX_CLOCK_REALTIME bit set
because it has been using CLOCK_REALTIME based absolute timeouts
forever. Due to that, the time namespace adjustment which is applied when
FUTEX_CLOCK_REALTIME is not set, will wrongly take place for FUTEX_LOCK_PI
and wreckage the timeout.

Exclude it from that procedure.

Fixes: c2f7d08ccc ("futex: Adjust absolute futex timeouts with per time namespace offset")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210422194704.984540159@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pull/331/head^2
Thomas Gleixner 2021-04-22 21:44:19 +02:00 committed by Greg Kroah-Hartman
parent 2543329485
commit d19a456aca
1 changed files with 2 additions and 2 deletions

View File

@ -3784,7 +3784,7 @@ 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 (!(op & FUTEX_CLOCK_REALTIME))
else if (cmd != FUTEX_LOCK_PI && !(op & FUTEX_CLOCK_REALTIME))
t = timens_ktime_to_host(CLOCK_MONOTONIC, t);
tp = &t;
}
@ -3978,7 +3978,7 @@ SYSCALL_DEFINE6(futex_time32, 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 (!(op & FUTEX_CLOCK_REALTIME))
else if (cmd != FUTEX_LOCK_PI && !(op & FUTEX_CLOCK_REALTIME))
t = timens_ktime_to_host(CLOCK_MONOTONIC, t);
tp = &t;
}