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authorThomas Gleixner <tglx@linutronix.de>2021-04-22 21:44:19 +0200
committerThomas Gleixner <tglx@linutronix.de>2021-05-06 20:12:40 +0200
commitcdf78db4070967869e4d027c11f4dd825d8f815a (patch)
tree6cd0278eab7ea2ef64e828b71f6846205d2efeb2 /kernel/futex.c
parent4fbf5d6837bf81fd7a27d771358f4ee6c4f243f8 (diff)
downloadlinux-cdf78db4070967869e4d027c11f4dd825d8f815a.tar.gz
futex: Do not apply time namespace adjustment on FUTEX_LOCK_PI
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: c2f7d08cccf4 ("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

Diffstat (limited to 'kernel/futex.c')
-rw-r--r--kernel/futex.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/futex.c b/kernel/futex.c
index 47402008a430..b0f53045f206 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -3780,7 +3780,7 @@ 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;
 	}
@@ -3974,7 +3974,7 @@ 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;
 	}