This is a note to let you know that I've just added the patch titled

futex: Fix OWNER_DEAD fixup

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: futex-fix-owner_dead-fixup.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From a97cb0e7b3f4c6297fd857055ae8e895f402f501 Mon Sep 17 00:00:00 2001

From: Peter Zijlstra peterz@infradead.org Date: Mon, 22 Jan 2018 11:39:47 +0100 Subject: futex: Fix OWNER_DEAD fixup

From: Peter Zijlstra peterz@infradead.org

commit a97cb0e7b3f4c6297fd857055ae8e895f402f501 upstream.

Both Geert and DaveJ reported that the recent futex commit:

c1e2f0eaf015 ("futex: Avoid violating the 10th rule of futex")

introduced a problem with setting OWNER_DEAD. We set the bit on an uninitialized variable and then entirely optimize it away as a dead-store.

Move the setting of the bit to where it is more useful.

Reported-by: Geert Uytterhoeven geert@linux-m68k.org Reported-by: Dave Jones davej@codemonkey.org.uk Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Cc: Andrew Morton akpm@linux-foundation.org Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Paul E. McKenney paulmck@us.ibm.com Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Fixes: c1e2f0eaf015 ("futex: Avoid violating the 10th rule of futex") Link: http://lkml.kernel.org/r/20180122103947.GD2228@hirez.programming.kicks-ass.n... Signed-off-by: Ingo Molnar mingo@kernel.org Cc: Ozkan Sezer sezeroz@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- kernel/futex.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/kernel/futex.c +++ b/kernel/futex.c @@ -2311,9 +2311,6 @@ static int fixup_pi_state_owner(u32 __us raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock);

oldowner = pi_state->owner; - /* Owner died? */ - if (!pi_state->owner) - newtid |= FUTEX_OWNER_DIED;

/* * We are here because either: @@ -2374,6 +2371,9 @@ retry: }

newtid = task_pid_vnr(newowner) | FUTEX_WAITERS; + /* Owner died? */ + if (!pi_state->owner) + newtid |= FUTEX_OWNER_DIED;

if (get_futex_value_locked(&uval, uaddr)) goto handle_fault;

Patches currently in stable-queue which might be from peterz@infradead.org are

queue-4.14/futex-fix-owner_dead-fixup.patch