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

membarrier: Disable preemption when calling smp_call_function_many()

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: membarrier-disable-preemption-when-calling-smp_call_function_many.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 541676078b52f365f53d46ee5517d305cd1b6350 Mon Sep 17 00:00:00 2001

From: Mathieu Desnoyers mathieu.desnoyers@efficios.com Date: Fri, 15 Dec 2017 14:23:10 -0500 Subject: membarrier: Disable preemption when calling smp_call_function_many()

From: Mathieu Desnoyers mathieu.desnoyers@efficios.com

commit 541676078b52f365f53d46ee5517d305cd1b6350 upstream.

smp_call_function_many() requires disabling preemption around the call.

Signed-off-by: Mathieu Desnoyers mathieu.desnoyers@efficios.com Cc: Andrea Parri parri.andrea@gmail.com Cc: Andrew Hunter ahh@google.com Cc: Avi Kivity avi@scylladb.com Cc: Benjamin Herrenschmidt benh@kernel.crashing.org Cc: Boqun Feng boqun.feng@gmail.com Cc: Dave Watson davejwatson@fb.com Cc: H. Peter Anvin hpa@zytor.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Maged Michael maged.michael@gmail.com Cc: Michael Ellerman mpe@ellerman.id.au Cc: Paul E . McKenney paulmck@linux.vnet.ibm.com Cc: Paul E. McKenney paulmck@linux.vnet.ibm.com Cc: Paul Mackerras paulus@samba.org Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Link: http://lkml.kernel.org/r/20171215192310.25293-1-mathieu.desnoyers@efficios.c... Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- kernel/sched/membarrier.c | 2 ++ 1 file changed, 2 insertions(+)

--- a/kernel/sched/membarrier.c +++ b/kernel/sched/membarrier.c @@ -89,7 +89,9 @@ static int membarrier_private_expedited( rcu_read_unlock(); } if (!fallback) { + preempt_disable(); smp_call_function_many(tmpmask, ipi_mb, NULL, 1); + preempt_enable(); free_cpumask_var(tmpmask); } cpus_read_unlock();

Patches currently in stable-queue which might be from mathieu.desnoyers@efficios.com are

queue-4.14/membarrier-disable-preemption-when-calling-smp_call_function_many.patch queue-4.14/kvm-fix-stack-out-of-bounds-read-in-write_mmio.patch