Patch "membarrier: Disable preemption when calling smp_call_function_many()" has been added to the 4.14-stable tree

Patch "membarrier: Disable preemption when calling smp_call_function_many()" has been added to the 4.14-stable tree

[gregkh]

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;a=summary

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.com
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