From aad2de527db618942ce1f5cad0d9c2e29ec42f2e Mon Sep 17 00:00:00 2001
From: Eduardo Habkost <ehabkost@redhat.com>
Date: Thu, 19 Oct 2017 01:34:50 +0200
Subject: [PATCH 61/69] iothread: Make iothread_stop() idempotent

RH-Author: Eduardo Habkost <ehabkost@redhat.com>
Message-id: <20171019013453.21449-2-ehabkost@redhat.com>
Patchwork-id: 77367
O-Subject: [RHV7.5 qemu-kvm-rhev PATCH 1/4] iothread: Make iothread_stop() idempotent
Bugzilla: 1460848
RH-Acked-by: Michael S. Tsirkin <mst@redhat.com>
RH-Acked-by: Igor Mammedov <imammedo@redhat.com>
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>

Currently, iothread_stop_all() makes all iothread objects unsafe
to be destroyed, because qemu_thread_join() ends up being called
twice.

To fix this, make iothread_stop() idempotent by checking
thread->stopped.

Fixes the following crash:

  qemu-system-x86_64 -object iothread,id=iothread0 -monitor stdio -display none
  QEMU 2.10.50 monitor - type 'help' for more information
  (qemu) quit
  qemu: qemu_thread_join: No such process
  Aborted (core dumped)

Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20170926130028.12471-1-ehabkost@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 65072c157e466db2785748a929e775703b20eefe)
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 iothread.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/iothread.c b/iothread.c
index beeb870..d67bdd4 100644
--- a/iothread.c
+++ b/iothread.c
@@ -68,7 +68,7 @@ static int iothread_stop(Object *object, void *opaque)
     IOThread *iothread;
 
     iothread = (IOThread *)object_dynamic_cast(object, TYPE_IOTHREAD);
-    if (!iothread || !iothread->ctx) {
+    if (!iothread || !iothread->ctx || iothread->stopping) {
         return 0;
     }
     iothread->stopping = true;
-- 
1.8.3.1