[PATCH] pl031: add finalize function to avoid memleaks

[<pannengyuan@huawei.com>]

From: Pan Nengyuan <pannengyuan@huawei.com>

There is a memory leak when we call 'device_list_properties' with
typename = pl031. It's easy to reproduce as follow:

  virsh qemu-monitor-command vm1 --pretty '{"execute": "device-list-properties", "arguments": {"typename": "pl031"}}'

The memory leak stack:
  Direct leak of 48 byte(s) in 1 object(s) allocated from:
    #0 0x7f6e0925a970 in __interceptor_calloc (/lib64/libasan.so.5+0xef970)
    #1 0x7f6e06f4d49d in g_malloc0 (/lib64/libglib-2.0.so.0+0x5249d)
    #2 0x564a0f7654ea in timer_new_full /mnt/sdb/qemu/include/qemu/timer.h:530
    #3 0x564a0f76555d in timer_new /mnt/sdb/qemu/include/qemu/timer.h:551
    #4 0x564a0f765589 in timer_new_ns /mnt/sdb/qemu/include/qemu/timer.h:569
    #5 0x564a0f76747d in pl031_init /mnt/sdb/qemu/hw/rtc/pl031.c:198
    #6 0x564a0fd4a19d in object_init_with_type /mnt/sdb/qemu/qom/object.c:360
    #7 0x564a0fd4b166 in object_initialize_with_type /mnt/sdb/qemu/qom/object.c:467
    #8 0x564a0fd4c8e6 in object_new_with_type /mnt/sdb/qemu/qom/object.c:636
    #9 0x564a0fd4c98e in object_new /mnt/sdb/qemu/qom/object.c:646
    #10 0x564a0fc69d43 in qmp_device_list_properties /mnt/sdb/qemu/qom/qom-qmp-cmds.c:204
    #11 0x564a0ef18e64 in qdev_device_help /mnt/sdb/qemu/qdev-monitor.c:278

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com>
---
 hw/rtc/pl031.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/hw/rtc/pl031.c b/hw/rtc/pl031.c
index ae47f09635..50664ca000 100644
--- a/hw/rtc/pl031.c
+++ b/hw/rtc/pl031.c
@@ -194,6 +194,15 @@ static void pl031_init(Object *obj)
     s->timer = timer_new_ns(rtc_clock, pl031_interrupt, s);
 }
 
+static void pl031_finalize(Object *obj)
+{
+    PL031State *s = PL031(obj);
+    if (s->timer) {
+        timer_del(s->timer);
+        timer_free(s->timer);
+    }
+}
+
 static int pl031_pre_save(void *opaque)
 {
     PL031State *s = opaque;
@@ -329,6 +338,7 @@ static const TypeInfo pl031_info = {
     .parent        = TYPE_SYS_BUS_DEVICE,
     .instance_size = sizeof(PL031State),
     .instance_init = pl031_init,
+    .instance_finalize = pl031_finalize,
     .class_init    = pl031_class_init,
 };
 
-- 
2.21.0.windows.1