[PATCH 1/2] hw/ipmi/bmc: Delay timer_new_ns() from init to realize to avoid memleaks

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

In commit f3a508eb4e the Euler Robot reported calling timer_new()
in instance_init() can leak heap memory. The easier fix is to
delay the timer creation at instance realize(). Similarly move
timer_del() into a new instance unrealize() method.

This case was found with the following coccinelle script:

    @ match @
    identifier instance_init;
    typedef Object;
    identifier obj;
    expression val, scale;
    identifier clock_type, callback, opaque;
    position pos;
    @@
    static void instance_init(Object *obj)
    {
      <...
    (
      val = timer_new@pos(clock_type, scale, callback, opaque);
    |
      val = timer_new_ns@pos(clock_type, callback, opaque);
    |
      val = timer_new_us@pos(clock_type, callback, opaque);
    |
      val = timer_new_ms@pos(clock_type, callback, opaque);
    )
      ...>
    }

    @ script:python @
    f << match.instance_init;
    p << match.pos;
    @@
    print "check %s:%s:%s in %s()" % (p[0].file, p[0].line, p[0].column, f)

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
Cc: Pan Nengyuan <pannengyuan@huawei.com>
---
 hw/ipmi/ipmi_bmc_extern.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/hw/ipmi/ipmi_bmc_extern.c b/hw/ipmi/ipmi_bmc_extern.c
index f9a13e0a44..9144ac6c38 100644
--- a/hw/ipmi/ipmi_bmc_extern.c
+++ b/hw/ipmi/ipmi_bmc_extern.c
@@ -463,6 +463,15 @@ static void ipmi_bmc_extern_realize(DeviceState *dev, Error **errp)
 
     qemu_chr_fe_set_handlers(&ibe->chr, can_receive, receive,
                              chr_event, NULL, ibe, NULL, true);
+
+    ibe->extern_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, extern_timeout, ibe);
+}
+
+static void ipmi_bmc_extern_unrealize(DeviceState *dev, Error **errp)
+{
+    IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(dev);
+
+    timer_del(ibe->extern_timer);
 }
 
 static int ipmi_bmc_extern_post_migrate(void *opaque, int version_id)
@@ -502,7 +511,6 @@ static void ipmi_bmc_extern_init(Object *obj)
 {
     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(obj);
 
-    ibe->extern_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, extern_timeout, ibe);
     vmstate_register(NULL, 0, &vmstate_ipmi_bmc_extern, ibe);
 }
 
@@ -510,7 +518,6 @@ static void ipmi_bmc_extern_finalize(Object *obj)
 {
     IPMIBmcExtern *ibe = IPMI_BMC_EXTERN(obj);
 
-    timer_del(ibe->extern_timer);
     timer_free(ibe->extern_timer);
 }
 
@@ -528,6 +535,7 @@ static void ipmi_bmc_extern_class_init(ObjectClass *oc, void *data)
     bk->handle_reset = ipmi_bmc_extern_handle_reset;
     dc->hotpluggable = false;
     dc->realize = ipmi_bmc_extern_realize;
+    dc->unrealize = ipmi_bmc_extern_unrealize;
     device_class_set_props(dc, ipmi_bmc_extern_properties);
 }
 
-- 
2.21.1