Re: [PATCH v3 1/6] s390x: fix memleaks in cpu_finalize

[Philippe Mathieu-Daudé]

On 2/27/20 9:41 AM, David Hildenbrand wrote:
> On 27.02.20 03:50, Pan Nengyuan wrote:
> > This patch fix memleaks when we call tests/qtest/cpu-plug-test on s390x. The 
> > leak stack is as follow:
> >
> > Direct leak of 48 byte(s) in 1 object(s) allocated from:
> >      #0 0x7fb43c7cd970 in __interceptor_calloc (/lib64/libasan.so.5+0xef970)
> >      #1 0x7fb43be2149d in g_malloc0 (/lib64/libglib-2.0.so.0+0x5249d)
> >      #2 0x558ba96da716 in timer_new_full 
> > /mnt/sdb/qemu-new/qemu/include/qemu/timer.h:530
> >      #3 0x558ba96da716 in timer_new 
> > /mnt/sdb/qemu-new/qemu/include/qemu/timer.h:551
> >      #4 0x558ba96da716 in timer_new_ns 
> > /mnt/sdb/qemu-new/qemu/include/qemu/timer.h:569
> >      #5 0x558ba96da716 in s390_cpu_initfn 
> > /mnt/sdb/qemu-new/qemu/target/s390x/cpu.c:285
> >      #6 0x558ba9c969ab in object_init_with_type 
> > /mnt/sdb/qemu-new/qemu/qom/object.c:372
> >      #7 0x558ba9c9eb5f in object_initialize_with_type 
> > /mnt/sdb/qemu-new/qemu/qom/object.c:516
> >      #8 0x558ba9c9f053 in object_new_with_type 
> > /mnt/sdb/qemu-new/qemu/qom/object.c:684
> >      #9 0x558ba967ede6 in s390x_new_cpu 
> > /mnt/sdb/qemu-new/qemu/hw/s390x/s390-virtio-ccw.c:64
> >      #10 0x558ba99764b3 in hmp_cpu_add 
> > /mnt/sdb/qemu-new/qemu/hw/core/machine-hmp-cmds.c:57
> >      #11 0x558ba9b1c27f in handle_hmp_command 
> > /mnt/sdb/qemu-new/qemu/monitor/hmp.c:1082
> >      #12 0x558ba96c1b02 in qmp_human_monitor_command 
> > /mnt/sdb/qemu-new/qemu/monitor/misc.c:142
> >
> > Reported-by: Euler Robot <address@hidden>
> > Signed-off-by: Pan Nengyuan <address@hidden>
> > ---
> > Cc: Richard Henderson <address@hidden>
> > Cc: David Hildenbrand <address@hidden>
> > Cc: Cornelia Huck <address@hidden>
> > Cc: address@hidden
> > ---
> > v2->v1:
> > - Similarly to other cleanups, move timer_new into realize(Suggested by 
> > Philippe Mathieu-Daudé)
> > v3->v2:
> > - Also do the timer_free in unrealize, it seems more balance.
> > ---
>
>
> As I already said, I think this is init and not realize stuff. Do we
> have a convention now and documented that?

The clearer doc I read so far is this post:
https://www.mail-archive.com/address@hidden/msg680187.html
(but see the thread for more helpful comments)

Another thread that you might find interesting is "how to handle QOM 
'container' objects whose contents depend on QOM properties?"
https://www.mail-archive.com/address@hidden/msg511703.html

> Anyhow, I don't really care
> [...]

Well, looking at the time spent on these series and their review, having 
it better documented might save time the whole community.

> > @@ -453,6 +466,7 @@ static void s390_cpu_class_init(ObjectClass *oc, void *data)
> >   
> >       device_class_set_parent_realize(dc, s390_cpu_realizefn,
> >                                       &scc->parent_realize);
> > +    dc->unrealize = s390_cpu_unrealizefn;
>
> Shouldn't we use device_class_set_parent_unrealize?