Re: [PATCH v3 2/2] misc/mos6522: Use timer_free() in the finalize function to avoid memleak

[Philippe Mathieu-Daudé]

On 1/12/21 12:27 PM, Gan Qixin wrote:
> When running device-introspect-test, a memory leak occurred in the 
> mos6522_init
> function, this patch use timer_free() in the finalize function to fix it.
> 
> ASAN shows memory leak stack:
> 
> Direct leak of 96 byte(s) in 2 object(s) allocated from:
>     #0 0xfffd5fe9e1f0 in __interceptor_calloc (/lib64/libasan.so.5+0xee1f0)
>     #1 0xfffd5f7b6800 in g_malloc0 (/lib64/libglib-2.0.so.0+0x56800)
>     #2 0xaaae50303d0c in timer_new_full qemu/include/qemu/timer.h:523
>     #3 0xaaae50303d0c in timer_new qemu/include/qemu/timer.h:544
>     #4 0xaaae50303d0c in timer_new_ns qemu/include/qemu/timer.h:562
>     #5 0xaaae50303d0c in mos6522_init qemu/hw/misc/mos6522.c:490
>     #6 0xaaae50b77d70 in object_init_with_type qemu/qom/object.c:371
>     #7 0xaaae50b7ae84 in object_initialize_with_type qemu/qom/object.c:515
>     #8 0xaaae50b7b0f8 in object_new_with_type qemu/qom/object.c:729
>     #9 0xaaae50bb6d58 in qmp_device_list_properties 
> qemu/qom/qom-qmp-cmds.c:153
>     #10 0xaaae50d7e1dc in qmp_marshal_device_list_properties 
> qemu/qapi/qapi-commands-qdev.c:59
>     #11 0xaaae50dc87a0 in do_qmp_dispatch_bh qemu/qapi/qmp-dispatch.c:110
>     #12 0xaaae50d931a0 in aio_bh_call qemu/util/async.c:136
> 
> Reported-by: Euler Robot <euler.robot@huawei.com>
> Signed-off-by: Gan Qixin <ganqixin@huawei.com>

As the change from v2 -> v3 is a rebase suggested by
Peter, you can keep David's tag IMO:

Acked-by: David Gibson <david@gibson.dropbear.id.au>

> ---
> Cc: David Gibson <david@gibson.dropbear.id.au>
> ---
>  hw/misc/mos6522.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/hw/misc/mos6522.c b/hw/misc/mos6522.c
> index ac4cd1d58e..1c57332b40 100644
> --- a/hw/misc/mos6522.c
> +++ b/hw/misc/mos6522.c
> @@ -490,6 +490,14 @@ static void mos6522_init(Object *obj)
>      s->timers[1].timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, mos6522_timer2, s);
>  }
>  
> +static void mos6522_finalize(Object *obj)
> +{
> +    MOS6522State *s = MOS6522(obj);
> +
> +    timer_free(s->timers[0].timer);
> +    timer_free(s->timers[1].timer);
> +}
> +
>  static Property mos6522_properties[] = {
>      DEFINE_PROP_UINT64("frequency", MOS6522State, frequency, 0),
>      DEFINE_PROP_END_OF_LIST()
> @@ -519,6 +527,7 @@ static const TypeInfo mos6522_type_info = {
>      .parent = TYPE_SYS_BUS_DEVICE,
>      .instance_size = sizeof(MOS6522State),
>      .instance_init = mos6522_init,
> +    .instance_finalize = mos6522_finalize,
>      .abstract = true,
>      .class_size = sizeof(MOS6522DeviceClass),
>      .class_init = mos6522_class_init,
>