Re: [Qemu-devel] [PATCH 2/3] hw: do not pass NULL to memory_region_init from instance_init

[Thomas Huth <thuth@redhat.com>]

On 29/09/15 14:37, Paolo Bonzini wrote:
> This causes the region to outlive the object, because it attaches the
> region to /machine.  This is not nice for the "realize" method, but
> much worse for "instance_init" because it can cause dangling pointers
> after a simple object_new/object_unref pair.
> 
> Reported-by: Markus Armbruster <armbru@redhat.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
...
> diff --git a/hw/display/tcx.c b/hw/display/tcx.c
> index 4635800..bf119bc 100644
> --- a/hw/display/tcx.c
> +++ b/hw/display/tcx.c
> @@ -944,7 +944,7 @@ static void tcx_initfn(Object *obj)
>      SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
>      TCXState *s = TCX(obj);
>  
> -    memory_region_init_ram(&s->rom, NULL, "tcx.prom", FCODE_MAX_ROM_SIZE,
> +    memory_region_init_ram(&s->rom, OBJECT(s), "tcx.prom", FCODE_MAX_ROM_SIZE,
>                             &error_fatal);

Why "OBJECT(s)" and not simply "obj" ?

 Thomas