On 18/01/20 17:23, Philippe Mathieu-Daudé wrote:
> When adding new devices implementing QOM interfaces, we might
> forgot to add the Kconfig dependency that pulls the required
> objects in when building.
>
> Since QOM dependencies are resolved at runtime, we don't get any
> link-time failures, and QEMU aborts while starting:
>
> $ qemu ...
> Segmentation fault (core dumped)
>
> (gdb) bt
> #0 0x00007ff6e96b1e35 in raise () from /lib64/libc.so.6
> #1 0x00007ff6e969c895 in abort () from /lib64/libc.so.6
> #2 0x00005572bc5051cf in type_initialize (ti=0x5572be6f1200) at
> qom/object.c:323
> #3 0x00005572bc505074 in type_initialize (ti=0x5572be6f1800) at
> qom/object.c:301
> #4 0x00005572bc505074 in type_initialize (ti=0x5572be6e48e0) at
> qom/object.c:301
> #5 0x00005572bc506939 in object_class_by_name (typename=0x5572bc56109a) at
> qom/object.c:959
> #6 0x00005572bc503dd5 in cpu_class_by_name (typename=0x5572bc56109a,
> cpu_model=0x5572be6d9930) at hw/core/cpu.c:286
>
> Since the caller has access to the qdev parent/interface names,
> we can simply display them to avoid starting a debugger:
>
> $ qemu ...
> qemu: missing interface 'fancy-if' for object 'fancy-dev'
> Aborted (core dumped)
>
> This commit is similar to e02bdf1cecd2 ("Display more helpful message
> when an object type is missing").
>
> Signed-off-by: Philippe Mathieu-Daudé <phi...@redhat.com>
> ---
> Cc: Cornelia Huck <coh...@redhat.com>
> Cc: Stefano Garzarella <sgarz...@redhat.com>
> Cc: Daniel P. Berrangé <berra...@redhat.com>
> ---
> qom/object.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/qom/object.c b/qom/object.c
> index 0d971ca897..36123fb330 100644
> --- a/qom/object.c
> +++ b/qom/object.c
> @@ -317,6 +317,11 @@ static void type_initialize(TypeImpl *ti)
>
> for (i = 0; i < ti->num_interfaces; i++) {
> TypeImpl *t = type_get_by_name(ti->interfaces[i].typename);
> + if (!t) {
> + error_report("missing interface '%s' for object '%s'",
> + ti->interfaces[i].typename, parent->name);
> + abort();
> + }
> for (e = ti->class->interfaces; e; e = e->next) {
> TypeImpl *target_type = OBJECT_CLASS(e->data)->type;
>
>
Queued, thanks.
Paolo
