Re: [PATCH] qom: fix objects with improper parent type

[Paolo Bonzini <pbonzini@redhat.com>]

On 06/10/20 21:20, snizovtsev@gmail.com wrote:
> On Tue, 2020-10-06 at 01:55 -0400, Michael S. Tsirkin wrote:
>> On Tue, Sep 29, 2020 at 04:47:14PM -0700, Sergey Nizovtsev wrote:
>>> Some objects accidentally inherit ObjectClass instead of Object.
>>> They compile silently but may crash after downcasting.
>>>
>>> In this patch, we introduce a coccinelle script to find broken
>>> declarations and fix them manually with proper base type.
>>>
>>> Signed-off-by: Sergey Nizovtsev <snizovtsev@gmail.com>
>>
>> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
>>
>> which tree should this go in through?
> 
> Well, since this may only affect some generic QOM walking code, i
> suggest it goes in QOM/QObject/QMP related tree.
> 
> So, `scripts/get_maintainer.pl -f qom/object.c`:
> 
> +CC Paolo Bonzini <pbonzini@redhat.com>
> -CC Ben Warren <ben@skyportsystems.com>

Queued, thanks.

Paolo

> On Tue, 2020-10-06 at 00:06 +0400, Marc-André Lureau wrote:
>> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> 
> On Mon, 2020-10-05 at 18:47 +0200, Igor Mammedov wrote:
>> Reviewed-by: Igor Mammedov <imammedo@redhat.com>
> 
>>
>>> ---
>>>  scripts/coccinelle/qobject-parent-type.cocci | 26
>>> ++++++++++++++++++++
>>>  include/hw/acpi/vmgenid.h                    |  2 +-
>>>  include/hw/misc/vmcoreinfo.h                 |  2 +-
>>>  include/net/can_host.h                       |  2 +-
>>>  MAINTAINERS                                  |  1 +
>>>  5 files changed, 30 insertions(+), 3 deletions(-)
>>>  create mode 100644 scripts/coccinelle/qobject-parent-type.cocci
>>>
>>> diff --git a/scripts/coccinelle/qobject-parent-type.cocci
>>> b/scripts/coccinelle/qobject-parent-type.cocci
>>> new file mode 100644
>>> index 0000000000..9afb3edd97
>>> --- /dev/null
>>> +++ b/scripts/coccinelle/qobject-parent-type.cocci
>>> @@ -0,0 +1,26 @@
>>> +// Highlight object declarations that don't look like object class
>>> but
>>> +// accidentally inherit from it.
>>> +
>>> +@match@
>>> +identifier obj_t, fld;
>>> +type parent_t =~ ".*Class$";
>>> +@@
>>> +struct obj_t {
>>> +    parent_t fld;
>>> +    ...
>>> +};
>>> +
>>> +@script:python filter depends on match@
>>> +obj_t << match.obj_t;
>>> +@@
>>> +is_class_obj = obj_t.endswith('Class')
>>> +cocci.include_match(not is_class_obj)
>>> +
>>> +@replacement depends on filter@
>>> +identifier match.obj_t, match.fld;
>>> +type match.parent_t;
>>> +@@
>>> +struct obj_t {
>>> +*   parent_t fld;
>>> +    ...
>>> +};
>>> diff --git a/include/hw/acpi/vmgenid.h b/include/hw/acpi/vmgenid.h
>>> index d50fbacb8e..cb4ad37fc5 100644
>>> --- a/include/hw/acpi/vmgenid.h
>>> +++ b/include/hw/acpi/vmgenid.h
>>> @@ -19,7 +19,7 @@
>>>  OBJECT_DECLARE_SIMPLE_TYPE(VmGenIdState, VMGENID)
>>>
>>>  struct VmGenIdState {
>>> -    DeviceClass parent_obj;
>>> +    DeviceState parent_obj;
>>>      QemuUUID guid;                /* The 128-bit GUID seen by the
>>> guest */
>>>      uint8_t vmgenid_addr_le[8];   /* Address of the GUID (little-
>>> endian) */
>>>  };
>>> diff --git a/include/hw/misc/vmcoreinfo.h
>>> b/include/hw/misc/vmcoreinfo.h
>>> index ebada6617a..0b7b55d400 100644
>>> --- a/include/hw/misc/vmcoreinfo.h
>>> +++ b/include/hw/misc/vmcoreinfo.h
>>> @@ -24,7 +24,7 @@ DECLARE_INSTANCE_CHECKER(VMCoreInfoState,
>>> VMCOREINFO,
>>>  typedef struct fw_cfg_vmcoreinfo FWCfgVMCoreInfo;
>>>
>>>  struct VMCoreInfoState {
>>> -    DeviceClass parent_obj;
>>> +    DeviceState parent_obj;
>>>
>>>      bool has_vmcoreinfo;
>>>      FWCfgVMCoreInfo vmcoreinfo;
>>> diff --git a/include/net/can_host.h b/include/net/can_host.h
>>> index 4e3ce3f954..caab71bdda 100644
>>> --- a/include/net/can_host.h
>>> +++ b/include/net/can_host.h
>>> @@ -35,7 +35,7 @@
>>>  OBJECT_DECLARE_TYPE(CanHostState, CanHostClass, CAN_HOST)
>>>
>>>  struct CanHostState {
>>> -    ObjectClass oc;
>>> +    Object oc;
>>>
>>>      CanBusState *bus;
>>>      CanBusClientState bus_client;
>>> diff --git a/MAINTAINERS b/MAINTAINERS
>>> index 5eed1e692b..2160b8196a 100644
>>> --- a/MAINTAINERS
>>> +++ b/MAINTAINERS
>>> @@ -2402,6 +2402,7 @@ F: qobject/
>>>  F: include/qapi/qmp/
>>>  X: include/qapi/qmp/dispatch.h
>>>  F: scripts/coccinelle/qobject.cocci
>>> +F: scripts/coccinelle/qobject-parent-type.cocci
>>>  F: tests/check-qdict.c
>>>  F: tests/check-qjson.c
>>>  F: tests/check-qlist.c
>>> -- 
>>> 2.28.0
>