Re: [Qemu-devel] [PATCH] hw/ppc: Use object_initialize_child for correct reference counting

[Philippe Mathieu-Daudé]

On 2/21/19 7:17 PM, Cédric Le Goater wrote:
> On 2/21/19 7:14 PM, Philippe Mathieu-Daudé wrote:
>> On 2/21/19 12:24 PM, Thomas Huth wrote:
>>> Both functions, object_initialize() and object_property_add_child() increase
>>> the reference counter of the new object, so one of the references has to be
>>> dropped afterwards to get the reference counting right. Otherwise the child
>>> object will not be properly cleaned up when the parent gets destroyed.
>>> Thus let's use now object_initialize_child() instead to get the reference
>>> counting here right.
>>>
>>> Suggested-by: Eduardo Habkost <address@hidden>
>>> Signed-off-by: Thomas Huth <address@hidden>
>>> ---
>>>  hw/ppc/pnv.c     | 12 ++++++------
>>>  hw/ppc/pnv_psi.c |  4 ++--
>>>  hw/ppc/spapr.c   |  6 +++---
>>>  3 files changed, 11 insertions(+), 11 deletions(-)
>>>
>>> diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
>>> index da54086..9e03e9c 100644
>>> --- a/hw/ppc/pnv.c
>>> +++ b/hw/ppc/pnv.c
>>> @@ -736,18 +736,18 @@ static void pnv_chip_power8_instance_init(Object *obj)
>>>  {
>>>      Pnv8Chip *chip8 = PNV8_CHIP(obj);
>>>  
>>> -    object_initialize(&chip8->psi, sizeof(chip8->psi), TYPE_PNV_PSI);
>>> -    object_property_add_child(obj, "psi", OBJECT(&chip8->psi), NULL);
>>> +    object_initialize_child(obj, "psi",  &chip8->psi, sizeof(chip8->psi),
>>> +                            TYPE_PNV_PSI, &error_abort, NULL);
>>>      object_property_add_const_link(OBJECT(&chip8->psi), "xics",
>>>                                     OBJECT(qdev_get_machine()), 
>>> &error_abort);
>>>  
>>> -    object_initialize(&chip8->lpc, sizeof(chip8->lpc), TYPE_PNV_LPC);
>>> -    object_property_add_child(obj, "lpc", OBJECT(&chip8->lpc), NULL);
>>> +    object_initialize_child(obj, "lpc",  &chip8->lpc, sizeof(chip8->lpc),
>>> +                            TYPE_PNV_LPC, &error_abort, NULL);
>>>      object_property_add_const_link(OBJECT(&chip8->lpc), "psi",
>>>                                     OBJECT(&chip8->psi), &error_abort);
>>>  
>>> -    object_initialize(&chip8->occ, sizeof(chip8->occ), TYPE_PNV_OCC);
>>> -    object_property_add_child(obj, "occ", OBJECT(&chip8->occ), NULL);
>>> +    object_initialize_child(obj, "occ",  &chip8->occ, sizeof(chip8->occ),
>>> +                            TYPE_PNV_OCC, &error_abort, NULL);
>>>      object_property_add_const_link(OBJECT(&chip8->occ), "psi",
>>>                                     OBJECT(&chip8->psi), &error_abort);
>>>  }
>>> diff --git a/hw/ppc/pnv_psi.c b/hw/ppc/pnv_psi.c
>>> index 8ced095..44bc0cb 100644
>>> --- a/hw/ppc/pnv_psi.c
>>> +++ b/hw/ppc/pnv_psi.c
>>> @@ -444,8 +444,8 @@ static void pnv_psi_init(Object *obj)
>>>  {
>>>      PnvPsi *psi = PNV_PSI(obj);
>>>  
>>> -    object_initialize(&psi->ics, sizeof(psi->ics), TYPE_ICS_SIMPLE);
>>> -    object_property_add_child(obj, "ics-psi", OBJECT(&psi->ics), NULL);
>>> +    object_initialize_child(obj, "ics-psi",  &psi->ics, sizeof(psi->ics),
>>> +                            TYPE_ICS_SIMPLE, &error_abort, NULL);
>>>  }
>>>  
>>>  static const uint8_t irq_to_xivr[] = {
>>> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
>>> index abf9ebc..6c58dca 100644
>>> --- a/hw/ppc/spapr.c
>>> +++ b/hw/ppc/spapr.c
>>> @@ -1696,9 +1696,9 @@ static void spapr_create_nvram(sPAPRMachineState 
>>> *spapr)
>>>  
>>>  static void spapr_rtc_create(sPAPRMachineState *spapr)
>>>  {
>>> -    object_initialize(&spapr->rtc, sizeof(spapr->rtc), TYPE_SPAPR_RTC);
>>> -    object_property_add_child(OBJECT(spapr), "rtc", OBJECT(&spapr->rtc),
>>> -                              &error_fatal);
>>> +    object_initialize_child(OBJECT(spapr), "rtc",
>>> +                            &spapr->rtc, sizeof(spapr->rtc), 
>>> TYPE_SPAPR_RTC,
>>> +                            &error_fatal, NULL);
>>>      object_property_set_bool(OBJECT(&spapr->rtc), true, "realized",
>>>                                &error_fatal);
>>>      object_property_add_alias(OBJECT(spapr), "rtc-time", 
>>> OBJECT(&spapr->rtc),
>>>
>>
>> What about intc/spapr_xive.c?
> 
> I have used the same pattern in many files :) In ARM also.

OK, tested a cocci script so will send a patch.

Regards,

Phil.