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

[Cédric Le Goater]

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.

C.


> 
> -- >8 --
> @@ -244,13 +244,15 @@ static void spapr_xive_instance_init(Obj
>  {
>      sPAPRXive *xive = SPAPR_XIVE(obj);
> 
> -    object_initialize(&xive->source, sizeof(xive->source),
> TYPE_XIVE_SOURCE);
> -    object_property_add_child(obj, "source", OBJECT(&xive->source), NULL);
> +    object_initialize_child(obj, "source", &xive->source,
> +                            sizeof(xive->source), TYPE_XIVE_SOURCE,
> +                            &error_abort, NULL);
> 
> -    object_initialize(&xive->end_source, sizeof(xive->end_source),
> -                      TYPE_XIVE_END_SOURCE);
> -    object_property_add_child(obj, "end_source", OBJECT(&xive->end_source),
> -                              NULL);
> +    object_initialize_child(obj, "end_source", &xive->end_source,
> +                            sizeof(xive->end_source), TYPE_XIVE_END_SOURCE,
> +                            &error_abort, NULL);
>  }
> ---
>