Re: [PATCH v2 23/44] qom: Crash more nicely on object_property_get_link() failure

[Markus Armbruster]

Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> writes:

> 02.07.2020 18:49, Markus Armbruster wrote:
>> Pass &error_abort instead of NULL where the returned value is
>> dereferenced or asserted to be non-null.  Drop a now redundant
>> assertion.
>>
>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
>> ---
>>   hw/core/platform-bus.c     | 6 +++---
>>   hw/ppc/spapr_drc.c         | 3 ++-
>>   hw/ppc/spapr_hcall.c       | 3 ++-
>>   hw/ppc/spapr_pci_nvlink2.c | 3 ++-
>>   ui/vnc.c                   | 2 +-
>>   5 files changed, 10 insertions(+), 7 deletions(-)
>>
>> diff --git a/hw/core/platform-bus.c b/hw/core/platform-bus.c
>> index d494e5cec1..5037ca265e 100644
>> --- a/hw/core/platform-bus.c
>> +++ b/hw/core/platform-bus.c
>> @@ -22,6 +22,7 @@
>>   #include "qemu/osdep.h"
>>   #include "hw/platform-bus.h"
>>   #include "hw/qdev-properties.h"
>> +#include "qapi/error.h"
>>   #include "qemu/error-report.h"
>>   #include "qemu/module.h"
>>   @@ -63,9 +64,8 @@ hwaddr
>> platform_bus_get_mmio_addr(PlatformBusDevice *pbus, SysBusDevice
>> *sbdev,
>>           return -1;
>>       }
>>   -    parent_mr = object_property_get_link(OBJECT(sbdev_mr),
>> "container", NULL);
>> -
>> -    assert(parent_mr);
>> +    parent_mr = object_property_get_link(OBJECT(sbdev_mr), "container",
>> +                                         &error_abort);
>>       if (parent_mr != pbus_mr_obj) {
>>           /* MMIO region is not mapped on platform bus */
>>           return -1;
>> diff --git a/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c
>> index d10193f39e..1f18b79348 100644
>> --- a/hw/ppc/spapr_drc.c
>> +++ b/hw/ppc/spapr_drc.c
>> @@ -870,7 +870,8 @@ int spapr_dt_drc(void *fdt, int offset, Object *owner, 
>> uint32_t drc_type_mask)
>>               continue;
>>           }
>>   -        obj = object_property_get_link(root_container,
>> prop->name, NULL);
>> +        obj = object_property_get_link(root_container, prop->name,
>> +                                       &error_abort);
>>           drc = SPAPR_DR_CONNECTOR(obj);
>>           drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
>>   diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
>> index 0f54988f2e..c1d01228c6 100644
>> --- a/hw/ppc/spapr_hcall.c
>> +++ b/hw/ppc/spapr_hcall.c
>> @@ -1655,7 +1655,8 @@ static void 
>> spapr_handle_transient_dev_before_cas(SpaprMachineState *spapr)
>>               continue;
>>           }
>>           drc = SPAPR_DR_CONNECTOR(object_property_get_link(drc_container,
>> -                                                          prop->name, 
>> NULL));
>> +                                                          prop->name,
>> +                                                          &error_abort));
>>             if (spapr_drc_transient(drc)) {
>>               spapr_drc_reset(drc);
>> diff --git a/hw/ppc/spapr_pci_nvlink2.c b/hw/ppc/spapr_pci_nvlink2.c
>> index 8332d5694e..dd8cd6db96 100644
>> --- a/hw/ppc/spapr_pci_nvlink2.c
>> +++ b/hw/ppc/spapr_pci_nvlink2.c
>> @@ -358,7 +358,8 @@ void spapr_phb_nvgpu_ram_populate_dt(SpaprPhbState 
>> *sphb, void *fdt)
>>       for (i = 0; i < sphb->nvgpus->num; ++i) {
>>           SpaprPhbPciNvGpuSlot *nvslot = &sphb->nvgpus->slots[i];
>>           Object *nv_mrobj = object_property_get_link(OBJECT(nvslot->gpdev),
>> -                                                    "nvlink2-mr[0]", NULL);
>> +                                                    "nvlink2-mr[0]",
>> +                                                    &error_abort);
>>           uint32_t associativity[] = {
>>               cpu_to_be32(0x4),
>>               SPAPR_GPU_NUMA_ID,
>
> the following
> uint64_t size = object_property_get_uint(nv_mrobj, "size", NULL);
>
> is a good candidate for error_abort as well.


Mission creep :)

We have many, many object_property_get_FOO() and _set_FOO() calls that
ignore errors.  Probably most of them should abort on error instead.
Let's leave that for a future series.

> with it or not:
> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

Thanks!