Re: [Qemu-devel] [PATCH 4/6] spapr: sanitize error handling in spapr_ics_create()

[Greg Kurz]

On Mon, 15 May 2017 13:59:33 +0200
Cédric Le Goater <address@hidden> wrote:

> On 05/15/2017 01:39 PM, Greg Kurz wrote:
> > The spapr_ics_create() function handles errors in a rather convoluted
> > way, with two local Error * variables. Moreover, failing to parent the
> > ICS object to the machine should be considered as a bug but it is
> > currently ignored.  
> 
> I am not sure what should be done for object_property_add_child()
> errors but QEMU generally uses NULL for 'Error **'. It might be 
> wrong though.
> 
> As for the local error handling, it is following what is described in 
> qapi/error.h. Isn't it ?
> 

Yes, it does follow the "Receive and accumulate multiple errors" recommandation,
but does it make sense to realize the ICS object if we failed to set nr-irqs ?

> Cheers,
> 
> C. 
> 
>  
> > This patch addresses both issues.
> > 
> > Signed-off-by: Greg Kurz <address@hidden>
> > ---
> >  hw/ppc/spapr.c |   19 ++++++++++++-------
> >  1 file changed, 12 insertions(+), 7 deletions(-)
> > 
> > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> > index 44f7dc7f40e9..c53989bb10b1 100644
> > --- a/hw/ppc/spapr.c
> > +++ b/hw/ppc/spapr.c
> > @@ -101,21 +101,26 @@ static ICSState *spapr_ics_create(sPAPRMachineState 
> > *spapr,
> >                                    const char *type_ics,
> >                                    int nr_irqs, Error **errp)
> >  {
> > -    Error *err = NULL, *local_err = NULL;
> > +    Error *local_err = NULL;
> >      Object *obj;
> >  
> >      obj = object_new(type_ics);
> > -    object_property_add_child(OBJECT(spapr), "ics", obj, NULL);
> > +    object_property_add_child(OBJECT(spapr), "ics", obj, &error_abort);
> >      object_property_add_const_link(obj, "xics", OBJECT(spapr), 
> > &error_abort);
> > -    object_property_set_int(obj, nr_irqs, "nr-irqs", &err);
> > +    object_property_set_int(obj, nr_irqs, "nr-irqs", &local_err);
> > +    if (local_err) {
> > +        goto error;
> > +    }
> >      object_property_set_bool(obj, true, "realized", &local_err);
> > -    error_propagate(&err, local_err);
> > -    if (err) {
> > -        error_propagate(errp, err);
> > -        return NULL;
> > +    if (local_err) {
> > +        goto error;
> >      }
> >  
> >      return ICS_SIMPLE(obj);
> > +
> > +error:
> > +    error_propagate(errp, local_err);
> > +    return NULL;
> >  }
> >  
> >  static void xics_system_init(MachineState *machine, int nr_irqs, Error 
> > **errp)
> >   
>

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