Re: [Qemu-ppc] [PULL 25/26] spapr_pci: factorize the use of SPAPR_MACHINE_GET_CLASS()

[Peter Maydell]

On 21 August 2018 at 05:33, David Gibson <address@hidden> wrote:
> From: Cédric Le Goater <address@hidden>
>
> It should save us some CPU cycles as these routines perform a lot of
> checks.
>
> Signed-off-by: Cédric Le Goater <address@hidden>
> Signed-off-by: David Gibson <address@hidden>
> ---
>  hw/ppc/spapr_pci.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)

Hi; Coverity points out in CID 1395183 that there's a bug in
this part of this patch:

> @@ -1558,6 +1559,7 @@ static void spapr_phb_realize(DeviceState *dev, Error 
> **errp)
>      sPAPRMachineState *spapr =
>          (sPAPRMachineState *) object_dynamic_cast(qdev_get_machine(),
>                                                    TYPE_SPAPR_MACHINE);
> +    sPAPRMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);

This has moved the call to SPAPR_MACHINE_GET_CLASS() above
the check for "is spapr NULL", which is wrong, because it
will unconditionally dereference the pointer you pass to it.

thanks
-- PMM