Zhao Liu <zhao1....@linux.intel.com> writes: > From: Zhao Liu <zhao1....@intel.com> > > As the comment in qapi/error, dereferencing @errp requires > ERRP_GUARD(): > > * = Why, when and how to use ERRP_GUARD() = > * > * Without ERRP_GUARD(), use of the @errp parameter is restricted: > * - It must not be dereferenced, because it may be null. > * - It should not be passed to error_prepend() or > * error_append_hint(), because that doesn't work with &error_fatal. > * ERRP_GUARD() lifts these restrictions. > * > * To use ERRP_GUARD(), add it right at the beginning of the function. > * @errp can then be used without worrying about the argument being > * NULL or &error_fatal. > * > * Using it when it's not needed is safe, but please avoid cluttering > * the source with useless code. > > Currently, since ct3_realize() - as a PCIDeviceClass.realize() method - > doesn't get the NULL errp parameter, it doesn't trigger the dereference > issue. > > To follow the requirement of errp, add missing ERRP_GUARD() in > ct3_realize(). > > Suggested-by: Markus Armbruster <arm...@redhat.com> > Signed-off-by: Zhao Liu <zhao1....@intel.com> > --- > Suggested by credit: > Markus: Referred his explanation about ERRP_GUARD(). > --- > hw/mem/cxl_type3.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c > index e8801805b90f..a3b0761f843b 100644 > --- a/hw/mem/cxl_type3.c > +++ b/hw/mem/cxl_type3.c > @@ -645,6 +645,7 @@ static DOEProtocol doe_cdat_prot[] = { > > static void ct3_realize(PCIDevice *pci_dev, Error **errp) > { > + ERRP_GUARD(); > CXLType3Dev *ct3d = CXL_TYPE3(pci_dev); > CXLComponentState *cxl_cstate = &ct3d->cxl_cstate; > ComponentRegisters *regs = &cxl_cstate->crb;
The dereference is cxl_doe_cdat_init(cxl_cstate, errp); if (*errp) { goto err_free_special_ops; } We check *errp, because cxl_doe_cdat_init() returns void. Could be improved to return bool, along with its callees ct3_load_cdat() and ct3_build_cdat(), but that's a slightly more ambitious cleanup, so Reviewed-by: Markus Armbruster <arm...@redhat.com>