Commit 3d85885a1b1f3 tried to fix error handling, but it actually
went into the wrong direction by dropping the local Error *.
In the default KVM case, the rationale is to try the in-kernel XICS first,
and if not possible, to fallback to userland XICS. Passing errp everywhere
makes this fallback impossible if errp is &error_fatal (which happens to
be the case). And anyway, if the caller would pass a regular &local_err,
things would be worse: we could possibly pass an already set *errp to
error_setg() and crash, or return an error even in case of success.
So we definitely need a local Error * and only propagate it when we're
done with the fallback logic. This is what this patch does.
Signed-off-by: Greg Kurz <groug@kaod.org>
---
hw/ppc/spapr.c | 22 ++++++++++++++--------
1 file changed, 14 insertions(+), 8 deletions(-)
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index f59999daacfc..db0fb385d4e0 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -186,27 +186,33 @@ static int xics_max_server_number(sPAPRMachineState *spapr)
static void xics_system_init(MachineState *machine, int nr_irqs, Error **errp)
{
sPAPRMachineState *spapr = SPAPR_MACHINE(machine);
+ Error *local_err = NULL;
if (kvm_enabled()) {
if (machine_kernel_irqchip_allowed(machine) &&
- !xics_kvm_init(spapr, errp)) {
+ !xics_kvm_init(spapr, &local_err)) {
spapr->icp_type = TYPE_KVM_ICP;
- spapr->ics = spapr_ics_create(spapr, TYPE_ICS_KVM, nr_irqs, errp);
+ spapr->ics = spapr_ics_create(spapr, TYPE_ICS_KVM, nr_irqs,
+ &local_err);
}
if (machine_kernel_irqchip_required(machine) && !spapr->ics) {
- error_prepend(errp, "kernel_irqchip requested but unavailable: ");
- return;
+ error_prepend(&local_err,
+ "kernel_irqchip requested but unavailable: ");
+ goto error;
}
+ error_free(local_err);
+ local_err = NULL;
}
if (!spapr->ics) {
xics_spapr_init(spapr);
spapr->icp_type = TYPE_ICP;
- spapr->ics = spapr_ics_create(spapr, TYPE_ICS_SIMPLE, nr_irqs, errp);
- if (!spapr->ics) {
- return;
- }
+ spapr->ics = spapr_ics_create(spapr, TYPE_ICS_SIMPLE, nr_irqs,
+ &local_err);
}
+
+error:
+ error_propagate(errp, local_err);
}
static int spapr_fixup_cpu_smt_dt(void *fdt, int offset, PowerPCCPU *cpu,
On Fri, Jun 15, 2018 at 06:58:00PM +0200, Greg Kurz wrote: > Commit 3d85885a1b1f3 tried to fix error handling, but it actually > went into the wrong direction by dropping the local Error *. > > In the default KVM case, the rationale is to try the in-kernel XICS first, > and if not possible, to fallback to userland XICS. Passing errp everywhere > makes this fallback impossible if errp is &error_fatal (which happens to > be the case). And anyway, if the caller would pass a regular &local_err, > things would be worse: we could possibly pass an already set *errp to > error_setg() and crash, or return an error even in case of success. > > So we definitely need a local Error * and only propagate it when we're > done with the fallback logic. This is what this patch does. > > Signed-off-by: Greg Kurz <groug@kaod.org> Applied to ppc-for-3.0, thanks. > --- > hw/ppc/spapr.c | 22 ++++++++++++++-------- > 1 file changed, 14 insertions(+), 8 deletions(-) > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index f59999daacfc..db0fb385d4e0 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -186,27 +186,33 @@ static int xics_max_server_number(sPAPRMachineState *spapr) > static void xics_system_init(MachineState *machine, int nr_irqs, Error **errp) > { > sPAPRMachineState *spapr = SPAPR_MACHINE(machine); > + Error *local_err = NULL; > > if (kvm_enabled()) { > if (machine_kernel_irqchip_allowed(machine) && > - !xics_kvm_init(spapr, errp)) { > + !xics_kvm_init(spapr, &local_err)) { > spapr->icp_type = TYPE_KVM_ICP; > - spapr->ics = spapr_ics_create(spapr, TYPE_ICS_KVM, nr_irqs, errp); > + spapr->ics = spapr_ics_create(spapr, TYPE_ICS_KVM, nr_irqs, > + &local_err); > } > if (machine_kernel_irqchip_required(machine) && !spapr->ics) { > - error_prepend(errp, "kernel_irqchip requested but unavailable: "); > - return; > + error_prepend(&local_err, > + "kernel_irqchip requested but unavailable: "); > + goto error; > } > + error_free(local_err); > + local_err = NULL; > } > > if (!spapr->ics) { > xics_spapr_init(spapr); > spapr->icp_type = TYPE_ICP; > - spapr->ics = spapr_ics_create(spapr, TYPE_ICS_SIMPLE, nr_irqs, errp); > - if (!spapr->ics) { > - return; > - } > + spapr->ics = spapr_ics_create(spapr, TYPE_ICS_SIMPLE, nr_irqs, > + &local_err); > } > + > +error: > + error_propagate(errp, local_err); > } > > static int spapr_fixup_cpu_smt_dt(void *fdt, int offset, PowerPCCPU *cpu, > -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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