[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH] spapr: fix core unplug crash
From: |
David Gibson |
Subject: |
Re: [Qemu-devel] [PATCH] spapr: fix core unplug crash |
Date: |
Mon, 11 Jul 2016 11:40:25 +1000 |
User-agent: |
Mutt/1.6.1 (2016-04-27) |
On Fri, Jul 08, 2016 at 03:12:07PM +0200, Greg Kurz wrote:
> If the host has 8 threads/core and the guest is started with:
>
> -smp cores=1,threads=4,maxcpus=12
>
> It is possible to crash QEMU by doing:
>
> (qemu) device_add host-spapr-cpu-core,core-id=16,id=foo
> (qemu) device_del foo
> Segmentation fault
>
> This is caused because spapr_core_unplug() assumes cpu_dt_id == core_id.
> Even if it happens to be the case when the host and guest have the same
> number of threads per core, it is conceptually wrong and we may pass a
> bogus id to spapr_dr_connector_by_id() and spapr_core_release() crashes.
>
> Let's use cc->core_id, which is the id that was used to create th DR
> connector.
>
> Signed-off-by: Greg Kurz <address@hidden>
Thanks, applied to ppc-for-2.7.
> ---
> hw/ppc/spapr_cpu_core.c | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/hw/ppc/spapr_cpu_core.c b/hw/ppc/spapr_cpu_core.c
> index 70b6b0b5ee17..106eaf45b399 100644
> --- a/hw/ppc/spapr_cpu_core.c
> +++ b/hw/ppc/spapr_cpu_core.c
> @@ -126,11 +126,9 @@ static void spapr_core_release(DeviceState *dev, void
> *opaque)
> void spapr_core_unplug(HotplugHandler *hotplug_dev, DeviceState *dev,
> Error **errp)
> {
> - sPAPRCPUCore *core = SPAPR_CPU_CORE(OBJECT(dev));
> - PowerPCCPU *cpu = POWERPC_CPU(core->threads);
> - int id = ppc_get_vcpu_dt_id(cpu);
> + CPUCore *cc = CPU_CORE(dev);
> sPAPRDRConnector *drc =
> - spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_CPU, id);
> + spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_CPU, cc->core_id);
> sPAPRDRConnectorClass *drck;
> Error *local_err = NULL;
>
>
--
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
signature.asc
Description: PGP signature