Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1607696

Re: [PATCH v1] KVM: kvm_io_bus_unregister_dev() should never fail

From Cornelia Huck <cornelia.huck@de.ibm.com>
Newsgroups linux.kernel
Subject Re: [PATCH v1] KVM: kvm_io_bus_unregister_dev() should never fail
Date 2017-03-23 17:50 +0100
Message-ID <toe5X-4Wc-3@gated-at.bofh.it> (permalink)
References <toc4a-3pL-23@gated-at.bofh.it> <todtg-4AG-9@gated-at.bofh.it> <todMC-4Je-23@gated-at.bofh.it>
Organization IBM Deutschland Research & Development GmbH Vorsitzende des Aufsichtsrats: Martina Koederitz Geschäftsführung: Dirk Wittkopp Sitz der Gesellschaft: Böblingen Registergericht: Amtsgericht Stuttgart, HRB 243294

Show all headers | View raw


On Thu, 23 Mar 2017 17:20:48 +0100
David Hildenbrand <david@redhat.com> wrote:

> 
> > As this may set kvm->buses[bus_idx] to NULL, don't you also need to
> > guard for bus == NULL in kvm_io_bus_destroy()? (I looked at the code on
> > kvm/queue.)
> 
> very right, so something like this?
> 
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index e1be4b4..ef1aa7f 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -728,7 +728,8 @@ static void kvm_destroy_vm(struct kvm *kvm)
>         spin_unlock(&kvm_lock);
>         kvm_free_irq_routing(kvm);
>         for (i = 0; i < KVM_NR_BUSES; i++) {
> -               kvm_io_bus_destroy(kvm->buses[i]);
> +               if (kvm->buses[i])
> +                       kvm_io_bus_destroy(kvm->buses[i]);
>                 kvm->buses[i] = NULL;
>         }
>         kvm_coalesced_mmio_free(kvm);
> 
> Thanks!
> 
> > 
> >>  	synchronize_srcu_expedited(&kvm->srcu);
> >>  	kfree(bus);
> >> -	return r;
> >> +	return;
> >>  }
> > 
> 
> 

Either that, or an early exit for bus == NULL in kvm_io_bus_destroy().
(I think the second option is more straightforward.)

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

[PATCH v1] KVM: kvm_io_bus_unregister_dev() should never fail David Hildenbrand <david@redhat.com> - 2017-03-23 15:40 +0100
  Re: [PATCH v1] KVM: kvm_io_bus_unregister_dev() should never fail Cornelia Huck <cornelia.huck@de.ibm.com> - 2017-03-23 17:10 +0100
    Re: [PATCH v1] KVM: kvm_io_bus_unregister_dev() should never fail David Hildenbrand <david@redhat.com> - 2017-03-23 17:30 +0100
      Re: [PATCH v1] KVM: kvm_io_bus_unregister_dev() should never fail Cornelia Huck <cornelia.huck@de.ibm.com> - 2017-03-23 17:50 +0100
        Re: [PATCH v1] KVM: kvm_io_bus_unregister_dev() should never fail David Hildenbrand <david@redhat.com> - 2017-03-23 18:20 +0100

csiph-web