Re: [PATCH] virt/kvm/assigned-dev.c: Set 'dev->irq_source_id' to '-1' after free it

From: Chen Gang
Date: Tue Aug 19 2014 - 11:44:18 EST


Hello maintainers:

Please help check this patch, when you have time.

Thanks.

On 08/08/2014 11:37 PM, Chen Gang wrote:
> As a generic function, deassign_guest_irq() assumes it can be called
> even if assign_guest_irq() is not be called successfully (which can be
> triggered by ioctl from user mode, indirectly).
>
> So for assign_guest_irq() failure process, need set 'dev->irq_source_id'
> to -1 after free 'dev->irq_source_id', or deassign_guest_irq() may free
> it again.
>
> Signed-off-by: Chen Gang <gang.chen.5i5j@xxxxxxxxx>
> ---
> virt/kvm/assigned-dev.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c
> index bf06577..5819a27 100644
> --- a/virt/kvm/assigned-dev.c
> +++ b/virt/kvm/assigned-dev.c
> @@ -526,8 +526,10 @@ static int assign_guest_irq(struct kvm *kvm,
> dev->irq_requested_type |= guest_irq_type;
> if (dev->ack_notifier.gsi != -1)
> kvm_register_irq_ack_notifier(kvm, &dev->ack_notifier);
> - } else
> + } else {
> kvm_free_irq_source_id(kvm, dev->irq_source_id);
> + dev->irq_source_id = -1;
> + }
>
> return r;
> }
>


--
Chen Gang

Open share and attitude like air water and life which God blessed
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