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

[Chen Gang <gang.chen.5i5j@gmail.com>]

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@gmail.com>
> ---
>  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

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