Re: [PATCH v2 0/3] vhost_task: Fix a bug where KVM wakes an exited task
From: Michael S. Tsirkin
Date: Thu Sep 18 2025 - 11:09:13 EST
On Wed, Aug 27, 2025 at 10:10:59PM +0200, Sebastian Andrzej Siewior wrote:
> On 2025-08-27 12:41:04 [-0700], Sean Christopherson wrote:
> > Michael,
>
> Sean,
>
> would the bellow work by chance? It is a quick shot but it looks
> symmetrical…
>
> diff --git a/kernel/vhost_task.c b/kernel/vhost_task.c
> index bc738fa90c1d6..27107dcc1cbfe 100644
> --- a/kernel/vhost_task.c
> +++ b/kernel/vhost_task.c
> @@ -100,6 +100,7 @@ void vhost_task_stop(struct vhost_task *vtsk)
> * freeing it below.
> */
> wait_for_completion(&vtsk->exited);
> + put_task_struct(vtsk->task);
> kfree(vtsk);
> }
> EXPORT_SYMBOL_GPL(vhost_task_stop);
> @@ -148,7 +149,7 @@ struct vhost_task *vhost_task_create(bool (*fn)(void *),
> return ERR_CAST(tsk);
> }
>
> - vtsk->task = tsk;
> + vtsk->task = get_task_struct(tsk);
> return vtsk;
> }
> EXPORT_SYMBOL_GPL(vhost_task_create);
>
> Sebastian
So how about switching to this approach then?
Instead of piling up fixes like we seem to do now ...
Sean?
--
MST