Re: [PATCH next] vhost_task: after freeing vhost_task it should not be accessed in vhost_task_fn

From: Mike Christie
Date: Tue Apr 30 2024 - 12:23:32 EST


On 4/30/24 8:05 AM, Edward Adam Davis wrote:
> static int vhost_task_fn(void *data)
> {
> struct vhost_task *vtsk = data;
> @@ -51,7 +51,7 @@ static int vhost_task_fn(void *data)
> schedule();
> }
>
> - mutex_lock(&vtsk->exit_mutex);
> + mutex_lock(&exit_mutex);
> /*
> * If a vhost_task_stop and SIGKILL race, we can ignore the SIGKILL.
> * When the vhost layer has called vhost_task_stop it's already stopped
> @@ -62,7 +62,7 @@ static int vhost_task_fn(void *data)
> vtsk->handle_sigkill(vtsk->data);
> }
> complete(&vtsk->exited);
> - mutex_unlock(&vtsk->exit_mutex);
> + mutex_unlock(&exit_mutex);
>

Edward, thanks for the patch. I think though I just needed to swap the
order of the calls above.

Instead of:

complete(&vtsk->exited);
mutex_unlock(&vtsk->exit_mutex);

it should have been:

mutex_unlock(&vtsk->exit_mutex);
complete(&vtsk->exited);

If my analysis is correct, then Michael do you want me to resubmit a
patch on top of your vhost branch or resubmit the entire patchset?