From mboxrd@z Thu Jan  1 00:00:00 1970
From: Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [PULL 2/2] vhost: replace rcu with mutex
Date: Tue, 03 Jun 2014 14:48:34 +0200
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To: Eric Dumazet <eric.dumazet@gmail.com>, "Michael S. Tsirkin" <mst@redhat.com>
Cc: netdev@vger.kernel.org, David Miller <davem@davemloft.net>, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org
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Il 02/06/2014 23:58, Eric Dumazet ha scritto:
> This looks dubious
>
> What about using kfree_rcu() instead ?

It would lead to unbound allocation from userspace.

> translate_desc() still uses rcu_read_lock(), its not clear if the mutex
> is really held.

Yes, vhost_get_vq_desc must be called with the vq mutex held.

The rcu_read_lock/unlock in translate_desc is unnecessary.

Paolo