linux-kernel - module refcount issues in the liquidio driver

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Message-ID: <YEnIvMOComLaaVa5@infradead.org>
Date:   Thu, 11 Mar 2021 08:37:32 +0100
From:   Christoph Hellwig <hch@...radead.org>
To:     Felix Manlunas <felix.manlunas@...ium.com>,
        Derek Chickles <dchickles@...vell.com>,
        Satanand Burla <sburla@...vell.com>
Cc:     netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: module refcount issues in the liquidio driver

Hi all,

I just stumbled over the odd handling of module refcounts in the liquidio
driver.  The big red flag is the call to module_refcount in
liquidio_watchdog, which will do the wrong thing for any external module
refcount, like a userspace open.

But more importantly the whole concept of acquiring module refcounts from
inside the driver is pretty bogus.  What problem does this try to solve?