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From:   David Howells <dhowells@redhat.com>
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References: <202006142054.C00B3E9C9@keescook> <20200612183450.4189588-1-keescook@chromium.org> <7be4d56b-0406-099b-e505-02e074c5173e@huawei.com>
To:     Kees Cook <keescook@chromium.org>
Cc:     dhowells@redhat.com, Xiaoming Ni <nixiaoming@huawei.com>,
        Peter Zijlstra <peterz@infradead.org>,
        David Windsor <dwindsor@gmail.com>,
        Hans Liljestrand <ishkamiel@gmail.com>,
        Elena Reshetova <elena.reshetova@intel.com>,
        Paul Moore <paul@paul-moore.com>, edumazet@google.com,
        paulmck@kernel.org, shakeelb@google.com,
        James Morris <jamorris@linux.microsoft.com>,
        alex.huangjianhui@huawei.com, dylix.dailei@huawei.com,
        chenzefeng2@huawei.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/3] Convert nsproxy, groups, and creds to refcount_t
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Date:   Tue, 21 Jul 2020 11:51:04 +0100
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Kees Cook <keescook@chromium.org> wrote:

> > Should mm->mm_users also be replaced by refcount_t?
> =

> I'll say "yes". :)
> https://lore.kernel.org/lkml/1487671124-11188-1-git-send-email-elena.res=
hetova@intel.com/
> =

> > In addition, is it better to change all variables that use
> > atomic_dec_and_test to control the release process to refconut_t?
> =

> For the most part, yes. The following may find a lot of them:
> scripts/coccinelle/api/atomic_as_refcounter.cocci

I've been gradually undoing some of the conversions as there's no equivale=
nt
of atomic_add_return() and atomic_dec_return() that allow me to log the
altered refcount through a tracepoint.

David