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Date:   Wed, 8 Jan 2020 06:45:43 +1100 (AEDT)
From:   James Morris <jmorris@namei.org>
To:     Ondrej Mosnacek <omosnace@redhat.com>
cc:     linux-security-module@vger.kernel.org,
        "Serge E. Hallyn" <serge@hallyn.com>,
        Casey Schaufler <casey@schaufler-ca.com>,
        selinux@vger.kernel.org, Paul Moore <paul@paul-moore.com>,
        Stephen Smalley <sds@tycho.nsa.gov>,
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        Kees Cook <keescook@chromium.org>,
        Micah Morton <mortonm@chromium.org>,
        Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Subject: Re: [PATCH 1/2] selinux: treat atomic flags more carefully
In-Reply-To: <20200107133154.588958-2-omosnace@redhat.com>
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References: <20200107133154.588958-1-omosnace@redhat.com> <20200107133154.588958-2-omosnace@redhat.com>
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On Tue, 7 Jan 2020, Ondrej Mosnacek wrote:

> The disabled/enforcing/initialized flags are all accessed concurrently
> by threads so use the appropriate accessors that ensure atomicity and
> document that it is expected.
> 
> Use smp_load/acquire...() helpers (with memory barriers) for the
> initialized flag, since it gates access to the rest of the state
> structures.
> 
> Note that the disabled flag is currently not used for anything other
> than avoiding double disable, but it will be used for bailing out of
> hooks once security_delete_hooks() is removed.
> 
> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>


Reviewed-by: James Morris <jamorris@linux.microsoft.com>

-- 
James Morris
<jmorris@namei.org>