Date:   Tue, 14 Dec 2021 15:05:34 +0800
From:   Leo Yan <leo.yan@linaro.org>
To:     Balbir Singh <bsingharora@gmail.com>
Cc:     "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Leon Romanovsky <leon@kernel.org>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Mike Leach <mike.leach@linaro.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jan Harkes <jaharkes@cs.cmu.edu>, coda@cs.cmu.edu,
        Paul Moore <paul@paul-moore.com>,
        Eric Paris <eparis@redhat.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, coresight@lists.linaro.org,
        linux-arm-kernel@lists.infradead.org, codalist@coda.cs.cmu.edu,
        linux-audit@redhat.com
Subject: Re: [PATCH v2 4/7] connector/cn_proc: Use task_is_in_init_pid_ns()
Message-ID: <20211214070534.GA1721898@leoy-ThinkPad-X240s>
References: <20211208083320.472503-1-leo.yan@linaro.org>
 <20211208083320.472503-5-leo.yan@linaro.org>
 <YbgyiIZDDaOB93Em@balbir-desktop>
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On Tue, Dec 14, 2021 at 04:58:32PM +1100, Balbir Singh wrote:
> On Wed, Dec 08, 2021 at 04:33:17PM +0800, Leo Yan wrote:
> > This patch replaces open code with task_is_in_init_pid_ns() to check if
> > a task is in root PID namespace.
> > 
> > Signed-off-by: Leo Yan <leo.yan@linaro.org>
> > ---
> >  drivers/connector/cn_proc.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/connector/cn_proc.c b/drivers/connector/cn_proc.c
> > index 646ad385e490..ccac1c453080 100644
> > --- a/drivers/connector/cn_proc.c
> > +++ b/drivers/connector/cn_proc.c
> > @@ -358,7 +358,7 @@ static void cn_proc_mcast_ctl(struct cn_msg *msg,
> >  	 * other namespaces.
> >  	 */
> >  	if ((current_user_ns() != &init_user_ns) ||
> > -	    (task_active_pid_ns(current) != &init_pid_ns))
> > +	    !task_is_in_init_pid_ns(current))
> >  		return;
> >
> 
> Sounds like there might scope for other wrappers - is_current_in_user_init_ns()

Indeed, for new wrapper is_current_in_user_init_ns(), I searched kernel
and located there have multiple places use open code.  If no one works
on this refactoring, I will send a new patchset for it separately.

> Acked-by: Balbir Singh <bsingharora@gmail.com>

Thank you for review, Balbir!  Also thanks review from Leon and
Suzuki.

Leo