Date: Tue, 12 Apr 2016 10:08:57 +0300
From: Cyrill Gorcunov <gorcunov@gmail.com>
To: Andrey Vagin <avagin@openvz.org>
Cc: linux-kernel@vger.kernel.org, Oleg Nesterov <oleg@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Pavel Emelyanov <xemul@parallels.com>, Roger Luethi <rl@hellgate.ch>,
        Arnd Bergmann <arnd@arndb.de>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        David Ahern <dsahern@gmail.com>, Andy Lutomirski <luto@amacapital.net>,
        Pavel Odintsov <pavel.odintsov@gmail.com>
Subject: Re: [PATCH 04/15] task_diag: add a new interface to get information
 about tasks (v4)
Message-ID: <20160412070857.GU2000@uranus.lan>
References: <1460417755-18201-1-git-send-email-avagin@openvz.org>
 <1460417755-18201-5-git-send-email-avagin@openvz.org>
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On Mon, Apr 11, 2016 at 04:35:44PM -0700, Andrey Vagin wrote:
...
> +static int __taskdiag_dumpit(struct task_iter *iter,
> +			     struct task_diag_cb *cb, struct task_struct **start)
> +{
> +	struct user_namespace *userns = current_user_ns();
> +	struct task_struct *task = *start;
> +	int rc;
> +
> +	for (; task; task = iter_next(iter)) {
> +		if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
> +			continue;
> +
> +		rc = task_diag_fill(task, cb->resp, &iter->req,
> +				cb, iter->ns, userns);
> +		if (rc < 0) {
> +			if (rc != -EMSGSIZE)
> +				return rc;
> +			break;
> +		}
> +	}
> +	*start = task;

task = NULL always here?

> +
> +	return 0;
> +}

	Cyrill