From: Oleg Nesterov <oleg@redhat.com>
To: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>,
Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
Cyrill Gorcunov <gorcunov@openvz.org>,
John Stultz <john.stultz@linaro.org>,
Thomas Gleixner <tglx@linutronix.de>,
Nicolas Pitre <nicolas.pitre@linaro.org>,
Michal Hocko <mhocko@suse.com>,
Stanislav Kinsburskiy <skinsbursky@virtuozzo.com>,
Mateusz Guzik <mguzik@redhat.com>,
linux-kernel@vger.kernel.org,
Pavel Emelyanov <xemul@virtuozzo.com>,
Konstantin Khorenko <khorenko@virtuozzo.com>
Subject: task_is_descendant() cleanup
Date: Mon, 23 Jan 2017 13:52:23 +0100 [thread overview]
Message-ID: <20170123125222.GA28626@redhat.com> (raw)
In-Reply-To: <20170123115534.GA11827@redhat.com>
On 01/23, Oleg Nesterov wrote:
>
> Btw task_is_descendant() looks wrong at first glance.
No, I missed the 2nd ->group_leader dereference. Still this function looks
overcomplicated and the usage of thread_group_leader/group_leader just add
the unnecessary confusion. It can be simplified a little bit:
static int task_is_descendant(struct task_struct *parent,
struct task_struct *child)
{
int rc = 0;
struct task_struct *walker;
if (!parent || !child)
return 0;
rcu_read_lock();
for (walker = child; walker->pid; walker = rcu_dereference(walker->real_parent))
if (same_thread_group(parent, walker)) {
rc = 1;
break;
}
rcu_read_unlock();
return rc;
}
Kees, I can send a patch if you think this very minor cleanup makes any sense.
Oleg.
next prev parent reply other threads:[~2017-01-23 12:52 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-19 16:43 [PATCH] prctl: propagate has_child_subreaper flag to every descendant Pavel Tikhomirov
2017-01-20 18:14 ` Oleg Nesterov
2017-01-22 10:00 ` Pavel Tikhomirov
2017-01-22 10:11 ` Pavel Tikhomirov
2017-01-23 11:55 ` Oleg Nesterov
2017-01-23 12:52 ` Oleg Nesterov [this message]
2017-01-25 21:59 ` task_is_descendant() cleanup Kees Cook
2017-01-30 13:49 ` Oleg Nesterov
2017-01-23 14:30 ` [PATCH] prctl: propagate has_child_subreaper flag to every descendant Pavel Tikhomirov
2017-01-23 16:06 ` Oleg Nesterov
2017-01-23 11:57 ` [PATCH] introduce the walk_process_tree() helper Oleg Nesterov
2017-01-23 12:07 ` Oleg Nesterov
2017-01-24 15:01 ` Pavel Tikhomirov
2017-01-23 16:44 ` setns() && PR_SET_CHILD_SUBREAPER Oleg Nesterov
2017-01-23 18:21 ` Eric W. Biederman
2017-01-24 14:07 ` Oleg Nesterov
2017-01-24 15:24 ` Eric W. Biederman
2017-01-30 18:16 ` Oleg Nesterov
2017-01-30 18:17 ` [PATCH] exit: fix the setns() && PR_SET_CHILD_SUBREAPER interaction Oleg Nesterov
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