diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2014-12-10 15:55:08 -0800 |
|---|---|---|
| committer | Moyster <oysterized@gmail.com> | 2019-05-02 18:27:05 +0200 |
| commit | 5e0dbc3de354e611df4c74f28bbd16f96d013539 (patch) | |
| tree | 518ae9727e9a3fbea2534df2ccef4d337f1e9118 /kernel | |
| parent | 38b5fc54686dd479f58152ef99ec7bc62ab3214b (diff) | |
exit: reparent: document the ->has_child_subreaper checks
Swap the "init_task" and same_thread_group() checks. This way it is more
simple to document these checks and we can remove the link to the previous
discussion on lkml.
Change-Id: Ie062e114468bb4922193d1e14265f49fb96f24ad
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Sterling Alexander <stalexan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/exit.c | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index b3f31e8fb..edf774890 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -498,18 +498,16 @@ static struct task_struct *find_new_reaper(struct task_struct *father) if (father->signal->has_child_subreaper) { struct task_struct *reaper; - /* - * Find the first ancestor marked as child_subreaper. - * Note that the code below checks same_thread_group(reaper, - * pid_ns->child_reaper). This is what we need to DTRT in a - * PID namespace. However we still need the check above, see - * http://marc.info/?l=linux-kernel&m=131385460420380 + * Find the first ->is_child_subreaper ancestor in our pid_ns. + * We start from father to ensure we can not look into another + * namespace, this is safe because all its threads are dead. */ for (reaper = father; - reaper != &init_task; + !same_thread_group(reaper, pid_ns->child_reaper); reaper = reaper->real_parent) { - if (same_thread_group(reaper, pid_ns->child_reaper)) + /* call_usermodehelper() descendants need this check */ + if (reaper == &init_task) break; if (!reaper->signal->is_child_subreaper) continue; |