diff options
| author | Eric W. Biederman <ebiederm@xmission.com> | 2012-05-31 16:26:39 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-05-31 17:49:31 -0700 |
| commit | 3208450488ae724196f1efffc457e4265957c04e (patch) | |
| tree | bfad76a020bf5635e6529b3105f6ea4b521d7973 /kernel/signal.c | |
| parent | 9eaa3d9bb2c4da99b1161cfcc63f3e77d9d3d156 (diff) | |
pidns: use task_active_pid_ns in do_notify_parent
Using task_active_pid_ns is more robust because it works even after we
have called exit_namespaces. This change allows us to have parent
processes that are zombies. Normally a zombie parent processes is crazy
and the last thing you would want to have but in the case of not letting
the init process of a pid namespace be reaped until all of it's children
are dead and reaped a zombie parent process is exactly what we want.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Louis Rilling <louis.rilling@kerlabs.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index f7b418217633..08dfbd748cd2 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1656,19 +1656,18 @@ bool do_notify_parent(struct task_struct *tsk, int sig) info.si_signo = sig; info.si_errno = 0; /* - * we are under tasklist_lock here so our parent is tied to - * us and cannot exit and release its namespace. + * We are under tasklist_lock here so our parent is tied to + * us and cannot change. * - * the only it can is to switch its nsproxy with sys_unshare, - * bu uncharing pid namespaces is not allowed, so we'll always - * see relevant namespace + * task_active_pid_ns will always return the same pid namespace + * until a task passes through release_task. * * write_lock() currently calls preempt_disable() which is the * same as rcu_read_lock(), but according to Oleg, this is not * correct to rely on this */ rcu_read_lock(); - info.si_pid = task_pid_nr_ns(tsk, tsk->parent->nsproxy->pid_ns); + info.si_pid = task_pid_nr_ns(tsk, task_active_pid_ns(tsk->parent)); info.si_uid = from_kuid_munged(task_cred_xxx(tsk->parent, user_ns), task_uid(tsk)); rcu_read_unlock(); |