pid namespaces: allow signalling cgroup-init
Only the global-init process must be special - any other cgroup-init
process must be killable to prevent run-away processes in the system.
TODO: Ideally we should allow killing the cgroup-init only from parent
cgroup and prevent it being killed from within the cgroup.
But that is a more complex change and will be addressed by a follow-on
patch. For now allow the cgroup-init to be terminated by any process
with sufficient privileges.
Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/signal.c b/kernel/signal.c
index 8214ffa..9892388 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1835,11 +1835,9 @@
continue;
/*
- * Init of a pid space gets no signals it doesn't want from
- * within that pid space. It can of course get signals from
- * its parent pid space.
+ * Global init gets no signals it doesn't want.
*/
- if (current == task_child_reaper(current))
+ if (is_global_init(current))
continue;
if (sig_kernel_stop(signr)) {
