pid namespaces: allow signalling cgroup-init
authorSukadev Bhattiprolu <sukadev@us.ibm.com>
Fri, 19 Oct 2007 06:40:13 +0000 (23:40 -0700)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Fri, 19 Oct 2007 18:53:40 +0000 (11:53 -0700)
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>
kernel/signal.c

index 8214ffad54bcebbbe63b639115d0bd983ba55101..98923882ba57294bede8c16810fee83ec6cc6ee0 100644 (file)
@@ -1835,11 +1835,9 @@ relock:
                        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)) {