Commit 751c644b authored Mar 26, 2013 by Eric W. Biederman

pid: Handle the exit of a multi-threaded init.



When a multi-threaded init exits and the initial thread is not the
last thread to exit the initial thread hangs around as a zombie
until the last thread exits.  In that case zap_pid_ns_processes
needs to wait until there are only 2 hashed pids in the pid
namespace not one.

v2. Replace thread_pid_vnr(me) == 1 with the test thread_group_leader(me)
    as suggested by Oleg.

Cc: stable@vger.kernel.org
Cc: Oleg Nesterov <oleg@redhat.com>
Reported-by: Caj Larsson <caj@omnicloud.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

parent 92f28d97

kernel/pid_namespace.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -181,6 +181,7 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns)
		int nr;
		int rc;
		struct task_struct task, me = current;
		int init_pids = thread_group_leader(me) ? 1 : 2;

		/* Don't allow any more processes into the pid namespace */
		disable_pid_allocation(pid_ns);
		@@ -230,7 +231,7 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns)
		*/
		for (;;) {
		set_current_state(TASK_UNINTERRUPTIBLE);
		if (pid_ns->nr_hashed == 1)
		if (pid_ns->nr_hashed == init_pids)
		break;
		schedule();
		}