userns: Convert taskstats to handle the user and pid namespaces.

- Explicitly limit exit task stat broadcast to the initial user and
  pid namespaces, as it is already limited to the initial network
  namespace.

- For broadcast task stats explicitly generate all of the idenitiers
  in terms of the initial user namespace and the initial pid
  namespace.

- For request stats report them in terms of the current user namespace
  and the current pid namespace.  Netlink messages are delivered
  syncrhonously to the kernel allowing us to get the user namespace
  and the pid namespace from the current task.

- Pass the namespaces for representing pids and uids and gids
  into bacct_add_task.

Cc: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

1 files changed, 7 insertions, 5 deletions

diff --git a/kernel/tsacct.c b/kernel/tsacct.c
index 23b4d78..625df0b 100644
--- a/kernel/tsacct.c
+++ b/kernel/tsacct.c
@@ -26,7 +26,9 @@
 /*
  * fill in basic accounting fields
  */
-void bacct_add_tsk(struct taskstats *stats, struct task_struct *tsk)
+void bacct_add_tsk(struct user_namespace *user_ns,
+		   struct pid_namespace *pid_ns,
+		   struct taskstats *stats, struct task_struct *tsk)
 {
 	const struct cred *tcred;
 	struct timespec uptime, ts;
@@ -55,13 +57,13 @@ void bacct_add_tsk(struct taskstats *stats, struct task_struct *tsk)
 		stats->ac_flag |= AXSIG;
 	stats->ac_nice	 = task_nice(tsk);
 	stats->ac_sched	 = tsk->policy;
-	stats->ac_pid	 = tsk->pid;
+	stats->ac_pid	 = task_pid_nr_ns(tsk, pid_ns);
 	rcu_read_lock();
 	tcred = __task_cred(tsk);
-	stats->ac_uid	 = tcred->uid;
-	stats->ac_gid	 = tcred->gid;
+	stats->ac_uid	 = from_kuid_munged(user_ns, tcred->uid);
+	stats->ac_gid	 = from_kgid_munged(user_ns, tcred->gid);
 	stats->ac_ppid	 = pid_alive(tsk) ?
-				rcu_dereference(tsk->real_parent)->tgid : 0;
+		task_tgid_nr_ns(rcu_dereference(tsk->real_parent), pid_ns) : 0;
 	rcu_read_unlock();
 	stats->ac_utime = cputime_to_usecs(tsk->utime);
 	stats->ac_stime = cputime_to_usecs(tsk->stime);