Handle pid namespaces in cgroups code
There's one place that works with task pids - its the "tasks" file in cgroups.
The read/write handlers assume, that the pid values go to/come from the user
space and thus it is a virtual pid, i.e. the pid as it is seen from inside a
namespace.
Tune the code accordingly.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 2c5cccb..4766bb6 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1269,7 +1269,7 @@
if (pid) {
rcu_read_lock();
- tsk = find_task_by_pid(pid);
+ tsk = find_task_by_vpid(pid);
if (!tsk || tsk->flags & PF_EXITING) {
rcu_read_unlock();
return -ESRCH;
@@ -1955,7 +1955,7 @@
while ((tsk = cgroup_iter_next(cgrp, &it))) {
if (unlikely(n == npids))
break;
- pidarray[n++] = task_pid_nr(tsk);
+ pidarray[n++] = task_pid_vnr(tsk);
}
cgroup_iter_end(cgrp, &it);
return n;