pidns: Use task_active_pid_ns where appropriate
The expressions tsk->nsproxy->pid_ns and task_active_pid_ns
aka ns_of_pid(task_pid(tsk)) should have the same number of
cache line misses with the practical difference that
ns_of_pid(task_pid(tsk)) is released later in a processes life.
Furthermore by using task_active_pid_ns it becomes trivial
to write an unshare implementation for the the pid namespace.
So I have used task_active_pid_ns everywhere I can.
In fork since the pid has not yet been attached to the
process I use ns_of_pid, to achieve the same effect.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index f24f724..0dbfba2 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -3390,7 +3390,7 @@
{
struct cgroup_pidlist *l;
/* don't need task_nsproxy() if we're looking at ourself */
- struct pid_namespace *ns = current->nsproxy->pid_ns;
+ struct pid_namespace *ns = task_active_pid_ns(current);
/*
* We can't drop the pidlist_mutex before taking the l->mutex in case
diff --git a/kernel/events/core.c b/kernel/events/core.c
index dbccf83..738f356 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6155,7 +6155,7 @@
event->parent = parent_event;
- event->ns = get_pid_ns(current->nsproxy->pid_ns);
+ event->ns = get_pid_ns(task_active_pid_ns(current));
event->id = atomic64_inc_return(&perf_event_id);
event->state = PERF_EVENT_STATE_INACTIVE;
diff --git a/kernel/fork.c b/kernel/fork.c
index 8b20ab7..7798c24 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1442,7 +1442,7 @@
if (thread_group_leader(p)) {
if (is_child_reaper(pid))
- p->nsproxy->pid_ns->child_reaper = p;
+ ns_of_pid(pid)->child_reaper = p;
p->signal->leader_pid = pid;
p->signal->tty = tty_kref_get(current->signal->tty);
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index ca27d2c..acc9268 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -84,7 +84,7 @@
goto out_ipc;
}
- new_nsp->pid_ns = copy_pid_ns(flags, task_cred_xxx(tsk, user_ns), task_active_pid_ns(tsk));
+ new_nsp->pid_ns = copy_pid_ns(flags, task_cred_xxx(tsk, user_ns), tsk->nsproxy->pid_ns);
if (IS_ERR(new_nsp->pid_ns)) {
err = PTR_ERR(new_nsp->pid_ns);
goto out_pid;
diff --git a/kernel/pid.c b/kernel/pid.c
index 2a624f1..3a5f238 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -345,7 +345,7 @@
struct pid *find_vpid(int nr)
{
- return find_pid_ns(nr, current->nsproxy->pid_ns);
+ return find_pid_ns(nr, task_active_pid_ns(current));
}
EXPORT_SYMBOL_GPL(find_vpid);
@@ -429,7 +429,7 @@
struct task_struct *find_task_by_vpid(pid_t vnr)
{
- return find_task_by_pid_ns(vnr, current->nsproxy->pid_ns);
+ return find_task_by_pid_ns(vnr, task_active_pid_ns(current));
}
struct pid *get_task_pid(struct task_struct *task, enum pid_type type)
@@ -484,7 +484,7 @@
pid_t pid_vnr(struct pid *pid)
{
- return pid_nr_ns(pid, current->nsproxy->pid_ns);
+ return pid_nr_ns(pid, task_active_pid_ns(current));
}
EXPORT_SYMBOL_GPL(pid_vnr);
@@ -495,7 +495,7 @@
rcu_read_lock();
if (!ns)
- ns = current->nsproxy->pid_ns;
+ ns = task_active_pid_ns(current);
if (likely(pid_alive(task))) {
if (type != PIDTYPE_PID)
task = task->group_leader;
diff --git a/kernel/signal.c b/kernel/signal.c
index 0af8868..b2445d8 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1752,7 +1752,7 @@
* see comment in do_notify_parent() about the following 4 lines
*/
rcu_read_lock();
- info.si_pid = task_pid_nr_ns(tsk, parent->nsproxy->pid_ns);
+ info.si_pid = task_pid_nr_ns(tsk, task_active_pid_ns(parent));
info.si_uid = from_kuid_munged(task_cred_xxx(parent, user_ns), task_uid(tsk));
rcu_read_unlock();
diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c
index 65bdcf1..5a63844 100644
--- a/kernel/sysctl_binary.c
+++ b/kernel/sysctl_binary.c
@@ -1344,7 +1344,7 @@
goto out_putname;
}
- mnt = current->nsproxy->pid_ns->proc_mnt;
+ mnt = task_active_pid_ns(current)->proc_mnt;
file = file_open_root(mnt->mnt_root, mnt, pathname, flags);
result = PTR_ERR(file);
if (IS_ERR(file))