#include <linux/pid_namespace.h>
#include <linux/init_task.h>
#include <linux/syscalls.h>
+#include <linux/proc_fs.h>
#define pid_hashfn(nr, ns) \
hash_long((unsigned long)nr + (unsigned long)ns, pidhash_shift)
.last_pid = 0,
.level = 0,
.child_reaper = &init_task,
+ .user_ns = &init_user_ns,
+ .proc_inum = PROC_PID_INIT_INO,
};
EXPORT_SYMBOL_GPL(init_pid_ns);
-int is_container_init(struct task_struct *tsk)
-{
- int ret = 0;
- struct pid *pid;
-
- rcu_read_lock();
- pid = task_pid(tsk);
- if (pid != NULL && pid->numbers[pid->level].nr == 1)
- ret = 1;
- rcu_read_unlock();
-
- return ret;
-}
-EXPORT_SYMBOL(is_container_init);
-
/*
* Note: disable interrupts while the pidmap_lock is held as an
* interrupt might come in and do read_lock(&tasklist_lock).
unsigned long flags;
spin_lock_irqsave(&pidmap_lock, flags);
- for (i = 0; i <= pid->level; i++)
- hlist_del_rcu(&pid->numbers[i].pid_chain);
+ for (i = 0; i <= pid->level; i++) {
+ struct upid *upid = pid->numbers + i;
+ struct pid_namespace *ns = upid->ns;
+ hlist_del_rcu(&upid->pid_chain);
+ switch(--ns->nr_hashed) {
+ case 1:
+ /* When all that is left in the pid namespace
+ * is the reaper wake up the reaper. The reaper
+ * may be sleeping in zap_pid_ns_processes().
+ */
+ wake_up_process(ns->child_reaper);
+ break;
+ case 0:
+ schedule_work(&ns->proc_work);
+ break;
+ }
+ }
spin_unlock_irqrestore(&pidmap_lock, flags);
for (i = 0; i <= pid->level; i++)
goto out;
tmp = ns;
+ pid->level = ns->level;
for (i = ns->level; i >= 0; i--) {
nr = alloc_pidmap(tmp);
if (nr < 0)
tmp = tmp->parent;
}
+ if (unlikely(is_child_reaper(pid))) {
+ if (pid_ns_prepare_proc(ns))
+ goto out_free;
+ }
+
get_pid_ns(ns);
- pid->level = ns->level;
atomic_set(&pid->count, 1);
for (type = 0; type < PIDTYPE_MAX; ++type)
INIT_HLIST_HEAD(&pid->tasks[type]);
upid = pid->numbers + ns->level;
spin_lock_irq(&pidmap_lock);
- for ( ; upid >= pid->numbers; --upid)
+ if (!(ns->nr_hashed & PIDNS_HASH_ADDING))
+ goto out_unlock;
+ for ( ; upid >= pid->numbers; --upid) {
hlist_add_head_rcu(&upid->pid_chain,
&pid_hash[pid_hashfn(upid->nr, upid->ns)]);
+ upid->ns->nr_hashed++;
+ }
spin_unlock_irq(&pidmap_lock);
out:
return pid;
+out_unlock:
+ spin_unlock(&pidmap_lock);
out_free:
while (++i <= ns->level)
free_pidmap(pid->numbers + i);
goto out;
}
+void disable_pid_allocation(struct pid_namespace *ns)
+{
+ spin_lock_irq(&pidmap_lock);
+ ns->nr_hashed &= ~PIDNS_HASH_ADDING;
+ spin_unlock_irq(&pidmap_lock);
+}
+
struct pid *find_pid_ns(int nr, struct pid_namespace *ns)
{
struct hlist_node *elem;
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);
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)
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);
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;
void __init pidmap_init(void)
{
+ /* Veryify no one has done anything silly */
+ BUILD_BUG_ON(PID_MAX_LIMIT >= PIDNS_HASH_ADDING);
+
/* bump default and minimum pid_max based on number of cpus */
pid_max = min(pid_max_max, max_t(int, pid_max,
PIDS_PER_CPU_DEFAULT * num_possible_cpus()));
/* Reserve PID 0. We never call free_pidmap(0) */
set_bit(0, init_pid_ns.pidmap[0].page);
atomic_dec(&init_pid_ns.pidmap[0].nr_free);
+ init_pid_ns.nr_hashed = PIDNS_HASH_ADDING;
init_pid_ns.pid_cachep = KMEM_CACHE(pid,
SLAB_HWCACHE_ALIGN | SLAB_PANIC);