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-rw-r--r--kernel/pid.c15
1 files changed, 12 insertions, 3 deletions
diff --git a/kernel/pid.c b/kernel/pid.c
index 36aa02f..de9af60 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -270,7 +270,6 @@ void free_pid(struct pid *pid)
wake_up_process(ns->child_reaper);
break;
case 0:
- ns->nr_hashed = -1;
schedule_work(&ns->proc_work);
break;
}
@@ -319,7 +318,7 @@ struct pid *alloc_pid(struct pid_namespace *ns)
upid = pid->numbers + ns->level;
spin_lock_irq(&pidmap_lock);
- if (ns->nr_hashed < 0)
+ if (!(ns->nr_hashed & PIDNS_HASH_ADDING))
goto out_unlock;
for ( ; upid >= pid->numbers; --upid) {
hlist_add_head_rcu(&upid->pid_chain,
@@ -342,6 +341,13 @@ out_free:
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;
@@ -573,6 +579,9 @@ void __init pidhash_init(void)
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()));
@@ -584,7 +593,7 @@ void __init pidmap_init(void)
/* 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 = 1;
+ init_pid_ns.nr_hashed = PIDNS_HASH_ADDING;
init_pid_ns.pid_cachep = KMEM_CACHE(pid,
SLAB_HWCACHE_ALIGN | SLAB_PANIC);
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