pid namespaces: create a slab-cache for 'struct pid_namespace'
This will help fixing memory leaks due to bad reference counting.
Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/pid.c b/kernel/pid.c
index f76097c60..d88b83e 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -40,6 +40,7 @@
static struct hlist_head *pid_hash;
static int pidhash_shift;
struct pid init_struct_pid = INIT_STRUCT_PID;
+static struct kmem_cache *pid_ns_cachep;
int pid_max = PID_MAX_DEFAULT;
@@ -486,7 +487,7 @@
struct pid_namespace *ns;
int i;
- ns = kmalloc(sizeof(struct pid_namespace), GFP_KERNEL);
+ ns = kmem_cache_alloc(pid_ns_cachep, GFP_KERNEL);
if (ns == NULL)
goto out;
@@ -516,7 +517,7 @@
out_free_map:
kfree(ns->pidmap[0].page);
out_free:
- kfree(ns);
+ kmem_cache_free(pid_ns_cachep, ns);
out:
return ERR_PTR(-ENOMEM);
}
@@ -527,7 +528,7 @@
for (i = 0; i < PIDMAP_ENTRIES; i++)
kfree(ns->pidmap[i].page);
- kfree(ns);
+ kmem_cache_free(pid_ns_cachep, ns);
}
struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *old_ns)
@@ -601,4 +602,6 @@
init_pid_ns.pid_cachep = create_pid_cachep(1);
if (init_pid_ns.pid_cachep == NULL)
panic("Can't create pid_1 cachep\n");
+
+ pid_ns_cachep = KMEM_CACHE(pid_namespace, SLAB_PANIC);
}