1 files changed, 12 insertions, 5 deletions

diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index 9ffea360a778..e19ce1454ee1 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -28,7 +28,7 @@
 #include <linux/fs.h>
 #include <linux/file.h>
 #include <net/genetlink.h>
-#include <asm/atomic.h>
+#include <linux/atomic.h>
 
 /*
  * Maximum length of a cpumask that can be specified in
@@ -285,7 +285,7 @@ ret:
 static int add_del_listener(pid_t pid, const struct cpumask *mask, int isadd)
 {
         struct listener_list *listeners;
-        struct listener *s, *tmp;
+        struct listener *s, *tmp, *s2;
         unsigned int cpu;
 
         if (!cpumask_subset(mask, cpu_possible_mask))
@@ -293,18 +293,25 @@ static int add_del_listener(pid_t pid, const struct cpumask *mask, int isadd)
 
         if (isadd == REGISTER) {
                 for_each_cpu(cpu, mask) {
-                        s = kmalloc_node(sizeof(struct listener), GFP_KERNEL,
-                                         cpu_to_node(cpu));
+                        s = kmalloc_node(sizeof(struct listener),
+                                        GFP_KERNEL, cpu_to_node(cpu));
                         if (!s)
                                 goto cleanup;
+
                         s->pid = pid;
-                        INIT_LIST_HEAD(&s->list);
                         s->valid = 1;
 
                         listeners = &per_cpu(listener_array, cpu);
                         down_write(&listeners->sem);
+                        list_for_each_entry(s2, &listeners->list, list) {
+                                if (s2->pid == pid && s2->valid)
+                                        goto exists;
+                        }
                         list_add(&s->list, &listeners->list);
+                        s = NULL;
+exists:
                         up_write(&listeners->sem);
+                        kfree(s); /* nop if NULL */
                 }
                 return 0;
         }