jump label: Tracepoint support for jump labels

Make use of the jump label infrastructure for tracepoints.

Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <a9ba2056e2c9cf332c3c300b577463ce66ff23a8.1284733808.git.jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 12 insertions, 2 deletions

diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index c77f3eceea25..d6073a50a6ca 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -25,6 +25,7 @@
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <linux/sched.h>
+#include <linux/jump_label.h>
 
 extern struct tracepoint __start___tracepoints[];
 extern struct tracepoint __stop___tracepoints[];
@@ -263,7 +264,13 @@ static void set_tracepoint(struct tracepoint_entry **entry,
          * is used.
          */
         rcu_assign_pointer(elem->funcs, (*entry)->funcs);
-        elem->state = active;
+        if (!elem->state && active) {
+                enable_jump_label(&elem->state);
+                elem->state = active;
+        } else if (elem->state && !active) {
+                disable_jump_label(&elem->state);
+                elem->state = active;
+        }
 }
 
 /*
@@ -277,7 +284,10 @@ static void disable_tracepoint(struct tracepoint *elem)
         if (elem->unregfunc && elem->state)
                 elem->unregfunc();
 
-        elem->state = 0;
+        if (elem->state) {
+                disable_jump_label(&elem->state);
+                elem->state = 0;
+        }
         rcu_assign_pointer(elem->funcs, NULL);
 }