ftrace: Make ftrace_hash_rec_enable return update bool

Change __ftrace_hash_rec_update to return true in case
we need to update dynamic ftrace call records. It return
false in case no update is needed.

Link: http://lkml.kernel.org/r/1458138873-1553-5-git-send-email-jolsa@kernel.org

Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 17 insertions, 10 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 57a6eea84694..11ffcfd3804e 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1610,7 +1610,7 @@ static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
         return  keep_regs;
 }
 
-static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
+static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
                                      int filter_hash,
                                      bool inc)
 {
@@ -1618,12 +1618,13 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
         struct ftrace_hash *other_hash;
         struct ftrace_page *pg;
         struct dyn_ftrace *rec;
+        bool update = false;
         int count = 0;
         int all = 0;
 
         /* Only update if the ops has been registered */
         if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
-                return;
+                return false;
 
         /*
          * In the filter_hash case:
@@ -1650,7 +1651,7 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
                  * then there's nothing to do.
                  */
                 if (ftrace_hash_empty(hash))
-                        return;
+                        return false;
         }
 
         do_for_each_ftrace_rec(pg, rec) {
@@ -1694,7 +1695,7 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
                 if (inc) {
                         rec->flags++;
                         if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX))
-                                return;
+                                return false;
 
                         /*
                          * If there's only a single callback registered to a
@@ -1720,7 +1721,7 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
                                 rec->flags |= FTRACE_FL_REGS;
                 } else {
                         if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0))
-                                return;
+                                return false;
                         rec->flags--;
 
                         /*
@@ -1753,22 +1754,28 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
                          */
                 }
                 count++;
+
+                /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
+                update |= ftrace_test_record(rec, 1) != FTRACE_UPDATE_IGNORE;
+
                 /* Shortcut, if we handled all records, we are done. */
                 if (!all && count == hash->count)
-                        return;
+                        return update;
         } while_for_each_ftrace_rec();
+
+        return update;
 }
 
-static void ftrace_hash_rec_disable(struct ftrace_ops *ops,
+static bool ftrace_hash_rec_disable(struct ftrace_ops *ops,
                                     int filter_hash)
 {
-        __ftrace_hash_rec_update(ops, filter_hash, 0);
+        return __ftrace_hash_rec_update(ops, filter_hash, 0);
 }
 
-static void ftrace_hash_rec_enable(struct ftrace_ops *ops,
+static bool ftrace_hash_rec_enable(struct ftrace_ops *ops,
                                    int filter_hash)
 {
-        __ftrace_hash_rec_update(ops, filter_hash, 1);
+        return __ftrace_hash_rec_update(ops, filter_hash, 1);
 }
 
 static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,