diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
index 2560b312ad57..33082c4e8154 100644
--- a/kernel/trace/fprobe.c
+++ b/kernel/trace/fprobe.c
@@ -403,13 +403,12 @@ static void fprobe_graph_remove_ips(unsigned long *addrs, int num)
 	lockdep_assert_held(&fprobe_mutex);
 
 	fprobe_graph_active--;
-	if (!fprobe_graph_active) {
-		/* Q: should we unregister it ? */
+	/* Q: should we unregister it ? */
+	if (!fprobe_graph_active)
 		unregister_ftrace_graph(&fprobe_graph_ops);
-		return;
-	}
 
-	ftrace_set_filter_ips(&fprobe_graph_ops.ops, addrs, num, 1, 0);
+	if (num)
+		ftrace_set_filter_ips(&fprobe_graph_ops.ops, addrs, num, 1, 0);
 }
 
 static int symbols_cmp(const void *a, const void *b)
@@ -679,8 +678,7 @@ int unregister_fprobe(struct fprobe *fp)
 	}
 	del_fprobe_hash(fp);
 
-	if (count)
-		fprobe_graph_remove_ips(addrs, count);
+	fprobe_graph_remove_ips(addrs, count);
 
 	kfree_rcu(hlist_array, rcu);
 	fp->hlist_array = NULL;
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 728ecda6e8d4..6b0c25761ccb 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3220,15 +3220,22 @@ static struct ftrace_hash *copy_hash(struct ftrace_hash *src)
  *  The filter_hash updates uses just the append_hash() function
  *  and the notrace_hash does not.
  */
-static int append_hash(struct ftrace_hash **hash, struct ftrace_hash *new_hash)
+static int append_hash(struct ftrace_hash **hash, struct ftrace_hash *new_hash,
+		       int size_bits)
 {
 	struct ftrace_func_entry *entry;
 	int size;
 	int i;
 
-	/* An empty hash does everything */
-	if (ftrace_hash_empty(*hash))
-		return 0;
+	if (*hash) {
+		/* An empty hash does everything */
+		if (ftrace_hash_empty(*hash))
+			return 0;
+	} else {
+		*hash = alloc_ftrace_hash(size_bits);
+		if (!*hash)
+			return -ENOMEM;
+	}
 
 	/* If new_hash has everything make hash have everything */
 	if (ftrace_hash_empty(new_hash)) {
@@ -3292,16 +3299,18 @@ static int intersect_hash(struct ftrace_hash **hash, struct ftrace_hash *new_has
 /* Return a new hash that has a union of all @ops->filter_hash entries */
 static struct ftrace_hash *append_hashes(struct ftrace_ops *ops)
 {
-	struct ftrace_hash *new_hash;
+	struct ftrace_hash *new_hash = NULL;
 	struct ftrace_ops *subops;
+	int size_bits;
 	int ret;
 
-	new_hash = alloc_ftrace_hash(ops->func_hash->filter_hash->size_bits);
-	if (!new_hash)
-		return NULL;
+	if (ops->func_hash->filter_hash)
+		size_bits = ops->func_hash->filter_hash->size_bits;
+	else
+		size_bits = FTRACE_HASH_DEFAULT_BITS;
 
 	list_for_each_entry(subops, &ops->subop_list, list) {
-		ret = append_hash(&new_hash, subops->func_hash->filter_hash);
+		ret = append_hash(&new_hash, subops->func_hash->filter_hash, size_bits);
 		if (ret < 0) {
 			free_ftrace_hash(new_hash);
 			return NULL;
@@ -3310,7 +3319,8 @@ static struct ftrace_hash *append_hashes(struct ftrace_ops *ops)
 		if (ftrace_hash_empty(new_hash))
 			break;
 	}
-	return new_hash;
+	/* Can't return NULL as that means this failed */
+	return new_hash ? : EMPTY_HASH;
 }
 
 /* Make @ops trace evenything except what all its subops do not trace */
@@ -3505,7 +3515,8 @@ int ftrace_startup_subops(struct ftrace_ops *ops, struct ftrace_ops *subops, int
 		filter_hash = alloc_and_copy_ftrace_hash(size_bits, ops->func_hash->filter_hash);
 		if (!filter_hash)
 			return -ENOMEM;
-		ret = append_hash(&filter_hash, subops->func_hash->filter_hash);
+		ret = append_hash(&filter_hash, subops->func_hash->filter_hash,
+				  size_bits);
 		if (ret < 0) {
 			free_ftrace_hash(filter_hash);
 			return ret;
@@ -5707,6 +5718,9 @@ __ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
 			return -ENOENT;
 		free_hash_entry(hash, entry);
 		return 0;
+	} else if (__ftrace_lookup_ip(hash, ip) != NULL) {
+		/* Already exists */
+		return 0;
 	}
 
 	entry = add_hash_entry(hash, ip);
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 4cb275316e51..513de9ceb80e 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1591,6 +1591,13 @@ s_next(struct seq_file *m, void *v, loff_t *pos)
 		return iter;
 #endif
 
+	/*
+	 * The iter is allocated in s_start() and passed via the 'v'
+	 * parameter. To stop the iterator, NULL must be returned. But
+	 * the return value is what the 'v' parameter in s_stop() receives
+	 * and frees. Free iter here as it will no longer be used.
+	 */
+	kfree(iter);
 	return NULL;
 }
 
@@ -1667,9 +1674,9 @@ static int s_show(struct seq_file *m, void *v)
 }
 #endif
 
-static void s_stop(struct seq_file *m, void *p)
+static void s_stop(struct seq_file *m, void *v)
 {
-	kfree(p);
+	kfree(v);
 	t_stop(m, NULL);
 }
 
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index d358c9935164..df56f9b76010 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -216,7 +216,7 @@ function_trace_call(unsigned long ip, unsigned long parent_ip,
 
 	parent_ip = function_get_true_parent_ip(parent_ip, fregs);
 
-	trace_ctx = tracing_gen_ctx();
+	trace_ctx = tracing_gen_ctx_dec();
 
 	data = this_cpu_ptr(tr->array_buffer.data);
 	if (!atomic_read(&data->disabled))
@@ -321,7 +321,6 @@ function_no_repeats_trace_call(unsigned long ip, unsigned long parent_ip,
 	struct trace_array *tr = op->private;
 	struct trace_array_cpu *data;
 	unsigned int trace_ctx;
-	unsigned long flags;
 	int bit;
 
 	if (unlikely(!tr->function_enabled))
@@ -347,8 +346,7 @@ function_no_repeats_trace_call(unsigned long ip, unsigned long parent_ip,
 	if (is_repeat_check(tr, last_info, ip, parent_ip))
 		goto out;
 
-	local_save_flags(flags);
-	trace_ctx = tracing_gen_ctx_flags(flags);
+	trace_ctx = tracing_gen_ctx_dec();
 	process_repeats(tr, ip, parent_ip, last_info, trace_ctx);
 
 	trace_function(tr, ip, parent_ip, trace_ctx);
diff --git a/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_fprobe.tc b/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_fprobe.tc
index dc25bcf4f9e2..449f9d8be746 100644
--- a/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_fprobe.tc
+++ b/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_fprobe.tc
@@ -7,12 +7,38 @@ echo 0 > events/enable
 echo > dynamic_events
 
 PLACE=$FUNCTION_FORK
+PLACE2="kmem_cache_free"
+PLACE3="schedule_timeout"
 
 echo "f:myevent1 $PLACE" >> dynamic_events
+
+# Make sure the event is attached and is the only one
+grep -q $PLACE enabled_functions
+cnt=`cat enabled_functions | wc -l`
+if [ $cnt -ne 1 ]; then
+	exit_fail
+fi
+
 echo "f:myevent2 $PLACE%return" >> dynamic_events
 
+# It should till be the only attached function
+cnt=`cat enabled_functions | wc -l`
+if [ $cnt -ne 1 ]; then
+	exit_fail
+fi
+
+# add another event
+echo "f:myevent3 $PLACE2" >> dynamic_events
+
+grep -q $PLACE2 enabled_functions
+cnt=`cat enabled_functions | wc -l`
+if [ $cnt -ne 2 ]; then
+	exit_fail
+fi
+
 grep -q myevent1 dynamic_events
 grep -q myevent2 dynamic_events
+grep -q myevent3 dynamic_events
 test -d events/fprobes/myevent1
 test -d events/fprobes/myevent2
 
@@ -21,6 +47,34 @@ echo "-:myevent2" >> dynamic_events
 grep -q myevent1 dynamic_events
 ! grep -q myevent2 dynamic_events
 
+# should still have 2 left
+cnt=`cat enabled_functions | wc -l`
+if [ $cnt -ne 2 ]; then
+	exit_fail
+fi
+
 echo > dynamic_events
 
+# Should have none left
+cnt=`cat enabled_functions | wc -l`
+if [ $cnt -ne 0 ]; then
+	exit_fail
+fi
+
+echo "f:myevent4 $PLACE" >> dynamic_events
+
+# Should only have one enabled
+cnt=`cat enabled_functions | wc -l`
+if [ $cnt -ne 1 ]; then
+	exit_fail
+fi
+
+echo > dynamic_events
+
+# Should have none left
+cnt=`cat enabled_functions | wc -l`
+if [ $cnt -ne 0 ]; then
+	exit_fail
+fi
+
 clear_trace