diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 4ea929a06291..9e53101233f6 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -280,6 +280,7 @@ static inline void ftrace_kill(void) { }
 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
 int register_ftrace_direct(unsigned long ip, unsigned long addr);
 int unregister_ftrace_direct(unsigned long ip, unsigned long addr);
+int modify_ftrace_direct(unsigned long ip, unsigned long old_addr, unsigned long new_addr);
 #else
 static inline int register_ftrace_direct(unsigned long ip, unsigned long addr)
 {
@@ -289,6 +290,11 @@ static inline int unregister_ftrace_direct(unsigned long ip, unsigned long addr)
 {
 	return -ENODEV;
 }
+static inline int modify_ftrace_direct(unsigned long ip,
+				       unsigned long old_addr, unsigned long new_addr)
+{
+	return -ENODEV;
+}
 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
 
 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index ebdd94e60f33..d3f5d7707861 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -4556,6 +4556,84 @@ int unregister_ftrace_direct(unsigned long ip, unsigned long addr)
 	return ret;
 }
 EXPORT_SYMBOL_GPL(unregister_ftrace_direct);
+
+static struct ftrace_ops stub_ops = {
+	.func		= ftrace_stub,
+};
+
+/**
+ * modify_ftrace_direct - Modify an existing direct call to call something else
+ * @ip: The instruction pointer to modify
+ * @old_addr: The address that the current @ip calls directly
+ * @new_addr: The address that the @ip should call
+ *
+ * This modifies a ftrace direct caller at an instruction pointer without
+ * having to disable it first. The direct call will switch over to the
+ * @new_addr without missing anything.
+ *
+ * Returns: zero on success. Non zero on error, which includes:
+ *  -ENODEV : the @ip given has no direct caller attached
+ *  -EINVAL : the @old_addr does not match the current direct caller
+ */
+int modify_ftrace_direct(unsigned long ip,
+			 unsigned long old_addr, unsigned long new_addr)
+{
+	struct ftrace_func_entry *entry;
+	struct dyn_ftrace *rec;
+	int ret = -ENODEV;
+
+	mutex_lock(&direct_mutex);
+	entry = __ftrace_lookup_ip(direct_functions, ip);
+	if (!entry) {
+		/* OK if it is off by a little */
+		rec = lookup_rec(ip, ip);
+		if (!rec || rec->ip == ip)
+			goto out_unlock;
+
+		entry = __ftrace_lookup_ip(direct_functions, rec->ip);
+		if (!entry)
+			goto out_unlock;
+
+		ip = rec->ip;
+		WARN_ON(!(rec->flags & FTRACE_FL_DIRECT));
+	}
+
+	ret = -EINVAL;
+	if (entry->direct != old_addr)
+		goto out_unlock;
+
+	/*
+	 * By setting a stub function at the same address, we force
+	 * the code to call the iterator and the direct_ops helper.
+	 * This means that @ip does not call the direct call, and
+	 * we can simply modify it.
+	 */
+	ret = ftrace_set_filter_ip(&stub_ops, ip, 0, 0);
+	if (ret)
+		goto out_unlock;
+
+	ret = register_ftrace_function(&stub_ops);
+	if (ret) {
+		ftrace_set_filter_ip(&stub_ops, ip, 1, 0);
+		goto out_unlock;
+	}
+
+	entry->direct = new_addr;
+
+	/*
+	 * By removing the stub, we put back the direct call, calling
+	 * the @new_addr.
+	 */
+	unregister_ftrace_function(&stub_ops);
+	ftrace_set_filter_ip(&stub_ops, ip, 1, 0);
+
+	ret = 0;
+
+ out_unlock:
+	mutex_unlock(&direct_mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(modify_ftrace_direct);
 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
 
 /**