4 files changed, 11 insertions, 0 deletions
diff --git a/samples/ftrace/ftrace-direct-modify.c b/samples/ftrace/ftrace-direct-modify.c
index 690e4a9ff333..2877cb053a82 100644
--- a/samples/ftrace/ftrace-direct-modify.c
+++ b/samples/ftrace/ftrace-direct-modify.c
@@ -4,6 +4,9 @@
 #include <linux/ftrace.h>
 #include <asm/asm-offsets.h>
 
+extern void my_direct_func1(void);
+extern void my_direct_func2(void);
+
 void my_direct_func1(void)
 {
 	trace_printk("my direct func1\n");
diff --git a/samples/ftrace/ftrace-direct-multi-modify.c b/samples/ftrace/ftrace-direct-multi-modify.c
index 91bc42a7adb9..6f43a39decd0 100644
--- a/samples/ftrace/ftrace-direct-multi-modify.c
+++ b/samples/ftrace/ftrace-direct-multi-modify.c
@@ -4,6 +4,9 @@
 #include <linux/ftrace.h>
 #include <asm/asm-offsets.h>
 
+extern void my_direct_func1(unsigned long ip);
+extern void my_direct_func2(unsigned long ip);
+
 void my_direct_func1(unsigned long ip)
 {
 	trace_printk("my direct func1 ip %lx\n", ip);
diff --git a/samples/ftrace/ftrace-direct-too.c b/samples/ftrace/ftrace-direct-too.c
index 6e0de725bf22..b97e5ed46233 100644
--- a/samples/ftrace/ftrace-direct-too.c
+++ b/samples/ftrace/ftrace-direct-too.c
@@ -5,6 +5,9 @@
 #include <linux/ftrace.h>
 #include <asm/asm-offsets.h>
 
+extern void my_direct_func(struct vm_area_struct *vma,
+			   unsigned long address, unsigned int flags);
+
 void my_direct_func(struct vm_area_struct *vma,
 			unsigned long address, unsigned int flags)
 {
diff --git a/samples/ftrace/ftrace-direct.c b/samples/ftrace/ftrace-direct.c
index a30aa42ec76a..c918b13edb49 100644
--- a/samples/ftrace/ftrace-direct.c
+++ b/samples/ftrace/ftrace-direct.c
@@ -5,6 +5,8 @@
 #include <linux/ftrace.h>
 #include <asm/asm-offsets.h>
 
+extern void my_direct_func(struct task_struct *p);
+
 void my_direct_func(struct task_struct *p)
 {
 	trace_printk("waking up %s-%d\n", p->comm, p->pid);