ftrace: Return ENOTSUPP when DYNAMIC_FTRACE_WITH_DIRECT_CALLS is not configured

When CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS is not set it's best to
have the stub functions return ENOTSUPP instead of ENODEV,
otherwise ENODEV is a valid error when ip is incorrect which is
indistinguishable from ftrace not compiled in.

Link: http://lkml.kernel.org/r/CAADnVQ+OzTikM9EhrfsC7NFsVYhATW1SVHxK64w3xn9qpk81pg@mail.gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index dfaa37e..af79b0f 100644 (file)
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -268,16 +268,16 @@ int ftrace_modify_direct_caller(struct ftrace_func_entry *entry,
 # define ftrace_direct_func_count 0
 static inline int register_ftrace_direct(unsigned long ip, unsigned long addr)
 {
-       return -ENODEV;
+       return -ENOTSUPP;
 }
 static inline int unregister_ftrace_direct(unsigned long ip, unsigned long addr)
 {
-       return -ENODEV;
+       return -ENOTSUPP;
 }
 static inline int modify_ftrace_direct(unsigned long ip,
                                       unsigned long old_addr, unsigned long new_addr)
 {
-       return -ENODEV;
+       return -ENOTSUPP;
 }
 static inline struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr)
 {