I guess that you used a broken gcc and cheated the check
to pass the compilation. Did you, please?

The test used to detect the offset is using a minimalistic
function is is afftected by the gcc bug.

The patch below might be used to cheat the offset check as well.

Torsten, please mention this somewhere if you, just by chance,
send a new version of the patchset.

From f6a438a3f2f60cc1acc859b41d0cc9259c9a331e Mon Sep 17 00:00:00 2001
From: root <redacted>
Date: Tue, 2 Feb 2016 15:35:06 +0100
Subject: [PATCH 2/2] livepatch: Make sure the TOC is handled when detecting
 ftrace location

There seems to be a bug in gcc on PPC. It does not handle TOC
if the function does not access global variables or functions
by default. But it should when profiling is enabled.

This patch works around this problem by adding a call
to a global function.

This patch is for testing only!
---
 kernel/livepatch/ftrace-test.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/livepatch/ftrace-test.c b/kernel/livepatch/ftrace-test.c
index 22f0c54bf7b3..a3b7aabb67e5 100644
--- a/kernel/livepatch/ftrace-test.c
+++ b/kernel/livepatch/ftrace-test.c

@@ -1,6 +1,9 @@
 /* Sample code to figure out mcount location offset */
+#include <linux/printk.h>
+
 
 int test(int a)
 {
+	printk("%d\n", a);
 	return ++a;
 }