powerpc64, ftrace: save toc only on modules for function graph

[karo-tx-linux.git] / arch / powerpc / kernel / ftrace.c

diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c
index 7538b944fa528a0ec88c591dc4cd40e1ec9f549c..5c6dfa97e83832e7cd323ba623bad8558f368e03 100644 (file)
--- a/arch/powerpc/kernel/ftrace.c
+++ b/arch/powerpc/kernel/ftrace.c
@@ -567,6 +567,10 @@ int ftrace_disable_ftrace_graph_caller(void)
 }
 #endif /* CONFIG_DYNAMIC_FTRACE */
 
+#ifdef CONFIG_PPC64
+extern void mod_return_to_handler(void);
+#endif
+
 /*
  * Hook the return address and push it in the stack of return addrs
  * in current thread info.
@@ -577,12 +581,17 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
        unsigned long long calltime;
        int faulted;
        struct ftrace_graph_ent trace;
-       unsigned long return_hooker = (unsigned long)
-                               &return_to_handler;
+       unsigned long return_hooker = (unsigned long)&return_to_handler;
 
        if (unlikely(atomic_read(&current->tracing_graph_pause)))
                return;
 
+#if CONFIG_PPC64
+       /* non core kernel code needs to save and restore the TOC */
+       if (REGION_ID(self_addr) != KERNEL_REGION_ID)
+               return_hooker = (unsigned long)&mod_return_to_handler;
+#endif
+
        return_hooker = GET_ADDR(return_hooker);
 
        /*