powerpc/ppc64: ftrace, handle module trampolines for dyn ftrace

Impact: Allow 64 bit PowerPC to trace modules with dynamic ftrace

This adds code to handle the PPC64 module trampolines, and allows for
PPC64 to use dynamic ftrace.

Thanks to Paul Mackerras for these updates:

  - fix the mod and rec->arch.mod NULL checks.
  - fix to is_bl_op compare.

Thanks to Milton Miller for:

  - finding the nasty race with using two nops, and recommending
    instead that I use a branch 8 forward.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h
index 17efecc2bf03..e5f2ae8362f7 100644
--- a/arch/powerpc/include/asm/ftrace.h
+++ b/arch/powerpc/include/asm/ftrace.h
@@ -16,7 +16,7 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr)
 }
 
 struct dyn_arch_ftrace {
-        /* nothing yet */
+        struct module *mod;
 };
 #endif /*  CONFIG_DYNAMIC_FTRACE */
 #endif /* __ASSEMBLY__ */