[FTRACE] Enabling function_graph causes OOPS

[Benjamin Herrenschmidt]

On Sun, 2009-09-13 at 00:07 -0400, Steven Rostedt wrote:
>                        982: R_PPC64_ADDR16_HIGHEST
> ftrace_return_to_handler
>  984:   60 84 00 00     ori     r4,r4,0
>                         986: R_PPC64_ADDR16_HIGHER
> ftrace_return_to_handler
>  988:   78 84 07 c6     rldicr  r4,r4,32,31
>  98c:   64 84 00 00     oris    r4,r4,0
>                         98e: R_PPC64_ADDR16_HI
> ftrace_return_to_handler
>  990:   60 84 00 00     ori     r4,r4,0
>                         992: R_PPC64_ADDR16_LO
> ftrace_return_to_handler
>  994:   e8 44 00 08     ld      r2,8(r4)
>  998:   48 00 00 01     bl      998 <.mod_return_to_handler+0x30>
>                         998:
> R_PPC64_REL24      .ftrace_return_to_handler
>  99c:   60 00 00 00     nop
>  9a0:   7c 68 03 a6     mtlr    r3

.../...

> Something is totally messed up here.

Could it be that we don't handle R_PPC64_ADDR16_* relocs in
arch/powerpc/kernel/modules/module_64.c ?

Sachin, do you see a bunch of "Unknown ADD relocation" in your dmesg ?

Ben.