o struct genapic contains pointer to probe() function which is of type
  __init. Hence MODPOST generates warning if kernel is compiled with
  CONFIG_RELOCATABLE=y for i386.

WARNING: vmlinux - Section mismatch: reference to .init.text: from .data between 'apic_summit' (at offset 0xc058b504) and 'apic_bigsmp'
WARNING: vmlinux - Section mismatch: reference to .init.text: from .data between 'apic_bigsmp' (at offset 0xc058b5a4) and 'cpu.4471'
WARNING: vmlinux - Section mismatch: reference to .init.text: from .data between 'apic_es7000' (at offset 0xc058b644) and 'apic_default'
WARNING: vmlinux - Section mismatch: reference to .init.text: from .data between 'apic_default' (at offset 0xc058b6e4) and 'interrupt'

o One of the possible options is to put special case check in MODPOST to
  not emit warnings for this case but I think it is not a very good option
  in terms of maintenance.

o Another option is to make probe() function non __init. Anyway this function
  is really small so not freeing this memory after init is not a big deal.
  Secondly, from a programming perspective, probably genapic should not
  provide pointers to functions which have been freed as genapic is non
  __init and is used even after initialization is complete.
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>