kprobes/x86: Allow probe on some kprobe preparation functions

kprobes/x86: Allow probe on some kprobe preparation functions

There is no need to prohibit probing on the functions
used in preparation phase. Those are safely probed because
those are not invoked from breakpoint/fault/debug handlers,
there is no chance to cause recursive exceptions.

Following functions are now removed from the kprobes blacklist:

	can_boost
	can_probe
	can_optimize
	is_IF_modifier
	__copy_instruction
	copy_optimized_instructions
	arch_copy_kprobe
	arch_prepare_kprobe
	arch_arm_kprobe
	arch_disarm_kprobe
	arch_remove_kprobe
	arch_trampoline_kprobe
	arch_prepare_kprobe_ftrace
	arch_prepare_optimized_kprobe
	arch_check_optimized_kprobe
	arch_within_optimized_kprobe
	__arch_remove_optimized_kprobe
	arch_remove_optimized_kprobe
	arch_optimize_kprobes
	arch_unoptimize_kprobe

I tested those functions by putting kprobes on all
instructions in the functions with the bash script
I sent to LKML. See:

  https://lkml.org/lkml/2014/3/27/33

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Jonathan Lebon <jlebon@redhat.com>
Link: http://lkml.kernel.org/r/20140417081747.26341.36065.stgit@ltc230.yrl.intra.hitachi.co.jp
Signed-off-by: Ingo Molnar <mingo@kernel.org>