ARM: optprobes: execute instruction during restoring if possible.

This patch removes software emulation or simulation for most of probed
instructions. If the instruction doesn't use PC relative addressing,
it will be translated into following instructions in the restore code
in code template:

 ldmia {r0 - r14}  // restore all instruction except PC
 <instruction>     // direct execute the probed instruction
 b next_insn       // branch to next instruction.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Jon Medhurst <tixy@linaro.org>

arch/arm/include/asm/probes.h

@@ -42,6 +42,7 @@ struct arch_probes_insn {
 	probes_insn_fn_t		*insn_fn;
 	int				stack_space;
 	unsigned long			register_usage_flags;
+	bool				kprobe_direct_exec;
 };
 
 #endif /* __ASSEMBLY__ */