[v5][PATCH 2/3] powerpc/kprobe: complete kprobe and migrate exception frame

[David Laight]

>  /* N.B. the only way to get here is from the beq following ret_from_except. */
>  resume_kernel:
> -	/* check current_thread_info->preempt_count */
> +	/* check current_thread_info, _TIF_EMULATE_STACK_STORE */
>  	CURRENT_THREAD_INFO(r9, r1)
> +	lwz	r8,TI_FLAGS(r9)
> +	andis.	r8,r8,_TIF_EMULATE_STACK_STORE at h
> +	beq+	1f
...
> +1:

Does this add a statically mispredicted branch to every
return to userspace ?
Or is there an earlier check for 'unlikely' conditions.

	David