Re: [PATCH] kprobes for s390 architecture

Mike Grundy
2006-06-26T10:49:32Z

On Mon, Jun 26, 2006 at 10:09:10AM +0200, Heiko Carstens wrote:
> > After reading your notes it's probably overkill doing the cs on each cpu, since
> > the interrupt will discard the prefetched instructions.
>
> Indeed. Another thing that should not be forgotten: it could be that the
> whole kernel text segment resides in a shared read only segment. So it can
> be shared by multiple z/VM guests.
> In that case the cs instruction will fail. Looks like you need to write the
> part that replaces the instruction in assembly and supply a fixup section
> which in turn makes sure that -EFAULT is returned.

If it fails, won't it will generate a program interrupt, 5 (access exception)?