Re: [PATCH] kprobes for s390 architecture

From: Mike Grundy
Date: Mon Jun 26 2006 - 06:53:12 EST


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)?

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/