Re: [RFC PATCH v2 2/3] tracefs: add instances support for uprobe events

From: Steven Rostedt
Date: Wed Aug 03 2016 - 21:05:07 EST


On Thu, 4 Aug 2016 01:46:04 +0530
Aravinda Prasad <aravinda@xxxxxxxxxxxxxxxxxx> wrote:

> On Thursday 04 August 2016 01:40 AM, Steven Rostedt wrote:
> > On Thu, 4 Aug 2016 01:00:51 +0530
> > Aravinda Prasad <aravinda@xxxxxxxxxxxxxxxxxx> wrote:
> >
> >>
> >>> Can a container have its own function tracing?
> >>
> >> Sorry, I didn't understand that. Do you mean to have a separate
> >> per-container trace files?
> >
> > Actually, it's more my ignorance of containers, as I haven't had the
> > need to play with them. Although, I think it may be time to do so.
> >
> > When a container enters kernel mode, I'm assuming that it's part of the
> > host at that moment, and the host needs to take care of separating
> > everything? That is, there's not a "second kernel" like VMs have, right?
>
> Yes. The host needs to take care of separating everything. There is no
> "second kernel".

That's what I figured. Thus, my worry is that something like the
function tracer can cause information leak to a container. How would
you separate functions for the container from functions for the host?

-- Steve