instrumenting vs. module loading

["Frank Ch. Eigler" <fche at redhat dot com>]

Hi -

On Fri, May 13, 2005 at 10:29:09AM -0400, William Cohen wrote:

> [...]  Hmmm, instrumenting each inline function site? For the kernel
> that is known.  What happens when a module is loaded that uses an
> instrumented inline function?

The way the translator probe points are going to be specified, the
target software is identified clearly (a particular module, or the
whole kernel).  If a probe point is for a module, and it's not loaded
at probe startup time, the initialization should abort.  Let's not
support a wildcard syntax for kernel-module selection until the
implications are better analyzed.

> Or unload for that matter?

I imagine the translator arranging to increment the use-count of
modules that it places instrumentation into, to prevent their
premature removal.  (How does raw kprobes deal with this case?)


- FChE

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