Re: [RFC PATCH 0/4] utrace: new modular infrastructure for user debug/tracing

[Chuck Ebbert <76306.1226@compuserve.com>]

In-Reply-To: <20060613231000.38B76180072@magilla.sf.frob.com>

On Tue, 13 Jun 2006 16:10:00 -0700, Roland McGrath wrote:

> I have been working on for a while, and imagining for much longer,
> replacing ptrace from the ground up.  This is what I've come up with so
> far, and I'm looking for some reactions on the direction.

At least three different sets of people want to extend the syscall
tracing.  Jeff Dike posted a patch that lets you supply a bitmask of
syscalls to trace.  Renzo Davoli posted one that lets you decide, after
trapping entrance to a syscall, whether to skip the trap that would
normally be done on exit from the same call.  Charles P. Wright also
had a similar patch.  I think this needs to be done at the utrace
level -- a tracing engine couldn't add that on its own (could it?)

Renzo Davoli also posted a patch to allow "batching" of ptrace requests
and Systemptap really needs this, too.  AFAICT this can be done by writing
a custom engine.

And BTW patches 1 and 2 never made it to the list.  The ones on your
server (http://redhat.com/~roland/utrace/) don't apply cleanly due to
whitespace damage but that can be fixed by stripping trailing whitespace
from the kernel files patch(1) complains about.

-- 
Chuck