dtrace discuss - Aug 2008 - Obtaining probe list requires root?

Hi,

I''m working on the Tcl bindings to libdtrace. I''ve just
stumbled upon
something I do not quite understand: In order to use dtrace_probe_iter I need 
the handle to be opened with DTRACE_O_NODEV unset. Otherwise it fails 
with /No probe matches description/, no matter what I try to list (even when 
that''s trivial like dtrace:::BEGIN or a wildcard). Now, even if
there''s a
good technical reason for this (I guess obtaining the list actually involves 
accessing the device) this should read something like /Don''t have
privileges
to iterate probes/ or anything that''s not confusing...

Kind regards,
Remigiusz ''lRem'' Modrzejewski

Hi,

Adding the following privileges to your user should help you :

dtrace_proc
dtrace_user

Seb


--
This message posted from opensolaris.org

On Wednesday 06 of August 2008 07:53:59 S?bastien Bouchex Bellomi?
wrote:
> Hi,
>
> Adding the following privileges to your user should help you :
>
> dtrace_proc
> dtrace_user
Nah. I just thought, that this should be accessible to unprivileged user. Or 
if not, then the error message should state that, not that there are no 
probes matching :::entry...

Kind regards,
Remigiusz ''lRem'' Modrzejewski

> Nah. I just thought, that this should be accessible to unprivileged user.
Or
> if not, then the error message should state that, not that there are no 
> probes matching :::entry...
The reason that no probes are available to unprivileged users is that even
trivial uses of DTrace can consume extensive system resources such as memory.
Initially, we wanted to take the conservative approach of disabling DTrace
for all but the root user by default. Now that we''ve built up some
experience
with DTrace, it may be time to consider adding dtrace_proc to the default
privilege set, and making sure we have the necessary resource controls.

Adam

-- 
Adam Leventhal, Fishworks                     http://blogs.sun.com/ahl