Re: Dtrace port status

On Thu, Sep 20, 2007 at 11:42:40PM -0700, Darren Reed wrote:
> John Birrell wrote:
> >DTrace consists mainly of kernel modules, however in order for DTrace
> >to inspect the kernel internals it has to have some code inside
> >existing BSD licensed files.
> >  
> 
> This should not be a problem.
> Code added to BSD licensed files should be BSD licensed.

Only if it is clean-room coded.

In the case of DTrace, the only reference is the OpenSolaris
CDDL code. It's hard to claim something as BSD licensed when
all you are really doing is adding stuff like:

(part of struct thread)
        uintptr_t       td_dtrace_pc;   /* DTrace saved pc from fasttrap. */
        uintptr_t       td_dtrace_npc;  /* DTrace next pc from fasttrap. */
        uintptr_t       td_dtrace_scrpc;
                                        /* DTrace per-thread scratch location. */
        uintptr_t       td_dtrace_astpc;
                                        /* DTrace return sequence location. */
        u_int64_t       td_hrtime;      /* Last time on cpu. */

Sun still claims CDDL on snippets as simple as this (because the
reference was CDDL'd).

I had hoped they'd just say "that's OK to be BSD licensed".

But, no, their attitude is that FreeBSD can just suck up Sun's
patent clauses in the CDDL.

I could just change the field names and re-arrange the words
in the comments to make it look like I thought of it. But if that's
OK by Sun's lawyers then they are just stupid. If they were to ask 
me in a court of law (in a proceeding like the ones SCO has
been in), what would my answer be? Answer: I read the OpenSolaris
code which is CDDL'd and I worked out what I had to add to FreeBSD
and I added it. With vi. :-)


--
John Birrell