Subject: part 1 of lwp id in ktrace patches.
To: None <>
From: Darren Reed <>
List: tech-kern
Date: 03/11/2003 02:29:36
I have completed (locally), part 1 of getting ktrace to return LWP ids
into ktrace information: stuffing the lwpid into ktr_buf.  I don't plan
to stop here, but just getting this far has taken a lot of changes.
Why so many changes ?  There's a ktrace record type for namei() lookups
and wherever a path name needs to be used (Unix domain sockets, file
access, etc), there's a namei() call that eventually happens and that
now needs a 'struct lwp *' so it can hand it off to the ktrace hook.
Similarly, because of interface changes required to pass 'struct lwp *',
it will seem like it is being passed when 'struct proc *' could still
have been passed.  I assure you I haven't made more changes than were

In some places, I decided to cut out a bunch of similar work (that is
converting from passing 'struct proc *' to 'struct lwp *') by using
LIST_FIRST(&p->p_lwps) to get the lwp id.  That's cheating, I know,
but I didn't really want to change all the ioctl handlers, too, with
the first patch for this.

No changes to ktrace(1) have been made, no ktruss(1) (yet).
I added -L to kdump to show LWP id's as pid/lwpid.

If anyone wants to review the patches, you can find them at:

Oh, just to finish off, I notice that neither pc532 nor sh5 kernels
could currently compile as they're without lwp support.  I hope I've
not broken any MD stuff on non-i386 platforms as I've only tried to
compile the kernel on i386. I did, however, go looking for places where
the system call (& return value) hooks for ktrace were and fixed those
for as many platforms as I could.

Oh, next phase will be to get rid of all LIST_FIRST()'s to get a
'struct lwp *'.  Once I start that ball rolling, I may well not stop
until I've done as much elimination of passing 'struct proc *' as
is makes reasonable sense O:-)

Anyway, if there are no emails saying "stop, you bloody idiot, you're
going to bring the house down" in the next day or so, I'll assume the
patches are fine and commit.