>>I trust that this restriction does not apply if the ktrace was initiated
>>by root?  I've not looked at the netbsd ktrace paths, but I had to
>>fix the freebsd kernel to allow ktrace across exec of a setuid binary
>>when the trace was initiated by root - otherwise its nearly impossible
>>to debug certain classes of bug.

>	the following line takes care of "invoked by root" case.

>	if ((caller->pc_ucred->cr_uid == target->p_ruid &&
>	     target->p_ruid == target->p_svuid &&
>	     caller->p_rgid == target->p_rgid &&        /* XXX */
>	     target->p_rgid == target->p_svgid &&
>	     (targetp->p_traceflag & KTRFAC_ROOT) == 0 &&
>	     (targetp->p_flag & P_SUGID) == 0) ||
>	     caller->pc_ucred->cr_uid == 0)		<----
>		return (1);

Hmm, wouldn't it be better to test caller->pc_ucred->cr_uid == 0
first?

Thanks
--sjg