docs/150255: dtrace description should mention makeoptions DEBUG=-g

[Alexander Pyhalov]

>Number:         150255
>Category:       docs
>Synopsis:       dtrace description should mention makeoptions DEBUG=-g
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-doc
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          change-request
>Submitter-Id:   current-users
>Arrival-Date:   Fri Sep 03 18:30:02 UTC 2010
>Closed-Date:
>Last-Modified:
>Originator:     Alexander Pyhalov
>Release:        9.0-current
>Organization:
SFEDU
>Environment:
FreeBSD freebsd.cc.rsu.ru 9.0-CURRENT FreeBSD 9.0-CURRENT #3: Fri Sep  3 22:40:30 MSD 2010     root at freebsd.cc.rsu.ru:/usr/obj/usr/src/sys/MyKern  i386

>Description:
Documentation in handbook doesn't clearly state that "makeoptions DEBUG=-g" option should be present in kernel config for DTrace to work. 
In the absence of this options all (or most) dtrace scripts complain on unknown uid_t symbol in psinfo.d, because this symbol is not found in kernel debugging info. This can be seen with ctfdump - kernel contains CTF data but no info about uid_t (and some other symbols).  
>How-To-Repeat:
Create kernel config with options KDTRACE_HOOKS and DDB_CTF but without "makeoptions DEBUG=-g", then execute "make kernel WITH_CTF=1 KERNCONF=YourConfig".
>Fix:
Document this behavior.

>Release-Note:
>Audit-Trail:
>Unformatted: