Great, in not more than 30 minutes from the mail I've got
        four answers ...
        Thanks to:
        Henrik Sloth	[hs_at_dksin.dk]
        Robert Romani	[romani_at_mail.dec.com]
        Olle Eriksson	[olle_at_cb.uu.se]
        Rainer Landes	[rlandes_at_fphws01.physik.uni-karlsruhe.de]
        First: the original question
        Whenever I use dbx or ladebug to debug code on various machine
        (AS1000 4/233, AS255, AXPpci, ...) the machine panics or hangs.
        
        The bug:
        There is a known (not to me) problem in the kernel debugging
        routine that manages stepping code.
        Solution:
        1) Compile a new kernel with no KDEBUG option
        2) Modify the current kernel:
           2.a) For this session only (this means that next time you
                reboot the bug will turn on again
                dbx -k /vmunix
                p db_enable
                if db_enable is 1 you have the bug
                assign db_enable = 0
           2.b) Permanent modification
                 As in step 2.a for current session +
                dbx /vmunix (we need the disk image)
                
                patch db_enable = 0
                This patches the disk image of the executable, so no
                kernel rebuild is required.
        Thanks and nice work
-- 
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   Marco Campani
   DIFI - Dipartimento di Fisica - Universita' degli Studi di Genova
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Received on Fri Feb 28 1997 - 10:17:37 NZDT