>>>>> "Matt" == Matthew Dillon <[EMAIL PROTECTED]> writes:

 Matt>     The problem is a NULL pointer dereference somewhere... please 
 Matt>     nm your kernel binary and extract out all elements with c0163
 Matt>     in them.  e.g.  nm /kernel | fgrep c0163 | sort.

OK, here's a -current system from today (11/29) morning [4am EST] with
kernel compiled with DDB and -g.


FreeBSD jabberwock 4.0-CURRENT FreeBSD 4.0-CURRENT #0: Mon Nov 29
17:11:27 EST 1999
vshah@jabberwock:/home/ncvs/FreeBSD/current-src/src/sys/compile/J39
i386


Tried doing a simple symlink over a NFS mounted filesystem:


fatal trap 12: page fault while in kernel mode
fault virtual address = 0x4
fault code            = supervisor read, page not present
instruction pointer   = 0x8:0xc0167979
stack pointer         = 0x10:0xc9d74e40
frame pointer         = 0x10:0xc9d74e58
code segment          = base 0x0; limit 0xfffff, type 0x1b
                      = DPL0, pres 1, def32 1, gran 1
processor flags       = interrupt enabled, resume, 10PL = 0
current process       = 315 (ln)
interrupt mask        = none
kernel: type 12 trap code = 0


db> trace
  
  vput(0) at vput+0x11
  symlink (c9d4e200, c9d74f80, bfbfdab5, bfbfda9e, bfbfd99c) at symlink+0x1e3
  syscall(2f, 2f, 2f, bfbfd99c, bfbfda9e) at syscall+0x176
  Xint0x80_syscall() at Xint0x80_syscall+0x26

db> show reg
   
  ...
  eip 0xc0167979 vput+0x11
  efl 0x10286    nfs_write+0xe2 


Hope this helps. If there is anything else I can do to debug this, let
me know.

Viren
-- 
Viren Shah                    | "You can't trust code that you did not totally
Research Associate, RST Inc.  | create yourself. (Especially code from 
[EMAIL PROTECTED]             | companies that employ people like me.)"
http://www.rstcorp.com/~vshah | - Ken Thompson "Reflections on Trusting Trust"


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