fatal trap 12, can't get core

[christopher floess]

Hi, I'm running 5.4 with a modified GENERIC kernel, and  I recently rebooted
my system to find out that it hangs on probing ad1 with a fatal trap 12.

Here's the entire error message

ad1 Timeout - Read_dma retrying (2 retries left) LBA 117231345
kernel trap 12 with interrupts disabled
Fatal trap 12: page fault while in kernel mode
fault virtual address = 0x6c
fault code           = supervisor read, page not present
instruction pointer   = 0x8:0xc063fb59

stack pointer         = 0x10:0xde0fac40
frame pointer        = 0x10:0xde0fac44
code segment        = base 0x0, limit 0xfffff, type ox1b
                          = DPL 0, pres 1, def32 1, gran 1
processor eflags       = resume, IOPL = 0
current process        = 6(thread taskq)
trap number             = 12
panic: page fault
cannot dump. no dump device

In my rc.conf I've got

dumpdev="/dev/ad0s1b"
dumpdir="/usr/crash"

For some reason it still says "no dump device".
Right now I'm able to boot my system into safe mode, but not single
user or normal. I
think I might not be able to get core dumps b/c my system doesn't get far
enough in the boot process,  so I'm trying to follow the directions here

http://www.freebsd.org/doc/en_US.ISO8859-1/books/faq/advanced.html#KERNEL-PANIC-TROUBLESHOOTING


but I'm not sure about this part of the instructions

% nm -n /kernel.that.caused.the.panic | grep f0xxxxxx

Do I need to replace "/kernel.that.caused.the.panic" with
/boot/kernel/kernel? If so, here' is the out put of

> nm -n /boot/kernel/kernel | grep c063fb59
c063fb3c t init_turnstile0
c063fb4c t turnstile_setowner
c063fb78 T turnstile_alloc
c063fbb0 T turnstile_free
c063fbc4 T turnstile_lookup

Can someone help me out here? Am I going about it all wrong? Let me know
what other info might be needed. Thanks ~ Chris

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