i386/121148: Repeatable sysctl crash (Fatal Trap 12) with ACPI enabled

[Jim Pingle]

 > my suspicion is that it actually just moves the layout of memory
 > around enough to avoid seeing the problem.

I have no doubt that you are correct in that. The code changes in that 
file seemed very unrelated to anything near the crash, but I thought it 
was worth mentioning anyhow.

>From single user mode, can you determine which of the following panic:
> sysctl dev.pcib.3

Crashes at the end. I had a debug kernel built already, I was also able 
to add the printfs with no problem. Here is the last bit of output:

dev.pcib.3.%parent: acpi0
lsp=0xc0bcf314 oidp=0xc0b678e0 iodpp=0xe8c76b4c
lsp=0xc525c7d0 oidp=0xc5262040 iodpp=0xe8c76b4c
lsp=0xc52d9700 oidp=0xc52ed4c0 iodpp=0xe8c76b4c
lsp=0xc52ee140 oidp=0xc52ed140 iodpp=0xe8c76b4c
[crashes here]

kdb says the crash happened at:
sysctl_sysctl_next_ls+0x32   movl 0x8(%esi),%eax
 > print %esi
c074b9ba
 > print %eax
c074b9ba

> sysctl dev.pcib.4

Yields: unknown oid 'dev.pcib.4'

 > I wonder if you could test setting debug.acpi.disabled="ec"
 > from the loader

This made it get farther along in the boot sequence, but it then crashed 
in devd, also a fatal trap 12, with a virtual fault address of 0x108. I 
can get the whole copy of the crash output if you'd like.

> If you can still recreate the panic with these printf's and the debugger
> compiled in, hopefully we can get more information out of your system as to
> exactly what is happening.

It still crashes in the same place, perfectly repeatable, and as far as 
I can tell the addresses are the same each time. Let me know how you'd 
like me to proceed.

Thanks for the quick response, and all the help/ideas.

Jim