Insta-panic for amd64 on reboot after upgrade from r320307 -> r320324

[Konstantin Belousov]

On Sun, Jun 25, 2017 at 05:07:31AM -0700, David Wolfskill wrote:
> Fatal trap 12: page fault while in kernel mode
> cpuid = 0; apic id = 00
> fault virtual address   = 0x10000000020
This is clearly an impossible address.

Did you built the kernel with NO_CLEAN ?  If yes, try the full build,
perhaps even after removing all previous kernel objects.

The layout of the struct vm_map_entry was changed, the faulted address
is somewhat consistent with ABI mismatch.

> fault code              = supervisor read data, page not present
> instruction pointer     = 0x20:0xffffffff80d585a4
> stack pointer           = 0x28:0xffffffff82290a30
> frame pointer           = 0x28:0xffffffff82290a60
> code segment            = base 0x0, limit 0xfffff, type 0x1b
>                         = DPL 0, pres 1, long 1, def32 0, gran 1
> processor eflags        = resume, IOPL = 0
> current process         = 0 ()
> [ thread pid 0 tid 0 ]
> Stopped at      vm_map_lookup_entry+0x24:       cmpq    %r15,0x20(%rbx)
> db> bt
> Tracing pid 0 tid 0 td 0xffffffff81e9e860
> vm_map_lookup_entry() at vm_map_lookup_entry+0x24/frame 0xffffffff82290a60
> vm_map_insert() at vm_map_insert+0x10b/frame 0xffffffff82290b00
> kmem_init() at kmem_init+0x72/frame 0xffffffff82290b30
> vm_mem_init() at vm_mem_init+0x46/frame 0xffffffff82290b50
> mi_startup() at mi_startup+0x9c/frame 0xffffffff82290b70
> btext() at btext+0x2c
> db> 
> 
> 
> (The laptop seems to have repeated the:
> 
> loading required module 'kernel'
> module 'kernel' exists but with wrong version
> 
> sequence a few times, based on the video I got of it.)
> 
> 
> The "saving grace" is that the panic happens before the file systems
> are mounted.... :-}
> 
> Unloading the (r320324) kernel and loading the r320307 kernel
> succeeds (at least enough to mount file systems).
> 
> Peace,
> david
> -- 
> David H. Wolfskill				david at catwhisker.org
> Trump (et al.): Hiding information doesn't prove its falsity.
> 
> See http://www.catwhisker.org/~david/publickey.gpg for my public key.