Loading carp module crash i386 (12-ALPHA2), seems VNET related

[Bjoern A. Zeeb]

On 21 Aug 2018, at 12:31, Olivier Cochard-Labbé wrote:

> On Tue, Aug 21, 2018 at 11:29 AM Marko Zec <zec at fer.hr> wrote:
>
>> On Mon, 20 Aug 2018 16:26:29 +0200
>> Olivier Cochard-Labbé <olivier at freebsd.org> wrote:
>>
>>> Just loading carp kernel module is enough to panic it:
>>>
>>> [root at router]~# uname -a
>>> FreeBSD router.bsdrp.net 12.0-ALPHA2 FreeBSD 12.0-ALPHA2  r338100M
>>> i386 [root at router]~# kldload carp
>>> Fatal trap 12: page fault while in kernel mode
>>
>> How many vnets were already instantiated at the time of kldloading
>> carp?  Does the panic ocur with no (non-default) vnets instantiated?
>>
>>
> Hi,
>
> None VNET were instantiated: Just start the latest 12-i386 image (
> https://download.freebsd.org/ftp/snapshots/VM-IMAGES/12.0-CURRENT/i386/Latest/)
> on a VM, and once logged as root enter 'kldload carp' to trigger a 
> panic.

 From the backtrace it seems like VNET_PCPUSTAT_SYSINIT() or the kernel 
linker, or possible pcpu things.  People have recently been touching 
almost all of this :(

Do you have a last-good revision?

/bz