Re: kernel panic caused by virtualbox(?)

On Thursday, August 04, 2016 05:10:29 PM Don Lewis wrote:
> Reposted to -current to get some more eyes on this ...
> 
> I just got a kernel panic when I started up a CentOS 7 VM in virtualbox.
> The host is:
> 	FreeBSD 12.0-CURRENT #17 r302500 GENERIC amd64
> The virtualbox version is:
> 	virtualbox-ose-5.0.26
> 	virtualbox-ose-kmod-5.0.26_1
> 
> The panic message is:
> 
> panic: Unregistered use of FPU in kernel
> cpuid = 1
> KDB: stack backtrace:
> db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe085a55d030
> vpanic() at vpanic+0x182/frame 0xfffffe085a55d0b0
> kassert_panic() at kassert_panic+0x126/frame 0xfffffe085a55d120
> trap() at trap+0x7ae/frame 0xfffffe085a55d330
> calltrap() at calltrap+0x8/frame 0xfffffe085a55d330
> --- trap 0x16, rip = 0xffffffff827dd3a9, rsp = 0xfffffe085a55d408, rbp = 0xfffffe085a55d430 ---
> g_pLogger() at 0xffffffff827dd3a9/frame 0xfffffe085a55d430
> g_pLogger() at 0xffffffff8274e5c7/frame 0x3
> KDB: enter: panic
> 
> Since g_pLogger is a symbol in vboxdrv.ko, it looks like virtualbox is
> the trigger.
> 
> There are no symbols for the virtualbox kmods, possibly because I
> installed them as an upgrade using packages (built with the same source
> tree version) instead of by using PORTS_MODULES in make.conf, so ports
> kgdb didn't have anything useful to say about what happened before the
> trap.
> 
> This panic is very repeatable.  I just got another one when starting the
> same VM., but this time the two calls before the trap were
> null_bug_bypass().  Hmn, that symbol is in nullfs ...
> 
> I don't see this with a Windows 7 VM.
> 
> All of the virtualbox kmod files are compiled with -mno-mmx -mno-sse
> -msoft-float -mno-aes -mno-avx

I suspect head packages are quite likely built against the a "wrong" KBI
and are too fragile to use for kmods vs compiling from ports. :-/  I would
try a built-from-ports kmod to see if the panics go away.

-- 
John Baldwin