random panic

[Patrick Welche <prlw1%cam.ac.uk@localhost>]

My -current/amd64 desktop machine just panicked, and I wasn't even
intentionally running anything on it (just had an idle ssh connection
in). All I see in dmesg is:

ums0: detached
uhidev2: detached
uhidev2: at uhub1 port 2 (addr 63) disconnected
uhidev2 at uhub1 port 2 configuration 1 interface 0
uhidev2: Logitech (0xdone
unmounted procfs on /proc type procfs
unmounted ptyfs on /dev/pts type ptyfs
unmounted /dev/wd1g on /home type ffs
unmounte
panic: prevented execution of 0x100 (SMEP)
cpu0: Begin traceback...
beep0: detached
midi0: detached
wd0: detached
com0: detachetf
trap() at netbsd:trap+0xb7a
--- trap (number 6) ---
?() at 100
ahci_ata_bio() at netbsd:ahci_ata_bio+0x79
wdstart1() at netbsopyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
    2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 201+0x68
spec_strategy() at netbsd:spec_strategy+0x73
VOP_STRATEGY() at netbsd:VOP_STRATEGY+0x54
wapbl_buffered_write_async() at neents of the University of California.  All rights reserved.

NetBSD 8.99.2 (QUARTZ) #20: Wed Aug 30 16:15:56 BST 2017
        prlw1@quartz:/usr/src/sys/arch/amd64/compile/QUARTZ
total memory = 16304 MB
avail memory = 15811 MB
cpu_rng: RDSEED
timecounter: Timecounx1c
sched_sync() at netbsd:sched_sync+0x91
cpu0: End traceback...

dumping to dev 0,17 (offset=162711, size=4174075):
dump Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,


Odd, as the "unmounted" suggests attempting to shutdown.

$ last | more
reboot    ~                         Wed Sep 13 12:26
prlw1     pts/0    10.111.65.25     Wed Sep 13 11:36 - crash  (00:50)

suggests otherwise?

And "dumping to" looks promising, yet:

# savecore -n
savecore: no core dump

The source would also have been of 30 Aug.

Cheers,

Patrick