Strange crash

[Paul Goyette <paul%vps1.whooppee.com@localhost>]

This is on a amd64/7.99.21 built from sources that were updated on
2015-09-20 at 02:09:58 UTC.

I just encountered a strange crash.  I had entered the command

	sysctl kern | grep dump

and got the following traceback:

#0  0xffffffff801196a5 in cpu_reboot (howto=howto@entry=256,
    bootstr=bootstr@entry=0x0)
    at /build/netbsd-local/src/sys/arch/amd64/amd64/machdep.c:671
#1  0xffffffff80233f76 in db_sync_cmd (addr=<optimized out>,
    have_addr=<optimized out>, count=<optimized out>, modif=<optimized out>)
    at /build/netbsd-local/src/sys/ddb/db_command.c:1359
#2  0xffffffff80234737 in db_command (
    last_cmdp=last_cmdp@entry=0xffffffff806b00a0 <db_last_command>)
    at /build/netbsd-local/src/sys/ddb/db_command.c:908
#3  0xffffffff80234a7e in db_command_loop ()
    at /build/netbsd-local/src/sys/ddb/db_command.c:566
#4  0xffffffff8023810d in db_trap (type=type@entry=6, code=code@entry=0)
    at /build/netbsd-local/src/sys/ddb/db_trap.c:90
#5  0xffffffff80116130 in kdb_trap (type=type@entry=6, code=code@entry=0,
    regs=regs@entry=0xfffffe800002ccd0)
    at /build/netbsd-local/src/sys/arch/amd64/amd64/db_interface.c:227
#6  0xffffffff8011a82f in trap (frame=0xfffffe800002ccd0)
    at /build/netbsd-local/src/sys/arch/amd64/amd64/trap.c:287
#7  0xffffffff80100fde in alltraps ()
#8  0xffffffff808f31ab in ?? ()
#9  0xffffffff803101ba in sysctl_dispatch (name=name@entry=0xfffffe800002ce50,
    namelen=3, oldp=0x7f7fffffc870, oldlenp=oldlenp@entry=0xfffffe800002ce48,
    newp=0x0, newlen=0, oname=oname@entry=0xfffffe800002ce50,
    l=l@entry=0xfffffe81f2015aa0, rnode=0xfffffe81fe72b370, rnode@entry=0x0)
    at /build/netbsd-local/src/sys/kern/kern_sysctl.c:454
#10 0xffffffff803103fd in sys___sysctl (l=0xfffffe81f2015aa0,
    uap=0xfffffe800002cf00, retval=<optimized out>)
    at /build/netbsd-local/src/sys/kern/kern_sysctl.c:310
#11 0xffffffff8012f0ac in sy_call (rval=0xfffffe800002ceb8,
    uap=0xfffffe800002cf00, l=0xfffffe81f2015aa0,
    sy=0xffffffff806b43d0 <sysent+4848>)
    at /build/netbsd-local/src/sys/sys/syscallvar.h:65
#12 sy_invoke (code=202, rval=0xfffffe800002ceb8, uap=0xfffffe800002cf00,
    l=0xfffffe81f2015aa0, sy=0xffffffff806b43d0 <sysent+4848>)
    at /build/netbsd-local/src/sys/sys/syscallvar.h:94
#13 syscall (frame=0xfffffe800002cf00)
    at /build/netbsd-local/src/sys/arch/x86/x86/syscall.c:156
#14 0xffffffff80100691 in Xsyscall ()


I just ran the same sysctl command again, with no ill effects.  I got
expected output...

Any clues?



+------------------+--------------------------+-------------------------+
| Paul Goyette     | PGP Key fingerprint:     | E-mail addresses:       |
| (Retired)        | FA29 0E3B 35AF E8AE 6651 | paul at whooppee.com    |
| Kernel Developer | 0786 F758 55DE 53BA 7731 | pgoyette at netbsd.org  |
+------------------+--------------------------+-------------------------+