kern/50703: Panic when the usb printer is power cycled.

[joseyluis%gmail.com@localhost]

>Number:         50703
>Category:       kern
>Synopsis:       Panic when the usb printer is power cycled.
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Jan 24 23:40:00 +0000 2016
>Originator:     Jose Luis Rodriguez Garcia
>Release:        7.0 amd64
>Organization:
>Environment:
NetBSD pc2.bigmail.com 7.0 NetBSD 7.0 (GENERIC.201509250726Z) amd64

>Description:
When I power cycle my usb printer, the NetBSD system panics and is rebooted.

It happened also with NetBSD 6.0.

Catpured output of the crash:

...
ulpt0: detached
ulpt0: at uhub3 port 5 (addr 2) disconnected
fatal privileged instruction fault in supervisor mode
trap type 0 code 0 rip fffffe813ecc4b03 cs 8 rflags 10246 cr2 7f7ff6741000 ilevel 2 rsp fffffe804000bf58
curlwp 0xfffffe813fb2c860 pid 0.5 lowest kstack 0xfffffe80400092c0
panic: trap
cpu0: Begin traceback...
vpanic() at netbsd:vpanic+0x13c
snprintf() at netbsd:snprintf
startlwp() at netbsd:startlwp
alltraps() at netbsd:alltraps+0x96
softint_dispatch() at netbsd:softint_dispatch+0x79
DDB lost frame for netbsd:Xsoftintr+0x4f, trying 0xfffffe804000bff0
Xsoftintr() at netbsd:Xsoftintr+0x4f
--- interrupt ---
0:
cpu0: End traceback...

dumping to dev 0,1 (offset=8410383, size=1046094):
dump
pc2#

(gdb) bt
#0  0xffffffff8063d735 in cpu_reboot ()
#1  0xffffffff80865182 in vpanic ()
#2  0xffffffff8086523d in panic ()
#3  0xffffffff808a84d6 in trap ()
#4  0xffffffff80100f46 in alltraps ()
#5  0xfffffe813ecc4b03 in ?? ()
#6  0xffffffff805e9458 in callout_softclock ()
#7  0xffffffff805df84a in softint_dispatch ()
#8  0xffffffff8011402f in Xsoftintr ()
     
From crash program:
crash> bt
_KERNEL_OPT_NARCNET() at 0
_KERNEL_OPT_ACPI_SCANPCI() at _KERNEL_OPT_ACPI_SCANPCI+0x1
vpanic() at vpanic+0x145
snprintf() at snprintf  
startlwp() at startlwp
calltrap() at calltrap+0x11
softint_dispatch() at softint_dispatch+0x79
DDB lost frame for Xsoftintr+0x4f, trying 0xfffffe804000bff0
Xsoftintr() at Xsoftintr+0x4f
--- interrupt ---
0:
pc2# vmstat -M netbsd.2.core -N netbsd.2 -s
     4096 bytes per page
       16 page colors
  1011774 pages managed
   656378 pages free
        0 pages paging
    37532 pages wired
   567186 zero pages
        1 reserve pagedaemon pages
       20 reserve kernel pages
   221764 anonymous pages
    39340 cached file pages
    26539 cached executable pages
     1024 minimum free pages
     1365 target free pages
   337258 maximum wired pages
        1 swap devices
  2097391 swap pages
        0 swap pages in use
        0 swap allocations
   522122 total faults taken
   522222 traps
   162879 device interrupts
   932702 CPU context switches
   171255 software interrupts
 35001151 system calls
        0 pagein requests
        0 pageout requests
        0 pages swapped in
        0 pages swapped out
     1478 forks total
      628 forks blocked parent
      628 forks shared address space with parent
   962126 pagealloc zero wanted and avail
   174069 pagealloc zero wanted and not avail
        0 aborts of idle page zeroing
  1667125 pagealloc desired color avail
    64543 pagealloc desired color not avail
  1151286 pagealloc local cpu avail
   580382 pagealloc local cpu not avail
       0 faults with no memory
        0 faults with no anons
        0 faults had to wait on pages
        0 faults found released page
     4869 faults relock (4835 ok)
   287638 anon page faults
        0 anon retry faults
    67031 amap copy faults
        0 neighbour anon page faults
   592873 neighbour object page faults
   264509 locked pager get faults
     4869 unlocked pager get faults
   273374 anon faults
    14248 anon copy on write faults
   224707 object faults
    39776 promote copy faults
  1013042 promote zero fill faults
        0 times daemon wokeup
        0 revolutions of the clock hand
        0 pages freed by daemon
        0 pages scanned by daemon
        0 anonymous pages scanned by daemon
        0 object pages scanned by daemon
        0 pages reactivated
        0 pages found busy by daemon
        0 total pending pageouts
        0 pages deactivated
   771968 total name lookups
   654541 good hits
    69894 negative hits
     1168 bad hits
       42 false hits
    26545 miss
    19778 too long
    30833 pass2 hits
    36441 2passes
          cache hits (84% pos + 9% neg) system 3% per-process
          deletions 0%, falsehits 0%, toolong 2%

pc2#


>How-To-Repeat:
Power off the printer and power on it.
>Fix: