panic using firefox

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

With a amd64 kernel built from Mar 28 16:05 GMT source, I just saw:

(gdb) target kvm netbsd.2.core
0xffffffff80119405 in cpu_reboot (howto=howto@entry=260, 
    bootstr=bootstr@entry=0x0) at ../../../../arch/amd64/amd64/machdep.c:671
671                     dumpsys();
(gdb) bt
#0  0xffffffff80119405 in cpu_reboot (howto=howto@entry=260, 
    bootstr=bootstr@entry=0x0) at ../../../../arch/amd64/amd64/machdep.c:671
#1  0xffffffff8051e392 in vpanic (fmt=fmt@entry=0xffffffff8079d3fb "trap", 
    ap=ap@entry=0xfffffe8040cc29a0) at ../../../../kern/subr_prf.c:342
#2  0xffffffff8051e44d in panic (fmt=fmt@entry=0xffffffff8079d3fb "trap")
    at ../../../../kern/subr_prf.c:258
#3  0xffffffff8011ae12 in trap (frame=0xfffffe8040cc2ac0)
    at ../../../../arch/amd64/amd64/trap.c:298
#4  0xffffffff80100fc6 in alltraps ()
#5  0xffffffff8054547a in filt_sordetach (kn=0xfffffe804e698780)
    at ../../../../kern/uipc_socket.c:2250
#6  0xffffffff804db191 in knote_detach (kn=0xfffffe804e698780, 
    fdp=0xfffffe806f6ba400, dofop=<optimized out>)
    at ../../../../kern/kern_event.c:1572
#7  0xffffffff804dc729 in kqueue_scan (kevcnt=8, 
    keops=0xffffffff8076a620 <kevent_native_ops>, 
    keops=0xffffffff8076a620 <kevent_native_ops>, kevbuf=0xfffffe8040cc2d18, 
    retval=0xfffffe8040cc2eb8, tsp=0x0, ulistp=0x7f7fd05fff70, maxevents=1, 
    fp=<optimized out>) at ../../../../kern/kern_event.c:1265
#8  kevent1 (retval=0xfffffe8040cc2eb8, fd=40, changelist=<optimized out>, 
    nchanges=<optimized out>, eventlist=0x7f7fd05fff70, nevents=1, 
    timeout=0x0, keops=keops@entry=0xffffffff8076a620 <kevent_native_ops>)
    at ../../../../kern/kern_event.c:896
#9  0xffffffff804dc8f9 in sys___kevent50 (l=<optimized out>, 
    uap=<optimized out>, retval=<optimized out>)
    at ../../../../kern/kern_event.c:817
#10 0xffffffff8013572e in sy_call (rval=0xfffffe8040cc2eb8, 
    uap=0xfffffe8040cc2f00, l=0xfffffe8132dc7180, 
    sy=0xffffffff80a40f08 <sysent+10440>) at ../../../../sys/syscallvar.h:65
#11 sy_invoke (code=435, rval=0xfffffe8040cc2eb8, uap=0xfffffe8040cc2f00, 
    l=0xfffffe8132dc7180, sy=0xffffffff80a40f08 <sysent+10440>)
    at ../../../../sys/syscallvar.h:94
#12 syscall (frame=0xfffffe8040cc2f00)
    at ../../../../arch/x86/x86/syscall.c:156
#13 0xffffffff80100661 in Xsyscall ()
(gdb) frame 5
#5  0xffffffff8054547a in filt_sordetach (kn=0xfffffe804e698780)
    at ../../../../kern/uipc_socket.c:2250
2250            SLIST_REMOVE(&so->so_rcv.sb_sel.sel_klist, kn, knote, kn_selnext);
(gdb) list
2245    {
2246            struct socket   *so;
2247    
2248            so = ((file_t *)kn->kn_obj)->f_socket;
2249            solock(so);
2250            SLIST_REMOVE(&so->so_rcv.sb_sel.sel_klist, kn, knote, kn_selnext);
2251            if (SLIST_EMPTY(&so->so_rcv.sb_sel.sel_klist))
2252                    so->so_rcv.sb_flags &= ~SB_KNOTE;
2253            sounlock(so);
2254    }
(gdb) print kn->kn_selnext
$1 = {sle_next = 0x0}
(gdb) print *kn
$2 = {kn_link = {sle_next = 0x0}, kn_selnext = {sle_next = 0x0}, kn_tqe = {
    tqe_next = 0xfffffe8041910000, tqe_prev = 0xfffffe8140926600}, 
  kn_kq = 0xfffffe8140926600, kn_kevent = {ident = 42, filter = 0, flags = 21, 
    fflags = 0, data = 2, udata = 0}, kn_status = 1, kn_sfflags = 1, 
  kn_sdata = 1, kn_obj = 0xfffffe8135828740, 
  kn_fop = 0xffffffff8076ee00 <soread_filtops>, 
  kn_kfilter = 0xffffffff80a41700 <sys_kfilters>, kn_hook = 0x0}

crash tells me that the running process were:

PID    LID S CPU     FLAGS       STRUCT LWP *               NAME WAIT
19492>  36 7   1   8020000   fffffe81310c6120      mozStorage #1
19492>  18 7   3         0   fffffe8132dc7180            firefox
0    >   2 7   0       201   fffffe814e138840             idle/0

The line numbers for uipc_socket.c don't match as I have a load of printfs
in there from trying to narrow down:

1) netbsd-7/i386 Issue with pflogd consuming 100% of CPU
   https://mail-index.netbsd.org/netbsd-users/2015/09/24/msg016939.html
 
2) netbsd-7/i386 pipe read returning EAGAIN
   https://mail-index.netbsd.org/current-users/2016/02/07/msg028841.html
 
3) (netbsd-current/amd64) Last version of of citrix Client core dumps
   https://mail-index.netbsd.org/netbsd-users/2016/02/03/msg017788.html
   maybe even
   https://mail-index.netbsd.org/current-users/2015/06/02/msg027506.html
   ?
 
4) netbsd-7 high cpu load with tcpdump  (and bind)
   http://mail-index.netbsd.org/current-users/2016/02/26/msg028923.html
 
5) netbsd-7/current/amd64 dansguardian
   http://mail-index.netbsd.org/current-users/2016/03/02/msg028961.html


Any hints / tips / guesses gratefully received!


Cheers,

Patrick