Hi All,

12.0-STABLE FreeBSD 12.0-STABLE #2 r343904M

After 19 days online I've got strange crash:

# kgdb /boot/kernel/kernel /var/crash/vmcore.last 
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 Reading symbols from /boot/kernel/kernel...Reading symbols from /usr/lib/debug//boot/kernel/kernel.debug...done. 
 done. 
  
 Unread portion of the kernel message buffer: 
  
  
 Fatal trap 12: page fault while in kernel mode 
 cpuid = 1; apic id = 01 
 fault virtual address   = 0xfffff80282bf3401 
 fault code              = supervisor write data, page not present 
 instruction pointer     = 0x20:0xffffffff826f26e0 
 stack pointer           = 0x28:0xfffffe006475d320 
 frame pointer           = 0x28:0xfffffe006475d320 
 code segment            = base rx0, limit 0xfffff, type 0x1b 
                         = DPL 0, pres 1, long 1, def32 0, gran 1 
 processor eflags        = interrupt enabled, resume, IOPL = 0 
 current process         = 37083 (syslogd) 
 trap number             = 12 
 panic: page fault 
 cpuid = 1 
 time = 1551808983 
 KDB: stack backtrace: 
 #0 0xffffffff80c531c7 at kdb_backtrace+0x67 
 #1 0xffffffff80c07143 at vpanic+0x1a3 
 #2 0xffffffff80c06f93 at panic+0x43 
 #3 0xffffffff8118d9ff at trap_fatal+0x35f 
 #4 0xffffffff8118da59 at trap_pfault+0x49 
 #5 0xffffffff8118d07e at trap+0x29e 
 #6 0xffffffff81168af5 at calltrap+0x8 
 #7 0xffffffff827bb83a at zil_itx_assign+0x3da 
 #8 0xffffffff827e4b99 at zfs_log_write+0x2d9 
 #9 0xffffffff827f2338 at zfs_freebsd_write+0xbc8 
 #10 0xffffffff81315acf at VOP_WRITE_APV+0xff 
 #11 0xffffffff80ce98fe at vn_write+0x1ee 
 #12 0xffffffff80ce9443 at vn_io_fault_doio+0x43 
 #13 0xffffffff80ce72da at vn_io_fault1+0x16a 
 #14 0xffffffff80ce54b5 at vn_io_fault+0x195 
 #15 0xffffffff80c70232 at dofilewrite+0xb2 
 #16 0xffffffff80c70130 at sys_writev+0x70 
 #17 0xffffffff8118e592 at amd64_syscall+0x352 
 Uptime: 19d17h37m19s 
 Dumping 1611 out of 8077 MB:..1%..11%..21%..31%..41%..51%..61%..71%..81%..91% 
  
 __curthread () at ./machine/pcpu.h:230 
 230             __asm("movq %%gs:%P1,%0" : "=r" (td) : "n" (OFFSETOF_CURTHREAD)); 
 (kgdb) bt 
 #0  __curthread () at ./machine/pcpu.h:230 
 #1  doadump (textdump=<optimized out>) at /usr/src/sys/kern/kern_shutdown.c:366 
 #2  0xffffffff80c06d2b in kern_reboot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:446 
 #3  0xffffffff80c071a3 in vpanic (fmt=<optimized out>, ap=0xfffffe006475d070) at /usr/src/sys/kern/kern_shutdown.c:872 
 #4  0xffffffff80c06f93 in panic (fmt=<unavailable>) at /usr/src/sys/kern/kern_shutdown.c:799 
 #5  0xffffffff8118d9ff in trap_fatal (frame=0xfffffe006475d260, eva=18446735288400032769) at /usr/src/sys/amd64/amd64/trap.c:929 
 #6  0xffffffff8118da59 in trap_pfault (frame=0xfffffe006475d260, usermode=0) at /usr/src/sys/amd64/amd64/trap.c:765 
 #7  0xffffffff8118d07e in trap (frame=0xfffffe006475d260) at /usr/src/sys/amd64/amd64/trap.c:441 
 #8  <signal handler called> 
 #9  0xffffffff826f26e0 in list_insert_tail (list=0xfffff80048db44c8, object=0xfffff80182bf3400) at /usr/src/sys/cddl/contrib/opensolaris/uts/common/os/list.c:121 
 #10 0xffffffff827bb83a in zil_itx_assign (zilog=0xfffff8001f588c00, itx=0xfffff80182bf3400, tx=0xfffff8004d651e00) 
     at /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zil.c:1737 
 #11 0xffffffff827e4b99 in zfs_log_write (zilog=0xfffff8001f588c00, tx=0xfffff8004d651e00, txtype=365662, zp=0xfffff80224bbd440, off=365662, resid=91, ioflag=8) 
     at /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_log.c:525 
 #12 0xffffffff827f2338 in zfs_write (vp=<optimized out>, uio=<optimized out>, ioflag=<optimized out>, cr=<optimized out>, ct=<optimized out>) 
     at /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c:1203 
 #13 zfs_freebsd_write (ap=<optimized out>) at /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c:4898 
 #14 0xffffffff81315acf in VOP_WRITE_APV (vop=<optimized out>, a=0xfffffe006475d788) at vnode_if.c:1000 
 #15 0xffffffff80ce98fe in VOP_WRITE (vp=<optimized out>, uio=<optimized out>, cred=<optimized out>, ioflag=<optimized out>) at ./vnode_if.h:413 
 #16 vn_write (fp=<optimized out>, uio=<optimized out>, active_cred=0x5945e, flags=<optimized out>, td=<optimized out>) at /usr/src/sys/kern/vfs_vnops.c:881 
 #17 0xffffffff80ce9443 in vn_io_fault_doio (args=0xfffffe006475d9b0, uio=0xfffff8002ab5bd00, td=0xfffff8007c685000) at /usr/src/sys/kern/vfs_vnops.c:946 
 #18 0xffffffff80ce72da in vn_io_fault1 (vp=<optimized out>, uio=<optimized out>, args=<optimized out>, td=<optimized out>) at /usr/src/sys/kern/vfs_vnops.c:1064 
 #19 0xffffffff80ce54b5 in vn_io_fault (fp=<optimized out>, uio=0xfffff8004ebef188, active_cred=0xfffff80021a684b0, flags=<optimized out>, td=<optimized out>) 
     at /usr/src/sys/kern/vfs_vnops.c:1168 
 #20 0xffffffff80c70232 in fo_write (fp=<optimized out>, uio=<optimized out>, active_cred=0xfffff80282bf3401, flags=<optimized out>, td=<optimized out>) 
     at /usr/src/sys/sys/file.h:314 
 #21 dofilewrite (td=0x0, fd=34, fp=0xfffff801a82000f0, auio=0xfffff8002ab5bd00, offset=<optimized out>, flags=<optimized out>) at /usr/src/sys/kern/sys_generic.c:567 
 #22 0xffffffff80c70130 in kern_writev (td=0xfffff8007c685000, fd=34, auio=0xfffff8002ab5bd00) at /usr/src/sys/kern/sys_generic.c:491 
 #23 sys_writev (td=0xfffff8007c685000, uap=0xfffff8007c6853c0) at /usr/src/sys/kern/sys_generic.c:477 
 #24 0xffffffff8118e592 in syscallenter (td=<optimized out>) at /usr/src/sys/amd64/amd64/../../kern/subr_syscall.c:135 
 #25 amd64_syscall (td=0xfffff8007c685000, traced=0) at /usr/src/sys/amd64/amd64/trap.c:1154 
 #26 <signal handler called> 
 #27 0x00000008004122ca in ?? () 
 Backtrace stopped: Cannot access memory at address 0x7fffffffc378 
 (kgdb) frame 9 
 #9  0xffffffff826f26e0 in list_insert_tail (list=0xfffff80048db44c8, object=0xfffff80182bf3400) at /usr/src/sys/cddl/contrib/opensolaris/uts/common/os/list.c:121 
 121             list_insert_before_node(list, lold, object); 
 (kgdb) frame 10 
 #10 0xffffffff827bb83a in zil_itx_assign (zilog=0xfffff8001f588c00, itx=0xfffff80182bf3400, tx=0xfffff8004d651e00) 
     at /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zil.c:1737 
 1737                    list_insert_tail(&ian->ia_list, itx); 
 (kgdb) frame 11 
 #11 0xffffffff827e4b99 in zfs_log_write (zilog=0xfffff8001f588c00, tx=0xfffff8004d651e00, txtype=365662, zp=0xfffff80224bbd440, off=365662, resid=91, ioflag=8) 
     at /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_log.c:525 
 525                     zil_itx_assign(zilog, itx, tx); 
 (kgdb) frame 12 
 #12 0xffffffff827f2338 in zfs_write (vp=<optimized out>, uio=<optimized out>, ioflag=<optimized out>, cr=<optimized out>, ct=<optimized out>) 
     at /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c:1203 
 1203                    zfs_log_write(zilog, tx, TX_WRITE, zp, woff, tx_bytes, ioflag); 
 (kgdb) frame 13 
 #13 zfs_freebsd_write (ap=<optimized out>) at /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c:4898 
 4898            return (zfs_write(ap->a_vp, ap->a_uio, ioflags(ap->a_ioflag), 
 (kgdb) frame 14 
 #14 0xffffffff81315acf in VOP_WRITE_APV (vop=<optimized out>, a=0xfffffe006475d788) at vnode_if.c:1000 
 1000                    rc = vop->vop_write(a); 
 (kgdb) frame 15 
 #15 0xffffffff80ce98fe in VOP_WRITE (vp=<optimized out>, uio=<optimized out>, cred=<optimized out>, ioflag=<optimized out>) at ./vnode_if.h:413 
 413             return (VOP_WRITE_APV(vp->v_op, &a)); 
 (kgdb) frame 16 
 #16 vn_write (fp=<optimized out>, uio=<optimized out>, active_cred=0x5945e, flags=<optimized out>, td=<optimized out>) at /usr/src/sys/kern/vfs_vnops.c:881 
 881                     error = VOP_WRITE(vp, uio, ioflag, fp->f_cred); 
 (kgdb) frame 17 
 #17 0xffffffff80ce9443 in vn_io_fault_doio (args=0xfffffe006475d9b0, uio=0xfffff8002ab5bd00, td=0xfffff8007c685000) at /usr/src/sys/kern/vfs_vnops.c:946 
 946                     error = (args->args.fop_args.doio)(args->args.fop_args.fp, 
 (kgdb) frame 18 
 #18 0xffffffff80ce72da in vn_io_fault1 (vp=<optimized out>, uio=<optimized out>, args=<optimized out>, td=<optimized out>) at /usr/src/sys/kern/vfs_vnops.c:1064 
 1064            error = vn_io_fault_doio(args, uio, td); 
 (kgdb) frame 19 
 #19 0xffffffff80ce54b5 in vn_io_fault (fp=<optimized out>, uio=0xfffff8004ebef188, active_cred=0xfffff80021a684b0, flags=<optimized out>, td=<optimized out>) 
     at /usr/src/sys/kern/vfs_vnops.c:1168 
 1168                    error = vn_io_fault1(vp, uio, &args, td); 
 (kgdb) frame 20 
 #20 0xffffffff80c70232 in fo_write (fp=<optimized out>, uio=<optimized out>, active_cred=0xfffff80282bf3401, flags=<optimized out>, td=<optimized out>) 
     at /usr/src/sys/sys/file.h:314 
 314             return ((*fp->f_ops->fo_write)(fp, uio, active_cred, flags, td)); 
 (kgdb) frame 21 
 #21 dofilewrite (td=0x0, fd=34, fp=0xfffff801a82000f0, auio=0xfffff8002ab5bd00, offset=<optimized out>, flags=<optimized out>) at /usr/src/sys/kern/sys_generic.c:567 
 567             if ((error = fo_write(fp, auio, td->td_ucred, flags, td))) { 
 (kgdb) frame 22 
 #22 0xffffffff80c70130 in kern_writev (td=0xfffff8007c685000, fd=34, auio=0xfffff8002ab5bd00) at /usr/src/sys/kern/sys_generic.c:491 
 491             error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0); 
 (kgdb)