Hi, Firefox browser freezed and i killed his process from htop (key F9). FreeBSD 12.1-RELEASE-p6 FreeBSD 12.1-RELEASE-p6 GENERIC amd64 Unread portion of the kernel message buffer: kernel trap 12 with interrupts disabled Fatal trap 12: page fault while in kernel mode cpuid = 5; apic id = 05 fault virtual address = 0xc fault code = supervisor read data, page not present instruction pointer = 0x20:0xffffffff80c334f3 stack pointer = 0x28:0xfffffe008e167790 frame pointer = 0x28:0xfffffe008e1677b0 code segment = base rx0, limit 0xfffff, type 0x1b = DPL 0, pres 1, long 1, def32 0, gran 1 processor eflags = resume, IOPL = 0 current process = 6694 (htop) trap number = 12 panic: page fault cpuid = 5 time = 1592648714 KDB: stack backtrace: #0 0xffffffff80c1d307 at kdb_backtrace+0x67 #1 0xffffffff80bd063d at vpanic+0x19d #2 0xffffffff80bd0493 at panic+0x43 #3 0xffffffff810a7dcc at trap_fatal+0x39c #4 0xffffffff810a7e19 at trap_pfault+0x49 #5 0xffffffff810a740f at trap+0x29f #6 0xffffffff81081bfc at calltrap+0x8 #7 0xffffffff80bd7af6 at tdsigwakeup+0x96 #8 0xffffffff80bd7502 at tdsendsignal+0xb52 #9 0xffffffff80bd5b29 at sys_kill+0x179 #10 0xffffffff810a8984 at amd64_syscall+0x364 #11 0xffffffff81082520 at fast_syscall_common+0x101 Uptime: 50m35s Dumping 1035 out of 12138 MB:..2%..11%..21%..31%..41%..51%..61%..72%..81%..92% warning: the debug information found in "/usr/lib/debug//boot/kernel/fusefs.ko.debug" does not match "/boot/kernel/fuse.ko" (CRC mismatch). __curthread () at /usr/src/sys/amd64/include/pcpu.h:234 234 __asm("movq %%gs:%P1,%0" : "=r" (td) : "n" (OFFSETOF_CURTHREAD)); (kgdb) bt #0 __curthread () at /usr/src/sys/amd64/include/pcpu.h:234 #1 doadump (textdump=<optimized out>) at /usr/src/sys/kern/kern_shutdown.c:371 #2 0xffffffff80bd0238 in kern_reboot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:451 #3 0xffffffff80bd0699 in vpanic (fmt=<optimized out>, ap=<optimized out>) at /usr/src/sys/kern/kern_shutdown.c:877 #4 0xffffffff80bd0493 in panic (fmt=<unavailable>) at /usr/src/sys/kern/kern_shutdown.c:804 #5 0xffffffff810a7dcc in trap_fatal (frame=0xfffffe008e1676d0, eva=12) at /usr/src/sys/amd64/amd64/trap.c:943 #6 0xffffffff810a7e19 in trap_pfault (frame=0xfffffe008e1676d0, usermode=0) at /usr/src/sys/amd64/amd64/trap.c:767 #7 0xffffffff810a740f in trap (frame=0xfffffe008e1676d0) at /usr/src/sys/amd64/amd64/trap.c:443 #8 <signal handler called> #9 propagate_priority (td=0xfffff80220bd4000) at /usr/src/sys/kern/subr_turnstile.c:279 #10 0xffffffff80bd7af6 in tdsigwakeup (td=0xfffff801742535e0, sig=9, action=0x0, intrval=4) at /usr/src/sys/kern/kern_sig.c:2411 #11 0xffffffff80bd7502 in tdsendsignal (p=<optimized out>, td=0xfffff801742535e0, sig=9, ksi=0xfffffe008e1678d8) at /usr/src/sys/kern/kern_sig.c:2375 #12 0xffffffff80bd5b29 in pksignal (p=<optimized out>, sig=1, ksi=0x0) at /usr/src/sys/kern/kern_sig.c:2064 #13 sys_kill (td=0xfffff802d8b7a5e0, uap=0xfffff802d8b7a9a0) at /usr/src/sys/kern/kern_sig.c:1774 #14 0xffffffff810a8984 in syscallenter (td=0xfffff802d8b7a5e0) at /usr/src/sys/amd64/amd64/../../kern/subr_syscall.c:135 #15 amd64_syscall (td=0xfffff802d8b7a5e0, traced=0) at /usr/src/sys/amd64/amd64/trap.c:1186 #16 <signal handler called> #17 0x00000008004566ca in ?? () Backtrace stopped: Cannot access memory at address 0x7fffffffe618 (kgdb) up 9 #9 propagate_priority (td=0xfffff80220bd4000) at /usr/src/sys/kern/subr_turnstile.c:279 279 mtx_unlock_spin(&ts->ts_lock); (kgdb) list 274 ts = td->td_blocked; 275 MPASS(ts != NULL); 276 THREAD_LOCKPTR_ASSERT(td, &ts->ts_lock); 277 /* Resort td on the list if needed. */ 278 if (!turnstile_adjust_thread(ts, td)) { 279 mtx_unlock_spin(&ts->ts_lock); 280 return; 281 } 282 /* The thread lock is released as ts lock above. */ 283 } (kgdb) up #10 0xffffffff80bd7af6 in tdsigwakeup (td=0xfffff801742535e0, sig=9, action=0x0, intrval=4) at /usr/src/sys/kern/kern_sig.c:2411 2411 sched_prio(td, PUSER); (kgdb) list 2406 * priority of the idle thread, since we still allow to signal 2407 * kernel processes. 2408 */ 2409 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2410 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2411 sched_prio(td, PUSER); 2412 if (TD_ON_SLEEPQ(td)) { 2413 /* 2414 * If thread is sleeping uninterruptibly 2415 * we can't interrupt the sleep... the signal will (kgdb)