syzbot

uvm_fault(0xffffffff839d3278, 0xfffuvm_fault(0xffffffff839d3278, 0xffff800029ee6000, 0, 2) -> e
kernel: page fault trap, code=2
Stopped at      kcov_remote_enter+0x122:        movq    $0,0(%rcx)
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*343333  78441      0           0  0x4000000    0  syz-executor
kcov_remote_enter(0,ffff8000ffff9698) at kcov_remote_enter+0x122 sys/dev/kcov.c:670
timeout_run(ffffffff838c9000,ffff80003c8fbaa8) at timeout_run+0xdf sys/kern/kern_timeout.c:696
softclock_process_tick_timeout(ffff80003c8fbaa8,0) at softclock_process_tick_timeout+0x230 sys/kern/kern_timeout.c:756
softclock(0) at softclock+0x152 sys/kern/kern_timeout.c:788
softintr_dispatch(0) at softintr_dispatch+0xf9 sys/kern/kern_softintr.c:87
dosoftint(0) at dosoftint+0x48 sys/arch/amd64/amd64/intr.c:862
Xsoftclock() at Xsoftclock+0x27
cnputc(66) at cnputc+0x67 sys/dev/cons.c:218
db_putchar(66) at db_putchar+0x36d sys/ddb/db_output.c:155
kprintf() at kprintf+0x29c5 sys/kern/subr_prf.c:-1
db_printf(ffffffff83422841) at db_printf+0x9b sys/kern/subr_prf.c:-1
fault(ffffffff834d9ce9) at fault+0xa3 sys/arch/amd64/amd64/trap.c:161
kpageflttrap(ffff8000380c9820,ffff800029d92004) at kpageflttrap+0x353 sys/arch/amd64/amd64/trap.c:296
kerntrap(ffff8000380c9820) at kerntrap+0x18a sys/arch/amd64/amd64/trap.c:528
end trace frame: 0xffff8000380c98a0, count: 0
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reports.  Insufficient info makes it difficult to find and fix bugs.
ddb> 
ddb> set $lines = 0
ddb> set $maxwidth = 0
ddb> show panic
*cpu0: uvm_fault(0xffffffff839d3278, 0xffff800029ee6000, 0, 2) -> e
ddb> trace
kcov_remote_enter(0,ffff8000ffff9698) at kcov_remote_enter+0x122 sys/dev/kcov.c:670
timeout_run(ffffffff838c9000,ffff80003c8fbaa8) at timeout_run+0xdf sys/kern/kern_timeout.c:696
softclock_process_tick_timeout(ffff80003c8fbaa8,0) at softclock_process_tick_timeout+0x230 sys/kern/kern_timeout.c:756
softclock(0) at softclock+0x152 sys/kern/kern_timeout.c:788
softintr_dispatch(0) at softintr_dispatch+0xf9 sys/kern/kern_softintr.c:87
dosoftint(0) at dosoftint+0x48 sys/arch/amd64/amd64/intr.c:862
Xsoftclock() at Xsoftclock+0x27
cnputc(66) at cnputc+0x67 sys/dev/cons.c:218
db_putchar(66) at db_putchar+0x36d sys/ddb/db_output.c:155
kprintf() at kprintf+0x29c5 sys/kern/subr_prf.c:-1
db_printf(ffffffff83422841) at db_printf+0x9b sys/kern/subr_prf.c:-1
fault(ffffffff834d9ce9) at fault+0xa3 sys/arch/amd64/amd64/trap.c:161
kpageflttrap(ffff8000380c9820,ffff800029d92004) at kpageflttrap+0x353 sys/arch/amd64/amd64/trap.c:296
kerntrap(ffff8000380c9820) at kerntrap+0x18a sys/arch/amd64/amd64/trap.c:528
alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b
ufs_lookup() at ufs_lookup+0x613 sys/ufs/ufs/ufs_lookup.c:279
VOP_LOOKUP(fffffd80712a56d0,ffff8000380c9c60,ffff8000380c9c90) at VOP_LOOKUP+0x6e sys/kern/vfs_vops.c:85
vfs_lookup(ffff8000380c9c30) at vfs_lookup+0x94a sys/kern/vfs_lookup.c:580
namei(ffff8000380c9c30) at namei+0x7c3 sys/kern/vfs_lookup.c:250
dosymlinkat(ffff80003c8fad18,200000000000,ffffff9c,200000000040) at dosymlinkat+0xef sys/kern/vfs_syscalls.c:1833
syscall(ffff8000380c9e00) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff8000380c9e00) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x36f923994d0, count: -22
ddb>