freebsd boot error: panic: sched_pickcpu: Failed to find a cpu.

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: c9cf854b powerpc: Allocate DPCPU block from domain-local m..
git tree: freebsd
console output: https://syzkaller.appspot.com/x/log.txt?x=112cca4d600000
dashboard link: https://syzkaller.appspot.com/bug?extid=0e1e04a6013d8a28a0ea

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+0e1e04...@syzkaller.appspotmail.com

panic: sched_pickcpu: Failed to find a cpu.
cpuid = 0
time = 1
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame
0xffffffff82e047a0
vpanic() at vpanic+0x1e0/frame 0xffffffff82e04800
panic() at panic+0x43/frame 0xffffffff82e04860
sched_pickcpu() at sched_pickcpu+0x8b9/frame 0xffffffff82e04950
sched_add() at sched_add+0xaa/frame 0xffffffff82e04990
gtaskqueue_start_threads() at gtaskqueue_start_threads+0x144/frame
0xffffffff82e04a30
taskqgroup_cpu_create() at taskqgroup_cpu_create+0x14e/frame
0xffffffff82e04a70
taskqgroup_adjust() at taskqgroup_adjust+0x256/frame 0xffffffff82e04b00
mi_startup() at mi_startup+0x3ec/frame 0xffffffff82e04b70
btext() at btext+0x2c
KDB: enter: panic
[ thread pid 0 tid 100000 ]
Stopped at kdb_enter+0x6a: movq $0,kdb_why
db>


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

> #syz fix Fix wrong assertion in r352658.

Your 'fix' command is accepted, but please keep
syzkaller-f...@googlegroups.com mailing list in CC next time. It
serves as a history of what happened with each bug report. Thank you.