VNET lock reversal

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From: Dustin Marquess <dmarquess_at_gmail.com>
Date: Wed, 11 May 2022 05:15:31 UTC

Just updated my -CURRENT box from a build almost exactly 14 days ago
to one just about an hour old.  When a VNET jail starts, I'm seeing a
lock reversal:

lock order reversal:
 1st 0xffffffff81e893a8 allprison (allprison, sx) @
/usr/src/sys/kern/kern_jail.c:1378
 2nd 0xffffffff81f99fe8 vnet_sysinit_sxlock (vnet_sysinit_sxlock, sx)
@ /usr/src/sys/net/vnet.c:579
lock order allprison -> vnet_sysinit_sxlock attempted at:
#0 0xffffffff80c9b7c6 at witness_checkorder+0xbd6
#1 0xffffffff80c35c67 at _sx_slock_int+0x67
#2 0xffffffff80d92185 at vnet_alloc+0x115
#3 0xffffffff80be7e02 at kern_jail_set+0x1722
#4 0xffffffff80be92f0 at sys_jail_set+0x40
#5 0xffffffff811200aa at amd64_syscall+0x13a
#6 0xffffffff810f12eb at fast_syscall_common+0xf8

I'll try and see if I can get a bisect going if somebody else hasn't
seen this yet.

-Dustin