The kvm(3) mode was actually non-functional since FreeBSD 8 for kernels
with VIMAGE, since FreeBSD 12 for the GENERIC kernel and since FreeBSD 14
for all kernels. The reason for that is that systat(1) tried to lookup
symbol "tcb" to check if kvm(3) is working. The symbol no longer exist in
the kernel.
A side effect was that systat(1) lost true kvm(3) support for all other
modes, e.g. -swap or -pigs. The tool was still working, but libkvm was
just a shim to sysctl(3) API.
So, contrary to what the header line says, this change actually restores
the kvm(3) support for other modes. Now we read the "allproc" symbol.
This was the last tool that abused _WANT_INPCB.
Gleb Smirnoff
985ac74138