Guest: DragonFly dfbsd 6.5-DEVELOPMENT #0 X86_64_GENERIC (stock INVARIANTS kernel), QEMU/KVM i8042
Compiler: cc 8.3 [DragonFly] Release/2019-02-22
Device: psm0 model IntelliMouse Explorer (generic vendortype) -- NO synaptics/elantech/trackpoint
        => hw.psm.synaptics.* / hw.psm.elantech.* CTLFLAG_ANYBODY sysctl trees NOT instantiated
        => smoother path unreachable on this guest (verified: sysctl -> "unknown oid")
Arithmetic proof run as uid 1001: int32 65536*65536 -> 0; division -> SIGFPE exit 136 (core dumped)
Fix check: git apply --check findings/poc/DF-3589/fix.diff -> OK (never applied to sys/)