Andrew Gallatin 8c5d766cd7 Add a dying flag to prevent races at detach.
I tried re-ordering ether_ifdetach(), but this created a new race
where sometimes, when under heavy receive load (>1Mpps) and running
tcpdump, the machine would panic.  At panic, the ithread was still in
the original (not dead) if_input() path, and was accessing stale BPF
data structs.  By using a dying flag, I can close the interface prior
to if_detach() to be certain the interface cannot send packets up in
the middle of ether_ifdetach.
2009-06-24 21:09:56 +00:00
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