Lock of NetBSD-current with ifconfig down / up

[John Klos <john%ziaspace.com@localhost>]

Hi,

Here's a nice issue :)

Plug in ure* USB ethernet to amd64 machine running NetBSD-current 
(9.99.99, 22-August-2022):

[ 1791670.446266] ure0 at uhub8 port 4
[ 1791670.446266] ure0: Realtek (0x0bda) USB 10/100/1000 LAN (0x8153), rev 2.10/30.00, addr 6
[ 1791670.446266] ure0: RTL8153 ver 5c30
[ 1791670.566267] rgephy0 at ure0 phy 0: RTL8251 1000BASE-T media interface, rev. 0
[ 1791670.586267] rgephy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT-FDX, auto
[ 1791670.586267] ure0: Ethernet address a0:ce:c8:e7:88:5f
[ 1791673.256299] ugen1 at uhub8 port 5
[ 1791673.256299] ugen1: VIA Labs, Inc. (0x2109) PD3.0 USB-C Device (0x8888), rev 2.01/0.01, addr 7

ifconfig ure0 up

No problem:

ure0: flags=0x8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
	capabilities=0x3ff00<IP4CSUM_Rx,IP4CSUM_Tx,TCP4CSUM_Rx,TCP4CSUM_Tx>
	capabilities=0x3ff00<UDP4CSUM_Rx,UDP4CSUM_Tx,TCP6CSUM_Rx,TCP6CSUM_Tx>
	capabilities=0x3ff00<UDP6CSUM_Rx,UDP6CSUM_Tx>
	enabled=0
	ec_capabilities=0x1<VLAN_MTU>
	ec_enabled=0
	address: a0:ce:c8:e7:88:5f
	media: Ethernet autoselect (100baseTX full-duplex)
	status: active
	inet6 fe80::a2ce:c8ff:fee7:885f%ure0/64 flags 0 scopeid 0x9

ifconfig ure0 down

Locks the machine. I couldn't get more information because it's 3000 miles 
away. There's nothing in dmesg because the machine was power cycled.

Initially I imagined it might be due to the ure* driver, but then it 
happened locally.

On an amd64 system running 9.99.98 from 16-July-2022, I ran "ifconfig re1 
down" and the machine locked - no ICMP, nothing for SIGINFO, no response 
to keyboard cnmagic.

It doesn't appear to be hardware, but here's this just because.

[     1.044097] re1 at pci2 dev 0 function 0: RealTek 8168/8111 PCIe Gigabit Ethernet (rev. 0x0c)
[     1.044097] re1: interrupting at msix2 vec 0
[     1.044097] re1: RTL8168G/8111G (0x4c00)
[     1.044097] re1: Ethernet address 4c:cc:6a:01:a5:e0
[     1.044097] re1: using 256 tx descriptors
[     1.044097] rgephy1 at re1 phy 7: RTL8251 1000BASE-T media interface, rev. 0

I've ordered some PS/2 keyboards, because I take it that's the only way to 
reliably get in to the kernel debugger on amd64, unless someone knows a 
trick to make USB keyboards usable.

send-pr?

Thanks,
John