Re: kern/55489: Infinite loop in "rump.ifconfig bridge0 create"

[Patrick Welche <prlw1%cam.ac.uk@localhost>]

The following reply was made to PR kern/55489; it has been noted by GNATS.

From: Patrick Welche <prlw1%cam.ac.uk@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: kern/55489: Infinite loop in "rump.ifconfig bridge0 create"
Date: Thu, 16 Jul 2020 14:27:58 +0100

 Work around:
 
 [   1.0200050] if_clone_attach bridge
 [   1.0200050] if_clone_attach lo
 [   1.0200050] if_clone_attach canlo
 [   1.0200050] if_clone_attach carp
 [   1.0200050] if_clone_attach ipsec
 [   1.0200050] if_clone_attach shmif
 [   1.0200050] mainbus0 (root)
 [   1.0500050] if_clone_attach virt
 [   1.0500050] if_clone_attach vlan
 [   1.0500050] if_clone_attach tun
 [   1.0500050] if_clone_attach tap
 [   1.0500050] if_clone_attach pppoe
 [   1.0500050] if_clone_attach l2tp
 [   1.0500050] if_clone_attach npflog
 [   1.0500050] if_clone_attach mpls
 [   1.0500050] if_clone_attach gif
 [   1.0500050] if_clone_attach canlo
 [   1.0500050] if_clone_attach agr
 
 $ rump.ifconfig -C
 agr canlo gif mpls npflog l2tp pppoe tap tun vlan virt shmif ipsec carp canlo gif mpls
 
 so it seems that canloop is attached twice. (bridge,lo) were attached
 before the first canloop attachment, and appear to be replaced by (mpls,gif)
 in the list which were the 2 entries before the second time canloop is
 attached.
 
 Removing netcan from RUMPNETCOMP in sys/rump/net/Makefile.rumpnetcomp
 gets
 
 [   1.0400050] if_clone_attach bridge
 [   1.0400050] if_clone_attach lo
 [   1.0400050] if_clone_attach carp
 [   1.0400050] if_clone_attach ipsec
 [   1.0400050] if_clone_attach shmif
 [   1.0400050] mainbus0 (root)
 [   1.0400050] if_clone_attach virt
 [   1.0400050] if_clone_attach vlan
 [   1.0400050] if_clone_attach tun
 [   1.0400050] if_clone_attach tap
 [   1.0400050] if_clone_attach pppoe
 [   1.0400050] if_clone_attach l2tp
 [   1.0400050] if_clone_attach npflog
 [   1.0400050] if_clone_attach mpls
 [   1.0400050] if_clone_attach gif
 [   1.0400050] if_clone_attach agr
 
 $ rump.ifconfig -C
 agr gif mpls npflog l2tp pppoe tap tun vlan virt shmif ipsec carp lo bridge
 $ rump.ifconfig bridge0 create
 $ rump.ifconfig -a
 lo0: flags=0x8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 33624
         inet 127.0.0.1/8 flags 0
         inet6 ::1/128 flags 0x20<NODAD>
         inet6 fe80::1%lo0/64 flags 0 scopeid 0x1
 bridge0: flags=0 mtu 1500
 
 and the problem is worked around.