>Synopsis: Encountered bus error on tcpdumping a cycled interface
>Category: system
>Environment:
System : OpenBSD 6.9
Details : OpenBSD 6.9 (GENERIC.MP) #551: Sun Apr 18 03:06:59 MDT
2021
dera...@octeon.openbsd.org:/usr/src/sys/arch/octeon/compile/GENERIC.MP
Architecture: OpenBSD.octeon
Machine : octeon
>Description:
I cycled a vlan (vlan6) interface to down and then back to up with ifconfig to
see if there is traffic flowing I tried tcpdumping and encountered a SIGBUS.
Here is what I see:
eta# tcpdump -v -n -i vlan6
tcpdump: listening on vlan6, link-type EN10MB
Bus error
eta# ifconfig vlan6
vlan6: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
lladdr fc:ec:da:04:8d:69
description: RPI Freifunk Franken VLAN
index 11 priority 0 llprio 3
encap: vnetid 6 parent cnmac1 txprio packet rxprio outer
groups: vlan
media: Ethernet autoselect (1000baseT full-duplex)
status: active
inet 192.168.36.1 netmask 0xffffff00 broadcast 192.168.36.255
A particular ktrace/kdump revealed this:
47271 tcpdump RET fstat 0
47271 tcpdump CALL
mmap(0,0x10000,0x3<PROT_READ|PROT_WRITE>,0x1002<MAP_PRIVATE|MAP_ANON>,-1,0)
47271 tcpdump RET mmap 252174057472/0x3ab6bec000
47271 tcpdump CALL fcntl(1,F_ISATTY)
47271 tcpdump RET fcntl 1
47271 tcpdump PSIG SIGBUS SIG_DFL code BUS_ADRALN<1> addr=0x39f0f3c04c
trapno=0
I assume the fcntl(... could be an isatty(3).
>How-To-Repeat:
No idea, I only upgraded this router today and added some networking
including wireguard tunnels.
>Fix:
Not provided. There is mention in comments at:
/usr/src/sys/arch/mips64/mips64/trap.c under BUS_ADRALN that this may be an
unaligned memory access.
dmesg:
OpenBSD 6.9 (GENERIC.MP) #551: Sun Apr 18 03:06:59 MDT 2021
dera...@octeon.openbsd.org:/usr/src/sys/arch/octeon/compile/GENERIC.MP
real mem = 536870912 (512MB)
avail mem = 521322496 (497MB)
random: good seed from bootblocks
mainbus0 at root: board 20004 rev 0.16, model CN3xxx/CN5xxx
cpu0 at mainbus0: CN50xx CPU rev 0.1 500 MHz, Software FP emulation
cpu0: cache L1-I 32KB 4 way D 16KB 64 way, L2 128KB 8 way
cpu1 at mainbus0: CN50xx CPU rev 0.1 500 MHz, Software FP emulation
cpu1: cache L1-I 32KB 4 way D 16KB 64 way, L2 128KB 8 way
clock0 at mainbus0: int 5
octcrypto0 at mainbus0
iobus0 at mainbus0
simplebus0 at iobus0: "soc"
octciu0 at simplebus0
octsmi0 at simplebus0
octpip0 at simplebus0
octgmx0 at octpip0 interface 0
cnmac0 at octgmx0: port 0 RGMII, address fc:ec:da:04:8d:68
atphy0 at cnmac0 phy 7: AR8035 10/100/1000 PHY, rev. 2
cnmac1 at octgmx0: port 1 RGMII, address fc:ec:da:04:8d:69
atphy1 at cnmac1 phy 6: AR8035 10/100/1000 PHY, rev. 2
cnmac2 at octgmx0: port 2 RGMII, address fc:ec:da:04:8d:6a
atphy2 at cnmac2 phy 5: AR8035 10/100/1000 PHY, rev. 2
com0 at simplebus0: ns16550a, 64 byte fifo
com0: console
dwctwo0 at iobus0 base 0x1180068000000 irq 56
usb0 at dwctwo0: USB revision 2.0
uhub0 at usb0 configuration 1 interface 0 "Octeon DWC2 root hub" rev 2.00/1.00
addr 1
octrng0 at iobus0 base 0x1400000000000 irq 0
umass0 at uhub0 port 1 configuration 1 interface 0 " UDinfo UF2 4GB" rev
2.00/1.00 addr 2
umass0: using SCSI over Bulk-Only
scsibus0 at umass0: 2 targets, initiator 0
sd0 at scsibus0 targ 1 lun 0: <, UDinfo UF2 4GB, PMAP> removable
serial.13fe420077C9177D2781
sd0: 3824MB, 512 bytes/sector, 7831552 sectors
vscsi0 at root
scsibus1 at vscsi0: 256 targets
softraid0 at root
scsibus2 at softraid0: 256 targets
root on sd0a (d5ffec0c72cad730.a) swap on sd0b dump on sd0b
WARNING: CHECK AND RESET THE DATE!
usbdevs:
Controller /dev/usb0:
addr 01: 0000:0000 Octeon, DWC2 root hub
high speed, self powered, config 1, rev 1.00
driver: uhub0
addr 02: 13fe:4200 , UDinfo UF2 4GB
high speed, power 200 mA, config 1, rev 1.00, iSerial 070877C9177D2781
driver: umass0
pcidump:
acpidump:
