selftests: net: cmsg_so_mark.sh test hangs

selftests: net: cmsg_so_mark.sh test hangs

[Naresh Kamboju]

The selftest net cmsg_so_mark.sh test hangs on all devices.
Test case run with "set -x" to identify which steps are causing the hang.
Am I missing any pre-requirements / setup ?

+ cd /opt/kselftests/default-in-kernel/net
+ sed -i '1i set -x' cmsg_so_mark.sh
+ ./cmsg_so_mark.sh
++ NS=ns
++ IP4=172.16.0.1/24
++ TGT4=172.16.0.2
++ IP6=2001:db8:1::1/64
++ TGT6=2001:db8:1::2
++ MARK=1000
++ trap cleanup EXIT
++ ip netns add ns
++ ip netns exec ns sysctl -w 'net.ipv4.ping_group_range=0 2147483647'
++ ip -netns ns link add type dummy
++ ip -netns ns link set dev dummy0 up
++ ip -netns ns addr add 172.16.0.1/24 dev dummy0
++ ip -netns ns addr add 2001:db8:1::1/64 dev dummy0
++ ip -netns ns rule add fwmark 1000 lookup 300
++ ip -6 -netns ns rule add fwmark 1000 lookup 300
++ ip -netns ns route add prohibit any table 300
++ ip -6 -netns ns route add prohibit any table 300
++ BAD=0
++ TOTAL=0
++ for ovr in setsock cmsg both
++ for i in 4 6
++ '[' 4 == 4 ']'
++ TGT=172.16.0.2
++ for p in u i r
++ '[' u == u ']'
++ prot=UDP
++ '[' u == i ']'
++ '[' u == r ']'
++ '[' setsock == setsock ']'
++ m=-M
++ '[' setsock == cmsg ']'
++ '[' setsock == both ']'
++ ip netns exec ns ./cmsg_sender -4 -p u -M 1001 172.16.0.2 1234


Test log:
  - https://lkft.validation.linaro.org/scheduler/job/5915863#L1646

metadata:
  git_ref: linux-6.0.y
  git_repo: https://gitlab.com/Linaro/lkft/mirrors/stable/linux-stable-rc
  git_sha: 7a60d1d7c4cda7564a42dca46c0a1e358ae4b887
  git_describe: v6.0.9-595-g7a60d1d7c4cd
  kernel_version: 6.0.11-rc2
  kernel-config: https://builds.tuxbuild.com/2IJaCkGKmSrmmsbPT5mEA6ObUqp/config
  build-url: https://gitlab.com/Linaro/lkft/mirrors/stable/linux-stable-rc/-/pipelines/710632137
  artifact-location: https://builds.tuxbuild.com/2IJaCkGKmSrmmsbPT5mEA6ObUqp
  toolchain: gcc-11

--
Linaro LKFT
https://lkft.linaro.org

Re: selftests: net: cmsg_so_mark.sh test hangs

[Jakub Kicinski]

On Mon, 5 Dec 2022 17:59:37 +0530 Naresh Kamboju wrote:
> The selftest net cmsg_so_mark.sh test hangs on all devices.
> Test case run with "set -x" to identify which steps are causing the hang.

Is it possible to get a stack trace of the script while it's blocked?
From /proc/$pid/stack ?

The test takes 30sec on a debug-heavy build for me so capturing a stack
a couple of minutes after starting should should us where it's stuck?

> Am I missing any pre-requirements / setup ?

And it works here..

The only thing I can see that may be blocking is getaddrinfo()... maybe?
Is there anything special going on with address resolution?