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Upgrade Ubuntu 23.04 to 24.04 LTS

· 10 min read

About​

Raspberry Pi で Ubuntu 23.04 から 24.04 LTS にアップグレードしようとしたら、do-release-upgrade でエラーが出たのでメモ。

Log​

元の環境の lunar はすでに EOL で repository が参照できない状態だったため apt update でエラーが出ていた。

$ cat /etc/os-release
PRETTY_NAME="Ubuntu 23.04"
NAME="Ubuntu"
VERSION_ID="23.04"
VERSION="23.04 (Lunar Lobster)"
VERSION_CODENAME=lunar
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=lunar
LOGO=ubuntu-logo

下記 URL を参考にして、do-release-upgrade を実行

$ sudo do-release-upgrade
Checking for a new Ubuntu release
Your Ubuntu release is not supported anymore.
For upgrade information, please visit:
http://www.ubuntu.com/releaseendoflife


= Welcome to Ubuntu 24.04 LTS 'Noble Numbat' =

The Ubuntu team is proud to announce Ubuntu 24.04 LTS 'Noble Numbat'.

To see what's new in this release, visit:
  https://wiki.ubuntu.com/NobleNumbat/ReleaseNotes

Ubuntu is a Linux distribution for your desktop or server, with a fast
and easy install, regular releases, a tight selection of excellent
applications installed by default, and almost any other software you
can imagine available through the network.

We hope you enjoy Ubuntu.

== Feedback and Helping ==

If you would like to help shape Ubuntu, take a look at the list of
ways you can participate at

  http://www.ubuntu.com/community/participate/

Your comments, bug reports, patches and suggestions will help ensure
that our next release is the best release of Ubuntu ever.  If you feel
that you have found a bug please read:

  http://help.ubuntu.com/community/ReportingBugs

Then report bugs using apport in Ubuntu.  For example:

  ubuntu-bug linux

will open a bug report in Launchpad regarding the linux package.

If you have a question, or if you think you may have found a bug but
aren't sure, first try asking on the #ubuntu or #ubuntu-bugs IRC
channels on Libera.Chat, on the Ubuntu Users mailing list, or on the
Ubuntu forums:

  http://help.ubuntu.com/community/InternetRelayChat
  http://lists.ubuntu.com/mailman/listinfo/ubuntu-users
  http://www.ubuntuforums.org/


== More Information ==

You can find out more about Ubuntu on our website, IRC channel and wiki.
If you're new to Ubuntu, please visit:

  http://www.ubuntu.com/


To sign up for future Ubuntu announcements, please subscribe to Ubuntu's
very low volume announcement list at:

  http://lists.ubuntu.com/mailman/listinfo/ubuntu-announce


Continue [yN] y
Get:1 Upgrade tool signature [833 B]
Get:2 Upgrade tool [1277 kB]
Fetched 1278 kB in 0s (0 B/s)
authenticate 'noble.tar.gz' against 'noble.tar.gz.gpg'
extracting 'noble.tar.gz'
[screen is terminating]
Reading cache

Checking package manager

Can not upgrade

An upgrade from 'lunar' to 'noble' is not supported with this tool.
=== Command detached from window (Fri Apr 18 20:12:30 2025) ===
=== Command terminated with exit status 1 (Fri Apr 18 20:12:40 2025) ===

うまくいかなかったので調べていると下記のドキュメントがあったので実施

cd $(mktemp -d)
mkdir noble
wget http://archive.ubuntu.com/ubuntu/dists/noble-updates/main/dist-upgrader-all/current/noble.tar.gz
tar xf noble.tar.gz -C noble
cd noble
sudo ./noble

結局先ほどと同じエラーが出た。lunar -> noble のアップデートはサポートされていないみたい。

Reading cache

Checking package manager

Can not upgrade

An upgrade from 'lunar' to 'noble' is not supported with this tool.
=== Command detached from window (Fri Apr 18 22:04:35 2025) ===

一旦 lunar -> mantic にアップグレードできないか試してみる。

cd ..
wget http://old-releases.ubuntu.com/ubuntu/dists/mantic-updates/main/dist-upgrader-all/current/mantic.tar.gz
mkdir mantic
tar xf mantic.tar.gz -C mantic/
cd mantic
sudo ./mantic --frontend=DistUpgradeViewText
Reading cache

Checking package manager

Continue running under SSH?

This session appears to be running under ssh. It is not recommended
to perform a upgrade over ssh currently because in case of failure it
is harder to recover.

If you continue, an additional ssh daemon will be started at port
'1022'.
Do you want to continue?

Continue [yN] y

Starting additional sshd

To make recovery in case of failure easier, an additional sshd will
be started on port '1022'. If anything goes wrong with the running
ssh you can still connect to the additional one.
If you run a firewall, you may need to temporarily open this port. As
this is potentially dangerous it's not done automatically. You can
open the port with e.g.:
'iptables -I INPUT -p tcp --dport 1022 -j ACCEPT'

To continue please press [ENTER]

Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Hit https://download.docker.com/linux/ubuntu lunar InRelease
Hit http://packages.openvpn.net/as/debian jammy InRelease
Ign http://ports.ubuntu.com/ubuntu-ports lunar InRelease
Ign http://ports.ubuntu.com/ubuntu-ports lunar-updates InRelease
Ign http://ports.ubuntu.com/ubuntu-ports lunar-backports InRelease
Ign http://ports.ubuntu.com/ubuntu-ports lunar-security InRelease
Err http://ports.ubuntu.com/ubuntu-ports lunar Release
  404  Not Found [IP: 2620:2d:4000:1::19 80]
Err http://ports.ubuntu.com/ubuntu-ports lunar-updates Release
  404  Not Found [IP: 2620:2d:4000:1::19 80]
Hit http://old-releases.ubuntu.com/ubuntu lunar InRelease
Err http://ports.ubuntu.com/ubuntu-ports lunar-backports Release
  404  Not Found [IP: 2620:2d:4000:1::19 80]
Hit http://old-releases.ubuntu.com/ubuntu lunar-updates InRelease
Err http://ports.ubuntu.com/ubuntu-ports lunar-security Release
  404  Not Found [IP: 2620:2d:4000:1::19 80]
Hit http://old-releases.ubuntu.com/ubuntu lunar-security InRelease
Fetched 0 B in 0s (0 B/s)
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done

Checking for installed snaps

Calculating snap size requirements

Updating repository information

Third party sources disabled

Some third party entries in your sources.list were disabled. You can
re-enable them after the upgrade with the 'software-properties' tool
or your package manager.

To continue please press [ENTER]

Hit https://download.docker.com/linux/ubuntu lunar InRelease
Hit http://packages.openvpn.net/as/debian jammy InRelease
Fetched 0 B in 0s (0 B/s)

Checking package manager
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done

Invalid package information

After updating your package information, the essential package
'ubuntu-minimal' could not be located. This may be because you have
no official mirrors listed in your software sources, or because of
excessive load on the mirror you are using. See /etc/apt/sources.list
for the current list of configured software sources.
In the case of an overloaded mirror, you may want to try the upgrade
again later.


Restoring original system state

Aborting
      g package lists... 3%
*** Collecting problem information

The collected information can be sent to the developers to improve the
application. This might take a few minutes.
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
=== Command terminated with exit status 1 (Fri Apr 18 22:10:12 2025) ===

ubuntu-minimal が見つからないというエラーが出ていそう？ 一度 /etc/apt/sources.list を修正して http://old-releases.ubuntu.com/ubuntu/ のみにして再実行してみる。

Reading cache

Checking package manager
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Hit http://packages.openvpn.net/as/debian jammy InRelease
Hit https://download.docker.com/linux/ubuntu lunar InRelease
Hit http://old-releases.ubuntu.com/ubuntu lunar InRelease
Hit http://old-releases.ubuntu.com/ubuntu lunar-updates InRelease
Hit http://old-releases.ubuntu.com/ubuntu lunar-security InRelease
Hit http://old-releases.ubuntu.com/ubuntu lunar-backports InRelease
Fetched 0 B in 0s (0 B/s)
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done

Checking for installed snaps

Calculating snap size requirements

Updating repository information

No valid mirror found

While scanning your repository information no mirror entry for the
upgrade was found. This can happen if you run an internal mirror or
if the mirror information is out of date.

Do you want to rewrite your 'sources.list' file anyway? If you choose
'Yes' here it will update all 'lunar' to 'mantic' entries.
If you select 'No' the upgrade will cancel.

Continue [yN] y
Hit https://download.docker.com/linux/ubuntu lunar InRelease
Hit http://packages.openvpn.net/as/debian jammy InRelease
Get:1 http://old-releases.ubuntu.com/ubuntu mantic InRelease [256 kB]
Get:2 http://old-releases.ubuntu.com/ubuntu mantic-updates InRelease [127 kB]
Get:3 http://old-releases.ubuntu.com/ubuntu mantic-security InRelease [127 kB]
Get:4 http://old-releases.ubuntu.com/ubuntu mantic-backports InRelease [127 kB]
Get:5 http://old-releases.ubuntu.com/ubuntu mantic/main arm64 Packages [1384 kB]
Get:6 http://old-releases.ubuntu.com/ubuntu mantic/main Translation-en [517 kB]
Get:7 http://old-releases.ubuntu.com/ubuntu mantic/main arm64 c-n-f Metadata [29.9 kB]
Get:8 http://old-releases.ubuntu.com/ubuntu mantic/restricted arm64 Packages [108 kB]
Get:9 http://old-releases.ubuntu.com/ubuntu mantic/restricted Translation-en [22.6 kB]
Get:10 http://old-releases.ubuntu.com/ubuntu mantic/restricted arm64 c-n-f Metadata [420 B]
Get:11 http://old-releases.ubuntu.com/ubuntu mantic/universe arm64 Packages [14.8 MB]
Get:12 http://old-releases.ubuntu.com/ubuntu mantic/universe Translation-en [5951 kB]
Get:13 http://old-releases.ubuntu.com/ubuntu mantic/universe arm64 c-n-f Metadata [295 kB]
Get:14 http://old-releases.ubuntu.com/ubuntu mantic/multiverse arm64 Packages [195 kB]
Get:15 http://old-releases.ubuntu.com/ubuntu mantic/multiverse Translation-en [113 kB]
Get:16 http://old-releases.ubuntu.com/ubuntu mantic/multiverse arm64 c-n-f Metadata [7168 B]
Get:17 http://old-releases.ubuntu.com/ubuntu mantic-updates/main arm64 Packages [369 kB]
Get:18 http://old-releases.ubuntu.com/ubuntu mantic-updates/main Translation-en [109 kB]
Get:19 http://old-releases.ubuntu.com/ubuntu mantic-updates/main arm64 c-n-f Metadata [9460 B]
Get:20 http://old-releases.ubuntu.com/ubuntu mantic-updates/restricted arm64 Packages [217 kB]
Get:21 http://old-releases.ubuntu.com/ubuntu mantic-updates/restricted Translation-en [35.7 kB]
Get:22 http://old-releases.ubuntu.com/ubuntu mantic-updates/restricted arm64 c-n-f Metadata [472 B]
Get:23 http://old-releases.ubuntu.com/ubuntu mantic-updates/universe arm64 Packages [404 kB]
Get:24 http://old-releases.ubuntu.com/ubuntu mantic-updates/universe Translation-en [158 kB]
Get:25 http://old-releases.ubuntu.com/ubuntu mantic-updates/universe arm64 c-n-f Metadata [14.3 kB]
Get:26 http://old-releases.ubuntu.com/ubuntu mantic-updates/multiverse arm64 Packages [5336 B]
Get:27 http://old-releases.ubuntu.com/ubuntu mantic-updates/multiverse Translation-en [2900 B]
Get:28 http://old-releases.ubuntu.com/ubuntu mantic-updates/multiverse arm64 c-n-f Metadata [228 B]
Get:29 http://old-releases.ubuntu.com/ubuntu mantic-security/main arm64 Packages [316 kB]
Get:30 http://old-releases.ubuntu.com/ubuntu mantic-security/main Translation-en [90.4 kB]
Get:31 http://old-releases.ubuntu.com/ubuntu mantic-security/main arm64 c-n-f Metadata [6880 B]
Get:32 http://old-releases.ubuntu.com/ubuntu mantic-security/restricted arm64 Packages [210 kB]
Get:33 http://old-releases.ubuntu.com/ubuntu mantic-security/restricted Translation-en [35.0 kB]
Get:34 http://old-releases.ubuntu.com/ubuntu mantic-security/restricted arm64 c-n-f Metadata [448 B]
Get:35 http://old-releases.ubuntu.com/ubuntu mantic-security/universe arm64 Packages [312 kB]
Get:36 http://old-releases.ubuntu.com/ubuntu mantic-security/universe Translation-en [129 kB]
Get:37 http://old-releases.ubuntu.com/ubuntu mantic-security/universe arm64 c-n-f Metadata [11.5 kB]
Get:38 http://old-releases.ubuntu.com/ubuntu mantic-security/multiverse arm64 Packages [4128 B]
Get:39 http://old-releases.ubuntu.com/ubuntu mantic-security/multiverse Translation-en [1732 B]
Get:40 http://old-releases.ubuntu.com/ubuntu mantic-security/multiverse arm64 c-n-f Metadata [232 B]
Get:41 http://old-releases.ubuntu.com/ubuntu mantic-backports/main arm64 c-n-f Metadata [112 B]
Get:42 http://old-releases.ubuntu.com/ubuntu mantic-backports/restricted arm64 c-n-f Metadata [116 B]
Get:43 http://old-releases.ubuntu.com/ubuntu mantic-backports/universe arm64 Packages [3944 B]
Get:44 http://old-releases.ubuntu.com/ubuntu mantic-backports/universe Translation-en [1392 B]
Get:45 http://old-releases.ubuntu.com/ubuntu mantic-backports/universe arm64 c-n-f Metadata [172 B]
Get:46 http://old-releases.ubuntu.com/ubuntu mantic-backports/multiverse arm64 c-n-f Metadata [116 B]
Fetched 26.5 MB in 6s (201 kB/s)

log を取りそこねたが、アップグレードにあたっていくつかのパッケージが削除されたりするけど良い？みたいな確認が出た。

Continue [yN] Details [d] とプロンプトが出たので d を選ぶと具体的なパッケージのリストが出てきた。

No longer supported: util-linux-extra


Remove: iptables-persistent

Remove (was auto installed) libevent-core-2.1-7a libsgutils2-2
  netfilter-persistent


Install: appstream dhcpcd-base dracut-install libduktape207 libeac3
  libsframe1 libsgutils2-1.46-2 linux-headers-6.5.0-1020-raspi
  linux-image-6.5.0-1020-raspi linux-modules-6.5.0-1020-raspi
  linux-raspi-headers-6.5.0-1020 netplan-generator python3-netplan
  systemd-dev ubuntu-pro-client xml-core


Upgrade: adduser apparmor apport apt apt-transport-https apt-utils
  ...

y を選択して進めると、無事にアップグレードが完了。

$ cat /etc/os-release
PRETTY_NAME="Ubuntu 23.10"
NAME="Ubuntu"
VERSION_ID="23.10"
VERSION="23.10 (Mantic Minotaur)"
VERSION_CODENAME=mantic
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=mantic
LOGO=ubuntu-logo

再起動して ssh 接続すると下記のようにログが出た。

Your Ubuntu release is not supported anymore.
For upgrade information, please visit:
http://www.ubuntu.com/releaseendoflife

New release '24.04.2 LTS' available.
Run 'do-release-upgrade' to upgrade to it.
$ sudo do-release-upgrade
[sudo] password for mmori:
Checking for a new Ubuntu release
Your Ubuntu release is not supported anymore.
For upgrade information, please visit:
http://www.ubuntu.com/releaseendoflife

Please install all available updates for your release before upgrading.
$ sudo apt update -y && sudo apt upgrade -y
...
E: dpkg was interrupted, you must manually run 'sudo dpkg --configure -a' to correct the problem.
$ sudo dpkg --configure -a
$ sudo apt update -y && sudo apt upgrade -y
$ sudo systemctl reboot
$ sudo do-release-upgrade

いくつか追加で処理が必要だったが、無事にアップグレードできた。

$ cat /etc/os-release
PRETTY_NAME="Ubuntu 24.04.2 LTS"
NAME="Ubuntu"
VERSION_ID="24.04"
VERSION="24.04.2 LTS (Noble Numbat)"
VERSION_CODENAME=noble
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=noble
LOGO=ubuntu-logo

System76 Meerkat で wifi の問題を調べる

· 8 min read

概要: iwlwifi driver のエラー​

System76 Meerkat を購入して起動したところ、wifi の接続が不安定だったので調べたときのメモ。

https://system76.com/desktops/meerkat/

基本的には有線接続する予定ですが、wifi module が入っているので試しに wifi に接続したところ boot 直後に一瞬つながるもののその後切れてしまいました。

その後 wifi 設定を開くと No Wi-Fi Adapter Found と表示されている。

journalctl でログを確認すると、以下のようなエラーが出続けているのがわかった。

kernel: iwlwifi 0000:00:14.3: Queue 1 is stuck 1 3
kernel: iwlwifi 0000:00:14.3: Microcode SW error detected. Restarting 0x0.
...
journalctl
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: Queue 1 is stuck 1 3
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: Microcode SW error detected. Restarting 0x0.
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: Start IWL Error Log Dump:
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: Transport status: 0x0000004A, valid: 6
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: Loaded firmware version: 89.e9cec78e.0 ma-b0-gf-a0-89.ucode
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00000084 | NMI_INTERRUPT_UNKNOWN       
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00800AF4 | trm_hw_status0
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00000000 | trm_hw_status1
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x002DDFC2 | branchlink2
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x002D3A62 | interruptlink1
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x002D3A62 | interruptlink2
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x0000841E | data1
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x01000000 | data2
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00000000 | data3
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x3B809C27 | beacon time
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x9D2253DC | tsf low
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00000013 | tsf hi
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00000000 | time gp1
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x017A9FE5 | time gp2
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00000001 | uCode revision type
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00000059 | uCode version major
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0xE9CEC78E | uCode version minor
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00000441 | hw version
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00C80002 | board version
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x0101001C | hcmd
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x80020000 | isr0
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00000000 | isr1
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x48F00002 | isr2
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00C3200C | isr3
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00200000 | isr4
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x0201001C | last cmd Id
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x0000841E | wait_event
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00000094 | l2p_control
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00002020 | l2p_duration
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x0000000F | l2p_mhvalid
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00060098 | l2p_addr_match
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00000009 | lmpm_pmg_sel
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00000000 | timestamp
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x000078B4 | flow_handler
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: Start IWL Error Log Dump:
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: Transport status: 0x0000004A, valid: 7
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x20000066 | NMI_INTERRUPT_HOST
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00000000 | umac branchlink1
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x8025FE96 | umac branchlink2
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x8028481E | umac interruptlink1
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x8028481E | umac interruptlink2
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x01000000 | umac data1
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x8028481E | umac data2
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00000000 | umac data3
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00000059 | umac major
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0xE9CEC78E | umac minor
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x017A9FE3 | frame pointer
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0xC0886260 | stack pointer
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x005701D2 | last host cmd
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00000400 | isr status reg
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: IML/ROM dump:
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00000B03 | IML/ROM error/state
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x000082D5 | IML/ROM data1
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00000080 | IML/ROM WFPM_AUTH_KEY_0
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: Fseq Registers:
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x65B00000 | FSEQ_ERROR_CODE
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x80840002 | FSEQ_TOP_INIT_VERSION
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x003B0000 | FSEQ_CNVIO_INIT_VERSION
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x0000A652 | FSEQ_OTP_VERSION
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00000003 | FSEQ_TOP_CONTENT_VERSION
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x4552414E | FSEQ_ALIVE_TOKEN
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x01080800 | FSEQ_CNVI_ID
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00400410 | FSEQ_CNVR_ID
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x01080800 | CNVI_AUX_MISC_CHIP
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00400410 | CNVR_AUX_MISC_CHIP
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00009061 | CNVR_SCU_SD_REGS_SD_REG_DIG_DCDC_VTRIM
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00000061 | CNVR_SCU_SD_REGS_SD_REG_ACTIVE_VDIG_MIRROR
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x003B0000 | FSEQ_PREV_CNVIO_INIT_VERSION
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00840002 | FSEQ_WIFI_FSEQ_VERSION
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x00840002 | FSEQ_BT_FSEQ_VERSION
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: 0x000000E6 | FSEQ_CLASS_TP_VERSION
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: UMAC CURRENT PC: 0x802842dc
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: LMAC1 CURRENT PC: 0xd0
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: WRT: Collecting data: ini trigger 4 fired (delay=0ms).
Mar 16 10:59:02 pop-os kernel: ieee80211 phy0: Hardware restart was requested
Mar 16 10:59:02 pop-os kernel: iwlwifi 0000:00:14.3: WRT: Invalid buffer destination
Mar 16 10:59:03 pop-os kernel: iwlwifi 0000:00:14.3: Not valid error log pointer 0x0024B5C0 for RT uCode
Mar 16 10:59:03 pop-os kernel: iwlwifi 0000:00:14.3: WFPM_UMAC_PD_NOTIFICATION: 0x1f
Mar 16 10:59:03 pop-os kernel: iwlwifi 0000:00:14.3: WFPM_LMAC2_PD_NOTIFICATION: 0x1f
Mar 16 10:59:03 pop-os kernel: iwlwifi 0000:00:14.3: WFPM_AUTH_KEY_0: 0x80
Mar 16 10:59:03 pop-os kernel: iwlwifi 0000:00:14.3: CNVI_SCU_SEQ_DATA_DW9: 0x0
Mar 16 10:59:03 pop-os kernel: iwlwifi 0000:00:14.3: RFIm is deactivated, reason = 4

問題が発生した環境は以下の通り。

$ cat /etc/os-release
NAME="Pop!_OS"
VERSION="22.04 LTS"
ID=pop
ID_LIKE="ubuntu debian"
PRETTY_NAME="Pop!_OS 22.04 LTS"
VERSION_ID="22.04"
HOME_URL="https://pop.system76.com"
SUPPORT_URL="https://support.system76.com"
BUG_REPORT_URL="https://github.com/pop-os/pop/issues"
PRIVACY_POLICY_URL="https://system76.com/privacy"
VERSION_CODENAME=jammy
UBUNTU_CODENAME=jammy
LOGO=distributor-logo-pop-os

$ uname -a
Linux pop-os 6.9.3-76060903-generic #202405300957~1738770968~22.04~d5f7c84 SMP PREEMPT_DYNAMIC Wed F x86_64 x86_64 x86_64 GNU/Linux

見つけた情報↓

結論から言うと以下の２パターンで解決できた。

  1. iwlwifi の設定で 11n_disable=1 を設定する (https://support.system76.com/articles/wireless/#n-mode)
  2. 2.5GHz の wifi を使用する

Solution1: iwlwifi の設定で 11n_disable=1 を設定する​

/etc/modprobe.d/iwlwifi.conf に以下のように 11n_disable=1 を追加する。

# /etc/modprobe.d/iwlwifi.conf
options iwlwifi power_save=0
options iwlwifi 11n_disable=1
# iwlwifi will dyamically load either iwldvm or iwlmvm depending on the
# microcode file installed on the system.  When removing iwlwifi, first
# remove the iwl?vm module and then iwlwifi.
remove iwlwifi \
(/sbin/lsmod | grep -o -e ^iwlmvm -e ^iwldvm -e ^iwlwifi | xargs /sbin/rmmod) \
&& /sbin/modprobe -r mac80211

この設定の意味はざっくりとしかわかっていないが、wifi 規格の 802.11n の機能を有効・無効にするものらしい。

$ modinfo iwlwifi | grep 11n_disable
parm:           11n_disable:disable 11n functionality, bitmap: 1: full, 2: disable agg TX, 4: disable agg RX, 8 enable agg TX (uint)

https://elixir.bootlin.com/linux/v6.9.3/source/drivers/net/wireless/intel/iwlwifi/iwl-modparams.h#L23-L28

1 を設定すると 11n の機能を全て無効にするため、速度は遅くなるが安定するらしい。

ちなみに 2, 4, 6 (2+4), 8 でも動作確認したが、エラーは出続けた。

Solution2: 2.5GHz の wifi を使用する​

これは単純に 2.5GHz の wifi を選ぶだけ。

2.5GHz の場合は iwlwifi.conf の設定を変更しなくても問題なく接続できた。

2.5GHz には機能がそもそもないのか実装が違うのかなどは不明。

まとめ​

どちらの解決策を選んでもネットワークは遅くなってしまうが、動くことのほうが優先なので仕方ない…。

Container の互換性を調べていたら色々と脱線した話

· 14 min read

概要​

Docker などのコンテナ技術では、ホスト OS のカーネルを共有してコンテナイメージにディストリビューションやアプリケーションの依存関係を含めることで、異なる実行環境を再現しています。

このとき、ホスト OS とコンテナイメージのディストリビューションが異なるとカーネルの違いによって原理的には互換性の問題が発生するはずです。 今回は実際に古いカーネルを使用しているホスト OS 上で比較的新しいカーネルを使用しているディストリビューションを使用してアプリケーションを実行してどのような問題が起こるのか試してみました。

実行環境​

  • env1

    • Host OS: 
      • [mmori@localhost ~]$ cat /etc/redhat-release
        CentOS Linux release 7.9.2009 (Core)
        [mmori@localhost ~]$ uname -a
        Linux localhost.localdomain 3.10.0-1160.71.1.el7.x86_64 #1 SMP Tue Jun 28 15:37:28 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
    • Container: 
      • [mmori@localhost ~]$ sudo docker image ls
        REPOSITORY    TAG       IMAGE ID       CREATED         SIZE
        rockylinux    9.3       b72d2d915008   5 months ago    176MB

  • env2

    • Host OS: 
      • [mmori@localhost ~]$ cat /etc/redhat-release
        Rocky Linux release 9.3 (Blue Onyx)
        [mmori@localhost ~]$ uname -a
        Linux localhost.localdomain 5.14.0-362.8.1.el9_3.x86_64 #1 SMP PREEMPT_DYNAMIC Wed Nov 8 17:36:32 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux
    • Container: 
      • [mmori@localhost ~]$ sudo podman image ls
        REPOSITORY             TAG             IMAGE ID      CREATED      SIZE
        quay.io/centos/centos  centos7.9.2009  8652b9f0cb4c  3 years ago  212 MB

方針​

カーネルのバージョンを確認して実装されているシステムコールの差分から互換性の問題を調査する。

Red Hat Enterprise Linux のリリース日 を見ると、RHEL 7 と RHEL 9 のカーネルバージョンは以下の通り。

リリースカーネルバージョン
RHEL 7.93.10.0-1160
RHEL 9.35.14.0-362.8.1.el9_3

Linux v3.10.0 と v5.14.0 のシステムコールのテーブルを確認する。

...
309	common	getcpu			sys_getcpu
310	64	process_vm_readv	sys_process_vm_readv
311	64	process_vm_writev	sys_process_vm_writev
312	common	kcmp			sys_kcmp
313	common	finit_module		sys_finit_module

#
# x32-specific system call numbers start at 512 to avoid cache impact
# for native 64-bit operation.
#
512	x32	rt_sigaction		compat_sys_rt_sigaction
513	x32	rt_sigreturn		stub_x32_rt_sigreturn
514	x32	ioctl			compat_sys_ioctl
515	x32	readv			compat_sys_readv
516	x32	writev			compat_sys_writev
...
...
309	common	getcpu			sys_getcpu
310	64	process_vm_readv	sys_process_vm_readv
311	64	process_vm_writev	sys_process_vm_writev
312	common	kcmp			sys_kcmp
313	common	finit_module		sys_finit_module
314	common	sched_setattr		sys_sched_setattr
315	common	sched_getattr		sys_sched_getattr
316	common	renameat2		sys_renameat2
317	common	seccomp			sys_seccomp
318	common	getrandom		sys_getrandom
319	common	memfd_create		sys_memfd_create
320	common	kexec_file_load		sys_kexec_file_load
321	common	bpf			sys_bpf
322	64	execveat		sys_execveat
323	common	userfaultfd		sys_userfaultfd
324	common	membarrier		sys_membarrier
325	common	mlock2			sys_mlock2
326	common	copy_file_range		sys_copy_file_range
327	64	preadv2			sys_preadv2
328	64	pwritev2		sys_pwritev2
329	common	pkey_mprotect		sys_pkey_mprotect
330	common	pkey_alloc		sys_pkey_alloc
331	common	pkey_free		sys_pkey_free
332	common	statx			sys_statx
333	common	io_pgetevents		sys_io_pgetevents
334	common	rseq			sys_rseq
# don't use numbers 387 through 423, add new calls after the last
# 'common' entry
424	common	pidfd_send_signal	sys_pidfd_send_signal
425	common	io_uring_setup		sys_io_uring_setup
426	common	io_uring_enter		sys_io_uring_enter
427	common	io_uring_register	sys_io_uring_register
428	common	open_tree		sys_open_tree
429	common	move_mount		sys_move_mount
430	common	fsopen			sys_fsopen
431	common	fsconfig		sys_fsconfig
432	common	fsmount			sys_fsmount
433	common	fspick			sys_fspick
434	common	pidfd_open		sys_pidfd_open
435	common	clone3			sys_clone3
436	common	close_range		sys_close_range
437	common	openat2			sys_openat2
438	common	pidfd_getfd		sys_pidfd_getfd
439	common	faccessat2		sys_faccessat2
440	common	process_madvise		sys_process_madvise
441	common	epoll_pwait2		sys_epoll_pwait2
442	common	mount_setattr		sys_mount_setattr
443	common	quotactl_fd		sys_quotactl_fd
444	common	landlock_create_ruleset	sys_landlock_create_ruleset
445	common	landlock_add_rule	sys_landlock_add_rule
446	common	landlock_restrict_self	sys_landlock_restrict_self
447	common	memfd_secret		sys_memfd_secret

#
# Due to a historical design error, certain syscalls are numbered differently
# in x32 as compared to native x86_64.  These syscalls have numbers 512-547.
# Do not add new syscalls to this range.  Numbers 548 and above are available
# for non-x32 use.
#
512	x32	rt_sigaction		compat_sys_rt_sigaction
513	x32	rt_sigreturn		compat_sys_x32_rt_sigreturn
514	x32	ioctl			compat_sys_ioctl
515	x32	readv			sys_readv
516	x32	writev			sys_writev
...

簡単に使えそうなシステムコールとして 318 番の getrandom があるのでこれを使ってみる。

調査、テストコード​

getrandom​

SYSCALL_DEFINE3(getrandom, char __user *, ubuf, size_t, len, unsigned int, flags)
{
	struct iov_iter iter;
	int ret;

	if (flags & ~(GRND_NONBLOCK | GRND_RANDOM | GRND_INSECURE))
		return -EINVAL;

	/*
	 * Requesting insecure and blocking randomness at the same time makes
	 * no sense.
	 */
	if ((flags & (GRND_INSECURE | GRND_RANDOM)) == (GRND_INSECURE | GRND_RANDOM))
		return -EINVAL;

	if (!crng_ready() && !(flags & GRND_INSECURE)) {
		if (flags & GRND_NONBLOCK)
			return -EAGAIN;
		ret = wait_for_random_bytes();
		if (unlikely(ret))
			return ret;
	}

	ret = import_ubuf(ITER_DEST, ubuf, len, &iter);
	if (unlikely(ret))
		return ret;
	return get_random_bytes_user(&iter);
}
  • test code
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/syscall.h>

#define BUF_SIZE 16

void print_buf(char *buf, int size) {
	printf("buf = ");
	for (int i = 0; i < size; i++) {
		printf("%02x,", (unsigned char)buf[i]);
	}
	printf("\n");
}

int main() {
	int ret;
	char *buf = (char *) malloc(sizeof(char) * BUF_SIZE);
	memset(buf, 0, BUF_SIZE);
	print_buf(buf, BUF_SIZE);
	ret = syscall(SYS_getrandom, buf, BUF_SIZE, 0);
	printf("ret = %d\n", ret);
	print_buf(buf, BUF_SIZE);
}

pidfd_open​

最初は getrandom だけで試すつもりだったが、実際に実行すると centos7 のカーネルでも getrandom が使えてしまった。 （RHEL 7 のベースとなるバージョンは Linux v3.10.0 で getrandom は実装されていないはずだが、3.10.0-1160.71.1.el7.x86_64 では追加のパッチがあたっているのだろう。）

追加で pidfd_open を試してみる。

存在する pid を引数にして実行すると process を参照する file descriptor を取得できる。 man page の use case を見ると使いみちが色々とある。

   Use cases for PID file descriptors
       A PID file descriptor returned by pidfd_open() (or by clone(2)
       with the CLONE_PID flag) can be used for the following purposes:

       •  The pidfd_send_signal(2) system call can be used to send a
          signal to the process referred to by a PID file descriptor.

       •  A PID file descriptor can be monitored using poll(2),
          select(2), and epoll(7).  When the process that it refers to
          terminates, these interfaces indicate the file descriptor as
          readable.  Note, however, that in the current implementation,
          nothing can be read from the file descriptor (read(2) on the
          file descriptor fails with the error EINVAL).

       •  If the PID file descriptor refers to a child of the calling
          process, then it can be waited on using waitid(2).

       •  The pidfd_getfd(2) system call can be used to obtain a
          duplicate of a file descriptor of another process referred to
          by a PID file descriptor.

       •  A PID file descriptor can be used as the argument of setns(2)
          in order to move into one or more of the same namespaces as
          the process referred to by the file descriptor.

       •  A PID file descriptor can be used as the argument of
          process_madvise(2) in order to provide advice on the memory
          usage patterns of the process referred to by the file
          descriptor.

process の監視などに使えそう。 調べてみると python の新しい機能として pidfd が使われるようになっているらしい。

実装や man page については以下の通り。

/**
 * sys_pidfd_open() - Open new pid file descriptor.
 *
 * @pid:   pid for which to retrieve a pidfd
 * @flags: flags to pass
 *
 * This creates a new pid file descriptor with the O_CLOEXEC flag set for
 * the task identified by @pid. Without PIDFD_THREAD flag the target task
 * must be a thread-group leader.
 *
 * Return: On success, a cloexec pidfd is returned.
 *         On error, a negative errno number will be returned.
 */
SYSCALL_DEFINE2(pidfd_open, pid_t, pid, unsigned int, flags)
{
	int fd;
	struct pid *p;

	if (flags & ~(PIDFD_NONBLOCK | PIDFD_THREAD))
		return -EINVAL;

	if (pid <= 0)
		return -EINVAL;

	p = find_get_pid(pid);
	if (!p)
		return -ESRCH;

	fd = pidfd_create(p, flags);

	put_pid(p);
	return fd;
}
  • test code (ただ呼び出すだけのコード)
#include <stdio.h>
#include <stdlib.h>
#include <sys/syscall.h>
#include <unistd.h>

int main(int argc, char *argv[]) {
	int pid = getpid();
	if (argc != 1) {
		pid = atoi(argv[1]);
	}
	printf("pid: %d\n", pid);
	int pidfd = syscall(SYS_pidfd_open, pid, 0);
	if (pidfd < 0) {
		perror("pidfd_open");
		return 1;
	}
	printf("pidfd: %d\n", pidfd);
	sleep(1000);
	close(pidfd);
	return 0;
}
  • test code (man page のコード)
    • 監視対象のプロセスが終了すると poll で検知できる
#define _GNU_SOURCE
#include <poll.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/syscall.h>
#include <unistd.h>

static int
pidfd_open(pid_t pid, unsigned int flags)
{
	return syscall(SYS_pidfd_open, pid, flags);
}

int
main(int argc, char *argv[])
{
	int            pidfd, ready;
	struct pollfd  pollfd;

	if (argc != 2) {
		fprintf(stderr, "Usage: %s <pid>\n", argv[0]);
		exit(EXIT_SUCCESS);
	}

	pidfd = pidfd_open(atoi(argv[1]), 0);
	if (pidfd == -1) {
		perror("pidfd_open");
		exit(EXIT_FAILURE);
	}

	pollfd.fd = pidfd;
	pollfd.events = POLLIN;

	ready = poll(&pollfd, 1, -1);
	if (ready == -1) {
		perror("poll");
		exit(EXIT_FAILURE);
	}

	printf("Events (%#x): POLLIN is %sset\n", pollfd.revents,
			(pollfd.revents & POLLIN) ? "" : "not ");

	close(pidfd);
	exit(EXIT_SUCCESS);
}

実験​

getrandom​

getrandom を実行してみる。 （どちらでも実行できてしまったので今回の趣旨とは異なるが、一応載せておく）

env1​

[root@4871234db7f8 workspace]# gcc getrandom.c
[root@4871234db7f8 workspace]# ./a.out
buf = 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,
ret = 16
buf = 82,92,6f,1b,87,18,1e,8a,d8,ac,7e,5a,f7,9b,59,18,

env2​

[root@4b84690c185e workspace]# gcc getrandom.c
[root@4b84690c185e workspace]# ./a.out
buf = 00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,
ret = 16
buf = 19,95,66,4c,43,bb,5f,83,b5,44,2e,6c,db,92,90,66,

pidfd_open​

sleep するだけのプロセスを起動して pidfd_open で file descriptor を取得してみる。

#include <stdio.h>
#include <unistd.h>

int main() {
	printf("pid: %d\n", getpid());
	sleep(1000);
}

env1​

host OS が centos でシステムコールが実装されていないのでエラーになる。

[root@4871234db7f8 workspace]# ./sleep
pid: 80
[root@4871234db7f8 workspace]# ./pidfd_open 80
pid: 80
pidfd_open: Function not implemented

v3.10 では do_syscall64 がなく、arch/x86/kernel/entry_64.S で syscall table を直接 call している。 直前で NR_syscall のバリデーションをしているのでここでエラーハンドリング用の badsys に飛ばされる。

飛ばされたあとはリターンしてユーザプロセスに実行が遷移し、libc の syscall() でエラーハンドリングされているはず。

env2​

centos のコンテナではライブラリが古いので SYS_pidfd_open が定義されておらず、コンパイルエラーになる。

[root@4b84690c185e workspace]# gcc pidfd_open.c -o pidfd_open
pidfd_open.c: In function 'main':
pidfd_open.c:12:22: error: 'SYS_pidfd_open' undeclared (first use in this function)
  int pidfd = syscall(SYS_pidfd_open, pid, 0);
                      ^
pidfd_open.c:12:22: note: each undeclared identifier is reported only once for each function it appears in

pidfd_open は 434 番なので自分で定数を定義してコンパイルする。

#include <stdio.h>
#include <stdlib.h>
#include <sys/syscall.h>
#include <unistd.h>

+#define SYS_pidfd_open  434
+
int main(int argc, char *argv[]) {
        int pid = getpid();
        if (argc != 1) {
                pid = atoi(argv[1]);
        }
        printf("pid: %d\n", pid);
        int pidfd = syscall(SYS_pidfd_open, pid, 0);
        if (pidfd < 0) {
                perror("pidfd_open");
                return 1;
        }
        printf("pidfd: %d\n", pidfd);
        sleep(1000);
        close(pidfd);
        return 0;
}

実行できた。

[root@4b84690c185e workspace]# ./sleep
pid: 165
[root@4b84690c185e workspace]# ./pidfd_open 165
pid: 165
pidfd: 3

このとき、開かれた fd は procfs でみると下記のようにリンクが張られている。

[root@4b84690c185e workspace]# ls -la /proc/166/fd
total 0
dr-x------. 2 root root  0 May  3 05:28 .
dr-xr-xr-x. 9 root root  0 May  3 05:23 ..
lrwx------. 1 root root 64 May  3 05:28 0 -> /dev/pts/2
lrwx------. 1 root root 64 May  3 05:28 1 -> /dev/pts/2
lrwx------. 1 root root 64 May  3 05:28 2 -> /dev/pts/2
lrwx------. 1 root root 64 May  3 05:28 3 -> anon_inode:[pidfd]

pidfd_open + poll​

man page にあるコードを使用してプロセスの監視を行ってみる。

env1​

実行できないのはわかっているのでスキップ

env2​

先ほどと同様に sleep するプロセスを起動して監視してみる。

[root@4b84690c185e workspace]# ./sleep
pid: 185
^C

ctrl+c で終了させると poll が検知して終了した。

[root@4b84690c185e workspace]# ./pidfd_open_poll 185
Events (0x1): POLLIN is set

追加 (pidfd_send_signal)​

pidfd_send_signal を使ってみる。

こちらも試すだけなら man page のコードを使うだけで良さそう。

#define _GNU_SOURCE
#include <fcntl.h>
#include <limits.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/syscall.h>
#include <unistd.h>

static int pidfd_send_signal(int pidfd, int sig, siginfo_t *info,
		unsigned int flags)
{
	return syscall(SYS_pidfd_send_signal, pidfd, sig, info, flags);
}

int main(int argc, char *argv[])
{
	int        pidfd, sig;
	char       path[PATH_MAX];
	siginfo_t  info;

	if (argc != 3) {
		fprintf(stderr, "Usage: %s <pid> <signal>\n", argv[0]);
		exit(EXIT_FAILURE);
	}

	sig = atoi(argv[2]);

	/* Obtain a PID file descriptor by opening the /proc/PID directory
	   of the target process. */

	snprintf(path, sizeof(path), "/proc/%s", argv[1]);

	pidfd = open(path, O_RDONLY);
	if (pidfd == -1) {
		perror("open");
		exit(EXIT_FAILURE);
	}

	/* Populate a 'siginfo_t' structure for use with
	   pidfd_send_signal(). */

	memset(&info, 0, sizeof(info));
	info.si_code = SI_QUEUE;
	info.si_signo = sig;
	info.si_errno = 0;
	info.si_uid = getuid();
	info.si_pid = getpid();
	info.si_value.sival_int = 1234;

	/* Send the signal. */

	if (pidfd_send_signal(pidfd, sig, &info, 0) == -1) {
		perror("pidfd_send_signal");
		exit(EXIT_FAILURE);
	}

	exit(EXIT_SUCCESS);
}

sleep プロセスを作成して SIGTERM(15) を送信したところプロセスを終了させることができた。

[root@4b84690c185e workspace]# ./sleep
pid: 222
Terminated
[root@4b84690c185e workspace]# ./pidfd_send_signal 222 15

まとめ​

  • Container では host os のカーネルを共有しているため、期待されるカーネルバージョンの違いによってうまく動作しないアプリケーションがある。
  • Systemcall の実装状況も影響するため、互換性を確認する際には注意が必要。
  • 自分の周囲ではこの問題がそこまで指摘されていない（顕在化していないのは）ホストOS のバージョンが比較的新しいことや新しいシステムコールなどがそこまで使用されていないからかもしれない。
    • python3.9 では pidfd が使われているようなので、centos 上のコンテナで新しい python を使うと問題が起こるかもしれない
  • pidfd + poll を使ったプロセス監視や signal の送信などが単純に面白かった

Learning how to analyze programs and kernels with perf

· 5 min read

Overview​

One of the tools that seemed useful but wasn't used is perf. This time, let's learn the basics of using perf.

Goal​

  • Analyze a application using perf.
  • Attempt to create a flamegraph because it seems possible.
  • Investigate if there is anything usable in a GUI.

Preparation​

Install the necessary packages. If only perf is needed, it can be installed with the following:

sudo pacman -S perf

For Arch Linux, various tools are included in the linux-tools group, so it seems good to install them with:

paru -Sg linux-tools

Install the required packages for creating flamegraphs (available in AUR):

paru -S flamegraph

To analyze the kernel with perf, you need to change a kernel parameter called perf_event_paranoid. This parameter controls access to performance events, and its default value is 2. However, this prevents capturing kernel events, so we need to change it to -1.

FYI: Kernel Documentation - perf-security

cat /proc/sys/kernel/perf_event_paranoid
echo -1 | sudo tee /proc/sys/kernel/perf_event_paranoid

fio​

In this article, we will use fio, a tool for taking I/O benchmarks, as a test application.

sudo pacman -S fio

While researching how to use fio, it was found that there is a configuration item called ioengine. To see how the behavior changes when this ioengine is changed, we will analyze it with perf.

By the way, looking at the man page for fio reveals that there are many different ioengine options that can be configured.

FYI: fio Man Page

Although there is no particular preference, we will try libaio, sync, and mmap this time.

Memo about perf​

  • Use perf stat to display metrics such as execution time and CPU usage.
    • For example, the result when running pwd is shown below: 
      % perf stat pwd
      /home/mori/workspace/perf

       Performance counter stats for 'pwd':

                    1.83 msec task-clock:u                     #    0.161 CPUs utilized
                       0      context-switches:u               #    0.000 /sec
                       0      cpu-migrations:u                 #    0.000 /sec
                      67      page-faults:u                    #   36.526 K/sec
                 317,835      cycles:u                         #    0.173 GHz
                 232,109      instructions:u                   #    0.73  insn per cycle
                  52,250      branches:u                       #   28.485 M/sec
                   3,235      branch-misses:u                  #    6.19% of all branches

             0.011358294 seconds time elapsed

             0.000000000 seconds user
             0.003322000 seconds sys
      • branch-misses refers to failed speculative execution.
      • context-switches does not indicate the number of times the scheduler switches.
      • It remained 0 even with the sleep command or a program using pthread.
  • perf bench provides several benchmark tools. 
    % perf bench
    Usage:
            perf bench [<common options>] <collection> <benchmark> [<options>]

            # List of all available benchmark collections:

             sched: Scheduler and IPC benchmarks
           syscall: System call benchmarks
               mem: Memory access benchmarks
              numa: NUMA scheduling and MM benchmarks
             futex: Futex stressing benchmarks
             epoll: Epoll stressing benchmarks
         internals: Perf-internals benchmarks
        breakpoint: Breakpoint benchmarks
            uprobe: uprobe benchmarks
               all: All benchmarks
  • For detailed program analysis, use perf record and view the results with perf report.
    • When you run perf record, the results are saved in a file called perf.data (can be changed with the -o option).
    • You can specify events with the -e option; check the available events with perf list.
    • Adding the -g option allows you to obtain a call graph, which is necessary for creating a flamegraph later.
    • Use perf report -i with the perf.data obtained from perf record to display the results.
  • perf top is similar to a real-time perf report.
  • perf script outputs the results of perf record as a script.
    • It shows timestamps, event names, and event details.
    • Flamegraphs are created based on this script.
  • Use perf annotate to annotate assembly code.
  • perf diff is used to compare perf.data files.
    • It can be used to verify the effects when making performance improvements.
  • perf kvm is used to profile KVM.
    • You can use perf kvm --guest record to profile the guest machine, but I had trouble getting it to work, so I'll look into it later.

Example​

Let's use perf to analyze fio.

The command to capture the perf.data is as follows:

perf record -o /tmp/perf_libaio.data -g fio configs/seq_read_libaio.ini

To create a flamegraph from the obtained performance data:

perf script -i /tmp/per

f_libaio.data | stackcollapse-perf.pl | flamegraph.pl > images/perf_libaio.svg

Note: Be sure to include the -g option when recording with perf record to obtain the call graph.

Flamegraphs for changing the ioengine to libaio, sync, and mmap respectively:

libaio:

sync:

mmap:

There are many parts marked as "unknown," but this can likely be resolved by building fio with debugging information.

For a more thorough investigation, consider rebuilding and using tools like flamegraphs, perf report, and perf diff to examine the differences and confirm improvements when making changes.

Other Tools​

A relatively recent tool discovered is hotspot, a tool for displaying perf results in a GUI, supporting flamegraphs as well. (Found in AUR for Arch, but encountered a build error when attempting to install)

A tool introduced on Qiita while researching perf. When you upload the test.perf obtained with the following command, the results are displayed as shown in the image below:

perf script -i /tmp/perf_libaio.data -F +pid > test.perf

Wrap Up​

It seems beneficial to actively use perf when investigating bottlenecks or obtaining hints for improvements due to OS updates or application updates.

Steam Deck が発売されたので中身を見ていく‼

· 15 min read

steamdeck

はじめに​

Steam Deck は Valve が開発したゲーム機のふりをした Linux マシンで Arch Linux をベースにした SteamOS を搭載しています．

Arch ユーザとしてはさわらずにはいられないなのでこの記事ではデスクトップモードにして Steam Deck の中身を見ていきます．

デスクトップモード​

Steam Deck を起動するとゲーム用のモードで起動するので，まずは KDE のデスクトップに入る必要があります．

電源ボタンを長押しするとこのようなメニューが出てくるので，Switch to Desktop を選択します．

これで KDE のデスクトップに切り替わります！

Konsole がインストールされていたので，早速 SteamOS のインストールされた状態を見てみましょう．

ログインユーザの状態（などなど）​

ログインユーザ名は deck で id, groups の結果はこんな感じでした．いたって普通ですね．

(deck@steamdeck ~)$ id
uid=1000(deck) gid=1000(deck) groups=1000(deck),998(wheel)
(deck@steamdeck ~)$ groups
wheel deck

ちなみにシェルは bash ですが，エラーコードが出るなどプロンプトは見やすくなってます．

ただ，.bashrc と .bash_profile はまっさらでした．

#
# ~/.bashrc
#

# If not running interactively, don't do anything
[[ $- != *i* ]] && return
#  SPDX-License-Identifier: MIT
#
#  Copyright © 2020 Collabora Ltd.
#  Copyright © 2020 Valve Corporation.
#
#  This file is part of steamos-image-recipes.
#
#  steamos-image-recipes is free software; you can redistribute it and/or modify
#  it under the terms of the GNU Lesser General Public License as published
#  by the Free Software Foundation; either version 2.1 of the License, or
#  (at your option) any later version.

#
# ~/.bash_profile
#

[[ -f ~/.bashrc ]] && . ~/.bashrc

どこか別の場所でプロンプトの環境変数だけ設定しているみたいですね．

(deck@steamdeck ~)$ echo $PS
$PS1  $PS2  $PS4
(deck@steamdeck ~)$ echo $PS1
(\[\033[1;32m\]\u@\h\[\033[1;34m\] \W\[\033[0m\])\$
(deck@steamdeck ~)$ echo $PS2
>
(deck@steamdeck ~)$ echo $PS4
+

脱線ついでに，tty の切り替えをやってみましたが，画面が真っ暗になるだけでログインプロンプトは表示されませんでした．

プリインストールされているパッケージ​

それでは次にインストールされているパッケージを確認しようと思います．

Arch ベースなので sudo pacman -Q を実行したいのですが，その前にパスワードの設定をします．

passwd

パッケージリストはそこそこ多かったので gists に入れておきます．

SteamOS_preinstalled_pkgs.log

なんとなく目についたのはこのあたり．

  • AMD のチップだから amd-ucode が入ってる
  • btrfs-progs が入ってるけど Btrfs なの？
  • holo-* と steam* 関連は SteamOS 特有のなにか
  • holo-sudo は何ができるのか？
  • networkmanager は安定
  • openssh と openvpn がもともと入ってる
  • sshfs どこで使うんだろう？
  • なぜか zsh がすでに入ってる

AUR helper は yay が入っているようです．

(deck@steamdeck ~)$ yay -V
yay v10.3.0.r0.g4a93199 - libalpm v13.0.1

AUR からインストールされているパッケージはないみたい．「使いたいユーザは勝手に使えば？」みたいな感じなのかな…．

ミラーリスト​

ミラーリストは Steam Deck 用のサーバのみのようです．

(deck@steamdeck ~)$ cat /etc/pacman.d/mirrorlist
Server = https://steamdeck-packages.steamos.cloud/archlinux-mirror/$repo/os/$arch

Manjaro と同じで Arch のミラーよりもワンクッションおいて安定性を求める感じかなと妄想してみる．

ちなみにカーネルのバージョンは v5.13.0 のカスタムカーネルのようです．2022年10月3日なので2ヶ月位遅いのかな？（カスタムしたのが2ヶ月前なだけでベースバージョンはもっと前のやつかも）

(deck@steamdeck ~)$ uname -a
Linux steamdeck 5.13.0-valve21.3-1-neptune #1 SMP PREEMPT Mon, 03 Oct 2022 23:17:36 +0000 x86_64 GNU/Linux

Arch の現在のカーネルバージョンは v6.0.12 なので割と差が開いていますね．

mori@thinkpad-arch ~ % uname -a
Linux thinkpad-arch 6.0.12-arch1-1 #1 SMP PREEMPT_DYNAMIC Thu, 08 Dec 2022 11:03:38 +0000 x86_64 GNU/Linux

autostart, systemd​

起動時に自動で実行されるアプリケーションを見てみます．ここで Steam Client が実行されているはず（多分）．

(deck@steamdeck ~)$ ls -la .config/autostart/
total 8
drwxr-xr-x  2 deck deck 4096 Dec 17 17:34 .
drwxr-xr-x 17 deck deck 4096 Dec 17 20:57 ..
lrwxrwxrwx  1 deck deck   58 Dec 17 17:34 steamos-update-os-notifier.desktop -> /usr/share/applications/steamos-update-os-notifier.desktop

アップデートがあるときに通知するだけのやつみたいです．

[Desktop Entry]
Name=SteamOS Update Operating System Notifier
Comment=KUpdate Notifier for the new systemtray specification
Exec=/usr/lib/steamos/steamos-update-os-notifier
Icon=system-software-update
Type=Application
NoDisplay=true
OnlyShowIn=KDE
Keywords=kupdate-notifier;system;update;updater

じゃあ systemd にあるのかと思って systemctl list-units したけど特に見当たらず…．というか user が実行しそうな気がするからそもそも systemd に登録するはずないか…？

Steam client の実行については今の所不明ですが，systemd のターゲットの中に cryptsetup を見つけました．

...
home-swapfile.swap     loaded active active  Swap
basic.target           loaded active active  Basic System
bluetooth.target       loaded active active  Bluetooth Support
cryptsetup.target      loaded active active  Local Encrypted Volumes
getty.target           loaded active active  Login Prompts
graphical.target       loaded active active  Graphical Interface
integritysetup.target  loaded active active  Local Integrity Protected Volumes
...

ディスク暗号化してるのかと思いましたが，パッケージリストにはそれらしきものはないので結局よくわかりませんでした．

dm-crypt であれば mkinitcpio のコンフィグになにかあるかと思いましたが，そもそも /etc/mkinitcpio.conf が存在しませんでした．

どうやって initramfs を作っているのか…？

ディスクとパーティション​

接続されたデバイスは 512 GB の SSD のみでした．

なにやら複数のパーティションが作られていますね．

(deck@steamdeck ~)$ lsblk
NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
nvme0n1     259:0    0 476.9G  0 disk
├─nvme0n1p1 259:1    0    64M  0 part
├─nvme0n1p2 259:2    0    32M  0 part
├─nvme0n1p3 259:3    0    32M  0 part
├─nvme0n1p4 259:4    0     5G  0 part /
├─nvme0n1p5 259:5    0     5G  0 part
├─nvme0n1p6 259:6    0   256M  0 part /var
├─nvme0n1p7 259:7    0   256M  0 part
└─nvme0n1p8 259:8    0 466.3G  0 part /var/tmp
                                      /var/log
                                      /var/lib/systemd/coredump
                                      /var/lib/flatpak
                                      /var/lib/docker
                                      /var/cache/pacman
                                      /srv
                                      /root
                                      /opt
                                      /home

fstab ファイルの中身を確認するとこんな感じでした．

(deck@steamdeck ~)$ cat /etc/fstab
# Static information about the filesystems.
# See fstab(5) for details.

# <file system> <dir> <type> <options> <dump> <pass>
# SteamOS partitions
#/dev/disk/by-partsets/self/rootfs /       ext4    defaults                0       1
#/dev/disk/by-partsets/self/var    /var    ext4    defaults                0       2
/dev/disk/by-partsets/self/efi    /efi    vfat    defaults,nofail,umask=0077,x-systemd.automount,x-systemd.idle-timeout=1min 0       2
/dev/disk/by-partsets/shared/esp  /esp    vfat    defaults,nofail,umask=0077,x-systemd.automount,x-systemd.idle-timeout=1min 0       2
/dev/disk/by-partsets/shared/home /home   ext4    defaults,nofail,x-systemd.growfs 0       2

とりあえず ext4 でフォーマットしてるのかな？

lsblk したときの nvme0n1p8 の表記が btrfs のサブボリュームの表記の仕方に似ていたので btrfs なのかと思ったけど違いました．

cf:

mori@thinkpad-arch ~ % lsblk
NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
nvme0n1     259:0    0 476.9G  0 disk
├─nvme0n1p1 259:1    0   100M  0 part /boot
├─nvme0n1p2 259:2    0    16M  0 part
├─nvme0n1p3 259:3    0 220.3G  0 part
├─nvme0n1p4 259:4    0   548M  0 part
└─nvme0n1p5 259:5    0   256G  0 part /var/log
                                      /home
                                      /.snapshots
                                      /
mori@thinkpad-arch ~ % cat /etc/fstab
───────┬──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
       │ File: /etc/fstab
───────┼──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
   1   │ # Static information about the filesystems.
   2   │ # See fstab(5) for details.
   3   │
   4   │ # <file system> <dir> <type> <options> <dump> <pass>
   5   │ # /dev/nvme0n1p5
   6   │ UUID=ed5e0803-dd6b-434e-8094-635498d65036   /           btrfs       rw,noatime,compress=lzo,ssd,space_cache=v2,subvolid=256,subvol=/@,subvol=@  0 0
   7   │
   8   │ # /dev/nvme0n1p1
   9   │ UUID=3C4A-3D26          /boot       vfat        rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro   0 2
  10   │
  11   │ # /dev/nvme0n1p5
  12   │ UUID=ed5e0803-dd6b-434e-8094-635498d65036   /home       btrfs       rw,noatime,compress=lzo,ssd,space_cache=v2,subvolid=257,subvol=/@home,subvol=@home  0 0
  13   │
  14   │ # /dev/nvme0n1p5
  15   │ UUID=ed5e0803-dd6b-434e-8094-635498d65036   /.snapshots btrfs       rw,noatime,compress=lzo,ssd,space_cache=v2,subvolid=258,subvol=/@snapshots,subvol=@snapshots    0 0
  16   │
  17   │ # /dev/nvme0n1p5
  18   │ UUID=ed5e0803-dd6b-434e-8094-635498d65036   /var/log    btrfs       rw,noatime,compress=lzo,ssd,space_cache=v2,subvolid=259,subvol=/@var_log,subvol=@var_log    0 0
  19   │
───────┴──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────

Kernel​

最後にカーネルのソースコードを見ようかと思ったのですが，/usr/src 下にコードはありませんでした…．

パッケージの追加​

pacman は使えそうなのでためしに neofetch をインストールしてみます．ロゴは Arch なのかSteamOS なのか…．

まずはパッケージのデータベースを更新します．（jupiter と holo はArch では見たことがない名前ですね．）

(deck@steamdeck src)$ sudo pacman -Sy
[sudo] password for deck:
:: Synchronizing package databases...
 jupiter is up to date
 holo is up to date
 core is up to date
 extra is up to date
 community is up to date
 multilib is up to date

次に neofetch をインストールします．

...失敗しましたね．

(deck@steamdeck src)$ sudo pacman -S neofetch
resolving dependencies...
looking for conflicting packages...

Packages (1) neofetch-7.1.0-2

Total Installed Size:  0.33 MiB

:: Proceed with installation? [Y/n]
(1/1) checking keys in keyring                                                                                         [########################################################################] 100%
(1/1) checking package integrity                                                                                       [########################################################################] 100%
(1/1) loading package files                                                                                            [########################################################################] 100%
(1/1) checking for file conflicts                                                                                      [########################################################################] 100%
(1/1) checking available disk space                                                                                    [########################################################################] 100%
:: Processing package changes...
(1/1) installing neofetch                                                                                              [########################################################################] 100%
warning: warning given when extracting /usr/bin/neofetch (Can't create '/usr/bin/neofetch')
warning: warning given when extracting /usr/share/licenses/neofetch/ (Can't create '/usr/share/licenses/neofetch')
warning: warning given when extracting /usr/share/licenses/neofetch/LICENSE.md (Failed to create dir '/usr/share/licenses/neofetch')
warning: warning given when extracting /usr/share/man/man1/neofetch.1.gz (Can't create '/usr/share/man/man1/neofetch.1.gz')
Optional dependencies for neofetch
    catimg: Display Images
    chafa: Image to text support
    feh: Wallpaper Display
    imagemagick: Image cropping / Thumbnail creation / Take a screenshot
    jp2a: Display Images
    libcaca: Display Images
    nitrogen: Wallpaper Display
    w3m: Display Images
    xdotool: See https://github.com/dylanaraps/neofetch/wiki/Images-in-the-terminal [installed]
    xorg-xdpyinfo: Resolution detection (Single Monitor) [installed]
    xorg-xprop: Desktop Environment and Window Manager [installed]
    xorg-xrandr: Resolution detection (Multi Monitor + Refresh rates) [installed]
    xorg-xwininfo: See https://github.com/dylanaraps/neofetch/wiki/Images-in-the-terminal [installed]
:: Running post-transaction hooks...
(1/1) Arming ConditionNeedsUpdate...
touch: setting times of '/usr': Read-only file system
error: command failed to execute correctly

ファイルを持ってくることはできたけど /usr 以下に書き込めなかったという感じでしょうか．

しかし，ls -l / した限りでは root なら書き込めそうです．

(deck@steamdeck src)$ ls -l /
total 71
lrwxrwxrwx   1 root root     7 Apr 29  2022 bin -> usr/bin
drwxr-xr-x   1 root root   136 Dec 14 08:40 boot
drwxr-xr-x  21 root root  4120 Dec 17 21:49 dev
drwx------   4 root root 16384 Jan  1  1970 efi
drwx------   4 root root 16384 Jan  1  1970 esp
drwxr-xr-x   1 root root  1024 Dec 17 23:24 etc
drwxr-xr-x   5 root root  4096 Dec 17 17:34 home
lrwxrwxrwx   1 root root     7 Apr 29  2022 lib -> usr/lib
lrwxrwxrwx   1 root root     7 Apr 29  2022 lib64 -> usr/lib
lrwxrwxrwx   1 root root     7 Apr 29  2022 mnt -> var/mnt
drwxr-xr-x   2 root root  4096 Dec 17 17:34 opt
dr-xr-xr-x 332 root root     0 Dec 17 17:39 proc
drwxr-x---   6 root root  4096 Dec 17 22:43 root
drwxr-xr-x  25 root root   600 Dec 17 20:28 run
lrwxrwxrwx   1 root root     7 Apr 29  2022 sbin -> usr/bin
drwxr-xr-x   4 root root  4096 Dec 17 17:34 srv
dr-xr-xr-x  12 root root     0 Dec 17 17:39 sys
drwxrwxrwt  15 root root   580 Dec 17 21:46 tmp
drwxr-xr-x   1 root root    80 Dec 17 23:23 usr
drwxr-xr-x  14 root root  1024 Dec 17 19:02 var

'/usr': Read-only file system とあるので，アクセス権限以前の問題でしょうか？

調べてみると他のユーザも同じ状況のようです．

How to solve the read only system /usr

Developper Mode にしても Read-only は消えないようですね．

Steam Deck Developer Mode does not turn off the read-only filesystem

ただし，上記2つの URL の先でも示されているのですが，解決策はあるようです．

公式による解決策:

What if I want to do more than what’s available by flatpak?

Totally fine, though it comes with several caveats. Make sure you know what you’re doing and be careful about running random commands / scripts you find on the internet - you may get your Steam Deck into a bad state or compromise your data. In addition, anything you install outside of flatpak (via pacman for instance) may be wiped with the next SteamOS update.

With that out of the way, if you are going outside flatpak and need to edit the read-only image, you can enable that with the following command:

sudo steamos-readonly disable

See below for instructions on using sudo with Steam Deck. One more warning to complete the warning sandwich – don’t do the above unless you know what you’re doing.

そのとおりにやってみたところうまく行きました．

(deck@steamdeck src)$ sudo steamos-readonly disable
[sudo] password for deck:
(deck@steamdeck src)$ sudo pacman -S neofetch
resolving dependencies...
looking for conflicting packages...

Packages (1) neofetch-7.1.0-2

Total Installed Size:  0.33 MiB

:: Proceed with installation? [Y/n]
(1/1) checking keys in keyring                                                                                         [########################################################################] 100%
(1/1) checking package integrity                                                                                       [########################################################################] 100%
(1/1) loading package files                                                                                            [########################################################################] 100%
(1/1) checking for file conflicts                                                                                      [########################################################################] 100%
(1/1) checking available disk space                                                                                    [########################################################################] 100%
:: Processing package changes...
(1/1) installing neofetch                                                                                              [########################################################################] 100%
Optional dependencies for neofetch
    catimg: Display Images
    chafa: Image to text support
    feh: Wallpaper Display
    imagemagick: Image cropping / Thumbnail creation / Take a screenshot
    jp2a: Display Images
    libcaca: Display Images
    nitrogen: Wallpaper Display
    w3m: Display Images
    xdotool: See https://github.com/dylanaraps/neofetch/wiki/Images-in-the-terminal [installed]
    xorg-xdpyinfo: Resolution detection (Single Monitor) [installed]
    xorg-xprop: Desktop Environment and Window Manager [installed]
    xorg-xrandr: Resolution detection (Multi Monitor + Refresh rates) [installed]
    xorg-xwininfo: See https://github.com/dylanaraps/neofetch/wiki/Images-in-the-terminal [installed]
:: Running post-transaction hooks...
(1/1) Arming ConditionNeedsUpdate...

この方法でインストールしたパッケージは SteamOS のアプデートで消える可能性があるようなので Flatpak を使ったほうが良いみたいですが，とりあえずこれで何でもできますね．

neofetch の実行結果は冒頭の通りでした．Steam のロゴマークでしたね．

おわり​

Steam Deck は（一応）一般向けのゲーム機という位置づけなのでシステムが壊れないようにある程度の制限はあるようです．

また，全体的にディレクトリ構造がデフォルトとは違う，パーティションなどが複雑に分割されている，mkinitcpio などあるはずのものがないなど，普段使っている Arch の環境と違うことが多かったです．

Linux の勉強も兼ねてまた今度じっくり中身を見てみようと思います．