Comment 13 for bug 1903351

I've tested focal/groovy/hirsute and the changes seem to work.

---

root@9ff1aefae2e8:/tmp# cat /etc/os-release
NAME="Ubuntu"
VERSION="20.04.2 LTS (Focal Fossa)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 20.04.2 LTS"
VERSION_ID="20.04"
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"
VERSION_CODENAME=focal
UBUNTU_CODENAME=focal

root@9ff1aefae2e8:/tmp# sysctl -V
sysctl from procps-ng UNKNOWN

root@9ff1aefae2e8:/tmp# dpkg -l procps
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-==============-===================-============-=================================
ii procps 2:3.3.16-1ubuntu2.2 amd64 /proc file system utilities

root@9ff1aefae2e8:/tmp# echo "kernel.shmmax = 17179869184" > shmmax.conf
root@9ff1aefae2e8:/tmp# sysctl -e -p shmmax.conf; echo $?
sysctl: setting key "kernel.shmmax", ignoring: Read-only file system
0

root@9ff1aefae2e8:/tmp# echo "-kernel.shmmax = 17179869184" > shmmax.conf
root@9ff1aefae2e8:/tmp# sysctl -e -p shmmax.conf; echo $?
sysctl: setting key "kernel.shmmax", ignoring: Read-only file system
0

root@9ff1aefae2e8:/tmp# useradd test
root@9ff1aefae2e8:/tmp# su test
$ bash

test@9ff1aefae2e8:/tmp$ echo "kernel.shmmax = 17179869184" > shmmax.conf
test@9ff1aefae2e8:/tmp$ sysctl -e -p shmmax.conf; echo $?
sysctl: permission denied on key "kernel.shmmax", ignoring
0

test@9ff1aefae2e8:/tmp$ echo "-kernel.shmmax = 17179869184" > shmmax.conf
test@9ff1aefae2e8:/tmp$ sysctl -e -p shmmax.conf; echo $?
sysctl: permission denied on key "kernel.shmmax", ignoring
0

---

root@bc651792633c:/tmp# cat /etc/os-release
NAME="Ubuntu"
VERSION="20.10 (Groovy Gorilla)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 20.10"
VERSION_ID="20.10"
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"
VERSION_CODENAME=groovy
UBUNTU_CODENAME=groovy

root@bc651792633c:/tmp# sysctl -V
sysctl from procps-ng 3.3.16

root@bc651792633c:/tmp# dpkg -l procps
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-==============-===================-============-=================================
ii procps 2:3.3.16-5ubuntu2.2 amd64 /proc file system utilities

root@bc651792633c:/tmp# echo "kernel.shmmax = 17179869184" > shmmax.conf
root@bc651792633c:/tmp# sysctl -e -p shmmax.conf; echo $?
sysctl: setting key "kernel.shmmax", ignoring: Read-only file system
0

root@bc651792633c:/tmp# echo "-kernel.shmmax = 17179869184" > shmmax.conf
root@bc651792633c:/tmp# sysctl -e -p shmmax.conf; echo $?
sysctl: setting key "kernel.shmmax", ignoring: Read-only file system
0

root@bc651792633c:/tmp# useradd test
root@bc651792633c:/tmp# su test
$ bash

test@bc651792633c:/tmp$ echo "kernel.shmmax = 17179869184" > shmmax.conf
test@bc651792633c:/tmp$ sysctl -e -p shmmax.conf; echo $?
sysctl: permission denied on key "kernel.shmmax", ignoring
0

test@bc651792633c:/tmp$ echo "-kernel.shmmax = 17179869184" > shmmax.conf
test@bc651792633c:/tmp$ sysctl -e -p shmmax.conf; echo $?
sysctl: permission denied on key "kernel.shmmax", ignoring
0

---

root@78489e17c933:/tmp# cat /etc/os-release
NAME="Ubuntu"
VERSION="21.04 (Hirsute Hippo)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 21.04"
VERSION_ID="21.04"
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"
VERSION_CODENAME=hirsute
UBUNTU_CODENAME=hirsute

root@78489e17c933:/tmp# sysctl -V
sysctl from procps-ng 3.3.16

root@78489e17c933:/tmp# dpkg -l procps
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-==============-===================-============-=================================
ii procps 2:3.3.16-5ubuntu3.1 amd64 /proc file system utilities

root@78489e17c933:/tmp# echo "kernel.shmmax = 17179869184" > shmmax.conf
root@78489e17c933:/tmp# sysctl -e -p shmmax.conf; echo $?
sysctl: setting key "kernel.shmmax", ignoring: Read-only file system
0

root@78489e17c933:/tmp# echo "-kernel.shmmax = 17179869184" > shmmax.conf
root@78489e17c933:/tmp# sysctl -e -p shmmax.conf; echo $?
sysctl: setting key "kernel.shmmax", ignoring: Read-only file system
0

root@78489e17c933:/tmp# useradd test
root@78489e17c933:/tmp# su test
$ bash

test@78489e17c933:/tmp$ echo "kernel.shmmax = 17179869184" > shmmax.conf
test@78489e17c933:/tmp$ sysctl -e -p shmmax.conf; echo $?
sysctl: permission denied on key "kernel.shmmax", ignoring
0

test@78489e17c933:/tmp$ echo "-kernel.shmmax = 17179869184" > shmmax.conf
test@78489e17c933:/tmp$ sysctl -e -p shmmax.conf; echo $?
sysctl: permission denied on key "kernel.shmmax", ignoring
0