Security is an important factor when it comes to an operating system. Hardening the system is done to prevent as many exploits as possible. There are multiple factors which should be considered.

## Apparmor and LSM

Apparmor is a Mandatory Access Control (MAC) system that restricts capabilities from a program on a computer. It can dissallow access to files which the program would not require. Make sure the `apparmor` USE flag is enabled and install the necessary programs:

``` shell-session
sh# emerge -av apparmor apparmor-utils
sh# rc-update add apparmor boot
```

Then add apparmor and other Linux Security Modules (LSM) to the `cmdline` and rebuild the initramfs:

``` title="/etc/kernel/cmdline"
... apparmor=1 lsm=landlock,lockdown,yama,capability,integrity,apparmor
```

``` shell-session
sh# emerge --config gentoo-kernel # or gentoo-kernel-bin etc.
```