Let's help users by documenting how to enable and check for Landlock in the kernel and the running system. The userspace-api section may not be the best place for this but it still makes sense to put all the user documentation at the same place. Cc: Paul Moore <paul@xxxxxxxxxxxxxx> Signed-off-by: Mickaël Salaün <mic@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20220512120847.124822-1-mic@xxxxxxxxxxx --- Documentation/userspace-api/landlock.rst | 26 ++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/Documentation/userspace-api/landlock.rst b/Documentation/userspace-api/landlock.rst index 7b4fe6218132..e69dbddcc191 100644 --- a/Documentation/userspace-api/landlock.rst +++ b/Documentation/userspace-api/landlock.rst @@ -388,6 +388,32 @@ Starting with the Landlock ABI version 2, it is now possible to securely control renaming and linking thanks to the new `LANDLOCK_ACCESS_FS_REFER` access right. +Landlock support +================ + +Kernel configuration +-------------------- + +Landlock can be supported since Linux 5.13 but it must be configured in the +kernel with `CONFIG_SECURITY_LANDLOCK=y`, and it should be enabled at boot time +with `CONFIG_LSM=landlock,[...]`. The `[...]` must be replaced with the list +of LSMs that may be useful for the running system (see the `CONFIG_LSM` help). + +Running system configuration +---------------------------- + +If the running kernel doesn't have `landlock` in `CONFIG_LSM`, then we can +still enable it by adding `lsm=landlock,[...]` to +Documentation/admin-guide/kernel-parameters.rst. The `[...]` must be replaced +with the list of LSMs that may be useful for the running system (see the +`CONFIG_LSM` help). + +Running system check +-------------------- + +We can check that Landlock is enabled by looking for "landlock: Up and running" +in kernel logs: `dmesg | grep landlock` + Questions and answers ===================== base-commit: 67761d8181f0fb9dbd264caa5b6408dbc0d8e86a -- 2.36.0
