Re: [PATCH] README.md: clarify minimum supported kernel and policy versions

[Petr Lautrbach <plautrba@redhat.com>]

Stephen Smalley <stephen.smalley.work@gmail.com> writes:

> Clarify the minimum supported kernel and policy versions.
>
> The Linux v3.0 kernel requirement is only for libselinux and anything
> that uses libselinux to access selinuxfs. The policy build toolchain
> does not link with libselinux or have any other runtime dependencies
> on a particular Linux kernel version or even on Linux at all.
>
> Note the libsepol version in which kernel policy version 24 was first
> introduced, and also note the first userspace release tag that
> included the relevant libsepol versions. At that time, the release
> tags were date-based rather than version-based and the versions were
> updated more frequently than just once per release, so userspace
> release 20090403 was the first to include both libsepol version
> updates.
>
> Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>

Acked-by: Petr Lautrbach <lautrbach@redhat.com>

> ---
>  README.md | 22 ++++++++++++++++------
>  1 file changed, 16 insertions(+), 6 deletions(-)
>
> diff --git a/README.md b/README.md
> index f256912c..bfd32b89 100644
> --- a/README.md
> +++ b/README.md
> @@ -25,18 +25,28 @@ for more information.
>  
>  Minimum Supported Kernel Version
>  --------------------------------
> -Linux v3.0 (for /sys/fs/selinux mount point directory)
> +Linux v3.0 (for /sys/fs/selinux mount point directory) for libselinux
> +and anything that uses libselinux to access selinuxfs.
> +
> +Note that the policy build toolchain (e.g. libsepol, checkpolicy,
> +checkmodule, secilc, semodule_package/expand/link) does not link with
> +libselinux or have any other runtime dependencies on a particular
> +Linux kernel version. The policy build toolchain has in the past
> +successfully been built and run on non-Linux platforms as well
> +(e.g. macOS), although this is not officially supported.
>  
>  Minimum Supported Policy Version
>  --------------------------------
>  Kernel policy version 24 (boundary) for the SELinux and Xen
> -targets. Support for this policy version first shipped in Linux
> -v2.6.28 and Xen 4.0.0. libsepol dropped support for kernel policy
> -versions older than 24 starting with libsepol 3.12.
> +targets. Support for this policy version first shipped in libsepol
> +2.0.34 (userspace release 20090403), Linux v2.6.28, and Xen
> +4.0.0. libsepol dropped support for kernel policy versions older than
> +24 starting with libsepol 3.12.
>  
>  Modular policy version 10 (boundary alias). Support for this modular
> -policy version first shipped in libsepol 2.0.35. libsepol dropped
> -support for modular policies older than 10 starting with libsepol 3.12
> +policy version first shipped in libsepol 2.0.35 (userspace release
> +20090403). libsepol dropped support for modular policies older than 10
> +starting with libsepol 3.12
>  
>  Installation
>  ------------
> -- 
> 2.55.0