doc: ReSTify and split LSM.txt

The existing LSM.txt file covered both usage and development, so split
this into two files, one under admin-guide and one under kernel
development.

Cc: James Morris <james.l.morris@oracle.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

4 files changed, 15 insertions, 43 deletions

diff --git a/Documentation/security/00-INDEX b/Documentation/security/00-INDEX
index c4df62a9ae5b..190a023a7e72 100644
--- a/Documentation/security/00-INDEX
+++ b/Documentation/security/00-INDEX
@@ -1,7 +1,5 @@
 00-INDEX
 	- this file.
-LSM.txt
-	- description of the Linux Security Module framework.
 SELinux.txt
 	- how to get started with the SELinux security enhancement.
 Smack.txt
diff --git a/Documentation/security/LSM.rst b/Documentation/security/LSM.rst
new file mode 100644
index 000000000000..d75778b0fa10
--- /dev/null
+++ b/Documentation/security/LSM.rst
@@ -0,0 +1,14 @@
+=================================
+Linux Security Module Development
+=================================
+
+Based on https://lkml.org/lkml/2007/10/26/215,
+a new LSM is accepted into the kernel when its intent (a description of
+what it tries to protect against and in what cases one would expect to
+use it) has been appropriately documented in ``Documentation/security/LSM``.
+This allows an LSM's code to be easily compared to its goals, and so
+that end users and distros can make a more informed decision about which
+LSMs suit their requirements.
+
+For extensive documentation on the available LSM hook interfaces, please
+see ``include/linux/lsm_hooks.h``.
diff --git a/Documentation/security/LSM.txt b/Documentation/security/LSM.txt
deleted file mode 100644
index c2683f28ed36..000000000000
--- a/Documentation/security/LSM.txt
+++ /dev/null
@@ -1,41 +0,0 @@
-Linux Security Module framework
--------------------------------
-
-The Linux Security Module (LSM) framework provides a mechanism for
-various security checks to be hooked by new kernel extensions. The name
-"module" is a bit of a misnomer since these extensions are not actually
-loadable kernel modules. Instead, they are selectable at build-time via
-CONFIG_DEFAULT_SECURITY and can be overridden at boot-time via the
-"security=..." kernel command line argument, in the case where multiple
-LSMs were built into a given kernel.
-
-The primary users of the LSM interface are Mandatory Access Control
-(MAC) extensions which provide a comprehensive security policy. Examples
-include SELinux, Smack, Tomoyo, and AppArmor. In addition to the larger
-MAC extensions, other extensions can be built using the LSM to provide
-specific changes to system operation when these tweaks are not available
-in the core functionality of Linux itself.
-
-Without a specific LSM built into the kernel, the default LSM will be the
-Linux capabilities system. Most LSMs choose to extend the capabilities
-system, building their checks on top of the defined capability hooks.
-For more details on capabilities, see capabilities(7) in the Linux
-man-pages project.
-
-A list of the active security modules can be found by reading
-/sys/kernel/security/lsm. This is a comma separated list, and
-will always include the capability module. The list reflects the
-order in which checks are made. The capability module will always
-be first, followed by any "minor" modules (e.g. Yama) and then
-the one "major" module (e.g. SELinux) if there is one configured.
-
-Based on https://lkml.org/lkml/2007/10/26/215,
-a new LSM is accepted into the kernel when its intent (a description of
-what it tries to protect against and in what cases one would expect to
-use it) has been appropriately documented in Documentation/security/.
-This allows an LSM's code to be easily compared to its goals, and so
-that end users and distros can make a more informed decision about which
-LSMs suit their requirements.
-
-For extensive documentation on the available LSM hook interfaces, please
-see include/linux/security.h.
diff --git a/Documentation/security/index.rst b/Documentation/security/index.rst
index 4212d7ac58b6..94ba1cfc01c5 100644
--- a/Documentation/security/index.rst
+++ b/Documentation/security/index.rst
@@ -7,5 +7,6 @@ Security Documentation
 
    credentials
    IMA-templates
+   LSM
    self-protection
    tpm/index