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.
  
  Based on http://kerneltrap.org/Linux/Documenting_Security_Module_Intent,
  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.