Previously, when LSMs registered, they independently passed their name
and hook count. This had two implications:

1) Is required us to clone the name, so we could present it in
   security FS. This required memory allocation at start time.
2) Every time we wanted to tie more information back from
   the security hooks, to the LSM, we would have to add
   duplicated fields in struct security_hook_list.

It also introduces a new file -- security/security.h, which is meant
to be private headers to be shared only between pieces of security
"infrastructure".

Signed-off-by: Sargun Dhillon <redacted>
---
 include/linux/lsm_hooks.h  | 44 ++++++++++-------------
 security/apparmor/lsm.c    |  6 ++--
 security/commoncap.c       |  8 +++--
 security/inode.c           | 56 +++++++++++++++++++++++++----
 security/loadpin/loadpin.c |  4 ++-
 security/security.c        | 89 +++++++++++++++++++++++-----------------------
 security/security.h        | 10 ++++++
 security/selinux/hooks.c   |  6 ++--
 security/smack/smack_lsm.c |  3 +-
 security/tomoyo/tomoyo.c   |  4 ++-
 security/yama/yama_lsm.c   |  4 ++-
 11 files changed, 147 insertions(+), 87 deletions(-)
 create mode 100644 security/security.h

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 9d0b286f3dba..65f346cb6639 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h

@@ -2004,11 +2004,20 @@ struct security_hook_heads {
  * Security module hook list structure.
  * For use with generic list macros for common operations.
  */
+struct security_hook_list;
+struct lsm_info {
+       struct hlist_node               list;
+       const char                      *name;
+       const unsigned int              count;
+       struct security_hook_list       *hooks;
+} __randomize_layout;
+
 struct security_hook_list {
        struct hlist_node               list;
        struct hlist_head               *head;
        union security_list_options     hook;
-       char                            *lsm;
+       /* This field is not currently in use */
+       struct lsm_info                 *info;

 } __randomize_layout;

 /*

@@ -2020,33 +2029,18 @@ struct security_hook_list {
 #define LSM_HOOK_INIT(HEAD, HOOK) \
        { .head = &security_hook_heads.HEAD, .hook = { .HEAD = HOOK } }

-extern struct security_hook_heads security_hook_heads;
-extern char *lsm_names;
+#define LSM_MODULE_INIT(NAME, HOOKS)           \
+       {                                       \
+               .name   = NAME,                 \
+               .hooks  = HOOKS,                \
+               .count  = ARRAY_SIZE(HOOKS),    \
+       }