LSM: shrink the common_audit_data data union

After shrinking the common_audit_data stack usage for private LSM data I'm
not going to shrink the data union.  To do this I'm going to move anything
larger than 2 void * ptrs to it's own structure and require it to be declared
separately on the calling stack.  Thus hot paths which don't need more than
a couple pointer don't have to declare space to hold large unneeded
structures.  I could get this down to one void * by dealing with the key
struct and the struct path.  We'll see if that is helpful after taking care of
networking.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 18 insertions, 17 deletions

diff --git a/include/linux/lsm_audit.h b/include/linux/lsm_audit.h
index 6f4fb37aac88..d1b073ffec24 100644
--- a/include/linux/lsm_audit.h
+++ b/include/linux/lsm_audit.h
@@ -22,6 +22,23 @@
 #include <linux/key.h>
 #include <linux/skbuff.h>
 
+struct lsm_network_audit {
+        int netif;
+        struct sock *sk;
+        u16 family;
+        __be16 dport;
+        __be16 sport;
+        union {
+                struct {
+                        __be32 daddr;
+                        __be32 saddr;
+                } v4;
+                struct {
+                        struct in6_addr daddr;
+                        struct in6_addr saddr;
+                } v6;
+        } fam;
+};
 
 /* Auxiliary data to use in generating the audit record. */
 struct common_audit_data {
@@ -41,23 +58,7 @@ struct common_audit_data {
                 struct path path;
                 struct dentry *dentry;
                 struct inode *inode;
-                struct {
-                        int netif;
-                        struct sock *sk;
-                        u16 family;
-                        __be16 dport;
-                        __be16 sport;
-                        union {
-                                struct {
-                                        __be32 daddr;
-                                        __be32 saddr;
-                                } v4;
-                                struct {
-                                        struct in6_addr daddr;
-                                        struct in6_addr saddr;
-                                } v6;
-                        } fam;
-                } net;
+                struct lsm_network_audit *net;
                 int cap;
                 int ipc_id;
                 struct task_struct *tsk;