audit: move audit_get_tty to reduce scope and kabi changes

The only users of audit_get_tty and audit_put_tty are internal to
audit, so move it out of include/linux/audit.h to kernel.h and create
a proper function rather than inlining it.  This also reduces kABI
changes.
Suggested-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: line wrapped description]
Signed-off-by: Paul Moore <paul@paul-moore.com>

include/linux/audit.h

@@ -26,7 +26,6 @@
 #include <linux/sched.h>
 #include <linux/ptrace.h>
 #include <uapi/linux/audit.h>
-#include <linux/tty.h>
 
 #define AUDIT_INO_UNSET ((unsigned long)-1)
 #define AUDIT_DEV_UNSET ((dev_t)-1)
@@ -344,23 +343,6 @@ static inline unsigned int audit_get_sessionid(struct task_struct *tsk)
 	return tsk->sessionid;
 }
 
-static inline struct tty_struct *audit_get_tty(struct task_struct *tsk)
-{
-	struct tty_struct *tty = NULL;
-	unsigned long flags;
-
-	spin_lock_irqsave(&tsk->sighand->siglock, flags);
-	if (tsk->signal)
-		tty = tty_kref_get(tsk->signal->tty);
-	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
-	return tty;
-}
-
-static inline void audit_put_tty(struct tty_struct *tty)
-{
-	tty_kref_put(tty);
-}
-
 extern void __audit_ipc_obj(struct kern_ipc_perm *ipcp);
 extern void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode);
 extern void __audit_bprm(struct linux_binprm *bprm);
@@ -518,12 +500,6 @@ static inline unsigned int audit_get_sessionid(struct task_struct *tsk)
 {
 	return -1;
 }
-static inline struct tty_struct *audit_get_tty(struct task_struct *tsk)
-{
-	return NULL;
-}
-static inline void audit_put_tty(struct tty_struct *tty)
-{ }
 static inline void audit_ipc_obj(struct kern_ipc_perm *ipcp)
 { }
 static inline void audit_ipc_set_perm(unsigned long qbytes, uid_t uid,

kernel/audit.c

@@ -1866,6 +1866,23 @@ void audit_log_d_path_exe(struct audit_buffer *ab,
 	audit_log_format(ab, " exe=(null)");
 }
 
+struct tty_struct *audit_get_tty(struct task_struct *tsk)
+{
+	struct tty_struct *tty = NULL;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tsk->sighand->siglock, flags);
+	if (tsk->signal)
+		tty = tty_kref_get(tsk->signal->tty);
+	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
+	return tty;
+}
+
+void audit_put_tty(struct tty_struct *tty)
+{
+	tty_kref_put(tty);
+}
+
 void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
 {
 	const struct cred *cred;

kernel/audit.h

@@ -23,6 +23,7 @@
 #include <linux/audit.h>
 #include <linux/skbuff.h>
 #include <uapi/linux/mqueue.h>
+#include <linux/tty.h>
 
 /* AUDIT_NAMES is the number of slots we reserve in the audit_context
  * for saving names from getname().  If we get more names we will allocate
@@ -262,6 +263,9 @@ extern struct audit_entry *audit_dupe_rule(struct audit_krule *old);
 extern void audit_log_d_path_exe(struct audit_buffer *ab,
 				 struct mm_struct *mm);
 
+extern struct tty_struct *audit_get_tty(struct task_struct *tsk);
+extern void audit_put_tty(struct tty_struct *tty);
+
 /* audit watch functions */
 #ifdef CONFIG_AUDIT_WATCH
 extern void audit_put_watch(struct audit_watch *watch);

kernel/auditsc.c

@@ -63,7 +63,6 @@
 #include <asm/unistd.h>
 #include <linux/security.h>
 #include <linux/list.h>
-#include <linux/tty.h>
 #include <linux/binfmts.h>
 #include <linux/highmem.h>
 #include <linux/syscalls.h>