5 files changed, 10 insertions, 26 deletions
diff --git a/kernel/acct.c b/kernel/acct.c
index dd68b9059418..f6006a60df5d 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -548,7 +548,7 @@ static void do_acct_process(struct bsd_acct_struct *acct,
 #endif
 
 	spin_lock_irq(&current->sighand->siglock);
-	tty = current->signal->tty;
+	tty = current->signal->tty;	/* Safe as we hold the siglock */
 	ac.ac_tty = tty ? old_encode_dev(tty_devnum(tty)) : 0;
 	ac.ac_utime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_utime)));
 	ac.ac_stime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_stime)));
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 59cedfb040e7..cf5bc2f5f9c3 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -246,8 +246,8 @@ static int audit_match_perm(struct audit_context *ctx, int mask)
 	unsigned n;
 	if (unlikely(!ctx))
 		return 0;
-
 	n = ctx->major;
+
 	switch (audit_classify_syscall(ctx->arch, n)) {
 	case 0:	/* native */
 		if ((mask & AUDIT_PERM_WRITE) &&
@@ -1204,13 +1204,13 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
 				 (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
 				 context->return_code);
 
-	mutex_lock(&tty_mutex);
-	read_lock(&tasklist_lock);
+	spin_lock_irq(&tsk->sighand->siglock);
 	if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
 		tty = tsk->signal->tty->name;
 	else
 		tty = "(none)";
-	read_unlock(&tasklist_lock);
+	spin_unlock_irq(&tsk->sighand->siglock);
+
 	audit_log_format(ab,
 		  " a0=%lx a1=%lx a2=%lx a3=%lx items=%d"
 		  " ppid=%d pid=%d auid=%u uid=%u gid=%u"
@@ -1230,7 +1230,6 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
 		  context->egid, context->sgid, context->fsgid, tty,
 		  tsk->sessionid);
 
-	mutex_unlock(&tty_mutex);
 
 	audit_log_task_info(ab, tsk);
 	if (context->filterkey) {
diff --git a/kernel/fork.c b/kernel/fork.c
index 7ce2ebe84796..30de644a40c4 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -802,6 +802,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
 
 	sig->leader = 0;	/* session leadership doesn't inherit */
 	sig->tty_old_pgrp = NULL;
+	sig->tty = NULL;
 
 	sig->utime = sig->stime = sig->cutime = sig->cstime = cputime_zero;
 	sig->gtime = cputime_zero;
@@ -838,6 +839,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
 void __cleanup_signal(struct signal_struct *sig)
 {
 	exit_thread_group_keys(sig);
+	tty_kref_put(sig->tty);
 	kmem_cache_free(signal_cachep, sig);
 }
 
@@ -1227,7 +1229,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 				p->nsproxy->pid_ns->child_reaper = p;
 
 			p->signal->leader_pid = pid;
-			p->signal->tty = current->signal->tty;
+			tty_kref_put(p->signal->tty);
+			p->signal->tty = tty_kref_get(current->signal->tty);
 			set_task_pgrp(p, task_pgrp_nr(current));
 			set_task_session(p, task_session_nr(current));
 			attach_pid(p, PIDTYPE_PGID, task_pgrp(current));
diff --git a/kernel/printk.c b/kernel/printk.c
index b51b1567bb55..a430fd04008b 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -1291,22 +1291,6 @@ static int __init disable_boot_consoles(void)
 }
 late_initcall(disable_boot_consoles);
 
-/**
- * tty_write_message - write a message to a certain tty, not just the console.
- * @tty: the destination tty_struct
- * @msg: the message to write
- *
- * This is used for messages that need to be redirected to a specific tty.
- * We don't put it into the syslog queue right now maybe in the future if
- * really needed.
- */
-void tty_write_message(struct tty_struct *tty, char *msg)
-{
-	if (tty && tty->ops->write)
-		tty->ops->write(tty, msg, strlen(msg));
-	return;
-}
-
 #if defined CONFIG_PRINTK
 
 /*
diff --git a/kernel/sys.c b/kernel/sys.c
index 038a7bc0901d..234d9454294e 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1060,9 +1060,7 @@ asmlinkage long sys_setsid(void)
 	group_leader->signal->leader = 1;
 	__set_special_pids(sid);
 
-	spin_lock(&group_leader->sighand->siglock);
-	group_leader->signal->tty = NULL;
-	spin_unlock(&group_leader->sighand->siglock);
+	proc_clear_tty(group_leader);
 
 	err = session;
 out: