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-rw-r--r--drivers/char/tty_io.c18
-rw-r--r--drivers/s390/char/fs3270.c1
-rw-r--r--fs/dquot.c2
-rw-r--r--security/selinux/hooks.c2
4 files changed, 5 insertions, 18 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index b5f57d0b30ee..f40298e9873a 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -739,13 +739,11 @@ void tty_vhangup_self(void)
{
struct tty_struct *tty;
- mutex_lock(&tty_mutex);
tty = get_current_tty();
if (tty) {
tty_vhangup(tty);
tty_kref_put(tty);
}
- mutex_unlock(&tty_mutex);
}
/**
@@ -801,11 +799,9 @@ void disassociate_ctty(int on_exit)
struct pid *tty_pgrp = NULL;
- mutex_lock(&tty_mutex);
tty = get_current_tty();
if (tty) {
tty_pgrp = get_pid(tty->pgrp);
- mutex_unlock(&tty_mutex);
lock_kernel();
if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY)
tty_vhangup(tty);
@@ -822,7 +818,6 @@ void disassociate_ctty(int on_exit)
kill_pgrp(old_pgrp, SIGCONT, on_exit);
put_pid(old_pgrp);
}
- mutex_unlock(&tty_mutex);
return;
}
if (tty_pgrp) {
@@ -837,7 +832,6 @@ void disassociate_ctty(int on_exit)
current->signal->tty_old_pgrp = NULL;
spin_unlock_irq(&current->sighand->siglock);
- mutex_lock(&tty_mutex);
tty = get_current_tty();
if (tty) {
unsigned long flags;
@@ -854,7 +848,6 @@ void disassociate_ctty(int on_exit)
" = NULL", tty);
#endif
}
- mutex_unlock(&tty_mutex);
/* Now clear signal->tty under the lock */
read_lock(&tasklist_lock);
@@ -3180,14 +3173,11 @@ static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
struct tty_struct *get_current_tty(void)
{
struct tty_struct *tty;
- WARN_ON_ONCE(!mutex_is_locked(&tty_mutex));
+ unsigned long flags;
+
+ spin_lock_irqsave(&current->sighand->siglock, flags);
tty = tty_kref_get(current->signal->tty);
- /*
- * session->tty can be changed/cleared from under us, make sure we
- * issue the load. The obtained pointer, when not NULL, is valid as
- * long as we hold tty_mutex.
- */
- barrier();
+ spin_unlock_irqrestore(&current->sighand->siglock, flags);
return tty;
}
EXPORT_SYMBOL_GPL(get_current_tty);
diff --git a/drivers/s390/char/fs3270.c b/drivers/s390/char/fs3270.c
index 3ef5425d0eb8..84fbc90480dc 100644
--- a/drivers/s390/char/fs3270.c
+++ b/drivers/s390/char/fs3270.c
@@ -431,6 +431,7 @@ fs3270_open(struct inode *inode, struct file *filp)
tty = get_current_tty();
if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) {
tty_kref_put(tty);
+ mutex_unlock(&tty_mutex);
rc = -ENODEV;
goto out;
}
diff --git a/fs/dquot.c b/fs/dquot.c
index 7417a6ca3129..ad7e59003e04 100644
--- a/fs/dquot.c
+++ b/fs/dquot.c
@@ -895,9 +895,7 @@ static void print_warning(struct dquot *dquot, const int warntype)
warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(dquot))
return;
- mutex_lock(&tty_mutex);
tty = get_current_tty();
- mutex_unlock(&tty_mutex);
if (!tty)
return;
tty_write_message(tty, dquot->dq_sb->s_id);
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 089d61a23952..48881394fbd4 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2121,9 +2121,7 @@ static inline void flush_unauthorized_files(struct files_struct *files)
long j = -1;
int drop_tty = 0;
- mutex_lock(&tty_mutex);
tty = get_current_tty();
- mutex_unlock(&tty_mutex);
if (tty) {
file_list_lock();
file = list_entry(tty->tty_files.next, typeof(*file), f_u.fu_list);