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Diffstat (limited to 'drivers/char/tty_io.c')
-rw-r--r--drivers/char/tty_io.c26
1 files changed, 18 insertions, 8 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 0350c42..cd5b829 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -136,6 +136,9 @@ LIST_HEAD(tty_drivers); /* linked list of tty drivers */
DEFINE_MUTEX(tty_mutex);
EXPORT_SYMBOL(tty_mutex);
+/* Spinlock to protect the tty->tty_files list */
+DEFINE_SPINLOCK(tty_files_lock);
+
static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *);
static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *);
ssize_t redirected_tty_write(struct file *, const char __user *,
@@ -235,11 +238,11 @@ static int check_tty_count(struct tty_struct *tty, const char *routine)
struct list_head *p;
int count = 0;
- file_list_lock();
+ spin_lock(&tty_files_lock);
list_for_each(p, &tty->tty_files) {
count++;
}
- file_list_unlock();
+ spin_unlock(&tty_files_lock);
if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
tty->driver->subtype == PTY_TYPE_SLAVE &&
tty->link && tty->link->count)
@@ -519,7 +522,7 @@ void __tty_hangup(struct tty_struct *tty)
workqueue with the lock held */
check_tty_count(tty, "tty_hangup");
- file_list_lock();
+ spin_lock(&tty_files_lock);
/* This breaks for file handles being sent over AF_UNIX sockets ? */
list_for_each_entry(filp, &tty->tty_files, f_u.fu_list) {
if (filp->f_op->write == redirected_tty_write)
@@ -530,7 +533,7 @@ void __tty_hangup(struct tty_struct *tty)
__tty_fasync(-1, filp, 0); /* can't block */
filp->f_op = &hung_up_tty_fops;
}
- file_list_unlock();
+ spin_unlock(&tty_files_lock);
tty_ldisc_hangup(tty);
@@ -1424,9 +1427,9 @@ static void release_one_tty(struct work_struct *work)
tty_driver_kref_put(driver);
module_put(driver->owner);
- file_list_lock();
+ spin_lock(&tty_files_lock);
list_del_init(&tty->tty_files);
- file_list_unlock();
+ spin_unlock(&tty_files_lock);
put_pid(tty->pgrp);
put_pid(tty->session);
@@ -1671,7 +1674,10 @@ int tty_release(struct inode *inode, struct file *filp)
* - do_tty_hangup no longer sees this file descriptor as
* something that needs to be handled for hangups.
*/
- file_kill(filp);
+ spin_lock(&tty_files_lock);
+ BUG_ON(list_empty(&filp->f_u.fu_list));
+ list_del_init(&filp->f_u.fu_list);
+ spin_unlock(&tty_files_lock);
filp->private_data = NULL;
/*
@@ -1840,7 +1846,11 @@ got_driver:
}
filp->private_data = tty;
- file_move(filp, &tty->tty_files);
+ BUG_ON(list_empty(&filp->f_u.fu_list));
+ file_sb_list_del(filp); /* __dentry_open has put it on the sb list */
+ spin_lock(&tty_files_lock);
+ list_add(&filp->f_u.fu_list, &tty->tty_files);
+ spin_unlock(&tty_files_lock);
check_tty_count(tty, "tty_open");
if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
tty->driver->subtype == PTY_TYPE_MASTER)
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