tty: the vhangup syscall is racy

[linux-2.6-omap-h63xx.git] / include / linux / tty.h

diff --git a/include/linux/tty.h b/include/linux/tty.h
index e3612c3ac194def233aa9be7c10dca0548a631c3..e00393a3d1c9376ca2ee9f607408fcf1700c7e99 100644 (file)
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -182,6 +182,7 @@ struct signal_struct;
 
 struct tty_port {
        struct tty_struct       *tty;           /* Back pointer */
+       spinlock_t              lock;           /* Lock protecting tty field */
        int                     blocked_open;   /* Waiting to open */
        int                     count;          /* Usage count */
        wait_queue_head_t       open_wait;      /* Open waiters */
@@ -209,6 +210,7 @@ struct tty_operations;
 
 struct tty_struct {
        int     magic;
+       struct kref kref;
        struct tty_driver *driver;
        const struct tty_operations *ops;
        int index;
@@ -218,6 +220,7 @@ struct tty_struct {
        spinlock_t ctrl_lock;
        /* Termios values are protected by the termios mutex */
        struct ktermios *termios, *termios_locked;
+       struct termiox *termiox;        /* May be NULL for unsupported */
        char name[64];
        struct pid *pgrp;               /* Protected by ctrl lock */
        struct pid *session;
@@ -311,6 +314,23 @@ extern int kmsg_redirect;
 extern void console_init(void);
 extern int vcs_init(void);
 
+/**
+ *     tty_kref_get            -       get a tty reference
+ *     @tty: tty device
+ *
+ *     Return a new reference to a tty object. The caller must hold
+ *     sufficient locks/counts to ensure that their existing reference cannot
+ *     go away
+ */
+
+extern inline struct tty_struct *tty_kref_get(struct tty_struct *tty)
+{
+       if (tty)
+               kref_get(&tty->kref);
+       return tty;
+}
+extern void tty_kref_put(struct tty_struct *tty);
+
 extern int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
                              const char *routine);
 extern char *tty_name(struct tty_struct *tty, char *buf);
@@ -341,6 +361,7 @@ extern int is_ignored(int sig);
 extern int tty_signal(int sig, struct tty_struct *tty);
 extern void tty_hangup(struct tty_struct *tty);
 extern void tty_vhangup(struct tty_struct *tty);
+extern void tty_vhangup_self(void);
 extern void tty_unhangup(struct file *filp);
 extern int tty_hung_up_p(struct file *filp);
 extern void do_SAK(struct tty_struct *tty);
@@ -386,6 +407,8 @@ extern int tty_write_lock(struct tty_struct *tty, int ndelay);
 extern void tty_port_init(struct tty_port *port);
 extern int tty_port_alloc_xmit_buf(struct tty_port *port);
 extern void tty_port_free_xmit_buf(struct tty_port *port);
+extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
+extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
 
 extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
 extern int tty_unregister_ldisc(int disc);