tty: Export redirect release

This will be required by the pty code when it removes tty_vhangup() on
master close.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Link: https://lore.kernel.org/r/20201124004902.1398477-2-minyard@acm.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 95ba028ef668364d64f186037ba5ab63a35df813..225f4933fbde2563b51670ab698b03711868fe87 100644 (file)
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -540,6 +540,28 @@ void tty_wakeup(struct tty_struct *tty)
 
 EXPORT_SYMBOL_GPL(tty_wakeup);
 
+/**
+ *     tty_release_redirect    -       Release a redirect on a pty if present
+ *     @tty: tty device
+ *
+ *     This is available to the pty code so if the master closes, if the
+ *     slave is a redirect it can release the redirect.
+ */
+struct file *tty_release_redirect(struct tty_struct *tty)
+{
+       struct file *f = NULL;
+
+       spin_lock(&redirect_lock);
+       if (redirect && file_tty(redirect) == tty) {
+               f = redirect;
+               redirect = NULL;
+       }
+       spin_unlock(&redirect_lock);
+
+       return f;
+}
+EXPORT_SYMBOL_GPL(tty_release_redirect);
+
 /**
  *     __tty_hangup            -       actual handler for hangup events
  *     @tty: tty device
@@ -566,7 +588,7 @@ EXPORT_SYMBOL_GPL(tty_wakeup);
 static void __tty_hangup(struct tty_struct *tty, int exit_session)
 {
        struct file *cons_filp = NULL;
-       struct file *filp, *f = NULL;
+       struct file *filp, *f;
        struct tty_file_private *priv;
        int    closecount = 0, n;
        int refs;
@@ -574,13 +596,7 @@ static void __tty_hangup(struct tty_struct *tty, int exit_session)
        if (!tty)
                return;
 
-
-       spin_lock(&redirect_lock);
-       if (redirect && file_tty(redirect) == tty) {
-               f = redirect;
-               redirect = NULL;
-       }
-       spin_unlock(&redirect_lock);
+       f = tty_release_redirect(tty);
 
        tty_lock(tty);
 

diff --git a/include/linux/tty.h b/include/linux/tty.h
index b57f6812b3bae1b2a680bcaead43ae726e8e86a8..dd6ded6138f79038acc7118694410a0de0a0c173 100644 (file)
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -421,6 +421,7 @@ extern void tty_kclose(struct tty_struct *tty);
 extern int tty_dev_name_to_number(const char *name, dev_t *number);
 extern int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout);
 extern void tty_ldisc_unlock(struct tty_struct *tty);
+extern struct file *tty_release_redirect(struct tty_struct *tty);
 #else
 static inline void tty_kref_put(struct tty_struct *tty)
 { }