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 <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
tadfisher · Jan 7, 2021 · f446776 · f446776
1 parent c31c3ea
commit f446776
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Showing 2 changed files with 25 additions and 8 deletions.
diff --git 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
@@ -566,21 +588,15 @@ 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;
 
 	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
@@ -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)
 { }