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path: root/drivers/tty/tty_buffer.c
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Diffstat (limited to 'drivers/tty/tty_buffer.c')
-rw-r--r--drivers/tty/tty_buffer.c41
1 files changed, 27 insertions, 14 deletions
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 75661641f5fe..2f78b77f0f81 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -37,6 +37,28 @@
#define TTY_BUFFER_PAGE (((PAGE_SIZE - sizeof(struct tty_buffer)) / 2) & ~0xFF)
+/*
+ * If all tty flip buffers have been processed by flush_to_ldisc() or
+ * dropped by tty_buffer_flush(), check if the linked pty has been closed.
+ * If so, wake the reader/poll to process
+ */
+static inline void check_other_closed(struct tty_struct *tty)
+{
+ unsigned long flags, old;
+
+ /* transition from TTY_OTHER_CLOSED => TTY_OTHER_DONE must be atomic */
+ for (flags = ACCESS_ONCE(tty->flags);
+ test_bit(TTY_OTHER_CLOSED, &flags);
+ ) {
+ old = flags;
+ __set_bit(TTY_OTHER_DONE, &flags);
+ flags = cmpxchg(&tty->flags, old, flags);
+ if (old == flags) {
+ wake_up_interruptible(&tty->read_wait);
+ break;
+ }
+ }
+}
/**
* tty_buffer_lock_exclusive - gain exclusive access to buffer
@@ -229,6 +251,8 @@ void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld)
if (ld && ld->ops->flush_buffer)
ld->ops->flush_buffer(tty);
+ check_other_closed(tty);
+
atomic_dec(&buf->priority);
mutex_unlock(&buf->lock);
}
@@ -471,8 +495,10 @@ static void flush_to_ldisc(struct work_struct *work)
smp_rmb();
count = head->commit - head->read;
if (!count) {
- if (next == NULL)
+ if (next == NULL) {
+ check_other_closed(tty);
break;
+ }
buf->head = next;
tty_buffer_free(port, head);
continue;
@@ -489,19 +515,6 @@ static void flush_to_ldisc(struct work_struct *work)
}
/**
- * tty_flush_to_ldisc
- * @tty: tty to push
- *
- * Push the terminal flip buffers to the line discipline.
- *
- * Must not be called from IRQ context.
- */
-void tty_flush_to_ldisc(struct tty_struct *tty)
-{
- flush_work(&tty->port->buf.work);
-}
-
-/**
* tty_flip_buffer_push - terminal
* @port: tty port to push
*