[PATCH] tty flush flip buffer on ldisc input queue flush
Flush the tty flip buffer when the line discipline
input queue is flushed, including the user call
tcflush(TCIFLUSH/TCIOFLUSH). This prevents unexpected
stale data after a user application calls tcflush().
Cc: Alan Cox <[EMAIL PROTECTED]>
Cc: Antonino Ingargiola <[EMAIL PROTECTED]>
Signed-off-by: Paul Fulghum <[EMAIL PROTECTED]>
--- a/drivers/char/tty_io.c 2007-05-04 05:46:55.0 -0500
+++ b/drivers/char/tty_io.c 2007-05-05 03:23:46.0 -0500
@@ -365,6 +365,29 @@ static void tty_buffer_free(struct tty_s
}
/**
+ * tty_buffer_flush- flush full tty buffers
+ * @tty: tty to flush
+ *
+ * flush all the buffers containing receive data
+ *
+ * Locking: none
+ */
+
+static void tty_buffer_flush(struct tty_struct *tty)
+{
+ struct tty_buffer *thead;
+ unsigned long flags;
+
+ spin_lock_irqsave(>buf.lock, flags);
+ while((thead = tty->buf.head) != NULL) {
+ tty->buf.head = thead->next;
+ tty_buffer_free(tty, thead);
+ }
+ tty->buf.tail = NULL;
+ spin_unlock_irqrestore(>buf.lock, flags);
+}
+
+/**
* tty_buffer_find - find a free tty buffer
* @tty: tty owning the buffer
* @size: characters wanted
@@ -1240,6 +1263,7 @@ void tty_ldisc_flush(struct tty_struct *
ld->flush_buffer(tty);
tty_ldisc_deref(ld);
}
+ tty_buffer_flush(tty);
}
EXPORT_SYMBOL_GPL(tty_ldisc_flush);
@@ -3336,6 +3360,15 @@ int tty_ioctl(struct inode * inode, stru
case TIOCMBIC:
case TIOCMBIS:
return tty_tiocmset(tty, file, cmd, p);
+ case TCFLSH:
+ switch (arg) {
+ case TCIFLUSH:
+ case TCIOFLUSH:
+ /* flush tty buffer and allow ldisc to process
ioctl */
+ tty_buffer_flush(tty);
+ break;
+ }
+ break;
}
if (tty->driver->ioctl) {
retval = (tty->driver->ioctl)(tty, file, cmd, arg);
-
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[PATCH] tty flush flip buffer on ldisc input queue flush
Flush the tty flip buffer when the line discipline
input queue is flushed, including the user call
tcflush(TCIFLUSH/TCIOFLUSH). This prevents unexpected
stale data after a user application calls tcflush().
Cc: Alan Cox [EMAIL PROTECTED]
Cc: Antonino Ingargiola [EMAIL PROTECTED]
Signed-off-by: Paul Fulghum [EMAIL PROTECTED]
--- a/drivers/char/tty_io.c 2007-05-04 05:46:55.0 -0500
+++ b/drivers/char/tty_io.c 2007-05-05 03:23:46.0 -0500
@@ -365,6 +365,29 @@ static void tty_buffer_free(struct tty_s
}
/**
+ * tty_buffer_flush- flush full tty buffers
+ * @tty: tty to flush
+ *
+ * flush all the buffers containing receive data
+ *
+ * Locking: none
+ */
+
+static void tty_buffer_flush(struct tty_struct *tty)
+{
+ struct tty_buffer *thead;
+ unsigned long flags;
+
+ spin_lock_irqsave(tty-buf.lock, flags);
+ while((thead = tty-buf.head) != NULL) {
+ tty-buf.head = thead-next;
+ tty_buffer_free(tty, thead);
+ }
+ tty-buf.tail = NULL;
+ spin_unlock_irqrestore(tty-buf.lock, flags);
+}
+
+/**
* tty_buffer_find - find a free tty buffer
* @tty: tty owning the buffer
* @size: characters wanted
@@ -1240,6 +1263,7 @@ void tty_ldisc_flush(struct tty_struct *
ld-flush_buffer(tty);
tty_ldisc_deref(ld);
}
+ tty_buffer_flush(tty);
}
EXPORT_SYMBOL_GPL(tty_ldisc_flush);
@@ -3336,6 +3360,15 @@ int tty_ioctl(struct inode * inode, stru
case TIOCMBIC:
case TIOCMBIS:
return tty_tiocmset(tty, file, cmd, p);
+ case TCFLSH:
+ switch (arg) {
+ case TCIFLUSH:
+ case TCIOFLUSH:
+ /* flush tty buffer and allow ldisc to process
ioctl */
+ tty_buffer_flush(tty);
+ break;
+ }
+ break;
}
if (tty-driver-ioctl) {
retval = (tty-driver-ioctl)(tty, file, cmd, arg);
-
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Please read the FAQ at http://www.tux.org/lkml/
