Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966961AbXEGVG7 (ORCPT ); Mon, 7 May 2007 17:06:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S966630AbXEGVG6 (ORCPT ); Mon, 7 May 2007 17:06:58 -0400 Received: from adsl-70-250-156-241.dsl.austtx.swbell.net ([70.250.156.241]:52963 "EHLO gw.microgate.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966588AbXEGVG5 (ORCPT ); Mon, 7 May 2007 17:06:57 -0400 Subject: [PATCH] tty flush flip buffer on ldisc input queue flush From: Paul Fulghum To: Andrew Morton Cc: Linux Kernel Mailing List , Antonino Ingargiola , Alan Cox Content-Type: text/plain Date: Mon, 07 May 2007 16:05:57 -0500 Message-Id: <1178571957.3665.8.camel@amdx2.microgate.com> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-4.fc4) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2002 Lines: 73 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 Cc: Antonino Ingargiola Signed-off-by: Paul Fulghum --- a/drivers/char/tty_io.c 2007-05-04 05:46:55.000000000 -0500 +++ b/drivers/char/tty_io.c 2007-05-05 03:23:46.000000000 -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); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/