From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alan Cox Subject: [PATCH 11/11] synclink: reworking locking a bit Date: Wed, 19 May 2010 13:03:33 +0100 Message-ID: <20100519120331.16717.38196.stgit@localhost.localdomain> References: <20100519120111.16717.71992.stgit@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:51118 "EHLO bob.linux.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751772Ab0ESMqB (ORCPT ); Wed, 19 May 2010 08:46:01 -0400 In-Reply-To: <20100519120111.16717.71992.stgit@localhost.localdomain> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: greg@kroah.com, linux-serial@vger.kernel.org Use the port mutex and port lock to fix the various races. The locking still isn't totally consistent but its better than before. Wants switching to the port helpers. Signed-off-by: Alan Cox --- drivers/char/synclink_gt.c | 12 +++++++++++- drivers/char/synclinkmp.c | 9 ++++++++- 2 files changed, 19 insertions(+), 2 deletions(-) diff --git a/drivers/char/synclink_gt.c b/drivers/char/synclink_gt.c index d0f81f5..c56b70a 100644 --- a/drivers/char/synclink_gt.c +++ b/drivers/char/synclink_gt.c @@ -675,12 +675,14 @@ static int open(struct tty_struct *tty, struct file *filp) goto cleanup; } + mutex_lock(&info->port.mutex); info->port.tty->low_latency = (info->port.flags & ASYNC_LOW_LATENCY) ? 1 : 0; spin_lock_irqsave(&info->netlock, flags); if (info->netcount) { retval = -EBUSY; spin_unlock_irqrestore(&info->netlock, flags); + mutex_unlock(&info->port.mutex); goto cleanup; } info->port.count++; @@ -692,7 +694,7 @@ static int open(struct tty_struct *tty, struct file *filp) if (retval < 0) goto cleanup; } - + mutex_unlock(&info->port.mutex); retval = block_til_ready(tty, filp, info); if (retval) { DBGINFO(("%s block_til_ready rc=%d\n", info->device_name, retval)); @@ -724,12 +726,14 @@ static void close(struct tty_struct *tty, struct file *filp) if (tty_port_close_start(&info->port, tty, filp) == 0) goto cleanup; + mutex_lock(&info->port.mutex); if (info->port.flags & ASYNC_INITIALIZED) wait_until_sent(tty, info->timeout); flush_buffer(tty); tty_ldisc_flush(tty); shutdown(info); + mutex_unlock(&info->port.mutex); tty_port_close_end(&info->port, tty); info->port.tty = NULL; @@ -740,17 +744,23 @@ cleanup: static void hangup(struct tty_struct *tty) { struct slgt_info *info = tty->driver_data; + unsigned long flags; if (sanity_check(info, tty->name, "hangup")) return; DBGINFO(("%s hangup\n", info->device_name)); flush_buffer(tty); + + mutex_lock(&info->port.mutex); shutdown(info); + spin_lock_irqsave(&info->port.lock, flags); info->port.count = 0; info->port.flags &= ~ASYNC_NORMAL_ACTIVE; info->port.tty = NULL; + spin_unlock_irqrestore(&info->port.lock, flags); + mutex_unlock(&info->port.mutex); wake_up_interruptible(&info->port.open_wait); } diff --git a/drivers/char/synclinkmp.c b/drivers/char/synclinkmp.c index 8da976b..cfa581e 100644 --- a/drivers/char/synclinkmp.c +++ b/drivers/char/synclinkmp.c @@ -812,13 +812,15 @@ static void close(struct tty_struct *tty, struct file *filp) if (tty_port_close_start(&info->port, tty, filp) == 0) goto cleanup; - + + mutex_lock(&info->port.mutex); if (info->port.flags & ASYNC_INITIALIZED) wait_until_sent(tty, info->timeout); flush_buffer(tty); tty_ldisc_flush(tty); shutdown(info); + mutex_unlock(&info->port.mutex); tty_port_close_end(&info->port, tty); info->port.tty = NULL; @@ -834,6 +836,7 @@ cleanup: static void hangup(struct tty_struct *tty) { SLMP_INFO *info = tty->driver_data; + unsigned long flags; if (debug_level >= DEBUG_LEVEL_INFO) printk("%s(%d):%s hangup()\n", @@ -842,12 +845,16 @@ static void hangup(struct tty_struct *tty) if (sanity_check(info, tty->name, "hangup")) return; + mutex_lock(&info->port.mutex); flush_buffer(tty); shutdown(info); + spin_lock_irqsave(&info->port.lock, flags); info->port.count = 0; info->port.flags &= ~ASYNC_NORMAL_ACTIVE; info->port.tty = NULL; + spin_unlock_irqrestore(&info->port.lock, flags); + mutex_unlock(&info->port.mutex); wake_up_interruptible(&info->port.open_wait); }