linux-kernel - [PATCH 3.8 009/121] mei: ignore client writing state during cb completion

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Message-Id: <1403021714-16320-10-git-send-email-kamal@canonical.com>
Date:	Tue, 17 Jun 2014 09:13:22 -0700
From:	Kamal Mostafa <kamal@...onical.com>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	kernel-team@...ts.ubuntu.com
Cc:	Alexander Usyskin <alexander.usyskin@...el.com>,
	Tomas Winkler <tomas.winkler@...el.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Kamal Mostafa <kamal@...onical.com>
Subject: [PATCH 3.8 009/121] mei: ignore client writing state during cb completion

3.8.13.24 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Alexander Usyskin <alexander.usyskin@...el.com>

commit 34ec43661fe8f1977dd0f05353302ae2ed10aabb upstream.

Ignore client writing state during cb completion to fix a memory
leak.

When moving cbs to the completion list we should not look at
writing_state as this state can be already overwritten by next
write, the fact that a cb is on the write waiting list means
that it was already written to the HW and we can safely complete it.

Same pays for wait in poll handler, we do not have to check the state
wake is done after completion list processing.

Signed-off-by: Alexander Usyskin <alexander.usyskin@...el.com>
Signed-off-by: Tomas Winkler <tomas.winkler@...el.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
[ kamal: backport to 3.8: context ]
Signed-off-by: Kamal Mostafa <kamal@...onical.com>
---
 drivers/misc/mei/interrupt.c | 3 +--
 drivers/misc/mei/main.c      | 3 +--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/misc/mei/interrupt.c b/drivers/misc/mei/interrupt.c
index 04fa213..b7fed05 100644
--- a/drivers/misc/mei/interrupt.c
+++ b/drivers/misc/mei/interrupt.c
@@ -906,8 +906,7 @@ static int mei_irq_thread_write_handler(struct mei_device *dev,
 
 		cl->status = 0;
 		list_del(&pos->list);
-		if (MEI_WRITING == cl->writing_state &&
-		    pos->fop_type == MEI_FOP_WRITE &&
+		if (pos->fop_type == MEI_FOP_WRITE &&
 		    cl != &dev->iamthif_cl) {
 			dev_dbg(&dev->pdev->dev, "MEI WRITE COMPLETE\n");
 			cl->writing_state = MEI_WRITE_COMPLETE;
diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index 43fb52f..9ad4ae0 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -701,8 +701,7 @@ static unsigned int mei_poll(struct file *file, poll_table *wait)
 	mutex_unlock(&dev->device_lock);
 	poll_wait(file, &cl->tx_wait, wait);
 	mutex_lock(&dev->device_lock);
-	if (MEI_WRITE_COMPLETE == cl->writing_state)
-		mask |= (POLLIN | POLLRDNORM);
+	mask |= (POLLIN | POLLRDNORM);
 
 out:
 	mutex_unlock(&dev->device_lock);
-- 
1.9.1

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