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From: Aleksa Savic <savicaleksa83@gmail.com>
To: linux-hwmon@vger.kernel.org
Cc: Aleksa Savic <savicaleksa83@gmail.com>,
	Jean Delvare <jdelvare@suse.com>,
	Guenter Roeck <linux@roeck-us.net>,
	linux-kernel@vger.kernel.org
Subject: [PATCH] hwmon: (gigabyte_waterforce) Mark status report as received under a spinlock
Date: Tue, 19 Dec 2023 15:36:19 +0100
Message-ID: <20231219143620.22179-1-savicaleksa83@gmail.com>
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Through hidraw, userspace can cause a status report to be sent
from the device. The parsing in waterforce_raw_event() may happen in
parallel to a waterforce_get_status() call (which resets the completion
for tracking the report) if it's running on a different CPU where
bottom half interrupts are not disabled.

Add a spinlock around the complete_all() call in waterforce_raw_event()
to prevent race issues.

Fixes: d5939a793693 ("hwmon: Add driver for Gigabyte AORUS Waterforce AIO coolers")
Signed-off-by: Aleksa Savic <savicaleksa83@gmail.com>
---
Does the above make sense? The raw event parsing is a softirq AFAIK and
presumably could run on a different CPU in parallel to a waterforce_get_status()
call.

Appreciate thoughts on this.
---
 drivers/hwmon/gigabyte_waterforce.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/hwmon/gigabyte_waterforce.c b/drivers/hwmon/gigabyte_waterforce.c
index 1799377fc2f1..85e523775714 100644
--- a/drivers/hwmon/gigabyte_waterforce.c
+++ b/drivers/hwmon/gigabyte_waterforce.c
@@ -276,8 +276,10 @@ static int waterforce_raw_event(struct hid_device *hdev, struct hid_report *repo
 	priv->duty_input[0] = data[WATERFORCE_FAN_DUTY];
 	priv->duty_input[1] = data[WATERFORCE_PUMP_DUTY];
 
+	spin_lock(&priv->status_report_request_lock);
 	if (!completion_done(&priv->status_report_received))
 		complete_all(&priv->status_report_received);
+	spin_unlock(&priv->status_report_request_lock);
 
 	priv->updated = jiffies;
 
-- 
2.43.0