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From:   Ricardo Ribalda <ribalda@chromium.org>
To:     Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     Ricardo Ribalda <ribalda@chromium.org>
Subject: [PATCH v5 01/12] media: uvcvideo: Fix race condition handling events
Date:   Mon, 21 Dec 2020 17:48:08 +0100
Message-Id: <20201221164819.792019-2-ribalda@chromium.org>
In-Reply-To: <20201221164819.792019-1-ribalda@chromium.org>
References: <20201221164819.792019-1-ribalda@chromium.org>
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The control and its data needs to be copied to the workqueue at the same
time to avoid half-updates of the events.
This is, events reported to userspace were the control id does not match
its value.

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/usb/uvc/uvc_ctrl.c | 2 +-
 drivers/media/usb/uvc/uvcvideo.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 011e69427b7c..aa18dcdf8165 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1332,7 +1332,7 @@ bool uvc_ctrl_status_event(struct urb *urb, struct uvc_video_chain *chain,
 		return false;
 	}
 
-	w->data = data;
+	memcpy(w->data, data, ctrl->info.size);
 	w->urb = urb;
 	w->chain = chain;
 	w->ctrl = ctrl;
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index a3dfacf069c4..0db6c2e0bd98 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -678,7 +678,7 @@ struct uvc_device {
 		struct urb *urb;
 		struct uvc_video_chain *chain;
 		struct uvc_control *ctrl;
-		const void *data;
+		u8 data[UVC_MAX_STATUS_SIZE];
 	} async_ctrl;
 };
 
-- 
2.29.2.684.gfbc64c5ab5-goog