The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y git checkout FETCH_HEAD git cherry-pick -x 4bc60736154bc9e0e39d3b88918f5d3762ebe5e0 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024061207-grooving-scholar-3378@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..
Possible dependencies:
4bc60736154b ("media: mc: mark the media devnode as registered from the, start")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 4bc60736154bc9e0e39d3b88918f5d3762ebe5e0 Mon Sep 17 00:00:00 2001 From: Hans Verkuil hverkuil-cisco@xs4all.nl Date: Fri, 23 Feb 2024 09:46:19 +0100 Subject: [PATCH] media: mc: mark the media devnode as registered from the, start
First the media device node was created, and if successful it was marked as 'registered'. This leaves a small race condition where an application can open the device node and get an error back because the 'registered' flag was not yet set.
Change the order: first set the 'registered' flag, then actually register the media device node. If that fails, then clear the flag.
Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Acked-by: Sakari Ailus sakari.ailus@linux.intel.com Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Fixes: cf4b9211b568 ("[media] media: Media device node support") Cc: stable@vger.kernel.org Signed-off-by: Sakari Ailus sakari.ailus@linux.intel.com
diff --git a/drivers/media/mc/mc-devnode.c b/drivers/media/mc/mc-devnode.c index 7f67825c8757..318e267e798e 100644 --- a/drivers/media/mc/mc-devnode.c +++ b/drivers/media/mc/mc-devnode.c @@ -245,15 +245,14 @@ int __must_check media_devnode_register(struct media_device *mdev, kobject_set_name(&devnode->cdev.kobj, "media%d", devnode->minor);
/* Part 3: Add the media and char device */ + set_bit(MEDIA_FLAG_REGISTERED, &devnode->flags); ret = cdev_device_add(&devnode->cdev, &devnode->dev); if (ret < 0) { + clear_bit(MEDIA_FLAG_REGISTERED, &devnode->flags); pr_err("%s: cdev_device_add failed\n", __func__); goto cdev_add_error; }
- /* Part 4: Activate this minor. The char device can now be used. */ - set_bit(MEDIA_FLAG_REGISTERED, &devnode->flags); - return 0;
cdev_add_error: