This is a note to let you know that I've just added the patch titled
driver core: Add missing dev->bus->need_parent_lock checks
to my driver-core git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git
in the driver-core-testing branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will be merged to the driver-core-next branch sometime soon,
after it passes testing, and the merge window is open.
If you have any questions about this process, please let me know.
>From e121a833745b4708b660e3fe6776129c2956b041 Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx>
Date: Thu, 13 Dec 2018 19:27:47 +0100
Subject: driver core: Add missing dev->bus->need_parent_lock checks
__device_release_driver() has to check dev->bus->need_parent_lock
before dropping the parent lock and acquiring it again as it may
attempt to drop a lock that hasn't been acquired or lock a device
that shouldn't be locked and create a lock imbalance.
Fixes: 8c97a46af04b (driver core: hold dev's parent lock when needed)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/base/dd.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 88713f182086..8ac10af17c00 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -933,11 +933,11 @@ static void __device_release_driver(struct device *dev, struct device *parent)
if (drv) {
while (device_links_busy(dev)) {
device_unlock(dev);
- if (parent)
+ if (parent && dev->bus->need_parent_lock)
device_unlock(parent);
device_links_unbind_consumers(dev);
- if (parent)
+ if (parent && dev->bus->need_parent_lock)
device_lock(parent);
device_lock(dev);
--
2.20.1
