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| author | David Gow <davidgow@google.com> | 2023-07-20 15:45:09 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-09-13 10:42:54 +0300 |
| commit | 297992e5c63528e603666e36081836204fc36ec9 (patch) | |
| tree | 599510d589e5b254457afe3fc595ea278c03af92 /drivers/base | |
| parent | 66eb45e7d5fc843b093c035b987603735caf92d6 (diff) | |
| download | linux-297992e5c63528e603666e36081836204fc36ec9.tar.xz | |
drivers: base: Free devm resources when unregistering a device
[ Upstream commit 699fb50d99039a50e7494de644f96c889279aca3 ]
In the current code, devres_release_all() only gets called if the device
has a bus and has been probed.
This leads to issues when using bus-less or driver-less devices where
the device might never get freed if a managed resource holds a reference
to the device. This is happening in the DRM framework for example.
We should thus call devres_release_all() in the device_del() function to
make sure that the device-managed actions are properly executed when the
device is unregistered, even if it has neither a bus nor a driver.
This is effectively the same change than commit 2f8d16a996da ("devres:
release resources on device_del()") that got reverted by commit
a525a3ddeaca ("driver core: free devres in device_release") over
memory leaks concerns.
This patch effectively combines the two commits mentioned above to
release the resources both on device_del() and device_release() and get
the best of both worlds.
Fixes: a525a3ddeaca ("driver core: free devres in device_release")
Signed-off-by: David Gow <davidgow@google.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/r/20230720-kunit-devm-inconsistencies-test-v3-3-6aa7e074f373@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/core.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index e30223c2672f..af90bfb0cc3d 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -3855,6 +3855,17 @@ void device_del(struct device *dev) device_platform_notify_remove(dev); device_links_purge(dev); + /* + * If a device does not have a driver attached, we need to clean + * up any managed resources. We do this in device_release(), but + * it's never called (and we leak the device) if a managed + * resource holds a reference to the device. So release all + * managed resources here, like we do in driver_detach(). We + * still need to do so again in device_release() in case someone + * adds a new resource after this point, though. + */ + devres_release_all(dev); + if (dev->bus) blocking_notifier_call_chain(&dev->bus->p->bus_notifier, BUS_NOTIFY_REMOVED_DEVICE, dev); |