kernel/linux.git/drivers/base/dd.c, branch v6.6.132

Revert "driver core: enforce device_lock for driver_match_device()"

2026-02-16T16:08:02+00:00

This reverts commit adc1796eced46b48e23ec200a219d635f33a38ee which is commit dc23806a7c47ec5f1293aba407fb69519f976ee0 upstream. It causes boot regressions on some systems as all of the "fixes" for drivers are not properly backported yet. Once that is completed, only then can this be applied, if really necessary given the potential for explosions, perhaps we might want to wait a few -rc releases first... Cc: Danilo Krummrich Cc: Rafael J. Wysocki (Intel) Cc: Danilo Krummrich Cc: Gui-Dong Han Cc: Qiu-ji Chen Reported-by: Mark Brown Link: https://lore.kernel.org/r/7dfd0e63-a725-4fac-b2a0-f2e621d99d1b@sirena.org.uk Signed-off-by: Greg Kroah-Hartman

driver core: enforce device_lock for driver_match_device()

2026-02-16T09:17:47+00:00

commit dc23806a7c47ec5f1293aba407fb69519f976ee0 upstream. Currently, driver_match_device() is called from three sites. One site (__device_attach_driver) holds device_lock(dev), but the other two (bind_store and __driver_attach) do not. This inconsistency means that bus match() callbacks are not guaranteed to be called with the lock held. Fix this by introducing driver_match_device_locked(), which guarantees holding the device lock using a scoped guard. Replace the unlocked calls in bind_store() and __driver_attach() with this new helper. Also add a lock assertion to driver_match_device() to enforce this guarantee. This consistency also fixes a known race condition. The driver_override implementation relies on the device_lock, so the missing lock led to the use-after-free (UAF) reported in Bugzilla for buses using this field. Stress testing the two newly locked paths for 24 hours with CONFIG_PROVE_LOCKING and CONFIG_LOCKDEP enabled showed no UAF recurrence and no lockdep warnings. Cc: stable@vger.kernel.org Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220789 Suggested-by: Qiu-ji Chen Signed-off-by: Gui-Dong Han Fixes: 49b420a13ff9 ("driver core: check bus->match without holding device lock") Reviewed-by: Danilo Krummrich Reviewed-by: Greg Kroah-Hartman Reviewed-by: Rafael J. Wysocki (Intel) Link: https://patch.msgid.link/20260113162843.12712-1-hanguidong02@gmail.com Signed-off-by: Danilo Krummrich Signed-off-by: Greg Kroah-Hartman

driver core: introduce device_set_driver() helper

2025-05-02T05:51:03+00:00

commit 04d3e5461c1f5cf8eec964ab64948ebed826e95e upstream. In preparation to closing a race when reading driver pointer in dev_uevent() code, instead of setting device->driver pointer directly introduce device_set_driver() helper. Signed-off-by: Dmitry Torokhov Reviewed-by: Masami Hiramatsu (Google) Link: https://lore.kernel.org/r/20250311052417.1846985-2-dmitry.torokhov@gmail.com Signed-off-by: Greg Kroah-Hartman

driver core: Release all resources during unbind before updating device links

2023-11-28T17:20:05+00:00

commit 2e84dc37920012b458e9458b19fc4ed33f81bc74 upstream. This commit fixes a bug in commit 9ed9895370ae ("driver core: Functional dependencies tracking support") where the device link status was incorrectly updated in the driver unbind path before all the device's resources were released. Fixes: 9ed9895370ae ("driver core: Functional dependencies tracking support") Cc: stable Reported-by: Uwe Kleine-König Closes: https://lore.kernel.org/all/20231014161721.f4iqyroddkcyoefo@pengutronix.de/ Signed-off-by: Saravana Kannan Cc: Thierry Reding Cc: Yang Yingliang Cc: Andy Shevchenko Cc: Mark Brown Cc: Matti Vaittinen Cc: James Clark Acked-by: "Rafael J. Wysocki" Tested-by: Uwe Kleine-König Acked-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20231018013851.3303928-1-saravanak@google.com Signed-off-by: Greg Kroah-Hartman

driver core: Call dma_cleanup() on the test_remove path

2023-08-05T06:31:41+00:00

When test_remove is enabled really_probe() does not properly pair dma_configure() with dma_remove(), it will end up calling dma_configure() twice. This corrupts the owner_cnt and renders the group unusable with VFIO/etc. Add the missing cleanup before going back to re_probe. Fixes: 25f3bcfc54bc ("driver core: Add dma_cleanup callback in bus_type") Reported-by: Zenghui Yu Tested-by: Zenghui Yu Closes: https://lore.kernel.org/all/6472f254-c3c4-8610-4a37-8d9dfdd54ce8@huawei.com/ Signed-off-by: Jason Gunthorpe Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/0-v2-4deed94e283e+40948-really_probe_dma_cleanup_jgg@nvidia.com Signed-off-by: Greg Kroah-Hartman

driver core: return bool from driver_probe_done

2023-06-05T16:55:20+00:00

bool is the most sensible return value for a yes/no return. Also add __init as this funtion is only called from the early boot code. Signed-off-by: Christoph Hellwig Acked-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20230531125535.676098-2-hch@lst.de Signed-off-by: Jens Axboe

driver core: Don't require dynamic_debug for initcall_debug probe timing

2023-04-20T12:17:47+00:00

Don't require the use of dynamic debug (or modification of the kernel to add a #define DEBUG to the top of this file) to get the printk message about driver probe timing. This printk is only emitted when initcall_debug is enabled on the kernel commandline, and it isn't immediately obvious that you have to do something else to debug boot timing issues related to driver probe. Add a comment too so it doesn't get converted back to pr_debug(). Fixes: eb7fbc9fb118 ("driver core: Add missing '\n' in log messages") Cc: stable Cc: Christophe JAILLET Cc: Brian Norris Reviewed-by: Brian Norris Acked-by: Randy Dunlap Signed-off-by: Stephen Boyd Link: https://lore.kernel.org/r/20230412225842.3196599-1-swboyd@chromium.org Signed-off-by: Greg Kroah-Hartman

driver core: Make state_synced device attribute writeable

2023-03-10T08:06:22+00:00

If the file is written to and sync_state() hasn't been called for the device yet, then call sync_state() for the device independent of the state of its consumers. This is useful for supplier devices that have one or more consumers that don't have a driver but the consumers are in a state that don't use the resources supplied by the supplier device. This gives finer grained control than using the fw_devlink.sync_state=timeout kernel commandline parameter. Signed-off-by: Saravana Kannan Link: https://lore.kernel.org/r/20230304005355.746421-3-saravanak@google.com Signed-off-by: Greg Kroah-Hartman

driver core: Add fw_devlink.sync_state command line param

2023-03-10T08:06:21+00:00

When all devices that could probe have finished probing (based on deferred_probe_timeout configuration or late_initcall() when !CONFIG_MODULES), this parameter controls what to do with devices that haven't yet received their sync_state() calls. fw_devlink.sync_state=strict is the default and the driver core will continue waiting on all consumers of a device to probe successfully before sync_state() is called for the device. This is the default behavior since calling sync_state() on a device when all its consumers haven't probed could make some systems unusable/unstable. When this option is selected, we also print the list of devices that haven't had sync_state() called on them by the time all devices the could probe have finished probing. fw_devlink.sync_state=timeout will cause the driver core to give up waiting on consumers and call sync_state() on any devices that haven't yet received their sync_state() calls. This option is provided for systems that won't become unusable/unstable as they might be able to save power (depends on state of hardware before kernel starts) if all devices get their sync_state(). Signed-off-by: Saravana Kannan Link: https://lore.kernel.org/r/20230304005355.746421-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman

drivers: base: dd: fix memory leak with using debugfs_lookup()

2023-02-08T12:33:13+00:00

When calling debugfs_lookup() the result must have dput() called on it, otherwise the memory will leak over time. To make things simpler, just call debugfs_lookup_and_remove() instead which handles all of the logic at once. Cc: "Rafael J. Wysocki" Link: https://lore.kernel.org/r/20230202141621.2296458-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman