kernel.git/drivers/leds/led-class.c, branch linux-5.4.y

leds: class: Protect brightness_show() with led_cdev->led_access mutex

2024-12-14T18:44:53Z

[ Upstream commit 4ca7cd938725a4050dcd62ae9472e931d603118d ] There is NULL pointer issue observed if from Process A where hid device being added which results in adding a led_cdev addition and later a another call to access of led_cdev attribute from Process B can result in NULL pointer issue. Use mutex led_cdev->led_access to protect access to led->cdev and its attribute inside brightness_show() and max_brightness_show() and also update the comment for mutex that it should be used to protect the led class device fields. Process A Process B kthread+0x114 worker_thread+0x244 process_scheduled_works+0x248 uhid_device_add_worker+0x24 hid_add_device+0x120 device_add+0x268 bus_probe_device+0x94 device_initial_probe+0x14 __device_attach+0xfc bus_for_each_drv+0x10c __device_attach_driver+0x14c driver_probe_device+0x3c __driver_probe_device+0xa0 really_probe+0x190 hid_device_probe+0x130 ps_probe+0x990 ps_led_register+0x94 devm_led_classdev_register_ext+0x58 led_classdev_register_ext+0x1f8 device_create_with_groups+0x48 device_create_groups_vargs+0xc8 device_add+0x244 kobject_uevent+0x14 kobject_uevent_env[jt]+0x224 mutex_unlock[jt]+0xc4 __mutex_unlock_slowpath+0xd4 wake_up_q+0x70 try_to_wake_up[jt]+0x48c preempt_schedule_common+0x28 __schedule+0x628 __switch_to+0x174 el0t_64_sync+0x1a8/0x1ac el0t_64_sync_handler+0x68/0xbc el0_svc+0x38/0x68 do_el0_svc+0x1c/0x28 el0_svc_common+0x80/0xe0 invoke_syscall+0x58/0x114 __arm64_sys_read+0x1c/0x2c ksys_read+0x78/0xe8 vfs_read+0x1e0/0x2c8 kernfs_fop_read_iter+0x68/0x1b4 seq_read_iter+0x158/0x4ec kernfs_seq_show+0x44/0x54 sysfs_kf_seq_show+0xb4/0x130 dev_attr_show+0x38/0x74 brightness_show+0x20/0x4c dualshock4_led_get_brightness+0xc/0x74 [ 3313.874295][ T4013] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000060 [ 3313.874301][ T4013] Mem abort info: [ 3313.874303][ T4013] ESR = 0x0000000096000006 [ 3313.874305][ T4013] EC = 0x25: DABT (current EL), IL = 32 bits [ 3313.874307][ T4013] SET = 0, FnV = 0 [ 3313.874309][ T4013] EA = 0, S1PTW = 0 [ 3313.874311][ T4013] FSC = 0x06: level 2 translation fault [ 3313.874313][ T4013] Data abort info: [ 3313.874314][ T4013] ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000 [ 3313.874316][ T4013] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 3313.874318][ T4013] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 3313.874320][ T4013] user pgtable: 4k pages, 39-bit VAs, pgdp=00000008f2b0a000 .. [ 3313.874332][ T4013] Dumping ftrace buffer: [ 3313.874334][ T4013] (ftrace buffer empty) .. .. [ dd3313.874639][ T4013] CPU: 6 PID: 4013 Comm: InputReader [ 3313.874648][ T4013] pc : dualshock4_led_get_brightness+0xc/0x74 [ 3313.874653][ T4013] lr : led_update_brightness+0x38/0x60 [ 3313.874656][ T4013] sp : ffffffc0b910bbd0 .. .. [ 3313.874685][ T4013] Call trace: [ 3313.874687][ T4013] dualshock4_led_get_brightness+0xc/0x74 [ 3313.874690][ T4013] brightness_show+0x20/0x4c [ 3313.874692][ T4013] dev_attr_show+0x38/0x74 [ 3313.874696][ T4013] sysfs_kf_seq_show+0xb4/0x130 [ 3313.874700][ T4013] kernfs_seq_show+0x44/0x54 [ 3313.874703][ T4013] seq_read_iter+0x158/0x4ec [ 3313.874705][ T4013] kernfs_fop_read_iter+0x68/0x1b4 [ 3313.874708][ T4013] vfs_read+0x1e0/0x2c8 [ 3313.874711][ T4013] ksys_read+0x78/0xe8 [ 3313.874714][ T4013] __arm64_sys_read+0x1c/0x2c [ 3313.874718][ T4013] invoke_syscall+0x58/0x114 [ 3313.874721][ T4013] el0_svc_common+0x80/0xe0 [ 3313.874724][ T4013] do_el0_svc+0x1c/0x28 [ 3313.874727][ T4013] el0_svc+0x38/0x68 [ 3313.874730][ T4013] el0t_64_sync_handler+0x68/0xbc [ 3313.874732][ T4013] el0t_64_sync+0x1a8/0x1ac Signed-off-by: Mukesh Ojha Reviewed-by: Anish Kumar Link: https://lore.kernel.org/r/20241103160527.82487-1-quic_mojha@quicinc.com Signed-off-by: Lee Jones Signed-off-by: Sasha Levin

leds: core: Flush scheduled work for system suspend

2020-08-19T06:16:11Z

[ Upstream commit 302a085c20194bfa7df52e0fe684ee0c41da02e6 ] Sometimes LED won't be turned off by LED_CORE_SUSPENDRESUME flag upon system suspend. led_set_brightness_nopm() uses schedule_work() to set LED brightness. However, there's no guarantee that the scheduled work gets executed because no one flushes the work. So flush the scheduled work to make sure LED gets turned off. Signed-off-by: Kai-Heng Feng Acked-by: Jacek Anaszewski Fixes: 81fe8e5b73e3 ("leds: core: Add led_set_brightness_nosleep{nopm} functions") Signed-off-by: Pavel Machek Signed-off-by: Sasha Levin

leds: core: Fix warning message when init_data

2020-04-23T08:36:37Z

[ Upstream commit 64ed6588c2ea618d3f9ca9d8b365ae4c19f76225 ] The warning message when a led is renamed due to name collition can fail to show proper original name if init_data is used. Eg: [ 9.073996] leds-gpio a0040000.leds_0: Led (null) renamed to red_led_1 due to name collision Fixes: bb4e9af0348d ("leds: core: Add support for composing LED class device names") Signed-off-by: Ricardo Ribalda Delgado Acked-by: Jacek Anaszewski Signed-off-by: Pavel Machek Signed-off-by: Sasha Levin

leds: Allow to call led_classdev_unregister() unconditionally

2019-08-26T18:03:58Z

If in the certain driver the LED is optional, and it's a majority of them, the call of led_classdev_unregister() still requires some additional checks. The usual pattern on unregistering is to check for NULL, but we also check for IS_ERR() in case device_create_with_groups() fails. The change will reduce a burden in a lot of drivers to repeatedly check for above conditions. Signed-off-by: Andy Shevchenko Signed-off-by: Jacek Anaszewski

leds: Switch to use fwnode instead of be stuck with OF one

2019-08-23T21:39:37Z

There is no need to be stuck with OF node when we may use agnostic firmware node instead. It allows users to get property if needed independently of provider. Note, some OF parts are left because %pfw [1] is in progress. [1]: https://lore.kernel.org/patchwork/cover/1054863/ Signed-off-by: Andy Shevchenko Signed-off-by: Jacek Anaszewski

Merge tag 'generic_lookup_helpers' into for-next

2019-07-30T20:36:31Z

Generic Device Lookup Helpers Persistent tag for others to pull this branch from Based on patch series from Suzuki K Poulose with Subject: [PATCH v3 0/7] drivers: Add generic device lookup helpers Signed-off-by: Greg Kroah-Hartman * tag 'generic_lookup_helpers': platform: Add platform_find_device_by_driver() helper drivers: Add generic helper to match any device drivers: Introduce device lookup variants by ACPI_COMPANION device drivers: Introduce device lookup variants by device type drivers: Introduce device lookup variants by fwnode drivers: Introduce device lookup variants by of_node drivers: Introduce device lookup variants by name

drivers: Introduce device lookup variants by name

2019-07-30T11:07:41Z

Add a helper to match the device name for device lookup. Also reuse this generic exported helper for the existing bus_find_device_by_name(). and add similar variants for driver/class. Cc: Alessandro Zummo Cc: Alexander Aring Cc: Alexander Shishkin Cc: Arnd Bergmann Cc: Dan Murphy Cc: Harald Freudenberger Cc: Heiko Carstens Cc: Jacek Anaszewski Cc: Lee Jones Cc: linux-leds@vger.kernel.org Cc: linux-rtc@vger.kernel.org Cc: linux-usb@vger.kernel.org Cc: linux-wpan@vger.kernel.org Cc: Maxime Coquelin Cc: Pavel Machek Cc: Peter Oberparleiter Cc: "Rafael J. Wysocki" Cc: Stefan Schmidt Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Signed-off-by: Suzuki K Poulose Reviewed-by: Heikki Krogerus Acked-by: Alexandre Belloni Link: https://lore.kernel.org/r/20190723221838.12024-2-suzuki.poulose@arm.com Signed-off-by: Greg Kroah-Hartman

leds: core: Add support for composing LED class device names

2019-07-25T18:07:52Z

Add generic support for composing LED class device name. The newly introduced led_compose_name() function composes device name according to either or pattern, depending on the configuration of initialization data. Backward compatibility with in-driver hard-coded LED class device names is assured thanks to the default_label and devicename properties of newly introduced struct led_init_data. In case none of the aforementioned properties was found, then, for OF nodes, the node name is adopted for LED class device name. At the occassion of amending the Documentation/leds/leds-class.txt unify spelling: colour -> color. Alongside these changes added is a new tool - tools/leds/get_led_device_info.sh. The tool allows retrieving details of a LED class device's parent device, which proves that using vendor or product name for devicename part of LED name doesn't convey any added value since that information had been already available in sysfs. The script performs also basic validation of a LED class device name. Signed-off-by: Jacek Anaszewski Cc: Baolin Wang Cc: Dan Murphy Cc: Daniel Mack Cc: Linus Walleij Cc: Oleh Kravchenko Cc: Sakari Ailus Cc: Simon Shields Reviewed-by: Linus Walleij Acked-by: Pavel Machek

leds: class: Improve LED and LED flash class registration API

2019-07-25T18:07:50Z

Replace of_led_classdev_register() with led_classdev_register_ext(), which accepts easily extendable struct led_init_data, instead of the fixed struct device_node argument. The latter can be now passed in an fwnode property of the struct led_init_data. The modification is driven by the need for passing additional arguments required for the forthcoming generic mechanism for composing LED names. Currently the LED name is conveyed in the "name" char pointer property of the struct led_classdev. This is redundant since LED class device name is accessible throughout the whole LED class device life time via associated struct device's kobj->name property. The change will not break any existing clients since the patch alters also existing led_classdev{_flash}_register() macro wrappers, that pass NULL in place of init_data, which leads to using legacy name initialization path basing on the struct led_classdev's "name" property. Three existing users of devm_of_led_classdev_registers() are modified to use devm_led_classdev_register(), which will not impact their operation since they in fact didn't need to pass struct device_node on registration from the beginning. Signed-off-by: Jacek Anaszewski Cc: Baolin Wang Cc: Dan Murphy Cc: Daniel Mack Cc: Linus Walleij Cc: Oleh Kravchenko Cc: Sakari Ailus Cc: Simon Shields Acked-by: Pavel Machek

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

2019-06-19T15:09:55Z

Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Enrico Weigelt Reviewed-by: Kate Stewart Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman