linux-stable.git/include/linux/leds.h, branch v5.4.299

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

2024-12-14T18:44:53+00:00

[ 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: Fix leds.h structure documentation

2019-10-08T20:05:58+00:00

Update the leds.h structure documentation to define the
correct arguments.

Signed-off-by: Dan Murphy 
Signed-off-by: Jacek Anaszewski

leds: Replace {devm_}led_classdev_register() macros with inlines

2019-09-01T11:33:16+00:00

Replace preprocessor macro aliases for legacy LED registration helpers
with inline functions. It will allow to avoid misleading compiler error
messages about missing symbol that actually wasn't explicitly used
in the code. It used to occur when CONFIG_LEDS_CLASS was undefined
and legacy (non-ext) function had been used in the code.

Signed-off-by: Jacek Anaszewski 
Acked-by: Pavel Machek

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

2019-07-25T18:07:52+00:00

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

2019-07-25T18:07:50+00:00

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

2019-06-19T15:09:55+00:00

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

leds: Add helper for getting default pattern from Device Tree

2019-01-16T21:08:07+00:00

Multiple LED triggers might need to access default pattern so add a
helper for that.

Signed-off-by: Krzysztof Kozlowski 
Acked-by: Pavel Machek 
Signed-off-by: Jacek Anaszewski

Merge tag 'leds-for-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds

2018-12-25T22:52:50+00:00

Pull LED updates from Jacek Anaszewski:
 "There are several few-liners, where most of them are fixes and
  improvments. One thing standing out is ground preparation for
  inititializing trigger parameters via Device Tree.

  We introduce LED_INIT_DEFAULT_TRIGGER flag for that purpose and set it
  when default trigger is matched. It indicates that trigger should
  parse DT properties to retrieve the initialization data when set as
  default one"

* tag 'leds-for-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds:
  led: triggers: Initialize LED_INIT_DEFAULT_TRIGGER if trigger is brought after class
  led: triggers: Add LED_INIT_DEFAULT_TRIGGER flag
  led: triggers: Break the for loop after default trigger is found
  leds: pwm: Use OF variant of LED registering function
  leds: pwm: Simplify with resource-managed devm_led_classdev_register()
  leds: gpio: Drop unneeded manual of_node assignment
  leds: 88pm860x: Use of_node_name_eq for node name comparisons
  leds: powernv: add of_node_put()

led: triggers: Add LED_INIT_DEFAULT_TRIGGER flag

2018-12-10T20:31:55+00:00

Add the flag LED_INIT_DEFAULT_TRIGGER for indicating that trigger
being set is a default trigger for the LED class device, and
thus it should be initialized with settings provided in the fwnode.

Set the flag in the led_trigger_set_default(). It is expected to be
cleared in the activate() op of a trigger after trigger fwnode
initialization data is parsed and applied. This should happen only
once after LED class device registration, to allow leaving triggers
in the idle state on re-apply and let the users apply their own
settings without interference from the default ones.

Signed-off-by: Jacek Anaszewski 
Acked-by: Pavel Machek 
Signed-off-by: Krzysztof Kozlowski

leds: trigger: Introduce audio mute LED trigger

2018-11-28T11:28:30+00:00

This patch adds a new LED trigger for coupling the audio mixer change
with the LED on laptops or other devices.  Currently there are two
trigger types, "audio-mute" and "audio-micmute".

The audio driver triggers the LED brightness change via
ledtrig_audio_set() call with the proper type (either mute or
mic-mute).  OTOH, the consumers may call ledtrig_audio_get() for the
initial brightness value that may have been set by the audio driver
beforehand.

This new stuff will be used by HD-audio codec driver and some platform
drivers (thinkpad_acpi and dell-laptop, also upcoming huawei-wmi).

Acked-by: Jacek Anaszewski 
Acked-by: Pavel Machek 
Acked-by: Pali Rohár 
Signed-off-by: Takashi Iwai