WSL2-Linux-Kernel/drivers/leds/led-class.c

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/*
* LED Class Core
*
* Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
* Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com>
*
* 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.
*/
#include <linux/ctype.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/leds.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
Revert "leds: convert blink timer to workqueue" This reverts commit 8b37e1bef5a6b60e949e28a4db3006e4b00bd758. It's broken as it changes led_blink_set() in a way that it can now sleep (while synchronously waiting for workqueue to be cancelled). That's a problem, because it's possible that this function gets called from atomic context (tpt_trig_timer() takes a readlock and thus disables preemption). This has been brought up 3 weeks ago already [1] but no proper fix has materialized, and I keep seeing the problem since 3.17-rc1. [1] https://lkml.org/lkml/2014/8/16/128 BUG: sleeping function called from invalid context at kernel/workqueue.c:2650 in_atomic(): 1, irqs_disabled(): 0, pid: 2335, name: wpa_supplicant 5 locks held by wpa_supplicant/2335: #0: (rtnl_mutex){+.+.+.}, at: [<ffffffff814c7c92>] rtnl_lock+0x12/0x20 #1: (&wdev->mtx){+.+.+.}, at: [<ffffffffc06e649c>] cfg80211_mgd_wext_siwessid+0x5c/0x180 [cfg80211] #2: (&local->mtx){+.+.+.}, at: [<ffffffffc0817dea>] ieee80211_prep_connection+0x17a/0x9a0 [mac80211] #3: (&local->chanctx_mtx){+.+.+.}, at: [<ffffffffc08081ed>] ieee80211_vif_use_channel+0x5d/0x2a0 [mac80211] #4: (&trig->leddev_list_lock){.+.+..}, at: [<ffffffffc081e68c>] tpt_trig_timer+0xec/0x170 [mac80211] CPU: 0 PID: 2335 Comm: wpa_supplicant Not tainted 3.17.0-rc3 #1 Hardware name: LENOVO 7470BN2/7470BN2, BIOS 6DET38WW (2.02 ) 12/19/2008 ffff8800360b5a50 ffff8800751f76d8 ffffffff8159e97f ffff8800360b5a30 ffff8800751f76e8 ffffffff810739a5 ffff8800751f77b0 ffffffff8106862f ffffffff810685d0 0aa2209200000000 ffff880000000004 ffff8800361c59d0 Call Trace: [<ffffffff8159e97f>] dump_stack+0x4d/0x66 [<ffffffff810739a5>] __might_sleep+0xe5/0x120 [<ffffffff8106862f>] flush_work+0x5f/0x270 [<ffffffff810685d0>] ? mod_delayed_work_on+0x80/0x80 [<ffffffff810945ca>] ? mark_held_locks+0x6a/0x90 [<ffffffff81068a5f>] ? __cancel_work_timer+0x6f/0x100 [<ffffffff810946ed>] ? trace_hardirqs_on_caller+0xfd/0x1c0 [<ffffffff81068a6b>] __cancel_work_timer+0x7b/0x100 [<ffffffff81068b0e>] cancel_delayed_work_sync+0xe/0x10 [<ffffffff8147cf3b>] led_blink_set+0x1b/0x40 [<ffffffffc081e6b0>] tpt_trig_timer+0x110/0x170 [mac80211] [<ffffffffc081ecdd>] ieee80211_mod_tpt_led_trig+0x9d/0x160 [mac80211] [<ffffffffc07e4278>] __ieee80211_recalc_idle+0x98/0x140 [mac80211] [<ffffffffc07e59ce>] ieee80211_idle_off+0xe/0x10 [mac80211] [<ffffffffc0804e5b>] ieee80211_add_chanctx+0x3b/0x220 [mac80211] [<ffffffffc08062e4>] ieee80211_new_chanctx+0x44/0xf0 [mac80211] [<ffffffffc080838a>] ieee80211_vif_use_channel+0x1fa/0x2a0 [mac80211] [<ffffffffc0817df8>] ieee80211_prep_connection+0x188/0x9a0 [mac80211] [<ffffffffc081c246>] ieee80211_mgd_auth+0x256/0x2e0 [mac80211] [<ffffffffc07eab33>] ieee80211_auth+0x13/0x20 [mac80211] [<ffffffffc06cb006>] cfg80211_mlme_auth+0x106/0x270 [cfg80211] [<ffffffffc06ce085>] cfg80211_conn_do_work+0x155/0x3b0 [cfg80211] [<ffffffffc06cf670>] cfg80211_connect+0x3f0/0x540 [cfg80211] [<ffffffffc06e6148>] cfg80211_mgd_wext_connect+0x158/0x1f0 [cfg80211] [<ffffffffc06e651e>] cfg80211_mgd_wext_siwessid+0xde/0x180 [cfg80211] [<ffffffffc06e36c0>] ? cfg80211_wext_giwessid+0x50/0x50 [cfg80211] [<ffffffffc06e36dd>] cfg80211_wext_siwessid+0x1d/0x40 [cfg80211] [<ffffffff81584d0c>] ioctl_standard_iw_point+0x14c/0x3e0 [<ffffffff810946ed>] ? trace_hardirqs_on_caller+0xfd/0x1c0 [<ffffffff8158502a>] ioctl_standard_call+0x8a/0xd0 [<ffffffff81584fa0>] ? ioctl_standard_iw_point+0x3e0/0x3e0 [<ffffffff81584b76>] wireless_process_ioctl.constprop.10+0xb6/0x100 [<ffffffff8158521d>] wext_handle_ioctl+0x5d/0xb0 [<ffffffff814cfb29>] dev_ioctl+0x329/0x620 [<ffffffff810946ed>] ? trace_hardirqs_on_caller+0xfd/0x1c0 [<ffffffff8149c7f2>] sock_ioctl+0x142/0x2e0 [<ffffffff811b0140>] do_vfs_ioctl+0x300/0x520 [<ffffffff815a67fb>] ? sysret_check+0x1b/0x56 [<ffffffff810946ed>] ? trace_hardirqs_on_caller+0xfd/0x1c0 [<ffffffff811b03e1>] SyS_ioctl+0x81/0xa0 [<ffffffff815a67d6>] system_call_fastpath+0x1a/0x1f wlan0: send auth to 00:0b:6b:3c:8c:e4 (try 1/3) wlan0: authenticated wlan0: associate with 00:0b:6b:3c:8c:e4 (try 1/3) wlan0: RX AssocResp from 00:0b:6b:3c:8c:e4 (capab=0x431 status=0 aid=2) wlan0: associated IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready cfg80211: Calling CRDA for country: NA wlan0: Limiting TX power to 27 (27 - 0) dBm as advertised by 00:0b:6b:3c:8c:e4 ================================= [ INFO: inconsistent lock state ] 3.17.0-rc3 #1 Not tainted --------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. swapper/0/0 [HC0[0]:SC1[1]:HE1:SE0] takes: ((&(&led_cdev->blink_work)->work)){+.?...}, at: [<ffffffff810685d0>] flush_work+0x0/0x270 {SOFTIRQ-ON-W} state was registered at: [<ffffffff81094dbe>] __lock_acquire+0x30e/0x1a30 [<ffffffff81096c81>] lock_acquire+0x91/0x110 [<ffffffff81068608>] flush_work+0x38/0x270 [<ffffffff81068a6b>] __cancel_work_timer+0x7b/0x100 [<ffffffff81068b0e>] cancel_delayed_work_sync+0xe/0x10 [<ffffffff8147cf3b>] led_blink_set+0x1b/0x40 [<ffffffffc081e6b0>] tpt_trig_timer+0x110/0x170 [mac80211] [<ffffffffc081ecdd>] ieee80211_mod_tpt_led_trig+0x9d/0x160 [mac80211] [<ffffffffc07e4278>] __ieee80211_recalc_idle+0x98/0x140 [mac80211] [<ffffffffc07e59ce>] ieee80211_idle_off+0xe/0x10 [mac80211] [<ffffffffc0804e5b>] ieee80211_add_chanctx+0x3b/0x220 [mac80211] [<ffffffffc08062e4>] ieee80211_new_chanctx+0x44/0xf0 [mac80211] [<ffffffffc080838a>] ieee80211_vif_use_channel+0x1fa/0x2a0 [mac80211] [<ffffffffc0817df8>] ieee80211_prep_connection+0x188/0x9a0 [mac80211] [<ffffffffc081c246>] ieee80211_mgd_auth+0x256/0x2e0 [mac80211] [<ffffffffc07eab33>] ieee80211_auth+0x13/0x20 [mac80211] [<ffffffffc06cb006>] cfg80211_mlme_auth+0x106/0x270 [cfg80211] [<ffffffffc06ce085>] cfg80211_conn_do_work+0x155/0x3b0 [cfg80211] [<ffffffffc06cf670>] cfg80211_connect+0x3f0/0x540 [cfg80211] [<ffffffffc06e6148>] cfg80211_mgd_wext_connect+0x158/0x1f0 [cfg80211] [<ffffffffc06e651e>] cfg80211_mgd_wext_siwessid+0xde/0x180 [cfg80211] [<ffffffffc06e36dd>] cfg80211_wext_siwessid+0x1d/0x40 [cfg80211] [<ffffffff81584d0c>] ioctl_standard_iw_point+0x14c/0x3e0 [<ffffffff8158502a>] ioctl_standard_call+0x8a/0xd0 [<ffffffff81584b76>] wireless_process_ioctl.constprop.10+0xb6/0x100 [<ffffffff8158521d>] wext_handle_ioctl+0x5d/0xb0 [<ffffffff814cfb29>] dev_ioctl+0x329/0x620 [<ffffffff8149c7f2>] sock_ioctl+0x142/0x2e0 [<ffffffff811b0140>] do_vfs_ioctl+0x300/0x520 [<ffffffff811b03e1>] SyS_ioctl+0x81/0xa0 [<ffffffff815a67d6>] system_call_fastpath+0x1a/0x1f irq event stamp: 493416 hardirqs last enabled at (493416): [<ffffffff81068a5f>] __cancel_work_timer+0x6f/0x100 hardirqs last disabled at (493415): [<ffffffff81067e9f>] try_to_grab_pending+0x1f/0x160 softirqs last enabled at (493408): [<ffffffff81053ced>] _local_bh_enable+0x1d/0x50 softirqs last disabled at (493409): [<ffffffff81054c75>] irq_exit+0xa5/0xb0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock((&(&led_cdev->blink_work)->work)); <Interrupt> lock((&(&led_cdev->blink_work)->work)); *** DEADLOCK *** 2 locks held by swapper/0/0: #0: (((&tpt_trig->timer))){+.-...}, at: [<ffffffff810b4c50>] call_timer_fn+0x0/0x180 #1: (&trig->leddev_list_lock){.+.?..}, at: [<ffffffffc081e68c>] tpt_trig_timer+0xec/0x170 [mac80211] stack backtrace: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.17.0-rc3 #1 Hardware name: LENOVO 7470BN2/7470BN2, BIOS 6DET38WW (2.02 ) 12/19/2008 ffffffff8246eb30 ffff88007c203b00 ffffffff8159e97f ffffffff81a194c0 ffff88007c203b50 ffffffff81599c29 0000000000000001 ffffffff00000001 ffff880000000000 0000000000000006 ffffffff81a194c0 ffffffff81093ad0 Call Trace: <IRQ> [<ffffffff8159e97f>] dump_stack+0x4d/0x66 [<ffffffff81599c29>] print_usage_bug+0x1f4/0x205 [<ffffffff81093ad0>] ? check_usage_backwards+0x140/0x140 [<ffffffff810944d3>] mark_lock+0x223/0x2b0 [<ffffffff81094d60>] __lock_acquire+0x2b0/0x1a30 [<ffffffff81096c81>] lock_acquire+0x91/0x110 [<ffffffff810685d0>] ? mod_delayed_work_on+0x80/0x80 [<ffffffffc081e5a0>] ? __ieee80211_get_rx_led_name+0x10/0x10 [mac80211] [<ffffffff81068608>] flush_work+0x38/0x270 [<ffffffff810685d0>] ? mod_delayed_work_on+0x80/0x80 [<ffffffff810945ca>] ? mark_held_locks+0x6a/0x90 [<ffffffff81068a5f>] ? __cancel_work_timer+0x6f/0x100 [<ffffffffc081e5a0>] ? __ieee80211_get_rx_led_name+0x10/0x10 [mac80211] [<ffffffff8109469d>] ? trace_hardirqs_on_caller+0xad/0x1c0 [<ffffffffc081e5a0>] ? __ieee80211_get_rx_led_name+0x10/0x10 [mac80211] [<ffffffff81068a6b>] __cancel_work_timer+0x7b/0x100 [<ffffffff81068b0e>] cancel_delayed_work_sync+0xe/0x10 [<ffffffff8147cf3b>] led_blink_set+0x1b/0x40 [<ffffffffc081e6b0>] tpt_trig_timer+0x110/0x170 [mac80211] [<ffffffff810b4cc5>] call_timer_fn+0x75/0x180 [<ffffffff810b4c50>] ? process_timeout+0x10/0x10 [<ffffffffc081e5a0>] ? __ieee80211_get_rx_led_name+0x10/0x10 [mac80211] [<ffffffff810b50ac>] run_timer_softirq+0x1fc/0x2f0 [<ffffffff81054805>] __do_softirq+0x115/0x2e0 [<ffffffff81054c75>] irq_exit+0xa5/0xb0 [<ffffffff810049b3>] do_IRQ+0x53/0xf0 [<ffffffff815a74af>] common_interrupt+0x6f/0x6f <EOI> [<ffffffff8147b56e>] ? cpuidle_enter_state+0x6e/0x180 [<ffffffff8147b732>] cpuidle_enter+0x12/0x20 [<ffffffff8108bba0>] cpu_startup_entry+0x330/0x360 [<ffffffff8158fb51>] rest_init+0xc1/0xd0 [<ffffffff8158fa90>] ? csum_partial_copy_generic+0x170/0x170 [<ffffffff81af3ff2>] start_kernel+0x44f/0x45a [<ffffffff81af399c>] ? set_init_arg+0x53/0x53 [<ffffffff81af35ad>] x86_64_start_reservations+0x2a/0x2c [<ffffffff81af36a0>] x86_64_start_kernel+0xf1/0xf4 Cc: Vincent Donnefort <vdonnefort@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Bryan Wu <cooloney@gmail.com>
2014-09-02 13:03:12 +04:00
#include <linux/timer.h>
#include <uapi/linux/uleds.h>
#include "leds.h"
static struct class *leds_class;
static ssize_t brightness_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
/* no lock needed for this */
led_update_brightness(led_cdev);
return sprintf(buf, "%u\n", led_cdev->brightness);
}
static ssize_t brightness_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t size)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
unsigned long state;
ssize_t ret;
mutex_lock(&led_cdev->led_access);
if (led_sysfs_is_disabled(led_cdev)) {
ret = -EBUSY;
goto unlock;
}
ret = kstrtoul(buf, 10, &state);
if (ret)
goto unlock;
if (state == LED_OFF)
led_trigger_remove(led_cdev);
led_set_brightness(led_cdev, state);
ret = size;
unlock:
mutex_unlock(&led_cdev->led_access);
return ret;
}
static DEVICE_ATTR_RW(brightness);
static ssize_t max_brightness_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
return sprintf(buf, "%u\n", led_cdev->max_brightness);
}
static DEVICE_ATTR_RO(max_brightness);
#ifdef CONFIG_LEDS_TRIGGERS
static DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store);
static struct attribute *led_trigger_attrs[] = {
&dev_attr_trigger.attr,
NULL,
};
static const struct attribute_group led_trigger_group = {
.attrs = led_trigger_attrs,
};
#endif
static struct attribute *led_class_attrs[] = {
&dev_attr_brightness.attr,
&dev_attr_max_brightness.attr,
NULL,
};
static const struct attribute_group led_group = {
.attrs = led_class_attrs,
};
static const struct attribute_group *led_groups[] = {
&led_group,
#ifdef CONFIG_LEDS_TRIGGERS
&led_trigger_group,
#endif
NULL,
};
#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
static ssize_t brightness_hw_changed_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
if (led_cdev->brightness_hw_changed == -1)
return -ENODATA;
return sprintf(buf, "%u\n", led_cdev->brightness_hw_changed);
}
static DEVICE_ATTR_RO(brightness_hw_changed);
static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
{
struct device *dev = led_cdev->dev;
int ret;
ret = device_create_file(dev, &dev_attr_brightness_hw_changed);
if (ret) {
dev_err(dev, "Error creating brightness_hw_changed\n");
return ret;
}
led_cdev->brightness_hw_changed_kn =
sysfs_get_dirent(dev->kobj.sd, "brightness_hw_changed");
if (!led_cdev->brightness_hw_changed_kn) {
dev_err(dev, "Error getting brightness_hw_changed kn\n");
device_remove_file(dev, &dev_attr_brightness_hw_changed);
return -ENXIO;
}
return 0;
}
static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
{
sysfs_put(led_cdev->brightness_hw_changed_kn);
device_remove_file(led_cdev->dev, &dev_attr_brightness_hw_changed);
}
void led_classdev_notify_brightness_hw_changed(struct led_classdev *led_cdev,
enum led_brightness brightness)
{
if (WARN_ON(!led_cdev->brightness_hw_changed_kn))
return;
led_cdev->brightness_hw_changed = brightness;
sysfs_notify_dirent(led_cdev->brightness_hw_changed_kn);
}
EXPORT_SYMBOL_GPL(led_classdev_notify_brightness_hw_changed);
#else
static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
{
return 0;
}
static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
{
}
#endif
/**
* led_classdev_suspend - suspend an led_classdev.
* @led_cdev: the led_classdev to suspend.
*/
void led_classdev_suspend(struct led_classdev *led_cdev)
{
led_cdev->flags |= LED_SUSPENDED;
led_set_brightness_nopm(led_cdev, 0);
}
EXPORT_SYMBOL_GPL(led_classdev_suspend);
/**
* led_classdev_resume - resume an led_classdev.
* @led_cdev: the led_classdev to resume.
*/
void led_classdev_resume(struct led_classdev *led_cdev)
{
led_set_brightness_nopm(led_cdev, led_cdev->brightness);
if (led_cdev->flash_resume)
led_cdev->flash_resume(led_cdev);
led_cdev->flags &= ~LED_SUSPENDED;
}
EXPORT_SYMBOL_GPL(led_classdev_resume);
#ifdef CONFIG_PM_SLEEP
static int led_suspend(struct device *dev)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
led_classdev_suspend(led_cdev);
return 0;
}
static int led_resume(struct device *dev)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
led_classdev_resume(led_cdev);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
static int match_name(struct device *dev, const void *data)
{
if (!dev_name(dev))
return 0;
return !strcmp(dev_name(dev), (char *)data);
}
static int led_classdev_next_name(const char *init_name, char *name,
size_t len)
{
unsigned int i = 0;
int ret = 0;
struct device *dev;
strlcpy(name, init_name, len);
while ((ret < len) &&
(dev = class_find_device(leds_class, NULL, name, match_name))) {
put_device(dev);
ret = snprintf(name, len, "%s_%u", init_name, ++i);
}
if (ret >= len)
return -ENOMEM;
return i;
}
/**
* of_led_classdev_register - register a new object of led_classdev class.
*
* @parent: parent of LED device
* @led_cdev: the led_classdev structure for this device.
* @np: DT node describing this LED
*/
int of_led_classdev_register(struct device *parent, struct device_node *np,
struct led_classdev *led_cdev)
{
char name[LED_MAX_NAME_SIZE];
int ret;
ret = led_classdev_next_name(led_cdev->name, name, sizeof(name));
if (ret < 0)
return ret;
leds: class: ensure workqueue is initialized before setting brightness An application can try to set brightness before all the initialization is done, in particular before the workqueue is initialized with the call to led_init_core(). Here's a WARNING easy to trigger: [ 36.780813] WARNING: CPU: 3 PID: 1411 at ../kernel/workqueue.c:1444 __queue_work+0x37b/0x420 [ 36.780815] Modules linked in: ... [ 36.780868] CPU: 3 PID: 1411 Comm: systemd-backlig Not tainted 4.16.9-1-default #1 openSUSE Tumbleweed (unreleased) [ 36.780868] Hardware name: Dell Inc. Precision 5510/0N8J4R, BIOS 1.6.1 12/11/2017 [ 36.780870] RIP: 0010:__queue_work+0x37b/0x420 [ 36.780871] RSP: 0018:ffffaced048b7d78 EFLAGS: 00010086 [ 36.780873] RAX: 0000000000000000 RBX: ffffffffb3f01440 RCX: 0000000000000000 [ 36.780873] RDX: ffffffffc05a90d8 RSI: 0000000000000000 RDI: ffff8eac7dce2700 [ 36.780874] RBP: ffff8ea547c16400 R08: ffff8ea547800000 R09: ffff8eac7dc22700 [ 36.780875] R10: 0000000000000000 R11: 0000000000000040 R12: 0000000000000003 [ 36.780876] R13: 0000000000000200 R14: ffffffffc05a90d0 R15: ffff8eac7dce8600 [ 36.780877] FS: 00007f871e61cf40(0000) GS:ffff8eac7dcc0000(0000) knlGS:0000000000000000 [ 36.780878] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 36.780879] CR2: 000055c91115e308 CR3: 0000000883ee0005 CR4: 00000000003606e0 [ 36.780880] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 36.780880] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 36.780881] Call Trace: [ 36.780886] queue_work_on+0x81/0x90 [ 36.780889] brightness_store+0x5d/0x90 [ 36.780892] kernfs_fop_write+0x105/0x180 [ 36.780894] __vfs_write+0x26/0x150 [ 36.780897] ? common_file_perm+0x51/0x150 [ 36.780900] ? security_file_permission+0x3c/0xb0 [ 36.780901] vfs_write+0xad/0x1a0 [ 36.780903] SyS_write+0x42/0x90 [ 36.780906] do_syscall_64+0x76/0x140 [ 36.780908] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 36.780910] RIP: 0033:0x7f871dd04c94 [ 36.780910] RSP: 002b:00007ffeb3a57d38 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 36.780912] RAX: ffffffffffffffda RBX: 000055c91115c810 RCX: 00007f871dd04c94 [ 36.780912] RDX: 0000000000000001 RSI: 000055c91115c810 RDI: 0000000000000004 [ 36.780913] RBP: 00007ffeb3a57e10 R08: 0000000000000003 R09: 0000000000000000 [ 36.780914] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 36.780914] R13: 000055c911158f30 R14: 000055c90f3a9a4e R15: 0000000000000004 [ 36.780917] Code: 74 18 e8 49 80 00 00 48 85 c0 74 0e 48 8b 40 20 48 3b 68 08 0f 84 c2 fc ff ff 0f 0b 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 <0f> 0b e9 82 fd ff ff 83 cd 02 49 8d 57 60 e9 69 fd ff ff 80 3d [ 36.780942] ---[ end trace 1fce4edad54c4017 ]--- This patch initializes and acquires the led_access mutex early in the of_led_classdev_register function, so that any application trying to write to sysfs to set brightness will block until initialization ends. Signed-off-by: Luis Henriques <lhenriques@suse.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
2018-05-24 01:22:21 +03:00
mutex_init(&led_cdev->led_access);
mutex_lock(&led_cdev->led_access);
led_cdev->dev = device_create_with_groups(leds_class, parent, 0,
led_cdev, led_cdev->groups, "%s", name);
leds: class: ensure workqueue is initialized before setting brightness An application can try to set brightness before all the initialization is done, in particular before the workqueue is initialized with the call to led_init_core(). Here's a WARNING easy to trigger: [ 36.780813] WARNING: CPU: 3 PID: 1411 at ../kernel/workqueue.c:1444 __queue_work+0x37b/0x420 [ 36.780815] Modules linked in: ... [ 36.780868] CPU: 3 PID: 1411 Comm: systemd-backlig Not tainted 4.16.9-1-default #1 openSUSE Tumbleweed (unreleased) [ 36.780868] Hardware name: Dell Inc. Precision 5510/0N8J4R, BIOS 1.6.1 12/11/2017 [ 36.780870] RIP: 0010:__queue_work+0x37b/0x420 [ 36.780871] RSP: 0018:ffffaced048b7d78 EFLAGS: 00010086 [ 36.780873] RAX: 0000000000000000 RBX: ffffffffb3f01440 RCX: 0000000000000000 [ 36.780873] RDX: ffffffffc05a90d8 RSI: 0000000000000000 RDI: ffff8eac7dce2700 [ 36.780874] RBP: ffff8ea547c16400 R08: ffff8ea547800000 R09: ffff8eac7dc22700 [ 36.780875] R10: 0000000000000000 R11: 0000000000000040 R12: 0000000000000003 [ 36.780876] R13: 0000000000000200 R14: ffffffffc05a90d0 R15: ffff8eac7dce8600 [ 36.780877] FS: 00007f871e61cf40(0000) GS:ffff8eac7dcc0000(0000) knlGS:0000000000000000 [ 36.780878] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 36.780879] CR2: 000055c91115e308 CR3: 0000000883ee0005 CR4: 00000000003606e0 [ 36.780880] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 36.780880] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 36.780881] Call Trace: [ 36.780886] queue_work_on+0x81/0x90 [ 36.780889] brightness_store+0x5d/0x90 [ 36.780892] kernfs_fop_write+0x105/0x180 [ 36.780894] __vfs_write+0x26/0x150 [ 36.780897] ? common_file_perm+0x51/0x150 [ 36.780900] ? security_file_permission+0x3c/0xb0 [ 36.780901] vfs_write+0xad/0x1a0 [ 36.780903] SyS_write+0x42/0x90 [ 36.780906] do_syscall_64+0x76/0x140 [ 36.780908] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 36.780910] RIP: 0033:0x7f871dd04c94 [ 36.780910] RSP: 002b:00007ffeb3a57d38 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 36.780912] RAX: ffffffffffffffda RBX: 000055c91115c810 RCX: 00007f871dd04c94 [ 36.780912] RDX: 0000000000000001 RSI: 000055c91115c810 RDI: 0000000000000004 [ 36.780913] RBP: 00007ffeb3a57e10 R08: 0000000000000003 R09: 0000000000000000 [ 36.780914] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 36.780914] R13: 000055c911158f30 R14: 000055c90f3a9a4e R15: 0000000000000004 [ 36.780917] Code: 74 18 e8 49 80 00 00 48 85 c0 74 0e 48 8b 40 20 48 3b 68 08 0f 84 c2 fc ff ff 0f 0b 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 <0f> 0b e9 82 fd ff ff 83 cd 02 49 8d 57 60 e9 69 fd ff ff 80 3d [ 36.780942] ---[ end trace 1fce4edad54c4017 ]--- This patch initializes and acquires the led_access mutex early in the of_led_classdev_register function, so that any application trying to write to sysfs to set brightness will block until initialization ends. Signed-off-by: Luis Henriques <lhenriques@suse.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
2018-05-24 01:22:21 +03:00
if (IS_ERR(led_cdev->dev)) {
mutex_unlock(&led_cdev->led_access);
return PTR_ERR(led_cdev->dev);
leds: class: ensure workqueue is initialized before setting brightness An application can try to set brightness before all the initialization is done, in particular before the workqueue is initialized with the call to led_init_core(). Here's a WARNING easy to trigger: [ 36.780813] WARNING: CPU: 3 PID: 1411 at ../kernel/workqueue.c:1444 __queue_work+0x37b/0x420 [ 36.780815] Modules linked in: ... [ 36.780868] CPU: 3 PID: 1411 Comm: systemd-backlig Not tainted 4.16.9-1-default #1 openSUSE Tumbleweed (unreleased) [ 36.780868] Hardware name: Dell Inc. Precision 5510/0N8J4R, BIOS 1.6.1 12/11/2017 [ 36.780870] RIP: 0010:__queue_work+0x37b/0x420 [ 36.780871] RSP: 0018:ffffaced048b7d78 EFLAGS: 00010086 [ 36.780873] RAX: 0000000000000000 RBX: ffffffffb3f01440 RCX: 0000000000000000 [ 36.780873] RDX: ffffffffc05a90d8 RSI: 0000000000000000 RDI: ffff8eac7dce2700 [ 36.780874] RBP: ffff8ea547c16400 R08: ffff8ea547800000 R09: ffff8eac7dc22700 [ 36.780875] R10: 0000000000000000 R11: 0000000000000040 R12: 0000000000000003 [ 36.780876] R13: 0000000000000200 R14: ffffffffc05a90d0 R15: ffff8eac7dce8600 [ 36.780877] FS: 00007f871e61cf40(0000) GS:ffff8eac7dcc0000(0000) knlGS:0000000000000000 [ 36.780878] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 36.780879] CR2: 000055c91115e308 CR3: 0000000883ee0005 CR4: 00000000003606e0 [ 36.780880] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 36.780880] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 36.780881] Call Trace: [ 36.780886] queue_work_on+0x81/0x90 [ 36.780889] brightness_store+0x5d/0x90 [ 36.780892] kernfs_fop_write+0x105/0x180 [ 36.780894] __vfs_write+0x26/0x150 [ 36.780897] ? common_file_perm+0x51/0x150 [ 36.780900] ? security_file_permission+0x3c/0xb0 [ 36.780901] vfs_write+0xad/0x1a0 [ 36.780903] SyS_write+0x42/0x90 [ 36.780906] do_syscall_64+0x76/0x140 [ 36.780908] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 36.780910] RIP: 0033:0x7f871dd04c94 [ 36.780910] RSP: 002b:00007ffeb3a57d38 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 36.780912] RAX: ffffffffffffffda RBX: 000055c91115c810 RCX: 00007f871dd04c94 [ 36.780912] RDX: 0000000000000001 RSI: 000055c91115c810 RDI: 0000000000000004 [ 36.780913] RBP: 00007ffeb3a57e10 R08: 0000000000000003 R09: 0000000000000000 [ 36.780914] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 36.780914] R13: 000055c911158f30 R14: 000055c90f3a9a4e R15: 0000000000000004 [ 36.780917] Code: 74 18 e8 49 80 00 00 48 85 c0 74 0e 48 8b 40 20 48 3b 68 08 0f 84 c2 fc ff ff 0f 0b 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 <0f> 0b e9 82 fd ff ff 83 cd 02 49 8d 57 60 e9 69 fd ff ff 80 3d [ 36.780942] ---[ end trace 1fce4edad54c4017 ]--- This patch initializes and acquires the led_access mutex early in the of_led_classdev_register function, so that any application trying to write to sysfs to set brightness will block until initialization ends. Signed-off-by: Luis Henriques <lhenriques@suse.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
2018-05-24 01:22:21 +03:00
}
led_cdev->dev->of_node = np;
if (ret)
dev_warn(parent, "Led %s renamed to %s due to name collision",
led_cdev->name, dev_name(led_cdev->dev));
if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) {
ret = led_add_brightness_hw_changed(led_cdev);
if (ret) {
device_unregister(led_cdev->dev);
leds: class: ensure workqueue is initialized before setting brightness An application can try to set brightness before all the initialization is done, in particular before the workqueue is initialized with the call to led_init_core(). Here's a WARNING easy to trigger: [ 36.780813] WARNING: CPU: 3 PID: 1411 at ../kernel/workqueue.c:1444 __queue_work+0x37b/0x420 [ 36.780815] Modules linked in: ... [ 36.780868] CPU: 3 PID: 1411 Comm: systemd-backlig Not tainted 4.16.9-1-default #1 openSUSE Tumbleweed (unreleased) [ 36.780868] Hardware name: Dell Inc. Precision 5510/0N8J4R, BIOS 1.6.1 12/11/2017 [ 36.780870] RIP: 0010:__queue_work+0x37b/0x420 [ 36.780871] RSP: 0018:ffffaced048b7d78 EFLAGS: 00010086 [ 36.780873] RAX: 0000000000000000 RBX: ffffffffb3f01440 RCX: 0000000000000000 [ 36.780873] RDX: ffffffffc05a90d8 RSI: 0000000000000000 RDI: ffff8eac7dce2700 [ 36.780874] RBP: ffff8ea547c16400 R08: ffff8ea547800000 R09: ffff8eac7dc22700 [ 36.780875] R10: 0000000000000000 R11: 0000000000000040 R12: 0000000000000003 [ 36.780876] R13: 0000000000000200 R14: ffffffffc05a90d0 R15: ffff8eac7dce8600 [ 36.780877] FS: 00007f871e61cf40(0000) GS:ffff8eac7dcc0000(0000) knlGS:0000000000000000 [ 36.780878] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 36.780879] CR2: 000055c91115e308 CR3: 0000000883ee0005 CR4: 00000000003606e0 [ 36.780880] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 36.780880] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 36.780881] Call Trace: [ 36.780886] queue_work_on+0x81/0x90 [ 36.780889] brightness_store+0x5d/0x90 [ 36.780892] kernfs_fop_write+0x105/0x180 [ 36.780894] __vfs_write+0x26/0x150 [ 36.780897] ? common_file_perm+0x51/0x150 [ 36.780900] ? security_file_permission+0x3c/0xb0 [ 36.780901] vfs_write+0xad/0x1a0 [ 36.780903] SyS_write+0x42/0x90 [ 36.780906] do_syscall_64+0x76/0x140 [ 36.780908] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 36.780910] RIP: 0033:0x7f871dd04c94 [ 36.780910] RSP: 002b:00007ffeb3a57d38 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 36.780912] RAX: ffffffffffffffda RBX: 000055c91115c810 RCX: 00007f871dd04c94 [ 36.780912] RDX: 0000000000000001 RSI: 000055c91115c810 RDI: 0000000000000004 [ 36.780913] RBP: 00007ffeb3a57e10 R08: 0000000000000003 R09: 0000000000000000 [ 36.780914] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 36.780914] R13: 000055c911158f30 R14: 000055c90f3a9a4e R15: 0000000000000004 [ 36.780917] Code: 74 18 e8 49 80 00 00 48 85 c0 74 0e 48 8b 40 20 48 3b 68 08 0f 84 c2 fc ff ff 0f 0b 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 <0f> 0b e9 82 fd ff ff 83 cd 02 49 8d 57 60 e9 69 fd ff ff 80 3d [ 36.780942] ---[ end trace 1fce4edad54c4017 ]--- This patch initializes and acquires the led_access mutex early in the of_led_classdev_register function, so that any application trying to write to sysfs to set brightness will block until initialization ends. Signed-off-by: Luis Henriques <lhenriques@suse.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
2018-05-24 01:22:21 +03:00
mutex_unlock(&led_cdev->led_access);
return ret;
}
}
led_cdev->work_flags = 0;
#ifdef CONFIG_LEDS_TRIGGERS
init_rwsem(&led_cdev->trigger_lock);
#endif
#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
led_cdev->brightness_hw_changed = -1;
#endif
/* add to the list of leds */
down_write(&leds_list_lock);
list_add_tail(&led_cdev->node, &leds_list);
up_write(&leds_list_lock);
if (!led_cdev->max_brightness)
led_cdev->max_brightness = LED_FULL;
led_update_brightness(led_cdev);
led_init_core(led_cdev);
#ifdef CONFIG_LEDS_TRIGGERS
led_trigger_set_default(led_cdev);
#endif
leds: class: ensure workqueue is initialized before setting brightness An application can try to set brightness before all the initialization is done, in particular before the workqueue is initialized with the call to led_init_core(). Here's a WARNING easy to trigger: [ 36.780813] WARNING: CPU: 3 PID: 1411 at ../kernel/workqueue.c:1444 __queue_work+0x37b/0x420 [ 36.780815] Modules linked in: ... [ 36.780868] CPU: 3 PID: 1411 Comm: systemd-backlig Not tainted 4.16.9-1-default #1 openSUSE Tumbleweed (unreleased) [ 36.780868] Hardware name: Dell Inc. Precision 5510/0N8J4R, BIOS 1.6.1 12/11/2017 [ 36.780870] RIP: 0010:__queue_work+0x37b/0x420 [ 36.780871] RSP: 0018:ffffaced048b7d78 EFLAGS: 00010086 [ 36.780873] RAX: 0000000000000000 RBX: ffffffffb3f01440 RCX: 0000000000000000 [ 36.780873] RDX: ffffffffc05a90d8 RSI: 0000000000000000 RDI: ffff8eac7dce2700 [ 36.780874] RBP: ffff8ea547c16400 R08: ffff8ea547800000 R09: ffff8eac7dc22700 [ 36.780875] R10: 0000000000000000 R11: 0000000000000040 R12: 0000000000000003 [ 36.780876] R13: 0000000000000200 R14: ffffffffc05a90d0 R15: ffff8eac7dce8600 [ 36.780877] FS: 00007f871e61cf40(0000) GS:ffff8eac7dcc0000(0000) knlGS:0000000000000000 [ 36.780878] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 36.780879] CR2: 000055c91115e308 CR3: 0000000883ee0005 CR4: 00000000003606e0 [ 36.780880] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 36.780880] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 36.780881] Call Trace: [ 36.780886] queue_work_on+0x81/0x90 [ 36.780889] brightness_store+0x5d/0x90 [ 36.780892] kernfs_fop_write+0x105/0x180 [ 36.780894] __vfs_write+0x26/0x150 [ 36.780897] ? common_file_perm+0x51/0x150 [ 36.780900] ? security_file_permission+0x3c/0xb0 [ 36.780901] vfs_write+0xad/0x1a0 [ 36.780903] SyS_write+0x42/0x90 [ 36.780906] do_syscall_64+0x76/0x140 [ 36.780908] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 36.780910] RIP: 0033:0x7f871dd04c94 [ 36.780910] RSP: 002b:00007ffeb3a57d38 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 36.780912] RAX: ffffffffffffffda RBX: 000055c91115c810 RCX: 00007f871dd04c94 [ 36.780912] RDX: 0000000000000001 RSI: 000055c91115c810 RDI: 0000000000000004 [ 36.780913] RBP: 00007ffeb3a57e10 R08: 0000000000000003 R09: 0000000000000000 [ 36.780914] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 36.780914] R13: 000055c911158f30 R14: 000055c90f3a9a4e R15: 0000000000000004 [ 36.780917] Code: 74 18 e8 49 80 00 00 48 85 c0 74 0e 48 8b 40 20 48 3b 68 08 0f 84 c2 fc ff ff 0f 0b 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 <0f> 0b e9 82 fd ff ff 83 cd 02 49 8d 57 60 e9 69 fd ff ff 80 3d [ 36.780942] ---[ end trace 1fce4edad54c4017 ]--- This patch initializes and acquires the led_access mutex early in the of_led_classdev_register function, so that any application trying to write to sysfs to set brightness will block until initialization ends. Signed-off-by: Luis Henriques <lhenriques@suse.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
2018-05-24 01:22:21 +03:00
mutex_unlock(&led_cdev->led_access);
dev_dbg(parent, "Registered led device: %s\n",
led_cdev->name);
return 0;
}
EXPORT_SYMBOL_GPL(of_led_classdev_register);
/**
* led_classdev_unregister - unregisters a object of led_properties class.
* @led_cdev: the led device to unregister
*
* Unregisters a previously registered via led_classdev_register object.
*/
void led_classdev_unregister(struct led_classdev *led_cdev)
{
#ifdef CONFIG_LEDS_TRIGGERS
down_write(&led_cdev->trigger_lock);
if (led_cdev->trigger)
led_trigger_set(led_cdev, NULL);
up_write(&led_cdev->trigger_lock);
#endif
led_cdev->flags |= LED_UNREGISTERING;
/* Stop blinking */
led_stop_software_blink(led_cdev);
led_set_brightness(led_cdev, LED_OFF);
flush_work(&led_cdev->set_brightness_work);
if (led_cdev->flags & LED_BRIGHT_HW_CHANGED)
led_remove_brightness_hw_changed(led_cdev);
device_unregister(led_cdev->dev);
down_write(&leds_list_lock);
list_del(&led_cdev->node);
up_write(&leds_list_lock);
mutex_destroy(&led_cdev->led_access);
}
EXPORT_SYMBOL_GPL(led_classdev_unregister);
static void devm_led_classdev_release(struct device *dev, void *res)
{
led_classdev_unregister(*(struct led_classdev **)res);
}
/**
* devm_of_led_classdev_register - resource managed led_classdev_register()
*
* @parent: parent of LED device
* @led_cdev: the led_classdev structure for this device.
*/
int devm_of_led_classdev_register(struct device *parent,
struct device_node *np,
struct led_classdev *led_cdev)
{
struct led_classdev **dr;
int rc;
dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL);
if (!dr)
return -ENOMEM;
rc = of_led_classdev_register(parent, np, led_cdev);
if (rc) {
devres_free(dr);
return rc;
}
*dr = led_cdev;
devres_add(parent, dr);
return 0;
}
EXPORT_SYMBOL_GPL(devm_of_led_classdev_register);
static int devm_led_classdev_match(struct device *dev, void *res, void *data)
{
struct led_cdev **p = res;
if (WARN_ON(!p || !*p))
return 0;
return *p == data;
}
/**
* devm_led_classdev_unregister() - resource managed led_classdev_unregister()
* @parent: The device to unregister.
* @led_cdev: the led_classdev structure for this device.
*/
void devm_led_classdev_unregister(struct device *dev,
struct led_classdev *led_cdev)
{
WARN_ON(devres_release(dev,
devm_led_classdev_release,
devm_led_classdev_match, led_cdev));
}
EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
static int __init leds_init(void)
{
leds_class = class_create(THIS_MODULE, "leds");
if (IS_ERR(leds_class))
return PTR_ERR(leds_class);
leds_class->pm = &leds_class_dev_pm_ops;
leds_class->dev_groups = led_groups;
return 0;
}
static void __exit leds_exit(void)
{
class_destroy(leds_class);
}
subsys_initcall(leds_init);
module_exit(leds_exit);
MODULE_AUTHOR("John Lenz, Richard Purdie");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("LED Class Interface");