linux-stable/drivers/leds/led-triggers.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* LED Triggers Core
*
* Copyright 2005-2007 Openedhand Ltd.
*
* Author: Richard Purdie <rpurdie@openedhand.com>
*/
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/timer.h>
#include <linux/rwsem.h>
#include <linux/leds.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include "leds.h"
/*
* Nests outside led_cdev->trigger_lock
*/
static DECLARE_RWSEM(triggers_list_lock);
LIST_HEAD(trigger_list);
/* Used by LED Class */
ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
struct led_trigger *trig;
int ret = count;
mutex_lock(&led_cdev->led_access);
if (led_sysfs_is_disabled(led_cdev)) {
ret = -EBUSY;
goto unlock;
}
if (sysfs_streq(buf, "none")) {
led_trigger_remove(led_cdev);
goto unlock;
}
down_read(&triggers_list_lock);
list_for_each_entry(trig, &trigger_list, next_trig) {
if (sysfs_streq(buf, trig->name)) {
down_write(&led_cdev->trigger_lock);
led_trigger_set(led_cdev, trig);
up_write(&led_cdev->trigger_lock);
up_read(&triggers_list_lock);
goto unlock;
}
}
/* we come here only if buf matches no trigger */
ret = -EINVAL;
up_read(&triggers_list_lock);
unlock:
mutex_unlock(&led_cdev->led_access);
return ret;
}
EXPORT_SYMBOL_GPL(led_trigger_store);
ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
struct led_trigger *trig;
int len = 0;
down_read(&triggers_list_lock);
down_read(&led_cdev->trigger_lock);
if (!led_cdev->trigger)
len += scnprintf(buf+len, PAGE_SIZE - len, "[none] ");
else
len += scnprintf(buf+len, PAGE_SIZE - len, "none ");
list_for_each_entry(trig, &trigger_list, next_trig) {
if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
trig->name))
len += scnprintf(buf+len, PAGE_SIZE - len, "[%s] ",
trig->name);
else
len += scnprintf(buf+len, PAGE_SIZE - len, "%s ",
trig->name);
}
up_read(&led_cdev->trigger_lock);
up_read(&triggers_list_lock);
len += scnprintf(len+buf, PAGE_SIZE - len, "\n");
return len;
}
EXPORT_SYMBOL_GPL(led_trigger_show);
/* Caller must ensure led_cdev->trigger_lock held */
int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
{
unsigned long flags;
char *event = NULL;
char *envp[2];
const char *name;
int ret;
if (!led_cdev->trigger && !trig)
return 0;
name = trig ? trig->name : "none";
event = kasprintf(GFP_KERNEL, "TRIGGER=%s", name);
/* Remove any existing trigger */
if (led_cdev->trigger) {
write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
list_del(&led_cdev->trig_list);
write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock,
flags);
cancel_work_sync(&led_cdev->set_brightness_work);
led_stop_software_blink(led_cdev);
if (led_cdev->trigger->deactivate)
led_cdev->trigger->deactivate(led_cdev);
device_remove_groups(led_cdev->dev, led_cdev->trigger->groups);
led_cdev->trigger = NULL;
led_cdev->trigger_data = NULL;
led_cdev->activated = false;
led_set_brightness(led_cdev, LED_OFF);
}
if (trig) {
write_lock_irqsave(&trig->leddev_list_lock, flags);
list_add_tail(&led_cdev->trig_list, &trig->led_cdevs);
write_unlock_irqrestore(&trig->leddev_list_lock, flags);
led_cdev->trigger = trig;
if (trig->activate)
ret = trig->activate(led_cdev);
else
ret = 0;
if (ret)
goto err_activate;
ret = device_add_groups(led_cdev->dev, trig->groups);
if (ret) {
dev_err(led_cdev->dev, "Failed to add trigger attributes\n");
goto err_add_groups;
}
}
if (event) {
envp[0] = event;
envp[1] = NULL;
if (kobject_uevent_env(&led_cdev->dev->kobj, KOBJ_CHANGE, envp))
dev_err(led_cdev->dev,
"%s: Error sending uevent\n", __func__);
kfree(event);
}
return 0;
err_add_groups:
if (trig->deactivate)
trig->deactivate(led_cdev);
err_activate:
write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
list_del(&led_cdev->trig_list);
write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock, flags);
led_cdev->trigger = NULL;
led_cdev->trigger_data = NULL;
led_set_brightness(led_cdev, LED_OFF);
kfree(event);
return ret;
}
EXPORT_SYMBOL_GPL(led_trigger_set);
void led_trigger_remove(struct led_classdev *led_cdev)
{
down_write(&led_cdev->trigger_lock);
led_trigger_set(led_cdev, NULL);
up_write(&led_cdev->trigger_lock);
}
EXPORT_SYMBOL_GPL(led_trigger_remove);
void led_trigger_set_default(struct led_classdev *led_cdev)
{
struct led_trigger *trig;
if (!led_cdev->default_trigger)
return;
down_read(&triggers_list_lock);
down_write(&led_cdev->trigger_lock);
list_for_each_entry(trig, &trigger_list, next_trig) {
if (!strcmp(led_cdev->default_trigger, trig->name)) {
led_cdev->flags |= LED_INIT_DEFAULT_TRIGGER;
led_trigger_set(led_cdev, trig);
break;
}
}
up_write(&led_cdev->trigger_lock);
up_read(&triggers_list_lock);
}
EXPORT_SYMBOL_GPL(led_trigger_set_default);
void led_trigger_rename_static(const char *name, struct led_trigger *trig)
{
/* new name must be on a temporary string to prevent races */
BUG_ON(name == trig->name);
down_write(&triggers_list_lock);
/* this assumes that trig->name was originaly allocated to
* non constant storage */
strcpy((char *)trig->name, name);
up_write(&triggers_list_lock);
}
EXPORT_SYMBOL_GPL(led_trigger_rename_static);
/* LED Trigger Interface */
int led_trigger_register(struct led_trigger *trig)
{
struct led_classdev *led_cdev;
struct led_trigger *_trig;
rwlock_init(&trig->leddev_list_lock);
INIT_LIST_HEAD(&trig->led_cdevs);
down_write(&triggers_list_lock);
/* Make sure the trigger's name isn't already in use */
list_for_each_entry(_trig, &trigger_list, next_trig) {
if (!strcmp(_trig->name, trig->name)) {
up_write(&triggers_list_lock);
return -EEXIST;
}
}
/* Add to the list of led triggers */
list_add_tail(&trig->next_trig, &trigger_list);
up_write(&triggers_list_lock);
/* Register with any LEDs that have this as a default trigger */
down_read(&leds_list_lock);
list_for_each_entry(led_cdev, &leds_list, node) {
down_write(&led_cdev->trigger_lock);
if (!led_cdev->trigger && led_cdev->default_trigger &&
!strcmp(led_cdev->default_trigger, trig->name)) {
led_cdev->flags |= LED_INIT_DEFAULT_TRIGGER;
led_trigger_set(led_cdev, trig);
}
up_write(&led_cdev->trigger_lock);
}
up_read(&leds_list_lock);
return 0;
}
EXPORT_SYMBOL_GPL(led_trigger_register);
void led_trigger_unregister(struct led_trigger *trig)
{
struct led_classdev *led_cdev;
leds: make sure we unregister a trigger only once Currently, we may attempt to unregister a trigger more than once, for example when we receive two consecutive reboot notifications, or when we do a regular unregistration plus reboot notification. This leads to the following error since we try to delete the list node twice: [ 2780.254922] WARNING: CPU: 0 PID: 13764 at lib/list_debug.c:53 __list_del_entry+0x3e/0xe0() [ 2780.265559] list_del corruption, ffffffffa5eb6470->next is LIST_POISON1 (dead000000100100) [ 2780.271710] Modules linked in: [ 2780.274156] CPU: 0 PID: 13764 Comm: kworker/0:2 Tainted: G W 3.14.0-next-20140403-sasha-00012-gef5fa7d-dirty #373 [ 2780.283063] Workqueue: events do_poweroff [ 2780.285644] 0000000000000009 ffff8800330dbb38 ffffffffa34bfa33 0000000000002fe0 [ 2780.291571] ffff8800330dbb88 ffff8800330dbb78 ffffffffa015a37c ffff8800330dbb68 [ 2780.296670] ffffffffa5eb6470 0000000000000000 ffffffffa5eb6400 ffffffffa5ad7430 [ 2780.299756] Call Trace: [ 2780.301530] dump_stack (lib/dump_stack.c:52) [ 2780.303802] warn_slowpath_common (kernel/panic.c:418) [ 2780.306151] warn_slowpath_fmt (kernel/panic.c:433) [ 2780.308156] __list_del_entry (lib/list_debug.c:51 (discriminator 1)) [ 2780.310800] list_del (lib/list_debug.c:78) [ 2780.313175] led_trigger_unregister (drivers/leds/led-triggers.c:225) [ 2780.315599] heartbeat_reboot_notifier (drivers/leds/trigger/ledtrig-heartbeat.c:119) [ 2780.317247] notifier_call_chain (kernel/notifier.c:95) [ 2780.320014] __blocking_notifier_call_chain (kernel/notifier.c:316) [ 2780.323263] blocking_notifier_call_chain (kernel/notifier.c:326) [ 2780.326096] kernel_power_off (include/linux/kmod.h:95 kernel/reboot.c:153 kernel/reboot.c:179) [ 2780.327883] do_poweroff (kernel/power/poweroff.c:23) [ 2780.330748] process_one_work (kernel/workqueue.c:2221 include/linux/jump_label.h:105 include/trace/events/workqueue.h:111 kernel/workqueue.c:2226) [ 2780.333027] ? process_one_work (include/linux/workqueue.h:186 kernel/workqueue.c:611 kernel/workqueue.c:638 kernel/workqueue.c:2214) [ 2780.335487] process_scheduled_works (include/linux/list.h:188 kernel/workqueue.c:2277) [ 2780.337101] worker_thread (kernel/workqueue.c:2352) [ 2780.338712] ? rescuer_thread (kernel/workqueue.c:2297) [ 2780.341326] kthread (kernel/kthread.c:219) [ 2780.343446] ? kthread_create_on_node (kernel/kthread.c:185) [ 2780.345733] ret_from_fork (arch/x86/kernel/entry_64.S:555) [ 2780.347168] ? kthread_create_on_node (kernel/kthread.c:185) Prevent it by making sure we don't attempt to unregister a trigger that is not in the triggers list. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Bryan Wu <cooloney@gmail.com>
2014-04-04 17:01:13 +00:00
if (list_empty_careful(&trig->next_trig))
return;
/* Remove from the list of led triggers */
down_write(&triggers_list_lock);
leds: make sure we unregister a trigger only once Currently, we may attempt to unregister a trigger more than once, for example when we receive two consecutive reboot notifications, or when we do a regular unregistration plus reboot notification. This leads to the following error since we try to delete the list node twice: [ 2780.254922] WARNING: CPU: 0 PID: 13764 at lib/list_debug.c:53 __list_del_entry+0x3e/0xe0() [ 2780.265559] list_del corruption, ffffffffa5eb6470->next is LIST_POISON1 (dead000000100100) [ 2780.271710] Modules linked in: [ 2780.274156] CPU: 0 PID: 13764 Comm: kworker/0:2 Tainted: G W 3.14.0-next-20140403-sasha-00012-gef5fa7d-dirty #373 [ 2780.283063] Workqueue: events do_poweroff [ 2780.285644] 0000000000000009 ffff8800330dbb38 ffffffffa34bfa33 0000000000002fe0 [ 2780.291571] ffff8800330dbb88 ffff8800330dbb78 ffffffffa015a37c ffff8800330dbb68 [ 2780.296670] ffffffffa5eb6470 0000000000000000 ffffffffa5eb6400 ffffffffa5ad7430 [ 2780.299756] Call Trace: [ 2780.301530] dump_stack (lib/dump_stack.c:52) [ 2780.303802] warn_slowpath_common (kernel/panic.c:418) [ 2780.306151] warn_slowpath_fmt (kernel/panic.c:433) [ 2780.308156] __list_del_entry (lib/list_debug.c:51 (discriminator 1)) [ 2780.310800] list_del (lib/list_debug.c:78) [ 2780.313175] led_trigger_unregister (drivers/leds/led-triggers.c:225) [ 2780.315599] heartbeat_reboot_notifier (drivers/leds/trigger/ledtrig-heartbeat.c:119) [ 2780.317247] notifier_call_chain (kernel/notifier.c:95) [ 2780.320014] __blocking_notifier_call_chain (kernel/notifier.c:316) [ 2780.323263] blocking_notifier_call_chain (kernel/notifier.c:326) [ 2780.326096] kernel_power_off (include/linux/kmod.h:95 kernel/reboot.c:153 kernel/reboot.c:179) [ 2780.327883] do_poweroff (kernel/power/poweroff.c:23) [ 2780.330748] process_one_work (kernel/workqueue.c:2221 include/linux/jump_label.h:105 include/trace/events/workqueue.h:111 kernel/workqueue.c:2226) [ 2780.333027] ? process_one_work (include/linux/workqueue.h:186 kernel/workqueue.c:611 kernel/workqueue.c:638 kernel/workqueue.c:2214) [ 2780.335487] process_scheduled_works (include/linux/list.h:188 kernel/workqueue.c:2277) [ 2780.337101] worker_thread (kernel/workqueue.c:2352) [ 2780.338712] ? rescuer_thread (kernel/workqueue.c:2297) [ 2780.341326] kthread (kernel/kthread.c:219) [ 2780.343446] ? kthread_create_on_node (kernel/kthread.c:185) [ 2780.345733] ret_from_fork (arch/x86/kernel/entry_64.S:555) [ 2780.347168] ? kthread_create_on_node (kernel/kthread.c:185) Prevent it by making sure we don't attempt to unregister a trigger that is not in the triggers list. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Bryan Wu <cooloney@gmail.com>
2014-04-04 17:01:13 +00:00
list_del_init(&trig->next_trig);
up_write(&triggers_list_lock);
/* Remove anyone actively using this trigger */
down_read(&leds_list_lock);
list_for_each_entry(led_cdev, &leds_list, node) {
down_write(&led_cdev->trigger_lock);
if (led_cdev->trigger == trig)
led_trigger_set(led_cdev, NULL);
up_write(&led_cdev->trigger_lock);
}
up_read(&leds_list_lock);
}
EXPORT_SYMBOL_GPL(led_trigger_unregister);
static void devm_led_trigger_release(struct device *dev, void *res)
{
led_trigger_unregister(*(struct led_trigger **)res);
}
int devm_led_trigger_register(struct device *dev,
struct led_trigger *trig)
{
struct led_trigger **dr;
int rc;
dr = devres_alloc(devm_led_trigger_release, sizeof(*dr),
GFP_KERNEL);
if (!dr)
return -ENOMEM;
*dr = trig;
rc = led_trigger_register(trig);
if (rc)
devres_free(dr);
else
devres_add(dev, dr);
return rc;
}
EXPORT_SYMBOL_GPL(devm_led_trigger_register);
/* Simple LED Tigger Interface */
void led_trigger_event(struct led_trigger *trig,
enum led_brightness brightness)
{
struct led_classdev *led_cdev;
if (!trig)
return;
read_lock(&trig->leddev_list_lock);
list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list)
led_set_brightness(led_cdev, brightness);
read_unlock(&trig->leddev_list_lock);
}
EXPORT_SYMBOL_GPL(led_trigger_event);
static void led_trigger_blink_setup(struct led_trigger *trig,
unsigned long *delay_on,
unsigned long *delay_off,
int oneshot,
int invert)
{
struct led_classdev *led_cdev;
if (!trig)
return;
read_lock(&trig->leddev_list_lock);
list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list) {
if (oneshot)
led_blink_set_oneshot(led_cdev, delay_on, delay_off,
invert);
else
led_blink_set(led_cdev, delay_on, delay_off);
}
read_unlock(&trig->leddev_list_lock);
}
void led_trigger_blink(struct led_trigger *trig,
unsigned long *delay_on,
unsigned long *delay_off)
{
led_trigger_blink_setup(trig, delay_on, delay_off, 0, 0);
}
EXPORT_SYMBOL_GPL(led_trigger_blink);
void led_trigger_blink_oneshot(struct led_trigger *trig,
unsigned long *delay_on,
unsigned long *delay_off,
int invert)
{
led_trigger_blink_setup(trig, delay_on, delay_off, 1, invert);
}
EXPORT_SYMBOL_GPL(led_trigger_blink_oneshot);
void led_trigger_register_simple(const char *name, struct led_trigger **tp)
{
struct led_trigger *trig;
int err;
trig = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
if (trig) {
trig->name = name;
err = led_trigger_register(trig);
if (err < 0) {
kfree(trig);
trig = NULL;
pr_warn("LED trigger %s failed to register (%d)\n",
name, err);
}
} else {
pr_warn("LED trigger %s failed to register (no memory)\n",
name);
}
*tp = trig;
}
EXPORT_SYMBOL_GPL(led_trigger_register_simple);
void led_trigger_unregister_simple(struct led_trigger *trig)
{
if (trig)
led_trigger_unregister(trig);
kfree(trig);
}
EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);