cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ledtrig-panic.c (1786B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Kernel Panic LED Trigger
      4 *
      5 * Copyright 2016 Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
      6 */
      7
      8#include <linux/kernel.h>
      9#include <linux/init.h>
     10#include <linux/notifier.h>
     11#include <linux/panic_notifier.h>
     12#include <linux/leds.h>
     13#include "../leds.h"
     14
     15static struct led_trigger *trigger;
     16
     17/*
     18 * This is called in a special context by the atomic panic
     19 * notifier. This means the trigger can be changed without
     20 * worrying about locking.
     21 */
     22static void led_trigger_set_panic(struct led_classdev *led_cdev)
     23{
     24	struct led_trigger *trig;
     25
     26	list_for_each_entry(trig, &trigger_list, next_trig) {
     27		if (strcmp("panic", trig->name))
     28			continue;
     29		if (led_cdev->trigger)
     30			list_del(&led_cdev->trig_list);
     31		list_add_tail(&led_cdev->trig_list, &trig->led_cdevs);
     32
     33		/* Avoid the delayed blink path */
     34		led_cdev->blink_delay_on = 0;
     35		led_cdev->blink_delay_off = 0;
     36
     37		led_cdev->trigger = trig;
     38		if (trig->activate)
     39			trig->activate(led_cdev);
     40		break;
     41	}
     42}
     43
     44static int led_trigger_panic_notifier(struct notifier_block *nb,
     45				      unsigned long code, void *unused)
     46{
     47	struct led_classdev *led_cdev;
     48
     49	list_for_each_entry(led_cdev, &leds_list, node)
     50		if (led_cdev->flags & LED_PANIC_INDICATOR)
     51			led_trigger_set_panic(led_cdev);
     52	return NOTIFY_DONE;
     53}
     54
     55static struct notifier_block led_trigger_panic_nb = {
     56	.notifier_call = led_trigger_panic_notifier,
     57};
     58
     59static long led_panic_blink(int state)
     60{
     61	led_trigger_event(trigger, state ? LED_FULL : LED_OFF);
     62	return 0;
     63}
     64
     65static int __init ledtrig_panic_init(void)
     66{
     67	atomic_notifier_chain_register(&panic_notifier_list,
     68				       &led_trigger_panic_nb);
     69
     70	led_trigger_register_simple("panic", &trigger);
     71	panic_blink = led_panic_blink;
     72	return 0;
     73}
     74device_initcall(ledtrig_panic_init);