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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event.c (4327B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * event.c - exporting ACPI events via procfs
      4 *
      5 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
      6 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
      7 *
      8 */
      9
     10#define pr_fmt(fmt) "ACPI: " fmt
     11
     12#include <linux/spinlock.h>
     13#include <linux/export.h>
     14#include <linux/proc_fs.h>
     15#include <linux/init.h>
     16#include <linux/poll.h>
     17#include <linux/gfp.h>
     18#include <linux/acpi.h>
     19#include <net/netlink.h>
     20#include <net/genetlink.h>
     21
     22#include "internal.h"
     23
     24/* ACPI notifier chain */
     25static BLOCKING_NOTIFIER_HEAD(acpi_chain_head);
     26
     27int acpi_notifier_call_chain(struct acpi_device *dev, u32 type, u32 data)
     28{
     29	struct acpi_bus_event event;
     30
     31	strcpy(event.device_class, dev->pnp.device_class);
     32	strcpy(event.bus_id, dev->pnp.bus_id);
     33	event.type = type;
     34	event.data = data;
     35	return (blocking_notifier_call_chain(&acpi_chain_head, 0, (void *)&event)
     36			== NOTIFY_BAD) ? -EINVAL : 0;
     37}
     38EXPORT_SYMBOL(acpi_notifier_call_chain);
     39
     40int register_acpi_notifier(struct notifier_block *nb)
     41{
     42	return blocking_notifier_chain_register(&acpi_chain_head, nb);
     43}
     44EXPORT_SYMBOL(register_acpi_notifier);
     45
     46int unregister_acpi_notifier(struct notifier_block *nb)
     47{
     48	return blocking_notifier_chain_unregister(&acpi_chain_head, nb);
     49}
     50EXPORT_SYMBOL(unregister_acpi_notifier);
     51
     52#ifdef CONFIG_NET
     53static unsigned int acpi_event_seqnum;
     54struct acpi_genl_event {
     55	acpi_device_class device_class;
     56	char bus_id[15];
     57	u32 type;
     58	u32 data;
     59};
     60
     61/* attributes of acpi_genl_family */
     62enum {
     63	ACPI_GENL_ATTR_UNSPEC,
     64	ACPI_GENL_ATTR_EVENT,	/* ACPI event info needed by user space */
     65	__ACPI_GENL_ATTR_MAX,
     66};
     67#define ACPI_GENL_ATTR_MAX (__ACPI_GENL_ATTR_MAX - 1)
     68
     69/* commands supported by the acpi_genl_family */
     70enum {
     71	ACPI_GENL_CMD_UNSPEC,
     72	ACPI_GENL_CMD_EVENT,	/* kernel->user notifications for ACPI events */
     73	__ACPI_GENL_CMD_MAX,
     74};
     75#define ACPI_GENL_CMD_MAX (__ACPI_GENL_CMD_MAX - 1)
     76
     77#define ACPI_GENL_FAMILY_NAME		"acpi_event"
     78#define ACPI_GENL_VERSION		0x01
     79#define ACPI_GENL_MCAST_GROUP_NAME 	"acpi_mc_group"
     80
     81static const struct genl_multicast_group acpi_event_mcgrps[] = {
     82	{ .name = ACPI_GENL_MCAST_GROUP_NAME, },
     83};
     84
     85static struct genl_family acpi_event_genl_family __ro_after_init = {
     86	.module = THIS_MODULE,
     87	.name = ACPI_GENL_FAMILY_NAME,
     88	.version = ACPI_GENL_VERSION,
     89	.maxattr = ACPI_GENL_ATTR_MAX,
     90	.mcgrps = acpi_event_mcgrps,
     91	.n_mcgrps = ARRAY_SIZE(acpi_event_mcgrps),
     92};
     93
     94int acpi_bus_generate_netlink_event(const char *device_class,
     95				      const char *bus_id,
     96				      u8 type, int data)
     97{
     98	struct sk_buff *skb;
     99	struct nlattr *attr;
    100	struct acpi_genl_event *event;
    101	void *msg_header;
    102	int size;
    103
    104	/* allocate memory */
    105	size = nla_total_size(sizeof(struct acpi_genl_event)) +
    106	    nla_total_size(0);
    107
    108	skb = genlmsg_new(size, GFP_ATOMIC);
    109	if (!skb)
    110		return -ENOMEM;
    111
    112	/* add the genetlink message header */
    113	msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++,
    114				 &acpi_event_genl_family, 0,
    115				 ACPI_GENL_CMD_EVENT);
    116	if (!msg_header) {
    117		nlmsg_free(skb);
    118		return -ENOMEM;
    119	}
    120
    121	/* fill the data */
    122	attr =
    123	    nla_reserve(skb, ACPI_GENL_ATTR_EVENT,
    124			sizeof(struct acpi_genl_event));
    125	if (!attr) {
    126		nlmsg_free(skb);
    127		return -EINVAL;
    128	}
    129
    130	event = nla_data(attr);
    131	memset(event, 0, sizeof(struct acpi_genl_event));
    132
    133	strscpy(event->device_class, device_class, sizeof(event->device_class));
    134	strscpy(event->bus_id, bus_id, sizeof(event->bus_id));
    135	event->type = type;
    136	event->data = data;
    137
    138	/* send multicast genetlink message */
    139	genlmsg_end(skb, msg_header);
    140
    141	genlmsg_multicast(&acpi_event_genl_family, skb, 0, 0, GFP_ATOMIC);
    142	return 0;
    143}
    144
    145EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
    146
    147static int __init acpi_event_genetlink_init(void)
    148{
    149	return genl_register_family(&acpi_event_genl_family);
    150}
    151
    152#else
    153int acpi_bus_generate_netlink_event(const char *device_class,
    154				      const char *bus_id,
    155				      u8 type, int data)
    156{
    157	return 0;
    158}
    159
    160EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
    161
    162static int acpi_event_genetlink_init(void)
    163{
    164	return -ENODEV;
    165}
    166#endif
    167
    168static int __init acpi_event_init(void)
    169{
    170	int error;
    171
    172	if (acpi_disabled)
    173		return 0;
    174
    175	/* create genetlink for acpi event */
    176	error = acpi_event_genetlink_init();
    177	if (error)
    178		pr_warn("Failed to create genetlink family for ACPI event\n");
    179
    180	return 0;
    181}
    182
    183fs_initcall(acpi_event_init);