drivers/misc/uid_sys_stats.c - kernel/msm-4.9 - Gitiles

 /* drivers/misc/uid_cputime.c
  *
  * Copyright (C) 2014 - 2015 Google, Inc.
  *
  * This software is licensed under the terms of the GNU General Public
  * License version 2, as published by the Free Software Foundation, and
  * may be copied, distributed, and modified under those terms.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  */

 #include <linux/atomic.h>
 #include <linux/err.h>
 #include <linux/hashtable.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/proc_fs.h>
 #include <linux/profile.h>
 #include <linux/rtmutex.h>
 #include <linux/sched.h>
 #include <linux/seq_file.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>


 #define UID_HASH_BITS	10
 DECLARE_HASHTABLE(hash_table, UID_HASH_BITS);

 static DEFINE_RT_MUTEX(uid_lock);
 static struct proc_dir_entry *cpu_parent;
 static struct proc_dir_entry *io_parent;
 static struct proc_dir_entry *proc_parent;

 struct io_stats {
 	u64 read_bytes;
 	u64 write_bytes;
 	u64 rchar;
 	u64 wchar;
 	u64 fsync;
 };

 #define UID_STATE_FOREGROUND	0
 #define UID_STATE_BACKGROUND	1
 #define UID_STATE_BUCKET_SIZE	2

 #define UID_STATE_TOTAL_CURR	2
 #define UID_STATE_TOTAL_LAST	3
 #define UID_STATE_SIZE		4

 struct uid_entry {
 	uid_t uid;
 	cputime_t utime;
 	cputime_t stime;
 	cputime_t active_utime;
 	cputime_t active_stime;
 	int state;
 	struct io_stats io[UID_STATE_SIZE];
 	struct hlist_node hash;
 };

 static struct uid_entry *find_uid_entry(uid_t uid)
 {
 	struct uid_entry *uid_entry;
 	hash_for_each_possible(hash_table, uid_entry, hash, uid) {
 		if (uid_entry->uid == uid)
 			return uid_entry;
 	}
 	return NULL;
 }

 static struct uid_entry *find_or_register_uid(uid_t uid)
 {
 	struct uid_entry *uid_entry;

 	uid_entry = find_uid_entry(uid);
 	if (uid_entry)
 		return uid_entry;

 	uid_entry = kzalloc(sizeof(struct uid_entry), GFP_ATOMIC);
 	if (!uid_entry)
 		return NULL;

 	uid_entry->uid = uid;

 	hash_add(hash_table, &uid_entry->hash, uid);

 	return uid_entry;
 }

 static int uid_cputime_show(struct seq_file *m, void *v)
 {
 	struct uid_entry *uid_entry;
 	struct task_struct *task, *temp;
 	struct user_namespace *user_ns = current_user_ns();
 	cputime_t utime;
 	cputime_t stime;
 	unsigned long bkt;
 	uid_t uid;

 	rt_mutex_lock(&uid_lock);

 	hash_for_each(hash_table, bkt, uid_entry, hash) {
 		uid_entry->active_stime = 0;
 		uid_entry->active_utime = 0;
 	}

 	read_lock(&tasklist_lock);
 	do_each_thread(temp, task) {
 		uid = from_kuid_munged(user_ns, task_uid(task));
 		uid_entry = find_or_register_uid(uid);
 		if (!uid_entry) {
 			read_unlock(&tasklist_lock);
 			rt_mutex_unlock(&uid_lock);
 			pr_err("%s: failed to find the uid_entry for uid %d\n",
 				__func__, uid);
 			return -ENOMEM;
 		}
 		task_cputime_adjusted(task, &utime, &stime);
 		uid_entry->active_utime += utime;
 		uid_entry->active_stime += stime;
 	} while_each_thread(temp, task);
 	read_unlock(&tasklist_lock);

 	hash_for_each(hash_table, bkt, uid_entry, hash) {
 		cputime_t total_utime = uid_entry->utime +
 							uid_entry->active_utime;
 		cputime_t total_stime = uid_entry->stime +
 							uid_entry->active_stime;
 		seq_printf(m, "%d: %llu %llu\n", uid_entry->uid,
 			(unsigned long long)jiffies_to_msecs(
 				cputime_to_jiffies(total_utime)) * USEC_PER_MSEC,
 			(unsigned long long)jiffies_to_msecs(
 				cputime_to_jiffies(total_stime)) * USEC_PER_MSEC);
 	}

 	rt_mutex_unlock(&uid_lock);
 	return 0;
 }

 static int uid_cputime_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, uid_cputime_show, PDE_DATA(inode));
 }

 static const struct file_operations uid_cputime_fops = {
 	.open		= uid_cputime_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };

 static int uid_remove_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, NULL, NULL);
 }

 static ssize_t uid_remove_write(struct file *file,
 			const char __user *buffer, size_t count, loff_t *ppos)
 {
 	struct uid_entry *uid_entry;
 	struct hlist_node *tmp;
 	char uids[128];
 	char *start_uid, *end_uid = NULL;
 	long int uid_start = 0, uid_end = 0;

 	if (count >= sizeof(uids))
 		count = sizeof(uids) - 1;

 	if (copy_from_user(uids, buffer, count))
 		return -EFAULT;

 	uids[count] = '\0';
 	end_uid = uids;
 	start_uid = strsep(&end_uid, "-");

 	if (!start_uid || !end_uid)
 		return -EINVAL;

 	if (kstrtol(start_uid, 10, &uid_start) != 0 ||
 		kstrtol(end_uid, 10, &uid_end) != 0) {
 		return -EINVAL;
 	}
 	rt_mutex_lock(&uid_lock);

 	for (; uid_start <= uid_end; uid_start++) {
 		hash_for_each_possible_safe(hash_table, uid_entry, tmp,
 							hash, (uid_t)uid_start) {
 			if (uid_start == uid_entry->uid) {
 				hash_del(&uid_entry->hash);
 				kfree(uid_entry);
 			}
 		}
 	}

 	rt_mutex_unlock(&uid_lock);
 	return count;
 }

 static const struct file_operations uid_remove_fops = {
 	.open		= uid_remove_open,
 	.release	= single_release,
 	.write		= uid_remove_write,
 };

 static u64 compute_write_bytes(struct task_struct *task)
 {
 	if (task->ioac.write_bytes <= task->ioac.cancelled_write_bytes)
 		return 0;

 	return task->ioac.write_bytes - task->ioac.cancelled_write_bytes;
 }

 static void add_uid_io_curr_stats(struct uid_entry *uid_entry,
 			struct task_struct *task)
 {
 	struct io_stats *io_curr = &uid_entry->io[UID_STATE_TOTAL_CURR];

 	io_curr->read_bytes += task->ioac.read_bytes;
 	io_curr->write_bytes += compute_write_bytes(task);
 	io_curr->rchar += task->ioac.rchar;
 	io_curr->wchar += task->ioac.wchar;
 	io_curr->fsync += task->ioac.syscfs;
 }

 static void clean_uid_io_last_stats(struct uid_entry *uid_entry,
 			struct task_struct *task)
 {
 	struct io_stats *io_last = &uid_entry->io[UID_STATE_TOTAL_LAST];

 	io_last->read_bytes -= task->ioac.read_bytes;
 	io_last->write_bytes -= compute_write_bytes(task);
 	io_last->rchar -= task->ioac.rchar;
 	io_last->wchar -= task->ioac.wchar;
 	io_last->fsync -= task->ioac.syscfs;
 }

 static void update_io_stats_all_locked(void)
 {
 	struct uid_entry *uid_entry;
 	struct task_struct *task, *temp;
 	struct io_stats *io_bucket, *io_curr, *io_last;
 	struct user_namespace *user_ns = current_user_ns();
 	unsigned long bkt;
 	uid_t uid;

 	hash_for_each(hash_table, bkt, uid_entry, hash)
 		memset(&uid_entry->io[UID_STATE_TOTAL_CURR], 0,
 			sizeof(struct io_stats));

 	rcu_read_lock();
 	do_each_thread(temp, task) {
 		uid = from_kuid_munged(user_ns, task_uid(task));
 		uid_entry = find_or_register_uid(uid);
 		if (!uid_entry)
 			continue;
 		add_uid_io_curr_stats(uid_entry, task);
 	} while_each_thread(temp, task);
 	rcu_read_unlock();

 	hash_for_each(hash_table, bkt, uid_entry, hash) {
 		io_bucket = &uid_entry->io[uid_entry->state];
 		io_curr = &uid_entry->io[UID_STATE_TOTAL_CURR];
 		io_last = &uid_entry->io[UID_STATE_TOTAL_LAST];

 		io_bucket->read_bytes +=
 			io_curr->read_bytes - io_last->read_bytes;
 		io_bucket->write_bytes +=
 			io_curr->write_bytes - io_last->write_bytes;
 		io_bucket->rchar += io_curr->rchar - io_last->rchar;
 		io_bucket->wchar += io_curr->wchar - io_last->wchar;
 		io_bucket->fsync += io_curr->fsync - io_last->fsync;

 		io_last->read_bytes = io_curr->read_bytes;
 		io_last->write_bytes = io_curr->write_bytes;
 		io_last->rchar = io_curr->rchar;
 		io_last->wchar = io_curr->wchar;
 		io_last->fsync = io_curr->fsync;
 	}
 }

 static void update_io_stats_uid_locked(uid_t target_uid)
 {
 	struct uid_entry *uid_entry;
 	struct task_struct *task, *temp;
 	struct io_stats *io_bucket, *io_curr, *io_last;
 	struct user_namespace *user_ns = current_user_ns();

 	uid_entry = find_or_register_uid(target_uid);
 	if (!uid_entry)
 		return;

 	memset(&uid_entry->io[UID_STATE_TOTAL_CURR], 0,
 		sizeof(struct io_stats));

 	rcu_read_lock();
 	do_each_thread(temp, task) {
 		if (from_kuid_munged(user_ns, task_uid(task)) != target_uid)
 			continue;
 		add_uid_io_curr_stats(uid_entry, task);
 	} while_each_thread(temp, task);
 	rcu_read_unlock();

 	io_bucket = &uid_entry->io[uid_entry->state];
 	io_curr = &uid_entry->io[UID_STATE_TOTAL_CURR];
 	io_last = &uid_entry->io[UID_STATE_TOTAL_LAST];

 	io_bucket->read_bytes +=
 		io_curr->read_bytes - io_last->read_bytes;
 	io_bucket->write_bytes +=
 		io_curr->write_bytes - io_last->write_bytes;
 	io_bucket->rchar += io_curr->rchar - io_last->rchar;
 	io_bucket->wchar += io_curr->wchar - io_last->wchar;
 	io_bucket->fsync += io_curr->fsync - io_last->fsync;

 	io_last->read_bytes = io_curr->read_bytes;
 	io_last->write_bytes = io_curr->write_bytes;
 	io_last->rchar = io_curr->rchar;
 	io_last->wchar = io_curr->wchar;
 	io_last->fsync = io_curr->fsync;
 }

 static int uid_io_show(struct seq_file *m, void *v)
 {
 	struct uid_entry *uid_entry;
 	unsigned long bkt;

 	rt_mutex_lock(&uid_lock);

 	update_io_stats_all_locked();

 	hash_for_each(hash_table, bkt, uid_entry, hash) {
 		seq_printf(m, "%d %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu\n",
 			uid_entry->uid,
 			uid_entry->io[UID_STATE_FOREGROUND].rchar,
 			uid_entry->io[UID_STATE_FOREGROUND].wchar,
 			uid_entry->io[UID_STATE_FOREGROUND].read_bytes,
 			uid_entry->io[UID_STATE_FOREGROUND].write_bytes,
 			uid_entry->io[UID_STATE_BACKGROUND].rchar,
 			uid_entry->io[UID_STATE_BACKGROUND].wchar,
 			uid_entry->io[UID_STATE_BACKGROUND].read_bytes,
 			uid_entry->io[UID_STATE_BACKGROUND].write_bytes,
 			uid_entry->io[UID_STATE_FOREGROUND].fsync,
 			uid_entry->io[UID_STATE_BACKGROUND].fsync);
 	}

 	rt_mutex_unlock(&uid_lock);

 	return 0;
 }

 static int uid_io_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, uid_io_show, PDE_DATA(inode));
 }

 static const struct file_operations uid_io_fops = {
 	.open		= uid_io_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };

 static int uid_procstat_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, NULL, NULL);
 }

 static ssize_t uid_procstat_write(struct file *file,
 			const char __user *buffer, size_t count, loff_t *ppos)
 {
 	struct uid_entry *uid_entry;
 	uid_t uid;
 	int argc, state;
 	char input[128];

 	if (count >= sizeof(input))
 		return -EINVAL;

 	if (copy_from_user(input, buffer, count))
 		return -EFAULT;

 	input[count] = '\0';

 	argc = sscanf(input, "%u %d", &uid, &state);
 	if (argc != 2)
 		return -EINVAL;

 	if (state != UID_STATE_BACKGROUND && state != UID_STATE_FOREGROUND)
 		return -EINVAL;

 	rt_mutex_lock(&uid_lock);

 	uid_entry = find_or_register_uid(uid);
 	if (!uid_entry) {
 		rt_mutex_unlock(&uid_lock);
 		return -EINVAL;
 	}

 	if (uid_entry->state == state) {
 		rt_mutex_unlock(&uid_lock);
 		return count;
 	}

 	update_io_stats_uid_locked(uid);

 	uid_entry->state = state;

 	rt_mutex_unlock(&uid_lock);

 	return count;
 }

 static const struct file_operations uid_procstat_fops = {
 	.open		= uid_procstat_open,
 	.release	= single_release,
 	.write		= uid_procstat_write,
 };

 static int process_notifier(struct notifier_block *self,
 			unsigned long cmd, void *v)
 {
 	struct task_struct *task = v;
 	struct uid_entry *uid_entry;
 	cputime_t utime, stime;
 	uid_t uid;

 	if (!task)
 		return NOTIFY_OK;

 	rt_mutex_lock(&uid_lock);
 	uid = from_kuid_munged(current_user_ns(), task_uid(task));
 	uid_entry = find_or_register_uid(uid);
 	if (!uid_entry) {
 		pr_err("%s: failed to find uid %d\n", __func__, uid);
 		goto exit;
 	}

 	task_cputime_adjusted(task, &utime, &stime);
 	uid_entry->utime += utime;
 	uid_entry->stime += stime;

 	update_io_stats_uid_locked(uid);
 	clean_uid_io_last_stats(uid_entry, task);

 exit:
 	rt_mutex_unlock(&uid_lock);
 	return NOTIFY_OK;
 }

 static struct notifier_block process_notifier_block = {
 	.notifier_call	= process_notifier,
 };

 static int __init proc_uid_sys_stats_init(void)
 {
 	hash_init(hash_table);

 	cpu_parent = proc_mkdir("uid_cputime", NULL);
 	if (!cpu_parent) {
 		pr_err("%s: failed to create uid_cputime proc entry\n",
 			__func__);
 		goto err;
 	}

 	proc_create_data("remove_uid_range", 0222, cpu_parent,
 		&uid_remove_fops, NULL);
 	proc_create_data("show_uid_stat", 0444, cpu_parent,
 		&uid_cputime_fops, NULL);

 	io_parent = proc_mkdir("uid_io", NULL);
 	if (!io_parent) {
 		pr_err("%s: failed to create uid_io proc entry\n",
 			__func__);
 		goto err;
 	}

 	proc_create_data("stats", 0444, io_parent,
 		&uid_io_fops, NULL);

 	proc_parent = proc_mkdir("uid_procstat", NULL);
 	if (!proc_parent) {
 		pr_err("%s: failed to create uid_procstat proc entry\n",
 			__func__);
 		goto err;
 	}

 	proc_create_data("set", 0222, proc_parent,
 		&uid_procstat_fops, NULL);

 	profile_event_register(PROFILE_TASK_EXIT, &process_notifier_block);

 	return 0;

 err:
 	remove_proc_subtree("uid_cputime", NULL);
 	remove_proc_subtree("uid_io", NULL);
 	remove_proc_subtree("uid_procstat", NULL);
 	return -ENOMEM;
 }

 early_initcall(proc_uid_sys_stats_init);
	/* drivers/misc/uid_cputime.c
	*
	* Copyright (C) 2014 - 2015 Google, Inc.
	*
	* This software is licensed under the terms of the GNU General Public
	* License version 2, as published by the Free Software Foundation, and
	* may be copied, distributed, and modified under those terms.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	*/

	#include <linux/atomic.h>
	#include <linux/err.h>
	#include <linux/hashtable.h>
	#include <linux/init.h>
	#include <linux/kernel.h>
	#include <linux/list.h>
	#include <linux/proc_fs.h>
	#include <linux/profile.h>
	#include <linux/rtmutex.h>
	#include <linux/sched.h>
	#include <linux/seq_file.h>
	#include <linux/slab.h>
	#include <linux/uaccess.h>


	#define UID_HASH_BITS 10
	DECLARE_HASHTABLE(hash_table, UID_HASH_BITS);

	static DEFINE_RT_MUTEX(uid_lock);
	static struct proc_dir_entry *cpu_parent;
	static struct proc_dir_entry *io_parent;
	static struct proc_dir_entry *proc_parent;

	struct io_stats {
	u64 read_bytes;
	u64 write_bytes;
	u64 rchar;
	u64 wchar;
	u64 fsync;
	};

	#define UID_STATE_FOREGROUND 0
	#define UID_STATE_BACKGROUND 1
	#define UID_STATE_BUCKET_SIZE 2

	#define UID_STATE_TOTAL_CURR 2
	#define UID_STATE_TOTAL_LAST 3
	#define UID_STATE_SIZE 4

	struct uid_entry {
	uid_t uid;
	cputime_t utime;
	cputime_t stime;
	cputime_t active_utime;
	cputime_t active_stime;
	int state;
	struct io_stats io[UID_STATE_SIZE];
	struct hlist_node hash;
	};

	static struct uid_entry *find_uid_entry(uid_t uid)
	{
	struct uid_entry *uid_entry;
	hash_for_each_possible(hash_table, uid_entry, hash, uid) {
	if (uid_entry->uid == uid)
	return uid_entry;
	}
	return NULL;
	}

	static struct uid_entry *find_or_register_uid(uid_t uid)
	{
	struct uid_entry *uid_entry;

	uid_entry = find_uid_entry(uid);
	if (uid_entry)
	return uid_entry;

	uid_entry = kzalloc(sizeof(struct uid_entry), GFP_ATOMIC);
	if (!uid_entry)
	return NULL;

	uid_entry->uid = uid;

	hash_add(hash_table, &uid_entry->hash, uid);

	return uid_entry;
	}

	static int uid_cputime_show(struct seq_file m, void v)
	{
	struct uid_entry *uid_entry;
	struct task_struct task, temp;
	struct user_namespace *user_ns = current_user_ns();
	cputime_t utime;
	cputime_t stime;
	unsigned long bkt;
	uid_t uid;

	rt_mutex_lock(&uid_lock);

	hash_for_each(hash_table, bkt, uid_entry, hash) {
	uid_entry->active_stime = 0;
	uid_entry->active_utime = 0;
	}

	read_lock(&tasklist_lock);
	do_each_thread(temp, task) {
	uid = from_kuid_munged(user_ns, task_uid(task));
	uid_entry = find_or_register_uid(uid);
	if (!uid_entry) {
	read_unlock(&tasklist_lock);
	rt_mutex_unlock(&uid_lock);
	pr_err("%s: failed to find the uid_entry for uid %d\n",
	__func__, uid);
	return -ENOMEM;
	}
	task_cputime_adjusted(task, &utime, &stime);
	uid_entry->active_utime += utime;
	uid_entry->active_stime += stime;
	} while_each_thread(temp, task);
	read_unlock(&tasklist_lock);

	hash_for_each(hash_table, bkt, uid_entry, hash) {
	cputime_t total_utime = uid_entry->utime +
	uid_entry->active_utime;
	cputime_t total_stime = uid_entry->stime +
	uid_entry->active_stime;
	seq_printf(m, "%d: %llu %llu\n", uid_entry->uid,
	(unsigned long long)jiffies_to_msecs(
	cputime_to_jiffies(total_utime)) * USEC_PER_MSEC,
	(unsigned long long)jiffies_to_msecs(
	cputime_to_jiffies(total_stime)) * USEC_PER_MSEC);
	}

	rt_mutex_unlock(&uid_lock);
	return 0;
	}

	static int uid_cputime_open(struct inode inode, struct file file)
	{
	return single_open(file, uid_cputime_show, PDE_DATA(inode));
	}

	static const struct file_operations uid_cputime_fops = {
	.open = uid_cputime_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
	};

	static int uid_remove_open(struct inode inode, struct file file)
	{
	return single_open(file, NULL, NULL);
	}

	static ssize_t uid_remove_write(struct file *file,
	const char __user buffer, size_t count, loff_t ppos)
	{
	struct uid_entry *uid_entry;
	struct hlist_node *tmp;
	char uids[128];
	char start_uid, end_uid = NULL;
	long int uid_start = 0, uid_end = 0;

	if (count >= sizeof(uids))
	count = sizeof(uids) - 1;

	if (copy_from_user(uids, buffer, count))
	return -EFAULT;

	uids[count] = '\0';
	end_uid = uids;
	start_uid = strsep(&end_uid, "-");

	if (!start_uid \|\| !end_uid)
	return -EINVAL;

	if (kstrtol(start_uid, 10, &uid_start) != 0 \|\|
	kstrtol(end_uid, 10, &uid_end) != 0) {
	return -EINVAL;
	}
	rt_mutex_lock(&uid_lock);

	for (; uid_start <= uid_end; uid_start++) {
	hash_for_each_possible_safe(hash_table, uid_entry, tmp,
	hash, (uid_t)uid_start) {
	if (uid_start == uid_entry->uid) {
	hash_del(&uid_entry->hash);
	kfree(uid_entry);
	}
	}
	}

	rt_mutex_unlock(&uid_lock);
	return count;
	}

	static const struct file_operations uid_remove_fops = {
	.open = uid_remove_open,
	.release = single_release,
	.write = uid_remove_write,
	};

	static u64 compute_write_bytes(struct task_struct *task)
	{
	if (task->ioac.write_bytes <= task->ioac.cancelled_write_bytes)
	return 0;

	return task->ioac.write_bytes - task->ioac.cancelled_write_bytes;
	}

	static void add_uid_io_curr_stats(struct uid_entry *uid_entry,
	struct task_struct *task)
	{
	struct io_stats *io_curr = &uid_entry->io[UID_STATE_TOTAL_CURR];

	io_curr->read_bytes += task->ioac.read_bytes;
	io_curr->write_bytes += compute_write_bytes(task);
	io_curr->rchar += task->ioac.rchar;
	io_curr->wchar += task->ioac.wchar;
	io_curr->fsync += task->ioac.syscfs;
	}

	static void clean_uid_io_last_stats(struct uid_entry *uid_entry,
	struct task_struct *task)
	{
	struct io_stats *io_last = &uid_entry->io[UID_STATE_TOTAL_LAST];

	io_last->read_bytes -= task->ioac.read_bytes;
	io_last->write_bytes -= compute_write_bytes(task);
	io_last->rchar -= task->ioac.rchar;
	io_last->wchar -= task->ioac.wchar;
	io_last->fsync -= task->ioac.syscfs;
	}

	static void update_io_stats_all_locked(void)
	{
	struct uid_entry *uid_entry;
	struct task_struct task, temp;
	struct io_stats io_bucket, io_curr, *io_last;
	struct user_namespace *user_ns = current_user_ns();
	unsigned long bkt;
	uid_t uid;

	hash_for_each(hash_table, bkt, uid_entry, hash)
	memset(&uid_entry->io[UID_STATE_TOTAL_CURR], 0,
	sizeof(struct io_stats));

	rcu_read_lock();
	do_each_thread(temp, task) {
	uid = from_kuid_munged(user_ns, task_uid(task));
	uid_entry = find_or_register_uid(uid);
	if (!uid_entry)
	continue;
	add_uid_io_curr_stats(uid_entry, task);
	} while_each_thread(temp, task);
	rcu_read_unlock();

	hash_for_each(hash_table, bkt, uid_entry, hash) {
	io_bucket = &uid_entry->io[uid_entry->state];
	io_curr = &uid_entry->io[UID_STATE_TOTAL_CURR];
	io_last = &uid_entry->io[UID_STATE_TOTAL_LAST];

	io_bucket->read_bytes +=
	io_curr->read_bytes - io_last->read_bytes;
	io_bucket->write_bytes +=
	io_curr->write_bytes - io_last->write_bytes;
	io_bucket->rchar += io_curr->rchar - io_last->rchar;
	io_bucket->wchar += io_curr->wchar - io_last->wchar;
	io_bucket->fsync += io_curr->fsync - io_last->fsync;

	io_last->read_bytes = io_curr->read_bytes;
	io_last->write_bytes = io_curr->write_bytes;
	io_last->rchar = io_curr->rchar;
	io_last->wchar = io_curr->wchar;
	io_last->fsync = io_curr->fsync;
	}
	}

	static void update_io_stats_uid_locked(uid_t target_uid)
	{
	struct uid_entry *uid_entry;
	struct task_struct task, temp;
	struct io_stats io_bucket, io_curr, *io_last;
	struct user_namespace *user_ns = current_user_ns();

	uid_entry = find_or_register_uid(target_uid);
	if (!uid_entry)
	return;

	memset(&uid_entry->io[UID_STATE_TOTAL_CURR], 0,
	sizeof(struct io_stats));

	rcu_read_lock();
	do_each_thread(temp, task) {
	if (from_kuid_munged(user_ns, task_uid(task)) != target_uid)
	continue;
	add_uid_io_curr_stats(uid_entry, task);
	} while_each_thread(temp, task);
	rcu_read_unlock();

	io_bucket = &uid_entry->io[uid_entry->state];
	io_curr = &uid_entry->io[UID_STATE_TOTAL_CURR];
	io_last = &uid_entry->io[UID_STATE_TOTAL_LAST];

	io_bucket->read_bytes +=
	io_curr->read_bytes - io_last->read_bytes;
	io_bucket->write_bytes +=
	io_curr->write_bytes - io_last->write_bytes;
	io_bucket->rchar += io_curr->rchar - io_last->rchar;
	io_bucket->wchar += io_curr->wchar - io_last->wchar;
	io_bucket->fsync += io_curr->fsync - io_last->fsync;

	io_last->read_bytes = io_curr->read_bytes;
	io_last->write_bytes = io_curr->write_bytes;
	io_last->rchar = io_curr->rchar;
	io_last->wchar = io_curr->wchar;
	io_last->fsync = io_curr->fsync;
	}

	static int uid_io_show(struct seq_file m, void v)
	{
	struct uid_entry *uid_entry;
	unsigned long bkt;

	rt_mutex_lock(&uid_lock);

	update_io_stats_all_locked();

	hash_for_each(hash_table, bkt, uid_entry, hash) {
	seq_printf(m, "%d %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu\n",
	uid_entry->uid,
	uid_entry->io[UID_STATE_FOREGROUND].rchar,
	uid_entry->io[UID_STATE_FOREGROUND].wchar,
	uid_entry->io[UID_STATE_FOREGROUND].read_bytes,
	uid_entry->io[UID_STATE_FOREGROUND].write_bytes,
	uid_entry->io[UID_STATE_BACKGROUND].rchar,
	uid_entry->io[UID_STATE_BACKGROUND].wchar,
	uid_entry->io[UID_STATE_BACKGROUND].read_bytes,
	uid_entry->io[UID_STATE_BACKGROUND].write_bytes,
	uid_entry->io[UID_STATE_FOREGROUND].fsync,
	uid_entry->io[UID_STATE_BACKGROUND].fsync);
	}

	rt_mutex_unlock(&uid_lock);

	return 0;
	}

	static int uid_io_open(struct inode inode, struct file file)
	{
	return single_open(file, uid_io_show, PDE_DATA(inode));
	}

	static const struct file_operations uid_io_fops = {
	.open = uid_io_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
	};

	static int uid_procstat_open(struct inode inode, struct file file)
	{
	return single_open(file, NULL, NULL);
	}

	static ssize_t uid_procstat_write(struct file *file,
	const char __user buffer, size_t count, loff_t ppos)
	{
	struct uid_entry *uid_entry;
	uid_t uid;
	int argc, state;
	char input[128];

	if (count >= sizeof(input))
	return -EINVAL;

	if (copy_from_user(input, buffer, count))
	return -EFAULT;

	input[count] = '\0';

	argc = sscanf(input, "%u %d", &uid, &state);
	if (argc != 2)
	return -EINVAL;

	if (state != UID_STATE_BACKGROUND && state != UID_STATE_FOREGROUND)
	return -EINVAL;

	rt_mutex_lock(&uid_lock);

	uid_entry = find_or_register_uid(uid);
	if (!uid_entry) {
	rt_mutex_unlock(&uid_lock);
	return -EINVAL;
	}

	if (uid_entry->state == state) {
	rt_mutex_unlock(&uid_lock);
	return count;
	}

	update_io_stats_uid_locked(uid);

	uid_entry->state = state;

	rt_mutex_unlock(&uid_lock);

	return count;
	}

	static const struct file_operations uid_procstat_fops = {
	.open = uid_procstat_open,
	.release = single_release,
	.write = uid_procstat_write,
	};

	static int process_notifier(struct notifier_block *self,
	unsigned long cmd, void *v)
	{
	struct task_struct *task = v;
	struct uid_entry *uid_entry;
	cputime_t utime, stime;
	uid_t uid;

	if (!task)
	return NOTIFY_OK;

	rt_mutex_lock(&uid_lock);
	uid = from_kuid_munged(current_user_ns(), task_uid(task));
	uid_entry = find_or_register_uid(uid);
	if (!uid_entry) {
	pr_err("%s: failed to find uid %d\n", __func__, uid);
	goto exit;
	}

	task_cputime_adjusted(task, &utime, &stime);
	uid_entry->utime += utime;
	uid_entry->stime += stime;

	update_io_stats_uid_locked(uid);
	clean_uid_io_last_stats(uid_entry, task);

	exit:
	rt_mutex_unlock(&uid_lock);
	return NOTIFY_OK;
	}

	static struct notifier_block process_notifier_block = {
	.notifier_call = process_notifier,
	};

	static int __init proc_uid_sys_stats_init(void)
	{
	hash_init(hash_table);

	cpu_parent = proc_mkdir("uid_cputime", NULL);
	if (!cpu_parent) {
	pr_err("%s: failed to create uid_cputime proc entry\n",
	__func__);
	goto err;
	}

	proc_create_data("remove_uid_range", 0222, cpu_parent,
	&uid_remove_fops, NULL);
	proc_create_data("show_uid_stat", 0444, cpu_parent,
	&uid_cputime_fops, NULL);

	io_parent = proc_mkdir("uid_io", NULL);
	if (!io_parent) {
	pr_err("%s: failed to create uid_io proc entry\n",
	__func__);
	goto err;
	}

	proc_create_data("stats", 0444, io_parent,
	&uid_io_fops, NULL);

	proc_parent = proc_mkdir("uid_procstat", NULL);
	if (!proc_parent) {
	pr_err("%s: failed to create uid_procstat proc entry\n",
	__func__);
	goto err;
	}

	proc_create_data("set", 0222, proc_parent,
	&uid_procstat_fops, NULL);

	profile_event_register(PROFILE_TASK_EXIT, &process_notifier_block);

	return 0;

	err:
	remove_proc_subtree("uid_cputime", NULL);
	remove_proc_subtree("uid_io", NULL);
	remove_proc_subtree("uid_procstat", NULL);
	return -ENOMEM;
	}

	early_initcall(proc_uid_sys_stats_init);