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Commit 28f0fe30 authored by jinqian's avatar jinqian Committed by John Stultz
Browse files

proc: uid: Adds accounting for the cputimes per uid. 

Adds proc files /proc/uid_cputime/show_uid_stat and
/proc/uid_cputime/remove_uid_range.

show_uid_stat lists the total utime and stime for the active as well as
terminated processes for each of the uids.

Writing a range of uids to remove_uid_range will delete the accounting
for all the uids within that range.

Change-Id: I21d9210379da730b33ddc1a0ea663c8c9d2ac15b
parent 87a7a2cf

drivers/misc/Kconfig

+6 −0
Original line number Diff line number Diff line
@@ -529,6 +529,12 @@ config VEXPRESS_SYSCFG 
	  bus. System Configuration interface is one of the possible means

	  of generating transactions on this bus.



config UID_CPUTIME

	tristate "Per-UID cpu time statistics"

	depends on PROFILING

	help

	  Per UID based cpu time statistics exported to /proc/uid_cputime



source "drivers/misc/c2port/Kconfig"

source "drivers/misc/eeprom/Kconfig"

source "drivers/misc/cb710/Kconfig"

drivers/misc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -57,3 +57,4 @@ obj-$(CONFIG_GENWQE) += genwqe/ 
obj-$(CONFIG_ECHO)		+= echo/

obj-$(CONFIG_VEXPRESS_SYSCFG)	+= vexpress-syscfg.o

obj-$(CONFIG_CXL_BASE)		+= cxl/

obj-$(CONFIG_UID_CPUTIME) += uid_cputime.o

drivers/misc/uid_cputime.c

0 → 100644
+235 −0
Original line number Diff line number Diff line 
/* 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/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_MUTEX(uid_lock);

static struct proc_dir_entry *parent;



struct uid_entry {

	uid_t uid;

	cputime_t utime;

	cputime_t stime;

	cputime_t active_utime;

	cputime_t active_stime;

	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_stat_show(struct seq_file *m, void *v)

{

	struct uid_entry *uid_entry;

	struct task_struct *task;

	cputime_t utime;

	cputime_t stime;

	unsigned long bkt;



	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);

	for_each_process(task) {

		uid_entry = find_or_register_uid(task_uid(task));

		if (!uid_entry) {

			read_unlock(&tasklist_lock);

			mutex_unlock(&uid_lock);

			pr_err("%s: failed to find the uid_entry for uid %d\n",

						__func__, task_uid(task));

			return -ENOMEM;

		}

		task_cputime_adjusted(task, &utime, &stime);

		uid_entry->active_utime += utime;

		uid_entry->active_stime += stime;

	}

	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: %u %u\n", uid_entry->uid,

						cputime_to_usecs(total_utime),

						cputime_to_usecs(total_stime));

	}



	mutex_unlock(&uid_lock);

	return 0;

}



static int uid_stat_open(struct inode *inode, struct file *file)

{

	return single_open(file, uid_stat_show, PDE_DATA(inode));

}



static const struct file_operations uid_stat_fops = {

	.open		= uid_stat_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;

	}



	mutex_lock(&uid_lock);



	for (; uid_start <= uid_end; uid_start++) {

		hash_for_each_possible_safe(hash_table, uid_entry, tmp,

							hash, uid_start) {

			hash_del(&uid_entry->hash);

			kfree(uid_entry);

		}

	}



	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 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;



	mutex_lock(&uid_lock);

	uid = 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;



exit:

	mutex_unlock(&uid_lock);

	return NOTIFY_OK;

}



static struct notifier_block process_notifier_block = {

	.notifier_call	= process_notifier,

};



static int __init proc_uid_cputime_init(void)

{

	hash_init(hash_table);



	parent = proc_mkdir("uid_cputime", NULL);

	if (!parent) {

		pr_err("%s: failed to create proc entry\n", __func__);

		return -ENOMEM;

	}



	proc_create_data("remove_uid_range", S_IWUGO, parent, &uid_remove_fops,

					NULL);



	proc_create_data("show_uid_stat", S_IWUGO, parent, &uid_stat_fops,

					NULL);



	profile_event_register(PROFILE_TASK_EXIT, &process_notifier_block);



	return 0;

}



early_initcall(proc_uid_cputime_init);