1 /* drivers/misc/uid_cputime.c
3 * Copyright (C) 2014 - 2015 Google, Inc.
5 * This software is licensed under the terms of the GNU General Public
6 * License version 2, as published by the Free Software Foundation, and
7 * may be copied, distributed, and modified under those terms.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
16 #include <linux/atomic.h>
17 #include <linux/err.h>
18 #include <linux/hashtable.h>
19 #include <linux/init.h>
20 #include <linux/kernel.h>
21 #include <linux/list.h>
22 #include <linux/proc_fs.h>
23 #include <linux/profile.h>
24 #include <linux/sched.h>
25 #include <linux/seq_file.h>
26 #include <linux/slab.h>
27 #include <linux/uaccess.h>
29 #define UID_HASH_BITS 10
30 DECLARE_HASHTABLE(hash_table, UID_HASH_BITS);
32 static DEFINE_MUTEX(uid_lock);
33 static struct proc_dir_entry *parent;
39 cputime_t active_utime;
40 cputime_t active_stime;
41 unsigned long long active_power;
42 unsigned long long power;
43 struct hlist_node hash;
46 static struct uid_entry *find_uid_entry(uid_t uid)
48 struct uid_entry *uid_entry;
49 hash_for_each_possible(hash_table, uid_entry, hash, uid) {
50 if (uid_entry->uid == uid)
56 static struct uid_entry *find_or_register_uid(uid_t uid)
58 struct uid_entry *uid_entry;
60 uid_entry = find_uid_entry(uid);
64 uid_entry = kzalloc(sizeof(struct uid_entry), GFP_ATOMIC);
70 hash_add(hash_table, &uid_entry->hash, uid);
75 static int uid_stat_show(struct seq_file *m, void *v)
77 struct uid_entry *uid_entry;
78 struct task_struct *task;
83 mutex_lock(&uid_lock);
85 hash_for_each(hash_table, bkt, uid_entry, hash) {
86 uid_entry->active_stime = 0;
87 uid_entry->active_utime = 0;
88 uid_entry->active_power = 0;
91 read_lock(&tasklist_lock);
92 for_each_process(task) {
93 uid_entry = find_or_register_uid(from_kuid_munged(
94 current_user_ns(), task_uid(task)));
96 read_unlock(&tasklist_lock);
97 mutex_unlock(&uid_lock);
98 pr_err("%s: failed to find the uid_entry for uid %d\n",
99 __func__, from_kuid_munged(current_user_ns(),
103 /* if this task is exiting, we have already accounted for the
106 if (task->cpu_power == ULLONG_MAX)
108 task_cputime_adjusted(task, &utime, &stime);
109 uid_entry->active_utime += utime;
110 uid_entry->active_stime += stime;
111 uid_entry->active_power += task->cpu_power;
113 read_unlock(&tasklist_lock);
115 hash_for_each(hash_table, bkt, uid_entry, hash) {
116 cputime_t total_utime = uid_entry->utime +
117 uid_entry->active_utime;
118 cputime_t total_stime = uid_entry->stime +
119 uid_entry->active_stime;
120 unsigned long long total_power = uid_entry->power +
121 uid_entry->active_power;
122 seq_printf(m, "%d: %u %u %llu\n", uid_entry->uid,
123 cputime_to_usecs(total_utime),
124 cputime_to_usecs(total_stime),
128 mutex_unlock(&uid_lock);
132 static int uid_stat_open(struct inode *inode, struct file *file)
134 return single_open(file, uid_stat_show, PDE_DATA(inode));
137 static const struct file_operations uid_stat_fops = {
138 .open = uid_stat_open,
141 .release = single_release,
144 static int uid_remove_open(struct inode *inode, struct file *file)
146 return single_open(file, NULL, NULL);
149 static ssize_t uid_remove_write(struct file *file,
150 const char __user *buffer, size_t count, loff_t *ppos)
152 struct uid_entry *uid_entry;
153 struct hlist_node *tmp;
155 char *start_uid, *end_uid = NULL;
156 long int uid_start = 0, uid_end = 0;
158 if (count >= sizeof(uids))
159 count = sizeof(uids) - 1;
161 if (copy_from_user(uids, buffer, count))
166 start_uid = strsep(&end_uid, "-");
168 if (!start_uid || !end_uid)
171 if (kstrtol(start_uid, 10, &uid_start) != 0 ||
172 kstrtol(end_uid, 10, &uid_end) != 0) {
176 mutex_lock(&uid_lock);
178 for (; uid_start <= uid_end; uid_start++) {
179 hash_for_each_possible_safe(hash_table, uid_entry, tmp,
181 hash_del(&uid_entry->hash);
186 mutex_unlock(&uid_lock);
190 static const struct file_operations uid_remove_fops = {
191 .open = uid_remove_open,
192 .release = single_release,
193 .write = uid_remove_write,
196 static int process_notifier(struct notifier_block *self,
197 unsigned long cmd, void *v)
199 struct task_struct *task = v;
200 struct uid_entry *uid_entry;
201 cputime_t utime, stime;
207 mutex_lock(&uid_lock);
208 uid = from_kuid_munged(current_user_ns(), task_uid(task));
209 uid_entry = find_or_register_uid(uid);
211 pr_err("%s: failed to find uid %d\n", __func__, uid);
215 task_cputime_adjusted(task, &utime, &stime);
216 uid_entry->utime += utime;
217 uid_entry->stime += stime;
218 uid_entry->power += task->cpu_power;
219 task->cpu_power = ULLONG_MAX;
222 mutex_unlock(&uid_lock);
226 static struct notifier_block process_notifier_block = {
227 .notifier_call = process_notifier,
230 static int __init proc_uid_cputime_init(void)
232 hash_init(hash_table);
234 parent = proc_mkdir("uid_cputime", NULL);
236 pr_err("%s: failed to create proc entry\n", __func__);
240 proc_create_data("remove_uid_range", S_IWUGO, parent, &uid_remove_fops,
243 proc_create_data("show_uid_stat", S_IRUGO, parent, &uid_stat_fops,
246 profile_event_register(PROFILE_TASK_EXIT, &process_notifier_block);
251 early_initcall(proc_uid_cputime_init);