1/* drivers/misc/uid_cputime.c 2 * 3 * Copyright (C) 2014 - 2015 Google, Inc. 4 * 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. 8 * 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. 13 * 14 */ 15 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> 28 29#define UID_HASH_BITS 10 30DECLARE_HASHTABLE(hash_table, UID_HASH_BITS); 31 32static DEFINE_MUTEX(uid_lock); 33static struct proc_dir_entry *parent; 34 35struct uid_entry { 36 uid_t uid; 37 cputime_t utime; 38 cputime_t stime; 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; 44}; 45 46static struct uid_entry *find_uid_entry(uid_t uid) 47{ 48 struct uid_entry *uid_entry; 49 hash_for_each_possible(hash_table, uid_entry, hash, uid) { 50 if (uid_entry->uid == uid) 51 return uid_entry; 52 } 53 return NULL; 54} 55 56static struct uid_entry *find_or_register_uid(uid_t uid) 57{ 58 struct uid_entry *uid_entry; 59 60 uid_entry = find_uid_entry(uid); 61 if (uid_entry) 62 return uid_entry; 63 64 uid_entry = kzalloc(sizeof(struct uid_entry), GFP_ATOMIC); 65 if (!uid_entry) 66 return NULL; 67 68 uid_entry->uid = uid; 69 70 hash_add(hash_table, &uid_entry->hash, uid); 71 72 return uid_entry; 73} 74 75static int uid_stat_show(struct seq_file *m, void *v) 76{ 77 struct uid_entry *uid_entry; 78 struct task_struct *task, *temp; 79 cputime_t utime; 80 cputime_t stime; 81 unsigned long bkt; 82 83 mutex_lock(&uid_lock); 84 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; 89 } 90 91 read_lock(&tasklist_lock); 92 do_each_thread(temp, task) { 93 uid_entry = find_or_register_uid(from_kuid_munged( 94 current_user_ns(), task_uid(task))); 95 if (!uid_entry) { 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(), 100 task_uid(task))); 101 return -ENOMEM; 102 } 103 /* if this task is exiting, we have already accounted for the 104 * time and power. 105 */ 106 if (task->cpu_power == ULLONG_MAX) 107 continue; 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; 112 } while_each_thread(temp, task); 113 read_unlock(&tasklist_lock); 114 115 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: %llu %llu %llu\n", uid_entry->uid, 123 (unsigned long long)jiffies_to_msecs( 124 cputime_to_jiffies(total_utime)) * USEC_PER_MSEC, 125 (unsigned long long)jiffies_to_msecs( 126 cputime_to_jiffies(total_stime)) * USEC_PER_MSEC, 127 total_power); 128 } 129 130 mutex_unlock(&uid_lock); 131 return 0; 132} 133 134static int uid_stat_open(struct inode *inode, struct file *file) 135{ 136 return single_open(file, uid_stat_show, PDE_DATA(inode)); 137} 138 139static const struct file_operations uid_stat_fops = { 140 .open = uid_stat_open, 141 .read = seq_read, 142 .llseek = seq_lseek, 143 .release = single_release, 144}; 145 146static int uid_remove_open(struct inode *inode, struct file *file) 147{ 148 return single_open(file, NULL, NULL); 149} 150 151static ssize_t uid_remove_write(struct file *file, 152 const char __user *buffer, size_t count, loff_t *ppos) 153{ 154 struct uid_entry *uid_entry; 155 struct hlist_node *tmp; 156 char uids[128]; 157 char *start_uid, *end_uid = NULL; 158 long int uid_start = 0, uid_end = 0; 159 160 if (count >= sizeof(uids)) 161 count = sizeof(uids) - 1; 162 163 if (copy_from_user(uids, buffer, count)) 164 return -EFAULT; 165 166 uids[count] = '\0'; 167 end_uid = uids; 168 start_uid = strsep(&end_uid, "-"); 169 170 if (!start_uid || !end_uid) 171 return -EINVAL; 172 173 if (kstrtol(start_uid, 10, &uid_start) != 0 || 174 kstrtol(end_uid, 10, &uid_end) != 0) { 175 return -EINVAL; 176 } 177 178 mutex_lock(&uid_lock); 179 180 for (; uid_start <= uid_end; uid_start++) { 181 hash_for_each_possible_safe(hash_table, uid_entry, tmp, 182 hash, uid_start) { 183 hash_del(&uid_entry->hash); 184 kfree(uid_entry); 185 } 186 } 187 188 mutex_unlock(&uid_lock); 189 return count; 190} 191 192static const struct file_operations uid_remove_fops = { 193 .open = uid_remove_open, 194 .release = single_release, 195 .write = uid_remove_write, 196}; 197 198static int process_notifier(struct notifier_block *self, 199 unsigned long cmd, void *v) 200{ 201 struct task_struct *task = v; 202 struct uid_entry *uid_entry; 203 cputime_t utime, stime; 204 uid_t uid; 205 206 if (!task) 207 return NOTIFY_OK; 208 209 mutex_lock(&uid_lock); 210 uid = from_kuid_munged(current_user_ns(), task_uid(task)); 211 uid_entry = find_or_register_uid(uid); 212 if (!uid_entry) { 213 pr_err("%s: failed to find uid %d\n", __func__, uid); 214 goto exit; 215 } 216 217 task_cputime_adjusted(task, &utime, &stime); 218 uid_entry->utime += utime; 219 uid_entry->stime += stime; 220 uid_entry->power += task->cpu_power; 221 task->cpu_power = ULLONG_MAX; 222 223exit: 224 mutex_unlock(&uid_lock); 225 return NOTIFY_OK; 226} 227 228static struct notifier_block process_notifier_block = { 229 .notifier_call = process_notifier, 230}; 231 232static int __init proc_uid_cputime_init(void) 233{ 234 hash_init(hash_table); 235 236 parent = proc_mkdir("uid_cputime", NULL); 237 if (!parent) { 238 pr_err("%s: failed to create proc entry\n", __func__); 239 return -ENOMEM; 240 } 241 242 proc_create_data("remove_uid_range", S_IWUGO, parent, &uid_remove_fops, 243 NULL); 244 245 proc_create_data("show_uid_stat", S_IRUGO, parent, &uid_stat_fops, 246 NULL); 247 248 profile_event_register(PROFILE_TASK_EXIT, &process_notifier_block); 249 250 return 0; 251} 252 253early_initcall(proc_uid_cputime_init); 254