Jin Qian | a1ad229 | 2015-09-07 14:55:10 +0530 | [diff] [blame] | 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 |
| 30 | DECLARE_HASHTABLE(hash_table, UID_HASH_BITS); |
| 31 | |
| 32 | static DEFINE_MUTEX(uid_lock); |
| 33 | static struct proc_dir_entry *parent; |
| 34 | |
| 35 | struct 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 | struct hlist_node hash; |
| 42 | }; |
| 43 | |
| 44 | static struct uid_entry *find_uid_entry(uid_t uid) |
| 45 | { |
| 46 | struct uid_entry *uid_entry; |
Srinivasarao P | e168fec | 2015-09-24 13:08:20 +0530 | [diff] [blame^] | 47 | struct hlist_node *node; |
| 48 | hash_for_each_possible(hash_table, uid_entry, node, hash, uid) { |
Jin Qian | a1ad229 | 2015-09-07 14:55:10 +0530 | [diff] [blame] | 49 | if (uid_entry->uid == uid) |
| 50 | return uid_entry; |
| 51 | } |
| 52 | return NULL; |
| 53 | } |
| 54 | |
| 55 | static struct uid_entry *find_or_register_uid(uid_t uid) |
| 56 | { |
| 57 | struct uid_entry *uid_entry; |
| 58 | |
| 59 | uid_entry = find_uid_entry(uid); |
| 60 | if (uid_entry) |
| 61 | return uid_entry; |
| 62 | |
| 63 | uid_entry = kzalloc(sizeof(struct uid_entry), GFP_ATOMIC); |
| 64 | if (!uid_entry) |
| 65 | return NULL; |
| 66 | |
| 67 | uid_entry->uid = uid; |
| 68 | |
| 69 | hash_add(hash_table, &uid_entry->hash, uid); |
| 70 | |
| 71 | return uid_entry; |
| 72 | } |
| 73 | |
| 74 | static int uid_stat_show(struct seq_file *m, void *v) |
| 75 | { |
| 76 | struct uid_entry *uid_entry; |
| 77 | struct task_struct *task; |
Jin Qian | a1ad229 | 2015-09-07 14:55:10 +0530 | [diff] [blame] | 78 | unsigned long bkt; |
Srinivasarao P | e168fec | 2015-09-24 13:08:20 +0530 | [diff] [blame^] | 79 | struct hlist_node *node; |
Jin Qian | a1ad229 | 2015-09-07 14:55:10 +0530 | [diff] [blame] | 80 | |
| 81 | mutex_lock(&uid_lock); |
| 82 | |
Srinivasarao P | e168fec | 2015-09-24 13:08:20 +0530 | [diff] [blame^] | 83 | hash_for_each(hash_table, bkt, node, uid_entry, hash) { |
Jin Qian | a1ad229 | 2015-09-07 14:55:10 +0530 | [diff] [blame] | 84 | uid_entry->active_stime = 0; |
| 85 | uid_entry->active_utime = 0; |
| 86 | } |
| 87 | |
| 88 | read_lock(&tasklist_lock); |
| 89 | for_each_process(task) { |
| 90 | uid_entry = find_or_register_uid(task_uid(task)); |
| 91 | if (!uid_entry) { |
| 92 | read_unlock(&tasklist_lock); |
| 93 | mutex_unlock(&uid_lock); |
| 94 | pr_err("%s: failed to find the uid_entry for uid %d\n", |
| 95 | __func__, task_uid(task)); |
| 96 | return -ENOMEM; |
| 97 | } |
Srinivasarao P | e168fec | 2015-09-24 13:08:20 +0530 | [diff] [blame^] | 98 | uid_entry->active_utime += task->utime; |
| 99 | uid_entry->active_stime += task->stime; |
Jin Qian | a1ad229 | 2015-09-07 14:55:10 +0530 | [diff] [blame] | 100 | } |
| 101 | read_unlock(&tasklist_lock); |
| 102 | |
Srinivasarao P | e168fec | 2015-09-24 13:08:20 +0530 | [diff] [blame^] | 103 | hash_for_each(hash_table, bkt, node, uid_entry, hash) { |
Jin Qian | a1ad229 | 2015-09-07 14:55:10 +0530 | [diff] [blame] | 104 | cputime_t total_utime = uid_entry->utime + |
| 105 | uid_entry->active_utime; |
| 106 | cputime_t total_stime = uid_entry->stime + |
| 107 | uid_entry->active_stime; |
| 108 | seq_printf(m, "%d: %u %u\n", uid_entry->uid, |
| 109 | cputime_to_usecs(total_utime), |
| 110 | cputime_to_usecs(total_stime)); |
| 111 | } |
| 112 | |
| 113 | mutex_unlock(&uid_lock); |
| 114 | return 0; |
| 115 | } |
| 116 | |
| 117 | static int uid_stat_open(struct inode *inode, struct file *file) |
| 118 | { |
Srinivasarao P | e168fec | 2015-09-24 13:08:20 +0530 | [diff] [blame^] | 119 | return single_open(file, uid_stat_show, PDE(inode)->data); |
Jin Qian | a1ad229 | 2015-09-07 14:55:10 +0530 | [diff] [blame] | 120 | } |
| 121 | |
| 122 | static const struct file_operations uid_stat_fops = { |
| 123 | .open = uid_stat_open, |
| 124 | .read = seq_read, |
| 125 | .llseek = seq_lseek, |
| 126 | .release = single_release, |
| 127 | }; |
| 128 | |
| 129 | static int uid_remove_open(struct inode *inode, struct file *file) |
| 130 | { |
| 131 | return single_open(file, NULL, NULL); |
| 132 | } |
| 133 | |
| 134 | static ssize_t uid_remove_write(struct file *file, |
| 135 | const char __user *buffer, size_t count, loff_t *ppos) |
| 136 | { |
| 137 | struct uid_entry *uid_entry; |
| 138 | struct hlist_node *tmp; |
| 139 | char uids[128]; |
| 140 | char *start_uid, *end_uid = NULL; |
| 141 | long int uid_start = 0, uid_end = 0; |
Srinivasarao P | e168fec | 2015-09-24 13:08:20 +0530 | [diff] [blame^] | 142 | struct hlist_node *node; |
Jin Qian | a1ad229 | 2015-09-07 14:55:10 +0530 | [diff] [blame] | 143 | |
| 144 | if (count >= sizeof(uids)) |
| 145 | count = sizeof(uids) - 1; |
| 146 | |
| 147 | if (copy_from_user(uids, buffer, count)) |
| 148 | return -EFAULT; |
| 149 | |
| 150 | uids[count] = '\0'; |
| 151 | end_uid = uids; |
| 152 | start_uid = strsep(&end_uid, "-"); |
| 153 | |
| 154 | if (!start_uid || !end_uid) |
| 155 | return -EINVAL; |
| 156 | |
| 157 | if (kstrtol(start_uid, 10, &uid_start) != 0 || |
| 158 | kstrtol(end_uid, 10, &uid_end) != 0) { |
| 159 | return -EINVAL; |
| 160 | } |
| 161 | |
| 162 | mutex_lock(&uid_lock); |
| 163 | |
| 164 | for (; uid_start <= uid_end; uid_start++) { |
Srinivasarao P | e168fec | 2015-09-24 13:08:20 +0530 | [diff] [blame^] | 165 | hash_for_each_possible_safe(hash_table, uid_entry, node, |
| 166 | tmp, hash, uid_start) { |
Jin Qian | a1ad229 | 2015-09-07 14:55:10 +0530 | [diff] [blame] | 167 | hash_del(&uid_entry->hash); |
| 168 | kfree(uid_entry); |
| 169 | } |
| 170 | } |
| 171 | |
| 172 | mutex_unlock(&uid_lock); |
| 173 | return count; |
| 174 | } |
| 175 | |
| 176 | static const struct file_operations uid_remove_fops = { |
| 177 | .open = uid_remove_open, |
| 178 | .release = single_release, |
| 179 | .write = uid_remove_write, |
| 180 | }; |
| 181 | |
| 182 | static int process_notifier(struct notifier_block *self, |
| 183 | unsigned long cmd, void *v) |
| 184 | { |
| 185 | struct task_struct *task = v; |
| 186 | struct uid_entry *uid_entry; |
Jin Qian | a1ad229 | 2015-09-07 14:55:10 +0530 | [diff] [blame] | 187 | uid_t uid; |
| 188 | |
| 189 | if (!task) |
| 190 | return NOTIFY_OK; |
| 191 | |
| 192 | mutex_lock(&uid_lock); |
| 193 | uid = task_uid(task); |
| 194 | uid_entry = find_or_register_uid(uid); |
| 195 | if (!uid_entry) { |
| 196 | pr_err("%s: failed to find uid %d\n", __func__, uid); |
| 197 | goto exit; |
| 198 | } |
| 199 | |
Srinivasarao P | e168fec | 2015-09-24 13:08:20 +0530 | [diff] [blame^] | 200 | uid_entry->utime += task->utime; |
| 201 | uid_entry->stime += task->stime; |
Jin Qian | a1ad229 | 2015-09-07 14:55:10 +0530 | [diff] [blame] | 202 | |
| 203 | exit: |
| 204 | mutex_unlock(&uid_lock); |
| 205 | return NOTIFY_OK; |
| 206 | } |
| 207 | |
| 208 | static struct notifier_block process_notifier_block = { |
| 209 | .notifier_call = process_notifier, |
| 210 | }; |
| 211 | |
| 212 | static int __init proc_uid_cputime_init(void) |
| 213 | { |
| 214 | hash_init(hash_table); |
| 215 | |
| 216 | parent = proc_mkdir("uid_cputime", NULL); |
| 217 | if (!parent) { |
| 218 | pr_err("%s: failed to create proc entry\n", __func__); |
| 219 | return -ENOMEM; |
| 220 | } |
| 221 | |
| 222 | proc_create_data("remove_uid_range", S_IWUGO, parent, &uid_remove_fops, |
| 223 | NULL); |
| 224 | |
Jin Qian | 78a5975 | 2015-05-11 17:57:52 -0700 | [diff] [blame] | 225 | proc_create_data("show_uid_stat", S_IRUGO, parent, &uid_stat_fops, |
Jin Qian | a1ad229 | 2015-09-07 14:55:10 +0530 | [diff] [blame] | 226 | NULL); |
| 227 | |
| 228 | profile_event_register(PROFILE_TASK_EXIT, &process_notifier_block); |
| 229 | |
| 230 | return 0; |
| 231 | } |
| 232 | |
| 233 | early_initcall(proc_uid_cputime_init); |