diff options
Diffstat (limited to 'drivers/misc/uid_cputime.c')
-rw-r--r-- | drivers/misc/uid_cputime.c | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/drivers/misc/uid_cputime.c b/drivers/misc/uid_cputime.c new file mode 100644 index 000000000000..acd7046ce497 --- /dev/null +++ b/drivers/misc/uid_cputime.c @@ -0,0 +1,237 @@ +/* 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(from_kuid_munged( + current_user_ns(), 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__, from_kuid_munged(current_user_ns(), + 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 = 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; + +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); |