blob: f6a6a3e1344e61f0b428a1be5ee6ec882b18a4eb [file] [log] [blame]
/* drivers/misc/uid_sys_stats.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/cpufreq_times.h>
#include <linux/err.h>
#include <linux/hashtable.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/mm.h>
#include <linux/proc_fs.h>
#include <linux/profile.h>
#include <linux/rtmutex.h>
#include <linux/sched/cputime.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_RT_MUTEX(uid_lock);
static struct proc_dir_entry *cpu_parent;
static struct proc_dir_entry *io_parent;
static struct proc_dir_entry *proc_parent;
struct io_stats {
u64 read_bytes;
u64 write_bytes;
u64 rchar;
u64 wchar;
u64 fsync;
};
#define UID_STATE_FOREGROUND 0
#define UID_STATE_BACKGROUND 1
#define UID_STATE_BUCKET_SIZE 2
#define UID_STATE_TOTAL_CURR 2
#define UID_STATE_TOTAL_LAST 3
#define UID_STATE_DEAD_TASKS 4
#define UID_STATE_SIZE 5
#define MAX_TASK_COMM_LEN 256
struct task_entry {
char comm[MAX_TASK_COMM_LEN];
pid_t pid;
struct io_stats io[UID_STATE_SIZE];
struct hlist_node hash;
};
struct uid_entry {
uid_t uid;
u64 utime;
u64 stime;
u64 active_utime;
u64 active_stime;
int state;
struct io_stats io[UID_STATE_SIZE];
struct hlist_node hash;
#ifdef CONFIG_UID_SYS_STATS_DEBUG
DECLARE_HASHTABLE(task_entries, UID_HASH_BITS);
#endif
};
static u64 compute_write_bytes(struct task_struct *task)
{
if (task->ioac.write_bytes <= task->ioac.cancelled_write_bytes)
return 0;
return task->ioac.write_bytes - task->ioac.cancelled_write_bytes;
}
static void compute_io_bucket_stats(struct io_stats *io_bucket,
struct io_stats *io_curr,
struct io_stats *io_last,
struct io_stats *io_dead)
{
/* tasks could switch to another uid group, but its io_last in the
* previous uid group could still be positive.
* therefore before each update, do an overflow check first
*/
int64_t delta;
delta = io_curr->read_bytes + io_dead->read_bytes -
io_last->read_bytes;
io_bucket->read_bytes += delta > 0 ? delta : 0;
delta = io_curr->write_bytes + io_dead->write_bytes -
io_last->write_bytes;
io_bucket->write_bytes += delta > 0 ? delta : 0;
delta = io_curr->rchar + io_dead->rchar - io_last->rchar;
io_bucket->rchar += delta > 0 ? delta : 0;
delta = io_curr->wchar + io_dead->wchar - io_last->wchar;
io_bucket->wchar += delta > 0 ? delta : 0;
delta = io_curr->fsync + io_dead->fsync - io_last->fsync;
io_bucket->fsync += delta > 0 ? delta : 0;
io_last->read_bytes = io_curr->read_bytes;
io_last->write_bytes = io_curr->write_bytes;
io_last->rchar = io_curr->rchar;
io_last->wchar = io_curr->wchar;
io_last->fsync = io_curr->fsync;
memset(io_dead, 0, sizeof(struct io_stats));
}
#ifdef CONFIG_UID_SYS_STATS_DEBUG
static void get_full_task_comm(struct task_entry *task_entry,
struct task_struct *task)
{
int i = 0, offset = 0, len = 0;
/* save one byte for terminating null character */
int unused_len = MAX_TASK_COMM_LEN - TASK_COMM_LEN - 1;
char buf[unused_len];
struct mm_struct *mm = task->mm;
/* fill the first TASK_COMM_LEN bytes with thread name */
__get_task_comm(task_entry->comm, TASK_COMM_LEN, task);
i = strlen(task_entry->comm);
while (i < TASK_COMM_LEN)
task_entry->comm[i++] = ' ';
/* next the executable file name */
if (mm) {
down_read(&mm->mmap_sem);
if (mm->exe_file) {
char *pathname = d_path(&mm->exe_file->f_path, buf,
unused_len);
if (!IS_ERR(pathname)) {
len = strlcpy(task_entry->comm + i, pathname,
unused_len);
i += len;
task_entry->comm[i++] = ' ';
unused_len--;
}
}
up_read(&mm->mmap_sem);
}
unused_len -= len;
/* fill the rest with command line argument
* replace each null or new line character
* between args in argv with whitespace */
len = get_cmdline(task, buf, unused_len);
while (offset < len) {
if (buf[offset] != '\0' && buf[offset] != '\n')
task_entry->comm[i++] = buf[offset];
else
task_entry->comm[i++] = ' ';
offset++;
}
/* get rid of trailing whitespaces in case when arg is memset to
* zero before being reset in userspace
*/
while (task_entry->comm[i-1] == ' ')
i--;
task_entry->comm[i] = '\0';
}
static struct task_entry *find_task_entry(struct uid_entry *uid_entry,
struct task_struct *task)
{
struct task_entry *task_entry;
hash_for_each_possible(uid_entry->task_entries, task_entry, hash,
task->pid) {
if (task->pid == task_entry->pid) {
/* if thread name changed, update the entire command */
int len = strnchr(task_entry->comm, ' ', TASK_COMM_LEN)
- task_entry->comm;
if (strncmp(task_entry->comm, task->comm, len))
get_full_task_comm(task_entry, task);
return task_entry;
}
}
return NULL;
}
static struct task_entry *find_or_register_task(struct uid_entry *uid_entry,
struct task_struct *task)
{
struct task_entry *task_entry;
pid_t pid = task->pid;
task_entry = find_task_entry(uid_entry, task);
if (task_entry)
return task_entry;
task_entry = kzalloc(sizeof(struct task_entry), GFP_ATOMIC);
if (!task_entry)
return NULL;
get_full_task_comm(task_entry, task);
task_entry->pid = pid;
hash_add(uid_entry->task_entries, &task_entry->hash, (unsigned int)pid);
return task_entry;
}
static void remove_uid_tasks(struct uid_entry *uid_entry)
{
struct task_entry *task_entry;
unsigned long bkt_task;
struct hlist_node *tmp_task;
hash_for_each_safe(uid_entry->task_entries, bkt_task,
tmp_task, task_entry, hash) {
hash_del(&task_entry->hash);
kfree(task_entry);
}
}
static void set_io_uid_tasks_zero(struct uid_entry *uid_entry)
{
struct task_entry *task_entry;
unsigned long bkt_task;
hash_for_each(uid_entry->task_entries, bkt_task, task_entry, hash) {
memset(&task_entry->io[UID_STATE_TOTAL_CURR], 0,
sizeof(struct io_stats));
}
}
static void add_uid_tasks_io_stats(struct uid_entry *uid_entry,
struct task_struct *task, int slot)
{
struct task_entry *task_entry = find_or_register_task(uid_entry, task);
struct io_stats *task_io_slot = &task_entry->io[slot];
task_io_slot->read_bytes += task->ioac.read_bytes;
task_io_slot->write_bytes += compute_write_bytes(task);
task_io_slot->rchar += task->ioac.rchar;
task_io_slot->wchar += task->ioac.wchar;
task_io_slot->fsync += task->ioac.syscfs;
}
static void compute_io_uid_tasks(struct uid_entry *uid_entry)
{
struct task_entry *task_entry;
unsigned long bkt_task;
hash_for_each(uid_entry->task_entries, bkt_task, task_entry, hash) {
compute_io_bucket_stats(&task_entry->io[uid_entry->state],
&task_entry->io[UID_STATE_TOTAL_CURR],
&task_entry->io[UID_STATE_TOTAL_LAST],
&task_entry->io[UID_STATE_DEAD_TASKS]);
}
}
static void show_io_uid_tasks(struct seq_file *m, struct uid_entry *uid_entry)
{
struct task_entry *task_entry;
unsigned long bkt_task;
hash_for_each(uid_entry->task_entries, bkt_task, task_entry, hash) {
/* Separated by comma because space exists in task comm */
seq_printf(m, "task,%s,%lu,%llu,%llu,%llu,%llu,%llu,%llu,%llu,%llu,%llu,%llu\n",
task_entry->comm,
(unsigned long)task_entry->pid,
task_entry->io[UID_STATE_FOREGROUND].rchar,
task_entry->io[UID_STATE_FOREGROUND].wchar,
task_entry->io[UID_STATE_FOREGROUND].read_bytes,
task_entry->io[UID_STATE_FOREGROUND].write_bytes,
task_entry->io[UID_STATE_BACKGROUND].rchar,
task_entry->io[UID_STATE_BACKGROUND].wchar,
task_entry->io[UID_STATE_BACKGROUND].read_bytes,
task_entry->io[UID_STATE_BACKGROUND].write_bytes,
task_entry->io[UID_STATE_FOREGROUND].fsync,
task_entry->io[UID_STATE_BACKGROUND].fsync);
}
}
#else
static void remove_uid_tasks(struct uid_entry *uid_entry) {};
static void set_io_uid_tasks_zero(struct uid_entry *uid_entry) {};
static void add_uid_tasks_io_stats(struct uid_entry *uid_entry,
struct task_struct *task, int slot) {};
static void compute_io_uid_tasks(struct uid_entry *uid_entry) {};
static void show_io_uid_tasks(struct seq_file *m,
struct uid_entry *uid_entry) {}
#endif
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;
#ifdef CONFIG_UID_SYS_STATS_DEBUG
hash_init(uid_entry->task_entries);
#endif
hash_add(hash_table, &uid_entry->hash, uid);
return uid_entry;
}
static int uid_cputime_show(struct seq_file *m, void *v)
{
struct uid_entry *uid_entry = NULL;
struct task_struct *task, *temp;
struct user_namespace *user_ns = current_user_ns();
u64 utime;
u64 stime;
unsigned long bkt;
uid_t uid;
rt_mutex_lock(&uid_lock);
hash_for_each(hash_table, bkt, uid_entry, hash) {
uid_entry->active_stime = 0;
uid_entry->active_utime = 0;
}
rcu_read_lock();
do_each_thread(temp, task) {
uid = from_kuid_munged(user_ns, task_uid(task));
if (!uid_entry || uid_entry->uid != uid)
uid_entry = find_or_register_uid(uid);
if (!uid_entry) {
rcu_read_unlock();
rt_mutex_unlock(&uid_lock);
pr_err("%s: failed to find the uid_entry for uid %d\n",
__func__, uid);
return -ENOMEM;
}
/* avoid double accounting of dying threads */
if (!(task->flags & PF_EXITING)) {
task_cputime_adjusted(task, &utime, &stime);
uid_entry->active_utime += utime;
uid_entry->active_stime += stime;
}
} while_each_thread(temp, task);
rcu_read_unlock();
hash_for_each(hash_table, bkt, uid_entry, hash) {
u64 total_utime = uid_entry->utime +
uid_entry->active_utime;
u64 total_stime = uid_entry->stime +
uid_entry->active_stime;
seq_printf(m, "%d: %llu %llu\n", uid_entry->uid,
ktime_to_us(total_utime), ktime_to_us(total_stime));
}
rt_mutex_unlock(&uid_lock);
return 0;
}
static int uid_cputime_open(struct inode *inode, struct file *file)
{
return single_open(file, uid_cputime_show, PDE_DATA(inode));
}
static const struct file_operations uid_cputime_fops = {
.open = uid_cputime_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;
uid_t uid_start = 0, uid_end = 0;
u64 uid;
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 (kstrtouint(start_uid, 10, &uid_start) != 0 ||
kstrtouint(end_uid, 10, &uid_end) != 0) {
return -EINVAL;
}
/* Also remove uids from /proc/uid_time_in_state */
cpufreq_task_times_remove_uids(uid_start, uid_end);
rt_mutex_lock(&uid_lock);
for (uid = uid_start; uid <= uid_end; uid++) {
hash_for_each_possible_safe(hash_table, uid_entry, tmp,
hash, uid) {
if (uid == uid_entry->uid) {
remove_uid_tasks(uid_entry);
hash_del(&uid_entry->hash);
kfree(uid_entry);
}
}
}
rt_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 void add_uid_io_stats(struct uid_entry *uid_entry,
struct task_struct *task, int slot)
{
struct io_stats *io_slot = &uid_entry->io[slot];
/* avoid double accounting of dying threads */
if (slot != UID_STATE_DEAD_TASKS && (task->flags & PF_EXITING))
return;
io_slot->read_bytes += task->ioac.read_bytes;
io_slot->write_bytes += compute_write_bytes(task);
io_slot->rchar += task->ioac.rchar;
io_slot->wchar += task->ioac.wchar;
io_slot->fsync += task->ioac.syscfs;
add_uid_tasks_io_stats(uid_entry, task, slot);
}
static void update_io_stats_all_locked(void)
{
struct uid_entry *uid_entry = NULL;
struct task_struct *task, *temp;
struct user_namespace *user_ns = current_user_ns();
unsigned long bkt;
uid_t uid;
hash_for_each(hash_table, bkt, uid_entry, hash) {
memset(&uid_entry->io[UID_STATE_TOTAL_CURR], 0,
sizeof(struct io_stats));
set_io_uid_tasks_zero(uid_entry);
}
rcu_read_lock();
do_each_thread(temp, task) {
uid = from_kuid_munged(user_ns, task_uid(task));
if (!uid_entry || uid_entry->uid != uid)
uid_entry = find_or_register_uid(uid);
if (!uid_entry)
continue;
add_uid_io_stats(uid_entry, task, UID_STATE_TOTAL_CURR);
} while_each_thread(temp, task);
rcu_read_unlock();
hash_for_each(hash_table, bkt, uid_entry, hash) {
compute_io_bucket_stats(&uid_entry->io[uid_entry->state],
&uid_entry->io[UID_STATE_TOTAL_CURR],
&uid_entry->io[UID_STATE_TOTAL_LAST],
&uid_entry->io[UID_STATE_DEAD_TASKS]);
compute_io_uid_tasks(uid_entry);
}
}
static void update_io_stats_uid_locked(struct uid_entry *uid_entry)
{
struct task_struct *task, *temp;
struct user_namespace *user_ns = current_user_ns();
memset(&uid_entry->io[UID_STATE_TOTAL_CURR], 0,
sizeof(struct io_stats));
set_io_uid_tasks_zero(uid_entry);
rcu_read_lock();
do_each_thread(temp, task) {
if (from_kuid_munged(user_ns, task_uid(task)) != uid_entry->uid)
continue;
add_uid_io_stats(uid_entry, task, UID_STATE_TOTAL_CURR);
} while_each_thread(temp, task);
rcu_read_unlock();
compute_io_bucket_stats(&uid_entry->io[uid_entry->state],
&uid_entry->io[UID_STATE_TOTAL_CURR],
&uid_entry->io[UID_STATE_TOTAL_LAST],
&uid_entry->io[UID_STATE_DEAD_TASKS]);
compute_io_uid_tasks(uid_entry);
}
static int uid_io_show(struct seq_file *m, void *v)
{
struct uid_entry *uid_entry;
unsigned long bkt;
rt_mutex_lock(&uid_lock);
update_io_stats_all_locked();
hash_for_each(hash_table, bkt, uid_entry, hash) {
seq_printf(m, "%d %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu\n",
uid_entry->uid,
uid_entry->io[UID_STATE_FOREGROUND].rchar,
uid_entry->io[UID_STATE_FOREGROUND].wchar,
uid_entry->io[UID_STATE_FOREGROUND].read_bytes,
uid_entry->io[UID_STATE_FOREGROUND].write_bytes,
uid_entry->io[UID_STATE_BACKGROUND].rchar,
uid_entry->io[UID_STATE_BACKGROUND].wchar,
uid_entry->io[UID_STATE_BACKGROUND].read_bytes,
uid_entry->io[UID_STATE_BACKGROUND].write_bytes,
uid_entry->io[UID_STATE_FOREGROUND].fsync,
uid_entry->io[UID_STATE_BACKGROUND].fsync);
show_io_uid_tasks(m, uid_entry);
}
rt_mutex_unlock(&uid_lock);
return 0;
}
static int uid_io_open(struct inode *inode, struct file *file)
{
return single_open(file, uid_io_show, PDE_DATA(inode));
}
static const struct file_operations uid_io_fops = {
.open = uid_io_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static int uid_procstat_open(struct inode *inode, struct file *file)
{
return single_open(file, NULL, NULL);
}
static ssize_t uid_procstat_write(struct file *file,
const char __user *buffer, size_t count, loff_t *ppos)
{
struct uid_entry *uid_entry;
uid_t uid;
int argc, state;
char input[128];
if (count >= sizeof(input))
return -EINVAL;
if (copy_from_user(input, buffer, count))
return -EFAULT;
input[count] = '\0';
argc = sscanf(input, "%u %d", &uid, &state);
if (argc != 2)
return -EINVAL;
if (state != UID_STATE_BACKGROUND && state != UID_STATE_FOREGROUND)
return -EINVAL;
rt_mutex_lock(&uid_lock);
uid_entry = find_or_register_uid(uid);
if (!uid_entry) {
rt_mutex_unlock(&uid_lock);
return -EINVAL;
}
if (uid_entry->state == state) {
rt_mutex_unlock(&uid_lock);
return count;
}
update_io_stats_uid_locked(uid_entry);
uid_entry->state = state;
rt_mutex_unlock(&uid_lock);
return count;
}
static const struct file_operations uid_procstat_fops = {
.open = uid_procstat_open,
.release = single_release,
.write = uid_procstat_write,
};
static int process_notifier(struct notifier_block *self,
unsigned long cmd, void *v)
{
struct task_struct *task = v;
struct uid_entry *uid_entry;
u64 utime, stime;
uid_t uid;
if (!task)
return NOTIFY_OK;
rt_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;
add_uid_io_stats(uid_entry, task, UID_STATE_DEAD_TASKS);
exit:
rt_mutex_unlock(&uid_lock);
return NOTIFY_OK;
}
static struct notifier_block process_notifier_block = {
.notifier_call = process_notifier,
};
static int __init proc_uid_sys_stats_init(void)
{
hash_init(hash_table);
cpu_parent = proc_mkdir("uid_cputime", NULL);
if (!cpu_parent) {
pr_err("%s: failed to create uid_cputime proc entry\n",
__func__);
goto err;
}
proc_create_data("remove_uid_range", 0222, cpu_parent,
&uid_remove_fops, NULL);
proc_create_data("show_uid_stat", 0444, cpu_parent,
&uid_cputime_fops, NULL);
io_parent = proc_mkdir("uid_io", NULL);
if (!io_parent) {
pr_err("%s: failed to create uid_io proc entry\n",
__func__);
goto err;
}
proc_create_data("stats", 0444, io_parent,
&uid_io_fops, NULL);
proc_parent = proc_mkdir("uid_procstat", NULL);
if (!proc_parent) {
pr_err("%s: failed to create uid_procstat proc entry\n",
__func__);
goto err;
}
proc_create_data("set", 0222, proc_parent,
&uid_procstat_fops, NULL);
profile_event_register(PROFILE_TASK_EXIT, &process_notifier_block);
return 0;
err:
remove_proc_subtree("uid_cputime", NULL);
remove_proc_subtree("uid_io", NULL);
remove_proc_subtree("uid_procstat", NULL);
return -ENOMEM;
}
early_initcall(proc_uid_sys_stats_init);