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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * taskstats.c - Export per-task statistics to userland
4 *
5 * Copyright (C) Shailabh Nagar, IBM Corp. 2006
6 * (C) Balbir Singh, IBM Corp. 2006
7 */
8
9#include <linux/kernel.h>
10#include <linux/taskstats_kern.h>
11#include <linux/tsacct_kern.h>
12#include <linux/delayacct.h>
13#include <linux/cpumask.h>
14#include <linux/percpu.h>
15#include <linux/slab.h>
16#include <linux/cgroupstats.h>
17#include <linux/cgroup.h>
18#include <linux/fs.h>
19#include <linux/file.h>
20#include <linux/pid_namespace.h>
21#include <net/genetlink.h>
22#include <linux/atomic.h>
23#include <linux/sched/cputime.h>
24
25/*
26 * Maximum length of a cpumask that can be specified in
27 * the TASKSTATS_CMD_ATTR_REGISTER/DEREGISTER_CPUMASK attribute
28 */
29#define TASKSTATS_CPUMASK_MAXLEN (100+6*NR_CPUS)
30
31static DEFINE_PER_CPU(__u32, taskstats_seqnum);
32static int family_registered;
33struct kmem_cache *taskstats_cache;
34
35static struct genl_family family;
36
37static const struct nla_policy taskstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1] = {
38 [TASKSTATS_CMD_ATTR_PID] = { .type = NLA_U32 },
39 [TASKSTATS_CMD_ATTR_TGID] = { .type = NLA_U32 },
40 [TASKSTATS_CMD_ATTR_REGISTER_CPUMASK] = { .type = NLA_STRING },
41 [TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK] = { .type = NLA_STRING },};
42
43/*
44 * We have to use TASKSTATS_CMD_ATTR_MAX here, it is the maxattr in the family.
45 * Make sure they are always aligned.
46 */
47static const struct nla_policy cgroupstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1] = {
48 [CGROUPSTATS_CMD_ATTR_FD] = { .type = NLA_U32 },
49};
50
51struct listener {
52 struct list_head list;
53 pid_t pid;
54 char valid;
55};
56
57struct listener_list {
58 struct rw_semaphore sem;
59 struct list_head list;
60};
61static DEFINE_PER_CPU(struct listener_list, listener_array);
62
63enum actions {
64 REGISTER,
65 DEREGISTER,
66 CPU_DONT_CARE
67};
68
69static int prepare_reply(struct genl_info *info, u8 cmd, struct sk_buff **skbp,
70 size_t size)
71{
72 struct sk_buff *skb;
73 void *reply;
74
75 /*
76 * If new attributes are added, please revisit this allocation
77 */
78 skb = genlmsg_new(size, GFP_KERNEL);
79 if (!skb)
80 return -ENOMEM;
81
82 if (!info) {
83 int seq = this_cpu_inc_return(taskstats_seqnum) - 1;
84
85 reply = genlmsg_put(skb, 0, seq, &family, 0, cmd);
86 } else
87 reply = genlmsg_put_reply(skb, info, &family, 0, cmd);
88 if (reply == NULL) {
89 nlmsg_free(skb);
90 return -EINVAL;
91 }
92
93 *skbp = skb;
94 return 0;
95}
96
97/*
98 * Send taskstats data in @skb to listener with nl_pid @pid
99 */
100static int send_reply(struct sk_buff *skb, struct genl_info *info)
101{
102 struct genlmsghdr *genlhdr = nlmsg_data(nlmsg_hdr(skb));
103 void *reply = genlmsg_data(genlhdr);
104
105 genlmsg_end(skb, reply);
106
107 return genlmsg_reply(skb, info);
108}
109
110/*
111 * Send taskstats data in @skb to listeners registered for @cpu's exit data
112 */
113static void send_cpu_listeners(struct sk_buff *skb,
114 struct listener_list *listeners)
115{
116 struct genlmsghdr *genlhdr = nlmsg_data(nlmsg_hdr(skb));
117 struct listener *s, *tmp;
118 struct sk_buff *skb_next, *skb_cur = skb;
119 void *reply = genlmsg_data(genlhdr);
120 int rc, delcount = 0;
121
122 genlmsg_end(skb, reply);
123
124 rc = 0;
125 down_read(&listeners->sem);
126 list_for_each_entry(s, &listeners->list, list) {
127 skb_next = NULL;
128 if (!list_is_last(&s->list, &listeners->list)) {
129 skb_next = skb_clone(skb_cur, GFP_KERNEL);
130 if (!skb_next)
131 break;
132 }
133 rc = genlmsg_unicast(&init_net, skb_cur, s->pid);
134 if (rc == -ECONNREFUSED) {
135 s->valid = 0;
136 delcount++;
137 }
138 skb_cur = skb_next;
139 }
140 up_read(&listeners->sem);
141
142 if (skb_cur)
143 nlmsg_free(skb_cur);
144
145 if (!delcount)
146 return;
147
148 /* Delete invalidated entries */
149 down_write(&listeners->sem);
150 list_for_each_entry_safe(s, tmp, &listeners->list, list) {
151 if (!s->valid) {
152 list_del(&s->list);
153 kfree(s);
154 }
155 }
156 up_write(&listeners->sem);
157}
158
159static void fill_stats(struct user_namespace *user_ns,
160 struct pid_namespace *pid_ns,
161 struct task_struct *tsk, struct taskstats *stats)
162{
163 memset(stats, 0, sizeof(*stats));
164 /*
165 * Each accounting subsystem adds calls to its functions to
166 * fill in relevant parts of struct taskstsats as follows
167 *
168 * per-task-foo(stats, tsk);
169 */
170
171 delayacct_add_tsk(stats, tsk);
172
173 /* fill in basic acct fields */
174 stats->version = TASKSTATS_VERSION;
175 stats->nvcsw = tsk->nvcsw;
176 stats->nivcsw = tsk->nivcsw;
177 bacct_add_tsk(user_ns, pid_ns, stats, tsk);
178
179 /* fill in extended acct fields */
180 xacct_add_tsk(stats, tsk);
181}
182
183static int fill_stats_for_pid(pid_t pid, struct taskstats *stats)
184{
185 struct task_struct *tsk;
186
187 tsk = find_get_task_by_vpid(pid);
188 if (!tsk)
189 return -ESRCH;
190 fill_stats(current_user_ns(), task_active_pid_ns(current), tsk, stats);
191 put_task_struct(tsk);
192 return 0;
193}
194
195static int fill_stats_for_tgid(pid_t tgid, struct taskstats *stats)
196{
197 struct task_struct *tsk, *first;
198 unsigned long flags;
199 int rc = -ESRCH;
200 u64 delta, utime, stime;
201 u64 start_time;
202
203 /*
204 * Add additional stats from live tasks except zombie thread group
205 * leaders who are already counted with the dead tasks
206 */
207 rcu_read_lock();
208 first = find_task_by_vpid(tgid);
209
210 if (!first || !lock_task_sighand(first, &flags))
211 goto out;
212
213 if (first->signal->stats)
214 memcpy(stats, first->signal->stats, sizeof(*stats));
215 else
216 memset(stats, 0, sizeof(*stats));
217
218 tsk = first;
219 start_time = ktime_get_ns();
220 do {
221 if (tsk->exit_state)
222 continue;
223 /*
224 * Accounting subsystem can call its functions here to
225 * fill in relevant parts of struct taskstsats as follows
226 *
227 * per-task-foo(stats, tsk);
228 */
229 delayacct_add_tsk(stats, tsk);
230
231 /* calculate task elapsed time in nsec */
232 delta = start_time - tsk->start_time;
233 /* Convert to micro seconds */
234 do_div(delta, NSEC_PER_USEC);
235 stats->ac_etime += delta;
236
237 task_cputime(tsk, &utime, &stime);
238 stats->ac_utime += div_u64(utime, NSEC_PER_USEC);
239 stats->ac_stime += div_u64(stime, NSEC_PER_USEC);
240
241 stats->nvcsw += tsk->nvcsw;
242 stats->nivcsw += tsk->nivcsw;
243 } while_each_thread(first, tsk);
244
245 unlock_task_sighand(first, &flags);
246 rc = 0;
247out:
248 rcu_read_unlock();
249
250 stats->version = TASKSTATS_VERSION;
251 /*
252 * Accounting subsystems can also add calls here to modify
253 * fields of taskstats.
254 */
255 return rc;
256}
257
258static void fill_tgid_exit(struct task_struct *tsk)
259{
260 unsigned long flags;
261
262 spin_lock_irqsave(&tsk->sighand->siglock, flags);
263 if (!tsk->signal->stats)
264 goto ret;
265
266 /*
267 * Each accounting subsystem calls its functions here to
268 * accumalate its per-task stats for tsk, into the per-tgid structure
269 *
270 * per-task-foo(tsk->signal->stats, tsk);
271 */
272 delayacct_add_tsk(tsk->signal->stats, tsk);
273ret:
274 spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
275 return;
276}
277
278static int add_del_listener(pid_t pid, const struct cpumask *mask, int isadd)
279{
280 struct listener_list *listeners;
281 struct listener *s, *tmp, *s2;
282 unsigned int cpu;
283 int ret = 0;
284
285 if (!cpumask_subset(mask, cpu_possible_mask))
286 return -EINVAL;
287
288 if (current_user_ns() != &init_user_ns)
289 return -EINVAL;
290
291 if (task_active_pid_ns(current) != &init_pid_ns)
292 return -EINVAL;
293
294 if (isadd == REGISTER) {
295 for_each_cpu(cpu, mask) {
296 s = kmalloc_node(sizeof(struct listener),
297 GFP_KERNEL, cpu_to_node(cpu));
298 if (!s) {
299 ret = -ENOMEM;
300 goto cleanup;
301 }
302 s->pid = pid;
303 s->valid = 1;
304
305 listeners = &per_cpu(listener_array, cpu);
306 down_write(&listeners->sem);
307 list_for_each_entry(s2, &listeners->list, list) {
308 if (s2->pid == pid && s2->valid)
309 goto exists;
310 }
311 list_add(&s->list, &listeners->list);
312 s = NULL;
313exists:
314 up_write(&listeners->sem);
315 kfree(s); /* nop if NULL */
316 }
317 return 0;
318 }
319
320 /* Deregister or cleanup */
321cleanup:
322 for_each_cpu(cpu, mask) {
323 listeners = &per_cpu(listener_array, cpu);
324 down_write(&listeners->sem);
325 list_for_each_entry_safe(s, tmp, &listeners->list, list) {
326 if (s->pid == pid) {
327 list_del(&s->list);
328 kfree(s);
329 break;
330 }
331 }
332 up_write(&listeners->sem);
333 }
334 return ret;
335}
336
337static int parse(struct nlattr *na, struct cpumask *mask)
338{
339 char *data;
340 int len;
341 int ret;
342
343 if (na == NULL)
344 return 1;
345 len = nla_len(na);
346 if (len > TASKSTATS_CPUMASK_MAXLEN)
347 return -E2BIG;
348 if (len < 1)
349 return -EINVAL;
350 data = kmalloc(len, GFP_KERNEL);
351 if (!data)
352 return -ENOMEM;
353 nla_strlcpy(data, na, len);
354 ret = cpulist_parse(data, mask);
355 kfree(data);
356 return ret;
357}
358
359static struct taskstats *mk_reply(struct sk_buff *skb, int type, u32 pid)
360{
361 struct nlattr *na, *ret;
362 int aggr;
363
364 aggr = (type == TASKSTATS_TYPE_PID)
365 ? TASKSTATS_TYPE_AGGR_PID
366 : TASKSTATS_TYPE_AGGR_TGID;
367
368 na = nla_nest_start_noflag(skb, aggr);
369 if (!na)
370 goto err;
371
372 if (nla_put(skb, type, sizeof(pid), &pid) < 0) {
373 nla_nest_cancel(skb, na);
374 goto err;
375 }
376 ret = nla_reserve_64bit(skb, TASKSTATS_TYPE_STATS,
377 sizeof(struct taskstats), TASKSTATS_TYPE_NULL);
378 if (!ret) {
379 nla_nest_cancel(skb, na);
380 goto err;
381 }
382 nla_nest_end(skb, na);
383
384 return nla_data(ret);
385err:
386 return NULL;
387}
388
389static int cgroupstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
390{
391 int rc = 0;
392 struct sk_buff *rep_skb;
393 struct cgroupstats *stats;
394 struct nlattr *na;
395 size_t size;
396 u32 fd;
397 struct fd f;
398
399 na = info->attrs[CGROUPSTATS_CMD_ATTR_FD];
400 if (!na)
401 return -EINVAL;
402
403 fd = nla_get_u32(info->attrs[CGROUPSTATS_CMD_ATTR_FD]);
404 f = fdget(fd);
405 if (!f.file)
406 return 0;
407
408 size = nla_total_size(sizeof(struct cgroupstats));
409
410 rc = prepare_reply(info, CGROUPSTATS_CMD_NEW, &rep_skb,
411 size);
412 if (rc < 0)
413 goto err;
414
415 na = nla_reserve(rep_skb, CGROUPSTATS_TYPE_CGROUP_STATS,
416 sizeof(struct cgroupstats));
417 if (na == NULL) {
418 nlmsg_free(rep_skb);
419 rc = -EMSGSIZE;
420 goto err;
421 }
422
423 stats = nla_data(na);
424 memset(stats, 0, sizeof(*stats));
425
426 rc = cgroupstats_build(stats, f.file->f_path.dentry);
427 if (rc < 0) {
428 nlmsg_free(rep_skb);
429 goto err;
430 }
431
432 rc = send_reply(rep_skb, info);
433
434err:
435 fdput(f);
436 return rc;
437}
438
439static int cmd_attr_register_cpumask(struct genl_info *info)
440{
441 cpumask_var_t mask;
442 int rc;
443
444 if (!alloc_cpumask_var(&mask, GFP_KERNEL))
445 return -ENOMEM;
446 rc = parse(info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK], mask);
447 if (rc < 0)
448 goto out;
449 rc = add_del_listener(info->snd_portid, mask, REGISTER);
450out:
451 free_cpumask_var(mask);
452 return rc;
453}
454
455static int cmd_attr_deregister_cpumask(struct genl_info *info)
456{
457 cpumask_var_t mask;
458 int rc;
459
460 if (!alloc_cpumask_var(&mask, GFP_KERNEL))
461 return -ENOMEM;
462 rc = parse(info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK], mask);
463 if (rc < 0)
464 goto out;
465 rc = add_del_listener(info->snd_portid, mask, DEREGISTER);
466out:
467 free_cpumask_var(mask);
468 return rc;
469}
470
471static size_t taskstats_packet_size(void)
472{
473 size_t size;
474
475 size = nla_total_size(sizeof(u32)) +
476 nla_total_size_64bit(sizeof(struct taskstats)) +
477 nla_total_size(0);
478
479 return size;
480}
481
482static int cmd_attr_pid(struct genl_info *info)
483{
484 struct taskstats *stats;
485 struct sk_buff *rep_skb;
486 size_t size;
487 u32 pid;
488 int rc;
489
490 size = taskstats_packet_size();
491
492 rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size);
493 if (rc < 0)
494 return rc;
495
496 rc = -EINVAL;
497 pid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_PID]);
498 stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID, pid);
499 if (!stats)
500 goto err;
501
502 rc = fill_stats_for_pid(pid, stats);
503 if (rc < 0)
504 goto err;
505 return send_reply(rep_skb, info);
506err:
507 nlmsg_free(rep_skb);
508 return rc;
509}
510
511static int cmd_attr_tgid(struct genl_info *info)
512{
513 struct taskstats *stats;
514 struct sk_buff *rep_skb;
515 size_t size;
516 u32 tgid;
517 int rc;
518
519 size = taskstats_packet_size();
520
521 rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size);
522 if (rc < 0)
523 return rc;
524
525 rc = -EINVAL;
526 tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]);
527 stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tgid);
528 if (!stats)
529 goto err;
530
531 rc = fill_stats_for_tgid(tgid, stats);
532 if (rc < 0)
533 goto err;
534 return send_reply(rep_skb, info);
535err:
536 nlmsg_free(rep_skb);
537 return rc;
538}
539
540static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
541{
542 if (info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK])
543 return cmd_attr_register_cpumask(info);
544 else if (info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK])
545 return cmd_attr_deregister_cpumask(info);
546 else if (info->attrs[TASKSTATS_CMD_ATTR_PID])
547 return cmd_attr_pid(info);
548 else if (info->attrs[TASKSTATS_CMD_ATTR_TGID])
549 return cmd_attr_tgid(info);
550 else
551 return -EINVAL;
552}
553
554static struct taskstats *taskstats_tgid_alloc(struct task_struct *tsk)
555{
556 struct signal_struct *sig = tsk->signal;
557 struct taskstats *stats;
558
559 if (sig->stats || thread_group_empty(tsk))
560 goto ret;
561
562 /* No problem if kmem_cache_zalloc() fails */
563 stats = kmem_cache_zalloc(taskstats_cache, GFP_KERNEL);
564
565 spin_lock_irq(&tsk->sighand->siglock);
566 if (!sig->stats) {
567 sig->stats = stats;
568 stats = NULL;
569 }
570 spin_unlock_irq(&tsk->sighand->siglock);
571
572 if (stats)
573 kmem_cache_free(taskstats_cache, stats);
574ret:
575 return sig->stats;
576}
577
578/* Send pid data out on exit */
579void taskstats_exit(struct task_struct *tsk, int group_dead)
580{
581 int rc;
582 struct listener_list *listeners;
583 struct taskstats *stats;
584 struct sk_buff *rep_skb;
585 size_t size;
586 int is_thread_group;
587
588 if (!family_registered)
589 return;
590
591 /*
592 * Size includes space for nested attributes
593 */
594 size = taskstats_packet_size();
595
596 is_thread_group = !!taskstats_tgid_alloc(tsk);
597 if (is_thread_group) {
598 /* PID + STATS + TGID + STATS */
599 size = 2 * size;
600 /* fill the tsk->signal->stats structure */
601 fill_tgid_exit(tsk);
602 }
603
604 listeners = raw_cpu_ptr(&listener_array);
605 if (list_empty(&listeners->list))
606 return;
607
608 rc = prepare_reply(NULL, TASKSTATS_CMD_NEW, &rep_skb, size);
609 if (rc < 0)
610 return;
611
612 stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID,
613 task_pid_nr_ns(tsk, &init_pid_ns));
614 if (!stats)
615 goto err;
616
617 fill_stats(&init_user_ns, &init_pid_ns, tsk, stats);
618
619 /*
620 * Doesn't matter if tsk is the leader or the last group member leaving
621 */
622 if (!is_thread_group || !group_dead)
623 goto send;
624
625 stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID,
626 task_tgid_nr_ns(tsk, &init_pid_ns));
627 if (!stats)
628 goto err;
629
630 memcpy(stats, tsk->signal->stats, sizeof(*stats));
631
632send:
633 send_cpu_listeners(rep_skb, listeners);
634 return;
635err:
636 nlmsg_free(rep_skb);
637}
638
639static const struct genl_ops taskstats_ops[] = {
640 {
641 .cmd = TASKSTATS_CMD_GET,
642 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
643 .doit = taskstats_user_cmd,
644 /* policy enforced later */
645 .flags = GENL_ADMIN_PERM | GENL_CMD_CAP_HASPOL,
646 },
647 {
648 .cmd = CGROUPSTATS_CMD_GET,
649 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
650 .doit = cgroupstats_user_cmd,
651 /* policy enforced later */
652 .flags = GENL_CMD_CAP_HASPOL,
653 },
654};
655
656static int taskstats_pre_doit(const struct genl_ops *ops, struct sk_buff *skb,
657 struct genl_info *info)
658{
659 const struct nla_policy *policy = NULL;
660
661 switch (ops->cmd) {
662 case TASKSTATS_CMD_GET:
663 policy = taskstats_cmd_get_policy;
664 break;
665 case CGROUPSTATS_CMD_GET:
666 policy = cgroupstats_cmd_get_policy;
667 break;
668 default:
669 return -EINVAL;
670 }
671
672 return nlmsg_validate_deprecated(info->nlhdr, GENL_HDRLEN,
673 TASKSTATS_CMD_ATTR_MAX, policy,
674 info->extack);
675}
676
677static struct genl_family family __ro_after_init = {
678 .name = TASKSTATS_GENL_NAME,
679 .version = TASKSTATS_GENL_VERSION,
680 .maxattr = TASKSTATS_CMD_ATTR_MAX,
681 .module = THIS_MODULE,
682 .ops = taskstats_ops,
683 .n_ops = ARRAY_SIZE(taskstats_ops),
684 .pre_doit = taskstats_pre_doit,
685};
686
687/* Needed early in initialization */
688void __init taskstats_init_early(void)
689{
690 unsigned int i;
691
692 taskstats_cache = KMEM_CACHE(taskstats, SLAB_PANIC);
693 for_each_possible_cpu(i) {
694 INIT_LIST_HEAD(&(per_cpu(listener_array, i).list));
695 init_rwsem(&(per_cpu(listener_array, i).sem));
696 }
697}
698
699static int __init taskstats_init(void)
700{
701 int rc;
702
703 rc = genl_register_family(&family);
704 if (rc)
705 return rc;
706
707 family_registered = 1;
708 pr_info("registered taskstats version %d\n", TASKSTATS_GENL_VERSION);
709 return 0;
710}
711
712/*
713 * late initcall ensures initialization of statistics collection
714 * mechanisms precedes initialization of the taskstats interface
715 */
716late_initcall(taskstats_init);
1/*
2 * taskstats.c - Export per-task statistics to userland
3 *
4 * Copyright (C) Shailabh Nagar, IBM Corp. 2006
5 * (C) Balbir Singh, IBM Corp. 2006
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 */
18
19#include <linux/kernel.h>
20#include <linux/taskstats_kern.h>
21#include <linux/tsacct_kern.h>
22#include <linux/delayacct.h>
23#include <linux/cpumask.h>
24#include <linux/percpu.h>
25#include <linux/slab.h>
26#include <linux/cgroupstats.h>
27#include <linux/cgroup.h>
28#include <linux/fs.h>
29#include <linux/file.h>
30#include <linux/pid_namespace.h>
31#include <net/genetlink.h>
32#include <linux/atomic.h>
33#include <linux/sched/cputime.h>
34
35/*
36 * Maximum length of a cpumask that can be specified in
37 * the TASKSTATS_CMD_ATTR_REGISTER/DEREGISTER_CPUMASK attribute
38 */
39#define TASKSTATS_CPUMASK_MAXLEN (100+6*NR_CPUS)
40
41static DEFINE_PER_CPU(__u32, taskstats_seqnum);
42static int family_registered;
43struct kmem_cache *taskstats_cache;
44
45static struct genl_family family;
46
47static const struct nla_policy taskstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1] = {
48 [TASKSTATS_CMD_ATTR_PID] = { .type = NLA_U32 },
49 [TASKSTATS_CMD_ATTR_TGID] = { .type = NLA_U32 },
50 [TASKSTATS_CMD_ATTR_REGISTER_CPUMASK] = { .type = NLA_STRING },
51 [TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK] = { .type = NLA_STRING },};
52
53/*
54 * We have to use TASKSTATS_CMD_ATTR_MAX here, it is the maxattr in the family.
55 * Make sure they are always aligned.
56 */
57static const struct nla_policy cgroupstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1] = {
58 [CGROUPSTATS_CMD_ATTR_FD] = { .type = NLA_U32 },
59};
60
61struct listener {
62 struct list_head list;
63 pid_t pid;
64 char valid;
65};
66
67struct listener_list {
68 struct rw_semaphore sem;
69 struct list_head list;
70};
71static DEFINE_PER_CPU(struct listener_list, listener_array);
72
73enum actions {
74 REGISTER,
75 DEREGISTER,
76 CPU_DONT_CARE
77};
78
79static int prepare_reply(struct genl_info *info, u8 cmd, struct sk_buff **skbp,
80 size_t size)
81{
82 struct sk_buff *skb;
83 void *reply;
84
85 /*
86 * If new attributes are added, please revisit this allocation
87 */
88 skb = genlmsg_new(size, GFP_KERNEL);
89 if (!skb)
90 return -ENOMEM;
91
92 if (!info) {
93 int seq = this_cpu_inc_return(taskstats_seqnum) - 1;
94
95 reply = genlmsg_put(skb, 0, seq, &family, 0, cmd);
96 } else
97 reply = genlmsg_put_reply(skb, info, &family, 0, cmd);
98 if (reply == NULL) {
99 nlmsg_free(skb);
100 return -EINVAL;
101 }
102
103 *skbp = skb;
104 return 0;
105}
106
107/*
108 * Send taskstats data in @skb to listener with nl_pid @pid
109 */
110static int send_reply(struct sk_buff *skb, struct genl_info *info)
111{
112 struct genlmsghdr *genlhdr = nlmsg_data(nlmsg_hdr(skb));
113 void *reply = genlmsg_data(genlhdr);
114
115 genlmsg_end(skb, reply);
116
117 return genlmsg_reply(skb, info);
118}
119
120/*
121 * Send taskstats data in @skb to listeners registered for @cpu's exit data
122 */
123static void send_cpu_listeners(struct sk_buff *skb,
124 struct listener_list *listeners)
125{
126 struct genlmsghdr *genlhdr = nlmsg_data(nlmsg_hdr(skb));
127 struct listener *s, *tmp;
128 struct sk_buff *skb_next, *skb_cur = skb;
129 void *reply = genlmsg_data(genlhdr);
130 int rc, delcount = 0;
131
132 genlmsg_end(skb, reply);
133
134 rc = 0;
135 down_read(&listeners->sem);
136 list_for_each_entry(s, &listeners->list, list) {
137 skb_next = NULL;
138 if (!list_is_last(&s->list, &listeners->list)) {
139 skb_next = skb_clone(skb_cur, GFP_KERNEL);
140 if (!skb_next)
141 break;
142 }
143 rc = genlmsg_unicast(&init_net, skb_cur, s->pid);
144 if (rc == -ECONNREFUSED) {
145 s->valid = 0;
146 delcount++;
147 }
148 skb_cur = skb_next;
149 }
150 up_read(&listeners->sem);
151
152 if (skb_cur)
153 nlmsg_free(skb_cur);
154
155 if (!delcount)
156 return;
157
158 /* Delete invalidated entries */
159 down_write(&listeners->sem);
160 list_for_each_entry_safe(s, tmp, &listeners->list, list) {
161 if (!s->valid) {
162 list_del(&s->list);
163 kfree(s);
164 }
165 }
166 up_write(&listeners->sem);
167}
168
169static void fill_stats(struct user_namespace *user_ns,
170 struct pid_namespace *pid_ns,
171 struct task_struct *tsk, struct taskstats *stats)
172{
173 memset(stats, 0, sizeof(*stats));
174 /*
175 * Each accounting subsystem adds calls to its functions to
176 * fill in relevant parts of struct taskstsats as follows
177 *
178 * per-task-foo(stats, tsk);
179 */
180
181 delayacct_add_tsk(stats, tsk);
182
183 /* fill in basic acct fields */
184 stats->version = TASKSTATS_VERSION;
185 stats->nvcsw = tsk->nvcsw;
186 stats->nivcsw = tsk->nivcsw;
187 bacct_add_tsk(user_ns, pid_ns, stats, tsk);
188
189 /* fill in extended acct fields */
190 xacct_add_tsk(stats, tsk);
191}
192
193static int fill_stats_for_pid(pid_t pid, struct taskstats *stats)
194{
195 struct task_struct *tsk;
196
197 tsk = find_get_task_by_vpid(pid);
198 if (!tsk)
199 return -ESRCH;
200 fill_stats(current_user_ns(), task_active_pid_ns(current), tsk, stats);
201 put_task_struct(tsk);
202 return 0;
203}
204
205static int fill_stats_for_tgid(pid_t tgid, struct taskstats *stats)
206{
207 struct task_struct *tsk, *first;
208 unsigned long flags;
209 int rc = -ESRCH;
210 u64 delta, utime, stime;
211 u64 start_time;
212
213 /*
214 * Add additional stats from live tasks except zombie thread group
215 * leaders who are already counted with the dead tasks
216 */
217 rcu_read_lock();
218 first = find_task_by_vpid(tgid);
219
220 if (!first || !lock_task_sighand(first, &flags))
221 goto out;
222
223 if (first->signal->stats)
224 memcpy(stats, first->signal->stats, sizeof(*stats));
225 else
226 memset(stats, 0, sizeof(*stats));
227
228 tsk = first;
229 start_time = ktime_get_ns();
230 do {
231 if (tsk->exit_state)
232 continue;
233 /*
234 * Accounting subsystem can call its functions here to
235 * fill in relevant parts of struct taskstsats as follows
236 *
237 * per-task-foo(stats, tsk);
238 */
239 delayacct_add_tsk(stats, tsk);
240
241 /* calculate task elapsed time in nsec */
242 delta = start_time - tsk->start_time;
243 /* Convert to micro seconds */
244 do_div(delta, NSEC_PER_USEC);
245 stats->ac_etime += delta;
246
247 task_cputime(tsk, &utime, &stime);
248 stats->ac_utime += div_u64(utime, NSEC_PER_USEC);
249 stats->ac_stime += div_u64(stime, NSEC_PER_USEC);
250
251 stats->nvcsw += tsk->nvcsw;
252 stats->nivcsw += tsk->nivcsw;
253 } while_each_thread(first, tsk);
254
255 unlock_task_sighand(first, &flags);
256 rc = 0;
257out:
258 rcu_read_unlock();
259
260 stats->version = TASKSTATS_VERSION;
261 /*
262 * Accounting subsystems can also add calls here to modify
263 * fields of taskstats.
264 */
265 return rc;
266}
267
268static void fill_tgid_exit(struct task_struct *tsk)
269{
270 unsigned long flags;
271
272 spin_lock_irqsave(&tsk->sighand->siglock, flags);
273 if (!tsk->signal->stats)
274 goto ret;
275
276 /*
277 * Each accounting subsystem calls its functions here to
278 * accumalate its per-task stats for tsk, into the per-tgid structure
279 *
280 * per-task-foo(tsk->signal->stats, tsk);
281 */
282 delayacct_add_tsk(tsk->signal->stats, tsk);
283ret:
284 spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
285 return;
286}
287
288static int add_del_listener(pid_t pid, const struct cpumask *mask, int isadd)
289{
290 struct listener_list *listeners;
291 struct listener *s, *tmp, *s2;
292 unsigned int cpu;
293 int ret = 0;
294
295 if (!cpumask_subset(mask, cpu_possible_mask))
296 return -EINVAL;
297
298 if (current_user_ns() != &init_user_ns)
299 return -EINVAL;
300
301 if (task_active_pid_ns(current) != &init_pid_ns)
302 return -EINVAL;
303
304 if (isadd == REGISTER) {
305 for_each_cpu(cpu, mask) {
306 s = kmalloc_node(sizeof(struct listener),
307 GFP_KERNEL, cpu_to_node(cpu));
308 if (!s) {
309 ret = -ENOMEM;
310 goto cleanup;
311 }
312 s->pid = pid;
313 s->valid = 1;
314
315 listeners = &per_cpu(listener_array, cpu);
316 down_write(&listeners->sem);
317 list_for_each_entry(s2, &listeners->list, list) {
318 if (s2->pid == pid && s2->valid)
319 goto exists;
320 }
321 list_add(&s->list, &listeners->list);
322 s = NULL;
323exists:
324 up_write(&listeners->sem);
325 kfree(s); /* nop if NULL */
326 }
327 return 0;
328 }
329
330 /* Deregister or cleanup */
331cleanup:
332 for_each_cpu(cpu, mask) {
333 listeners = &per_cpu(listener_array, cpu);
334 down_write(&listeners->sem);
335 list_for_each_entry_safe(s, tmp, &listeners->list, list) {
336 if (s->pid == pid) {
337 list_del(&s->list);
338 kfree(s);
339 break;
340 }
341 }
342 up_write(&listeners->sem);
343 }
344 return ret;
345}
346
347static int parse(struct nlattr *na, struct cpumask *mask)
348{
349 char *data;
350 int len;
351 int ret;
352
353 if (na == NULL)
354 return 1;
355 len = nla_len(na);
356 if (len > TASKSTATS_CPUMASK_MAXLEN)
357 return -E2BIG;
358 if (len < 1)
359 return -EINVAL;
360 data = kmalloc(len, GFP_KERNEL);
361 if (!data)
362 return -ENOMEM;
363 nla_strlcpy(data, na, len);
364 ret = cpulist_parse(data, mask);
365 kfree(data);
366 return ret;
367}
368
369static struct taskstats *mk_reply(struct sk_buff *skb, int type, u32 pid)
370{
371 struct nlattr *na, *ret;
372 int aggr;
373
374 aggr = (type == TASKSTATS_TYPE_PID)
375 ? TASKSTATS_TYPE_AGGR_PID
376 : TASKSTATS_TYPE_AGGR_TGID;
377
378 na = nla_nest_start(skb, aggr);
379 if (!na)
380 goto err;
381
382 if (nla_put(skb, type, sizeof(pid), &pid) < 0) {
383 nla_nest_cancel(skb, na);
384 goto err;
385 }
386 ret = nla_reserve_64bit(skb, TASKSTATS_TYPE_STATS,
387 sizeof(struct taskstats), TASKSTATS_TYPE_NULL);
388 if (!ret) {
389 nla_nest_cancel(skb, na);
390 goto err;
391 }
392 nla_nest_end(skb, na);
393
394 return nla_data(ret);
395err:
396 return NULL;
397}
398
399static int cgroupstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
400{
401 int rc = 0;
402 struct sk_buff *rep_skb;
403 struct cgroupstats *stats;
404 struct nlattr *na;
405 size_t size;
406 u32 fd;
407 struct fd f;
408
409 na = info->attrs[CGROUPSTATS_CMD_ATTR_FD];
410 if (!na)
411 return -EINVAL;
412
413 fd = nla_get_u32(info->attrs[CGROUPSTATS_CMD_ATTR_FD]);
414 f = fdget(fd);
415 if (!f.file)
416 return 0;
417
418 size = nla_total_size(sizeof(struct cgroupstats));
419
420 rc = prepare_reply(info, CGROUPSTATS_CMD_NEW, &rep_skb,
421 size);
422 if (rc < 0)
423 goto err;
424
425 na = nla_reserve(rep_skb, CGROUPSTATS_TYPE_CGROUP_STATS,
426 sizeof(struct cgroupstats));
427 if (na == NULL) {
428 nlmsg_free(rep_skb);
429 rc = -EMSGSIZE;
430 goto err;
431 }
432
433 stats = nla_data(na);
434 memset(stats, 0, sizeof(*stats));
435
436 rc = cgroupstats_build(stats, f.file->f_path.dentry);
437 if (rc < 0) {
438 nlmsg_free(rep_skb);
439 goto err;
440 }
441
442 rc = send_reply(rep_skb, info);
443
444err:
445 fdput(f);
446 return rc;
447}
448
449static int cmd_attr_register_cpumask(struct genl_info *info)
450{
451 cpumask_var_t mask;
452 int rc;
453
454 if (!alloc_cpumask_var(&mask, GFP_KERNEL))
455 return -ENOMEM;
456 rc = parse(info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK], mask);
457 if (rc < 0)
458 goto out;
459 rc = add_del_listener(info->snd_portid, mask, REGISTER);
460out:
461 free_cpumask_var(mask);
462 return rc;
463}
464
465static int cmd_attr_deregister_cpumask(struct genl_info *info)
466{
467 cpumask_var_t mask;
468 int rc;
469
470 if (!alloc_cpumask_var(&mask, GFP_KERNEL))
471 return -ENOMEM;
472 rc = parse(info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK], mask);
473 if (rc < 0)
474 goto out;
475 rc = add_del_listener(info->snd_portid, mask, DEREGISTER);
476out:
477 free_cpumask_var(mask);
478 return rc;
479}
480
481static size_t taskstats_packet_size(void)
482{
483 size_t size;
484
485 size = nla_total_size(sizeof(u32)) +
486 nla_total_size_64bit(sizeof(struct taskstats)) +
487 nla_total_size(0);
488
489 return size;
490}
491
492static int cmd_attr_pid(struct genl_info *info)
493{
494 struct taskstats *stats;
495 struct sk_buff *rep_skb;
496 size_t size;
497 u32 pid;
498 int rc;
499
500 size = taskstats_packet_size();
501
502 rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size);
503 if (rc < 0)
504 return rc;
505
506 rc = -EINVAL;
507 pid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_PID]);
508 stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID, pid);
509 if (!stats)
510 goto err;
511
512 rc = fill_stats_for_pid(pid, stats);
513 if (rc < 0)
514 goto err;
515 return send_reply(rep_skb, info);
516err:
517 nlmsg_free(rep_skb);
518 return rc;
519}
520
521static int cmd_attr_tgid(struct genl_info *info)
522{
523 struct taskstats *stats;
524 struct sk_buff *rep_skb;
525 size_t size;
526 u32 tgid;
527 int rc;
528
529 size = taskstats_packet_size();
530
531 rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size);
532 if (rc < 0)
533 return rc;
534
535 rc = -EINVAL;
536 tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]);
537 stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tgid);
538 if (!stats)
539 goto err;
540
541 rc = fill_stats_for_tgid(tgid, stats);
542 if (rc < 0)
543 goto err;
544 return send_reply(rep_skb, info);
545err:
546 nlmsg_free(rep_skb);
547 return rc;
548}
549
550static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
551{
552 if (info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK])
553 return cmd_attr_register_cpumask(info);
554 else if (info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK])
555 return cmd_attr_deregister_cpumask(info);
556 else if (info->attrs[TASKSTATS_CMD_ATTR_PID])
557 return cmd_attr_pid(info);
558 else if (info->attrs[TASKSTATS_CMD_ATTR_TGID])
559 return cmd_attr_tgid(info);
560 else
561 return -EINVAL;
562}
563
564static struct taskstats *taskstats_tgid_alloc(struct task_struct *tsk)
565{
566 struct signal_struct *sig = tsk->signal;
567 struct taskstats *stats;
568
569 if (sig->stats || thread_group_empty(tsk))
570 goto ret;
571
572 /* No problem if kmem_cache_zalloc() fails */
573 stats = kmem_cache_zalloc(taskstats_cache, GFP_KERNEL);
574
575 spin_lock_irq(&tsk->sighand->siglock);
576 if (!sig->stats) {
577 sig->stats = stats;
578 stats = NULL;
579 }
580 spin_unlock_irq(&tsk->sighand->siglock);
581
582 if (stats)
583 kmem_cache_free(taskstats_cache, stats);
584ret:
585 return sig->stats;
586}
587
588/* Send pid data out on exit */
589void taskstats_exit(struct task_struct *tsk, int group_dead)
590{
591 int rc;
592 struct listener_list *listeners;
593 struct taskstats *stats;
594 struct sk_buff *rep_skb;
595 size_t size;
596 int is_thread_group;
597
598 if (!family_registered)
599 return;
600
601 /*
602 * Size includes space for nested attributes
603 */
604 size = taskstats_packet_size();
605
606 is_thread_group = !!taskstats_tgid_alloc(tsk);
607 if (is_thread_group) {
608 /* PID + STATS + TGID + STATS */
609 size = 2 * size;
610 /* fill the tsk->signal->stats structure */
611 fill_tgid_exit(tsk);
612 }
613
614 listeners = raw_cpu_ptr(&listener_array);
615 if (list_empty(&listeners->list))
616 return;
617
618 rc = prepare_reply(NULL, TASKSTATS_CMD_NEW, &rep_skb, size);
619 if (rc < 0)
620 return;
621
622 stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID,
623 task_pid_nr_ns(tsk, &init_pid_ns));
624 if (!stats)
625 goto err;
626
627 fill_stats(&init_user_ns, &init_pid_ns, tsk, stats);
628
629 /*
630 * Doesn't matter if tsk is the leader or the last group member leaving
631 */
632 if (!is_thread_group || !group_dead)
633 goto send;
634
635 stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID,
636 task_tgid_nr_ns(tsk, &init_pid_ns));
637 if (!stats)
638 goto err;
639
640 memcpy(stats, tsk->signal->stats, sizeof(*stats));
641
642send:
643 send_cpu_listeners(rep_skb, listeners);
644 return;
645err:
646 nlmsg_free(rep_skb);
647}
648
649static const struct genl_ops taskstats_ops[] = {
650 {
651 .cmd = TASKSTATS_CMD_GET,
652 .doit = taskstats_user_cmd,
653 .policy = taskstats_cmd_get_policy,
654 .flags = GENL_ADMIN_PERM,
655 },
656 {
657 .cmd = CGROUPSTATS_CMD_GET,
658 .doit = cgroupstats_user_cmd,
659 .policy = cgroupstats_cmd_get_policy,
660 },
661};
662
663static struct genl_family family __ro_after_init = {
664 .name = TASKSTATS_GENL_NAME,
665 .version = TASKSTATS_GENL_VERSION,
666 .maxattr = TASKSTATS_CMD_ATTR_MAX,
667 .module = THIS_MODULE,
668 .ops = taskstats_ops,
669 .n_ops = ARRAY_SIZE(taskstats_ops),
670};
671
672/* Needed early in initialization */
673void __init taskstats_init_early(void)
674{
675 unsigned int i;
676
677 taskstats_cache = KMEM_CACHE(taskstats, SLAB_PANIC);
678 for_each_possible_cpu(i) {
679 INIT_LIST_HEAD(&(per_cpu(listener_array, i).list));
680 init_rwsem(&(per_cpu(listener_array, i).sem));
681 }
682}
683
684static int __init taskstats_init(void)
685{
686 int rc;
687
688 rc = genl_register_family(&family);
689 if (rc)
690 return rc;
691
692 family_registered = 1;
693 pr_info("registered taskstats version %d\n", TASKSTATS_GENL_VERSION);
694 return 0;
695}
696
697/*
698 * late initcall ensures initialization of statistics collection
699 * mechanisms precedes initialization of the taskstats interface
700 */
701late_initcall(taskstats_init);