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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);
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
34/*
35 * Maximum length of a cpumask that can be specified in
36 * the TASKSTATS_CMD_ATTR_REGISTER/DEREGISTER_CPUMASK attribute
37 */
38#define TASKSTATS_CPUMASK_MAXLEN (100+6*NR_CPUS)
39
40static DEFINE_PER_CPU(__u32, taskstats_seqnum);
41static int family_registered;
42struct kmem_cache *taskstats_cache;
43
44static struct genl_family family = {
45 .id = GENL_ID_GENERATE,
46 .name = TASKSTATS_GENL_NAME,
47 .version = TASKSTATS_GENL_VERSION,
48 .maxattr = TASKSTATS_CMD_ATTR_MAX,
49};
50
51static const struct nla_policy taskstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1] = {
52 [TASKSTATS_CMD_ATTR_PID] = { .type = NLA_U32 },
53 [TASKSTATS_CMD_ATTR_TGID] = { .type = NLA_U32 },
54 [TASKSTATS_CMD_ATTR_REGISTER_CPUMASK] = { .type = NLA_STRING },
55 [TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK] = { .type = NLA_STRING },};
56
57static const struct nla_policy cgroupstats_cmd_get_policy[CGROUPSTATS_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 int rc;
115
116 rc = genlmsg_end(skb, reply);
117 if (rc < 0) {
118 nlmsg_free(skb);
119 return rc;
120 }
121
122 return genlmsg_reply(skb, info);
123}
124
125/*
126 * Send taskstats data in @skb to listeners registered for @cpu's exit data
127 */
128static void send_cpu_listeners(struct sk_buff *skb,
129 struct listener_list *listeners)
130{
131 struct genlmsghdr *genlhdr = nlmsg_data(nlmsg_hdr(skb));
132 struct listener *s, *tmp;
133 struct sk_buff *skb_next, *skb_cur = skb;
134 void *reply = genlmsg_data(genlhdr);
135 int rc, delcount = 0;
136
137 rc = genlmsg_end(skb, reply);
138 if (rc < 0) {
139 nlmsg_free(skb);
140 return;
141 }
142
143 rc = 0;
144 down_read(&listeners->sem);
145 list_for_each_entry(s, &listeners->list, list) {
146 skb_next = NULL;
147 if (!list_is_last(&s->list, &listeners->list)) {
148 skb_next = skb_clone(skb_cur, GFP_KERNEL);
149 if (!skb_next)
150 break;
151 }
152 rc = genlmsg_unicast(&init_net, skb_cur, s->pid);
153 if (rc == -ECONNREFUSED) {
154 s->valid = 0;
155 delcount++;
156 }
157 skb_cur = skb_next;
158 }
159 up_read(&listeners->sem);
160
161 if (skb_cur)
162 nlmsg_free(skb_cur);
163
164 if (!delcount)
165 return;
166
167 /* Delete invalidated entries */
168 down_write(&listeners->sem);
169 list_for_each_entry_safe(s, tmp, &listeners->list, list) {
170 if (!s->valid) {
171 list_del(&s->list);
172 kfree(s);
173 }
174 }
175 up_write(&listeners->sem);
176}
177
178static void fill_stats(struct user_namespace *user_ns,
179 struct pid_namespace *pid_ns,
180 struct task_struct *tsk, struct taskstats *stats)
181{
182 memset(stats, 0, sizeof(*stats));
183 /*
184 * Each accounting subsystem adds calls to its functions to
185 * fill in relevant parts of struct taskstsats as follows
186 *
187 * per-task-foo(stats, tsk);
188 */
189
190 delayacct_add_tsk(stats, tsk);
191
192 /* fill in basic acct fields */
193 stats->version = TASKSTATS_VERSION;
194 stats->nvcsw = tsk->nvcsw;
195 stats->nivcsw = tsk->nivcsw;
196 bacct_add_tsk(user_ns, pid_ns, stats, tsk);
197
198 /* fill in extended acct fields */
199 xacct_add_tsk(stats, tsk);
200}
201
202static int fill_stats_for_pid(pid_t pid, struct taskstats *stats)
203{
204 struct task_struct *tsk;
205
206 rcu_read_lock();
207 tsk = find_task_by_vpid(pid);
208 if (tsk)
209 get_task_struct(tsk);
210 rcu_read_unlock();
211 if (!tsk)
212 return -ESRCH;
213 fill_stats(current_user_ns(), task_active_pid_ns(current), tsk, stats);
214 put_task_struct(tsk);
215 return 0;
216}
217
218static int fill_stats_for_tgid(pid_t tgid, struct taskstats *stats)
219{
220 struct task_struct *tsk, *first;
221 unsigned long flags;
222 int rc = -ESRCH;
223
224 /*
225 * Add additional stats from live tasks except zombie thread group
226 * leaders who are already counted with the dead tasks
227 */
228 rcu_read_lock();
229 first = find_task_by_vpid(tgid);
230
231 if (!first || !lock_task_sighand(first, &flags))
232 goto out;
233
234 if (first->signal->stats)
235 memcpy(stats, first->signal->stats, sizeof(*stats));
236 else
237 memset(stats, 0, sizeof(*stats));
238
239 tsk = first;
240 do {
241 if (tsk->exit_state)
242 continue;
243 /*
244 * Accounting subsystem can call its functions here to
245 * fill in relevant parts of struct taskstsats as follows
246 *
247 * per-task-foo(stats, tsk);
248 */
249 delayacct_add_tsk(stats, tsk);
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
369#if defined(CONFIG_64BIT) && !defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
370#define TASKSTATS_NEEDS_PADDING 1
371#endif
372
373static struct taskstats *mk_reply(struct sk_buff *skb, int type, u32 pid)
374{
375 struct nlattr *na, *ret;
376 int aggr;
377
378 aggr = (type == TASKSTATS_TYPE_PID)
379 ? TASKSTATS_TYPE_AGGR_PID
380 : TASKSTATS_TYPE_AGGR_TGID;
381
382 /*
383 * The taskstats structure is internally aligned on 8 byte
384 * boundaries but the layout of the aggregrate reply, with
385 * two NLA headers and the pid (each 4 bytes), actually
386 * force the entire structure to be unaligned. This causes
387 * the kernel to issue unaligned access warnings on some
388 * architectures like ia64. Unfortunately, some software out there
389 * doesn't properly unroll the NLA packet and assumes that the start
390 * of the taskstats structure will always be 20 bytes from the start
391 * of the netlink payload. Aligning the start of the taskstats
392 * structure breaks this software, which we don't want. So, for now
393 * the alignment only happens on architectures that require it
394 * and those users will have to update to fixed versions of those
395 * packages. Space is reserved in the packet only when needed.
396 * This ifdef should be removed in several years e.g. 2012 once
397 * we can be confident that fixed versions are installed on most
398 * systems. We add the padding before the aggregate since the
399 * aggregate is already a defined type.
400 */
401#ifdef TASKSTATS_NEEDS_PADDING
402 if (nla_put(skb, TASKSTATS_TYPE_NULL, 0, NULL) < 0)
403 goto err;
404#endif
405 na = nla_nest_start(skb, aggr);
406 if (!na)
407 goto err;
408
409 if (nla_put(skb, type, sizeof(pid), &pid) < 0) {
410 nla_nest_cancel(skb, na);
411 goto err;
412 }
413 ret = nla_reserve(skb, TASKSTATS_TYPE_STATS, sizeof(struct taskstats));
414 if (!ret) {
415 nla_nest_cancel(skb, na);
416 goto err;
417 }
418 nla_nest_end(skb, na);
419
420 return nla_data(ret);
421err:
422 return NULL;
423}
424
425static int cgroupstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
426{
427 int rc = 0;
428 struct sk_buff *rep_skb;
429 struct cgroupstats *stats;
430 struct nlattr *na;
431 size_t size;
432 u32 fd;
433 struct fd f;
434
435 na = info->attrs[CGROUPSTATS_CMD_ATTR_FD];
436 if (!na)
437 return -EINVAL;
438
439 fd = nla_get_u32(info->attrs[CGROUPSTATS_CMD_ATTR_FD]);
440 f = fdget(fd);
441 if (!f.file)
442 return 0;
443
444 size = nla_total_size(sizeof(struct cgroupstats));
445
446 rc = prepare_reply(info, CGROUPSTATS_CMD_NEW, &rep_skb,
447 size);
448 if (rc < 0)
449 goto err;
450
451 na = nla_reserve(rep_skb, CGROUPSTATS_TYPE_CGROUP_STATS,
452 sizeof(struct cgroupstats));
453 if (na == NULL) {
454 nlmsg_free(rep_skb);
455 rc = -EMSGSIZE;
456 goto err;
457 }
458
459 stats = nla_data(na);
460 memset(stats, 0, sizeof(*stats));
461
462 rc = cgroupstats_build(stats, f.file->f_dentry);
463 if (rc < 0) {
464 nlmsg_free(rep_skb);
465 goto err;
466 }
467
468 rc = send_reply(rep_skb, info);
469
470err:
471 fdput(f);
472 return rc;
473}
474
475static int cmd_attr_register_cpumask(struct genl_info *info)
476{
477 cpumask_var_t mask;
478 int rc;
479
480 if (!alloc_cpumask_var(&mask, GFP_KERNEL))
481 return -ENOMEM;
482 rc = parse(info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK], mask);
483 if (rc < 0)
484 goto out;
485 rc = add_del_listener(info->snd_portid, mask, REGISTER);
486out:
487 free_cpumask_var(mask);
488 return rc;
489}
490
491static int cmd_attr_deregister_cpumask(struct genl_info *info)
492{
493 cpumask_var_t mask;
494 int rc;
495
496 if (!alloc_cpumask_var(&mask, GFP_KERNEL))
497 return -ENOMEM;
498 rc = parse(info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK], mask);
499 if (rc < 0)
500 goto out;
501 rc = add_del_listener(info->snd_portid, mask, DEREGISTER);
502out:
503 free_cpumask_var(mask);
504 return rc;
505}
506
507static size_t taskstats_packet_size(void)
508{
509 size_t size;
510
511 size = nla_total_size(sizeof(u32)) +
512 nla_total_size(sizeof(struct taskstats)) + nla_total_size(0);
513#ifdef TASKSTATS_NEEDS_PADDING
514 size += nla_total_size(0); /* Padding for alignment */
515#endif
516 return size;
517}
518
519static int cmd_attr_pid(struct genl_info *info)
520{
521 struct taskstats *stats;
522 struct sk_buff *rep_skb;
523 size_t size;
524 u32 pid;
525 int rc;
526
527 size = taskstats_packet_size();
528
529 rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size);
530 if (rc < 0)
531 return rc;
532
533 rc = -EINVAL;
534 pid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_PID]);
535 stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID, pid);
536 if (!stats)
537 goto err;
538
539 rc = fill_stats_for_pid(pid, stats);
540 if (rc < 0)
541 goto err;
542 return send_reply(rep_skb, info);
543err:
544 nlmsg_free(rep_skb);
545 return rc;
546}
547
548static int cmd_attr_tgid(struct genl_info *info)
549{
550 struct taskstats *stats;
551 struct sk_buff *rep_skb;
552 size_t size;
553 u32 tgid;
554 int rc;
555
556 size = taskstats_packet_size();
557
558 rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size);
559 if (rc < 0)
560 return rc;
561
562 rc = -EINVAL;
563 tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]);
564 stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tgid);
565 if (!stats)
566 goto err;
567
568 rc = fill_stats_for_tgid(tgid, stats);
569 if (rc < 0)
570 goto err;
571 return send_reply(rep_skb, info);
572err:
573 nlmsg_free(rep_skb);
574 return rc;
575}
576
577static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
578{
579 if (info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK])
580 return cmd_attr_register_cpumask(info);
581 else if (info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK])
582 return cmd_attr_deregister_cpumask(info);
583 else if (info->attrs[TASKSTATS_CMD_ATTR_PID])
584 return cmd_attr_pid(info);
585 else if (info->attrs[TASKSTATS_CMD_ATTR_TGID])
586 return cmd_attr_tgid(info);
587 else
588 return -EINVAL;
589}
590
591static struct taskstats *taskstats_tgid_alloc(struct task_struct *tsk)
592{
593 struct signal_struct *sig = tsk->signal;
594 struct taskstats *stats;
595
596 if (sig->stats || thread_group_empty(tsk))
597 goto ret;
598
599 /* No problem if kmem_cache_zalloc() fails */
600 stats = kmem_cache_zalloc(taskstats_cache, GFP_KERNEL);
601
602 spin_lock_irq(&tsk->sighand->siglock);
603 if (!sig->stats) {
604 sig->stats = stats;
605 stats = NULL;
606 }
607 spin_unlock_irq(&tsk->sighand->siglock);
608
609 if (stats)
610 kmem_cache_free(taskstats_cache, stats);
611ret:
612 return sig->stats;
613}
614
615/* Send pid data out on exit */
616void taskstats_exit(struct task_struct *tsk, int group_dead)
617{
618 int rc;
619 struct listener_list *listeners;
620 struct taskstats *stats;
621 struct sk_buff *rep_skb;
622 size_t size;
623 int is_thread_group;
624
625 if (!family_registered)
626 return;
627
628 /*
629 * Size includes space for nested attributes
630 */
631 size = taskstats_packet_size();
632
633 is_thread_group = !!taskstats_tgid_alloc(tsk);
634 if (is_thread_group) {
635 /* PID + STATS + TGID + STATS */
636 size = 2 * size;
637 /* fill the tsk->signal->stats structure */
638 fill_tgid_exit(tsk);
639 }
640
641 listeners = __this_cpu_ptr(&listener_array);
642 if (list_empty(&listeners->list))
643 return;
644
645 rc = prepare_reply(NULL, TASKSTATS_CMD_NEW, &rep_skb, size);
646 if (rc < 0)
647 return;
648
649 stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID,
650 task_pid_nr_ns(tsk, &init_pid_ns));
651 if (!stats)
652 goto err;
653
654 fill_stats(&init_user_ns, &init_pid_ns, tsk, stats);
655
656 /*
657 * Doesn't matter if tsk is the leader or the last group member leaving
658 */
659 if (!is_thread_group || !group_dead)
660 goto send;
661
662 stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID,
663 task_tgid_nr_ns(tsk, &init_pid_ns));
664 if (!stats)
665 goto err;
666
667 memcpy(stats, tsk->signal->stats, sizeof(*stats));
668
669send:
670 send_cpu_listeners(rep_skb, listeners);
671 return;
672err:
673 nlmsg_free(rep_skb);
674}
675
676static const struct genl_ops taskstats_ops[] = {
677 {
678 .cmd = TASKSTATS_CMD_GET,
679 .doit = taskstats_user_cmd,
680 .policy = taskstats_cmd_get_policy,
681 .flags = GENL_ADMIN_PERM,
682 },
683 {
684 .cmd = CGROUPSTATS_CMD_GET,
685 .doit = cgroupstats_user_cmd,
686 .policy = cgroupstats_cmd_get_policy,
687 },
688};
689
690/* Needed early in initialization */
691void __init taskstats_init_early(void)
692{
693 unsigned int i;
694
695 taskstats_cache = KMEM_CACHE(taskstats, SLAB_PANIC);
696 for_each_possible_cpu(i) {
697 INIT_LIST_HEAD(&(per_cpu(listener_array, i).list));
698 init_rwsem(&(per_cpu(listener_array, i).sem));
699 }
700}
701
702static int __init taskstats_init(void)
703{
704 int rc;
705
706 rc = genl_register_family_with_ops(&family, taskstats_ops);
707 if (rc)
708 return rc;
709
710 family_registered = 1;
711 pr_info("registered taskstats version %d\n", TASKSTATS_GENL_VERSION);
712 return 0;
713}
714
715/*
716 * late initcall ensures initialization of statistics collection
717 * mechanisms precedes initialization of the taskstats interface
718 */
719late_initcall(taskstats_init);