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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 
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 
40 static DEFINE_PER_CPU(__u32, taskstats_seqnum);
41 static int family_registered;
42 struct kmem_cache *taskstats_cache;
43 
44 static 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 
51 static 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 
57 static const struct nla_policy cgroupstats_cmd_get_policy[CGROUPSTATS_CMD_ATTR_MAX+1] = {
58 	[CGROUPSTATS_CMD_ATTR_FD] = { .type = NLA_U32 },
59 };
60 
61 struct listener {
62 	struct list_head list;
63 	pid_t pid;
64 	char valid;
65 };
66 
67 struct listener_list {
68 	struct rw_semaphore sem;
69 	struct list_head list;
70 };
71 static DEFINE_PER_CPU(struct listener_list, listener_array);
72 
73 enum actions {
74 	REGISTER,
75 	DEREGISTER,
76 	CPU_DONT_CARE
77 };
78 
prepare_reply(struct genl_info * info,u8 cmd,struct sk_buff ** skbp,size_t size)79 static 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  */
send_reply(struct sk_buff * skb,struct genl_info * info)110 static 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  */
send_cpu_listeners(struct sk_buff * skb,struct listener_list * listeners)128 static 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 
fill_stats(struct user_namespace * user_ns,struct pid_namespace * pid_ns,struct task_struct * tsk,struct taskstats * stats)178 static 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 
fill_stats_for_pid(pid_t pid,struct taskstats * stats)202 static 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 
fill_stats_for_tgid(pid_t tgid,struct taskstats * stats)218 static 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;
257 out:
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 
fill_tgid_exit(struct task_struct * tsk)268 static 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);
283 ret:
284 	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
285 	return;
286 }
287 
add_del_listener(pid_t pid,const struct cpumask * mask,int isadd)288 static 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;
323 exists:
324 			up_write(&listeners->sem);
325 			kfree(s); /* nop if NULL */
326 		}
327 		return 0;
328 	}
329 
330 	/* Deregister or cleanup */
331 cleanup:
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 
parse(struct nlattr * na,struct cpumask * mask)347 static 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 
mk_reply(struct sk_buff * skb,int type,u32 pid)373 static 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);
421 err:
422 	return NULL;
423 }
424 
cgroupstats_user_cmd(struct sk_buff * skb,struct genl_info * info)425 static 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 
470 err:
471 	fdput(f);
472 	return rc;
473 }
474 
cmd_attr_register_cpumask(struct genl_info * info)475 static 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);
486 out:
487 	free_cpumask_var(mask);
488 	return rc;
489 }
490 
cmd_attr_deregister_cpumask(struct genl_info * info)491 static 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);
502 out:
503 	free_cpumask_var(mask);
504 	return rc;
505 }
506 
taskstats_packet_size(void)507 static 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 
cmd_attr_pid(struct genl_info * info)519 static 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);
543 err:
544 	nlmsg_free(rep_skb);
545 	return rc;
546 }
547 
cmd_attr_tgid(struct genl_info * info)548 static 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);
572 err:
573 	nlmsg_free(rep_skb);
574 	return rc;
575 }
576 
taskstats_user_cmd(struct sk_buff * skb,struct genl_info * info)577 static 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 
taskstats_tgid_alloc(struct task_struct * tsk)591 static 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);
611 ret:
612 	return sig->stats;
613 }
614 
615 /* Send pid data out on exit */
taskstats_exit(struct task_struct * tsk,int group_dead)616 void 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 = raw_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 
669 send:
670 	send_cpu_listeners(rep_skb, listeners);
671 	return;
672 err:
673 	nlmsg_free(rep_skb);
674 }
675 
676 static 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 */
taskstats_init_early(void)691 void __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 
taskstats_init(void)702 static 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  */
719 late_initcall(taskstats_init);
720