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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 | ||
46 | static const struct nla_policy taskstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1] = { | |
47 | [TASKSTATS_CMD_ATTR_PID] = { .type = NLA_U32 }, | |
48 | [TASKSTATS_CMD_ATTR_TGID] = { .type = NLA_U32 }, | |
49 | [TASKSTATS_CMD_ATTR_REGISTER_CPUMASK] = { .type = NLA_STRING }, | |
50 | [TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK] = { .type = NLA_STRING },}; | |
51 | ||
52 | /* | |
53 | * We have to use TASKSTATS_CMD_ATTR_MAX here, it is the maxattr in the family. | |
54 | * Make sure they are always aligned. | |
55 | */ | |
56 | static const struct nla_policy cgroupstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1] = { | |
57 | [CGROUPSTATS_CMD_ATTR_FD] = { .type = NLA_U32 }, | |
58 | }; | |
59 | ||
60 | struct listener { | |
61 | struct list_head list; | |
62 | pid_t pid; | |
63 | char valid; | |
64 | }; | |
65 | ||
66 | struct listener_list { | |
67 | struct rw_semaphore sem; | |
68 | struct list_head list; | |
69 | }; | |
70 | static DEFINE_PER_CPU(struct listener_list, listener_array); | |
71 | ||
72 | enum actions { | |
73 | REGISTER, | |
74 | DEREGISTER, | |
75 | CPU_DONT_CARE | |
76 | }; | |
77 | ||
78 | static int prepare_reply(struct genl_info *info, u8 cmd, struct sk_buff **skbp, | |
79 | size_t size) | |
80 | { | |
81 | struct sk_buff *skb; | |
82 | void *reply; | |
83 | ||
84 | /* | |
85 | * If new attributes are added, please revisit this allocation | |
86 | */ | |
87 | skb = genlmsg_new(size, GFP_KERNEL); | |
88 | if (!skb) | |
89 | return -ENOMEM; | |
90 | ||
91 | if (!info) { | |
92 | int seq = this_cpu_inc_return(taskstats_seqnum) - 1; | |
93 | ||
94 | reply = genlmsg_put(skb, 0, seq, &family, 0, cmd); | |
95 | } else | |
96 | reply = genlmsg_put_reply(skb, info, &family, 0, cmd); | |
97 | if (reply == NULL) { | |
98 | nlmsg_free(skb); | |
99 | return -EINVAL; | |
100 | } | |
101 | ||
102 | *skbp = skb; | |
103 | return 0; | |
104 | } | |
105 | ||
106 | /* | |
107 | * Send taskstats data in @skb to listener with nl_pid @pid | |
108 | */ | |
109 | static int send_reply(struct sk_buff *skb, struct genl_info *info) | |
110 | { | |
111 | struct genlmsghdr *genlhdr = nlmsg_data(nlmsg_hdr(skb)); | |
112 | void *reply = genlmsg_data(genlhdr); | |
113 | ||
114 | genlmsg_end(skb, reply); | |
115 | ||
116 | return genlmsg_reply(skb, info); | |
117 | } | |
118 | ||
119 | /* | |
120 | * Send taskstats data in @skb to listeners registered for @cpu's exit data | |
121 | */ | |
122 | static void send_cpu_listeners(struct sk_buff *skb, | |
123 | struct listener_list *listeners) | |
124 | { | |
125 | struct genlmsghdr *genlhdr = nlmsg_data(nlmsg_hdr(skb)); | |
126 | struct listener *s, *tmp; | |
127 | struct sk_buff *skb_next, *skb_cur = skb; | |
128 | void *reply = genlmsg_data(genlhdr); | |
129 | int rc, delcount = 0; | |
130 | ||
131 | genlmsg_end(skb, reply); | |
132 | ||
133 | rc = 0; | |
134 | down_read(&listeners->sem); | |
135 | list_for_each_entry(s, &listeners->list, list) { | |
136 | skb_next = NULL; | |
137 | if (!list_is_last(&s->list, &listeners->list)) { | |
138 | skb_next = skb_clone(skb_cur, GFP_KERNEL); | |
139 | if (!skb_next) | |
140 | break; | |
141 | } | |
142 | rc = genlmsg_unicast(&init_net, skb_cur, s->pid); | |
143 | if (rc == -ECONNREFUSED) { | |
144 | s->valid = 0; | |
145 | delcount++; | |
146 | } | |
147 | skb_cur = skb_next; | |
148 | } | |
149 | up_read(&listeners->sem); | |
150 | ||
151 | if (skb_cur) | |
152 | nlmsg_free(skb_cur); | |
153 | ||
154 | if (!delcount) | |
155 | return; | |
156 | ||
157 | /* Delete invalidated entries */ | |
158 | down_write(&listeners->sem); | |
159 | list_for_each_entry_safe(s, tmp, &listeners->list, list) { | |
160 | if (!s->valid) { | |
161 | list_del(&s->list); | |
162 | kfree(s); | |
163 | } | |
164 | } | |
165 | up_write(&listeners->sem); | |
166 | } | |
167 | ||
168 | static void fill_stats(struct user_namespace *user_ns, | |
169 | struct pid_namespace *pid_ns, | |
170 | struct task_struct *tsk, struct taskstats *stats) | |
171 | { | |
172 | memset(stats, 0, sizeof(*stats)); | |
173 | /* | |
174 | * Each accounting subsystem adds calls to its functions to | |
175 | * fill in relevant parts of struct taskstsats as follows | |
176 | * | |
177 | * per-task-foo(stats, tsk); | |
178 | */ | |
179 | ||
180 | delayacct_add_tsk(stats, tsk); | |
181 | ||
182 | /* fill in basic acct fields */ | |
183 | stats->version = TASKSTATS_VERSION; | |
184 | stats->nvcsw = tsk->nvcsw; | |
185 | stats->nivcsw = tsk->nivcsw; | |
186 | bacct_add_tsk(user_ns, pid_ns, stats, tsk); | |
187 | ||
188 | /* fill in extended acct fields */ | |
189 | xacct_add_tsk(stats, tsk); | |
190 | } | |
191 | ||
192 | static int fill_stats_for_pid(pid_t pid, struct taskstats *stats) | |
193 | { | |
194 | struct task_struct *tsk; | |
195 | ||
196 | rcu_read_lock(); | |
197 | tsk = find_task_by_vpid(pid); | |
198 | if (tsk) | |
199 | get_task_struct(tsk); | |
200 | rcu_read_unlock(); | |
201 | if (!tsk) | |
202 | return -ESRCH; | |
203 | fill_stats(current_user_ns(), task_active_pid_ns(current), tsk, stats); | |
204 | put_task_struct(tsk); | |
205 | return 0; | |
206 | } | |
207 | ||
208 | static int fill_stats_for_tgid(pid_t tgid, struct taskstats *stats) | |
209 | { | |
210 | struct task_struct *tsk, *first; | |
211 | unsigned long flags; | |
212 | int rc = -ESRCH; | |
213 | ||
214 | /* | |
215 | * Add additional stats from live tasks except zombie thread group | |
216 | * leaders who are already counted with the dead tasks | |
217 | */ | |
218 | rcu_read_lock(); | |
219 | first = find_task_by_vpid(tgid); | |
220 | ||
221 | if (!first || !lock_task_sighand(first, &flags)) | |
222 | goto out; | |
223 | ||
224 | if (first->signal->stats) | |
225 | memcpy(stats, first->signal->stats, sizeof(*stats)); | |
226 | else | |
227 | memset(stats, 0, sizeof(*stats)); | |
228 | ||
229 | tsk = first; | |
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 | 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; | |
247 | out: | |
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 | ||
258 | static 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); | |
273 | ret: | |
274 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags); | |
275 | return; | |
276 | } | |
277 | ||
278 | static 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; | |
313 | exists: | |
314 | up_write(&listeners->sem); | |
315 | kfree(s); /* nop if NULL */ | |
316 | } | |
317 | return 0; | |
318 | } | |
319 | ||
320 | /* Deregister or cleanup */ | |
321 | cleanup: | |
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 | ||
337 | static 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 | ||
359 | static 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(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); | |
385 | err: | |
386 | return NULL; | |
387 | } | |
388 | ||
389 | static 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 | ||
434 | err: | |
435 | fdput(f); | |
436 | return rc; | |
437 | } | |
438 | ||
439 | static 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); | |
450 | out: | |
451 | free_cpumask_var(mask); | |
452 | return rc; | |
453 | } | |
454 | ||
455 | static 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); | |
466 | out: | |
467 | free_cpumask_var(mask); | |
468 | return rc; | |
469 | } | |
470 | ||
471 | static 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 | ||
482 | static 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); | |
506 | err: | |
507 | nlmsg_free(rep_skb); | |
508 | return rc; | |
509 | } | |
510 | ||
511 | static 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); | |
535 | err: | |
536 | nlmsg_free(rep_skb); | |
537 | return rc; | |
538 | } | |
539 | ||
540 | static 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 | ||
554 | static 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); | |
574 | ret: | |
575 | return sig->stats; | |
576 | } | |
577 | ||
578 | /* Send pid data out on exit */ | |
579 | void 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 | ||
632 | send: | |
633 | send_cpu_listeners(rep_skb, listeners); | |
634 | return; | |
635 | err: | |
636 | nlmsg_free(rep_skb); | |
637 | } | |
638 | ||
639 | static const struct genl_ops taskstats_ops[] = { | |
640 | { | |
641 | .cmd = TASKSTATS_CMD_GET, | |
642 | .doit = taskstats_user_cmd, | |
643 | .policy = taskstats_cmd_get_policy, | |
644 | .flags = GENL_ADMIN_PERM, | |
645 | }, | |
646 | { | |
647 | .cmd = CGROUPSTATS_CMD_GET, | |
648 | .doit = cgroupstats_user_cmd, | |
649 | .policy = cgroupstats_cmd_get_policy, | |
650 | }, | |
651 | }; | |
652 | ||
653 | static struct genl_family family __ro_after_init = { | |
654 | .name = TASKSTATS_GENL_NAME, | |
655 | .version = TASKSTATS_GENL_VERSION, | |
656 | .maxattr = TASKSTATS_CMD_ATTR_MAX, | |
657 | .module = THIS_MODULE, | |
658 | .ops = taskstats_ops, | |
659 | .n_ops = ARRAY_SIZE(taskstats_ops), | |
660 | }; | |
661 | ||
662 | /* Needed early in initialization */ | |
663 | void __init taskstats_init_early(void) | |
664 | { | |
665 | unsigned int i; | |
666 | ||
667 | taskstats_cache = KMEM_CACHE(taskstats, SLAB_PANIC); | |
668 | for_each_possible_cpu(i) { | |
669 | INIT_LIST_HEAD(&(per_cpu(listener_array, i).list)); | |
670 | init_rwsem(&(per_cpu(listener_array, i).sem)); | |
671 | } | |
672 | } | |
673 | ||
674 | static int __init taskstats_init(void) | |
675 | { | |
676 | int rc; | |
677 | ||
678 | rc = genl_register_family(&family); | |
679 | if (rc) | |
680 | return rc; | |
681 | ||
682 | family_registered = 1; | |
683 | pr_info("registered taskstats version %d\n", TASKSTATS_GENL_VERSION); | |
684 | return 0; | |
685 | } | |
686 | ||
687 | /* | |
688 | * late initcall ensures initialization of statistics collection | |
689 | * mechanisms precedes initialization of the taskstats interface | |
690 | */ | |
691 | late_initcall(taskstats_init); |