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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 | ||
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 | */ | |
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 | ||
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 | */ | |
123 | static 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 | ||
169 | static 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 | ||
193 | static int fill_stats_for_pid(pid_t pid, struct taskstats *stats) | |
194 | { | |
195 | struct task_struct *tsk; | |
196 | ||
197 | rcu_read_lock(); | |
198 | tsk = find_task_by_vpid(pid); | |
199 | if (tsk) | |
200 | get_task_struct(tsk); | |
201 | rcu_read_unlock(); | |
202 | if (!tsk) | |
203 | return -ESRCH; | |
204 | fill_stats(current_user_ns(), task_active_pid_ns(current), tsk, stats); | |
205 | put_task_struct(tsk); | |
206 | return 0; | |
207 | } | |
208 | ||
209 | static int fill_stats_for_tgid(pid_t tgid, struct taskstats *stats) | |
210 | { | |
211 | struct task_struct *tsk, *first; | |
212 | unsigned long flags; | |
213 | int rc = -ESRCH; | |
214 | ||
215 | /* | |
216 | * Add additional stats from live tasks except zombie thread group | |
217 | * leaders who are already counted with the dead tasks | |
218 | */ | |
219 | rcu_read_lock(); | |
220 | first = find_task_by_vpid(tgid); | |
221 | ||
222 | if (!first || !lock_task_sighand(first, &flags)) | |
223 | goto out; | |
224 | ||
225 | if (first->signal->stats) | |
226 | memcpy(stats, first->signal->stats, sizeof(*stats)); | |
227 | else | |
228 | memset(stats, 0, sizeof(*stats)); | |
229 | ||
230 | tsk = first; | |
231 | do { | |
232 | if (tsk->exit_state) | |
233 | continue; | |
234 | /* | |
235 | * Accounting subsystem can call its functions here to | |
236 | * fill in relevant parts of struct taskstsats as follows | |
237 | * | |
238 | * per-task-foo(stats, tsk); | |
239 | */ | |
240 | delayacct_add_tsk(stats, tsk); | |
241 | ||
242 | stats->nvcsw += tsk->nvcsw; | |
243 | stats->nivcsw += tsk->nivcsw; | |
244 | } while_each_thread(first, tsk); | |
245 | ||
246 | unlock_task_sighand(first, &flags); | |
247 | rc = 0; | |
248 | out: | |
249 | rcu_read_unlock(); | |
250 | ||
251 | stats->version = TASKSTATS_VERSION; | |
252 | /* | |
253 | * Accounting subsystems can also add calls here to modify | |
254 | * fields of taskstats. | |
255 | */ | |
256 | return rc; | |
257 | } | |
258 | ||
259 | static void fill_tgid_exit(struct task_struct *tsk) | |
260 | { | |
261 | unsigned long flags; | |
262 | ||
263 | spin_lock_irqsave(&tsk->sighand->siglock, flags); | |
264 | if (!tsk->signal->stats) | |
265 | goto ret; | |
266 | ||
267 | /* | |
268 | * Each accounting subsystem calls its functions here to | |
269 | * accumalate its per-task stats for tsk, into the per-tgid structure | |
270 | * | |
271 | * per-task-foo(tsk->signal->stats, tsk); | |
272 | */ | |
273 | delayacct_add_tsk(tsk->signal->stats, tsk); | |
274 | ret: | |
275 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags); | |
276 | return; | |
277 | } | |
278 | ||
279 | static int add_del_listener(pid_t pid, const struct cpumask *mask, int isadd) | |
280 | { | |
281 | struct listener_list *listeners; | |
282 | struct listener *s, *tmp, *s2; | |
283 | unsigned int cpu; | |
284 | int ret = 0; | |
285 | ||
286 | if (!cpumask_subset(mask, cpu_possible_mask)) | |
287 | return -EINVAL; | |
288 | ||
289 | if (current_user_ns() != &init_user_ns) | |
290 | return -EINVAL; | |
291 | ||
292 | if (task_active_pid_ns(current) != &init_pid_ns) | |
293 | return -EINVAL; | |
294 | ||
295 | if (isadd == REGISTER) { | |
296 | for_each_cpu(cpu, mask) { | |
297 | s = kmalloc_node(sizeof(struct listener), | |
298 | GFP_KERNEL, cpu_to_node(cpu)); | |
299 | if (!s) { | |
300 | ret = -ENOMEM; | |
301 | goto cleanup; | |
302 | } | |
303 | s->pid = pid; | |
304 | s->valid = 1; | |
305 | ||
306 | listeners = &per_cpu(listener_array, cpu); | |
307 | down_write(&listeners->sem); | |
308 | list_for_each_entry(s2, &listeners->list, list) { | |
309 | if (s2->pid == pid && s2->valid) | |
310 | goto exists; | |
311 | } | |
312 | list_add(&s->list, &listeners->list); | |
313 | s = NULL; | |
314 | exists: | |
315 | up_write(&listeners->sem); | |
316 | kfree(s); /* nop if NULL */ | |
317 | } | |
318 | return 0; | |
319 | } | |
320 | ||
321 | /* Deregister or cleanup */ | |
322 | cleanup: | |
323 | for_each_cpu(cpu, mask) { | |
324 | listeners = &per_cpu(listener_array, cpu); | |
325 | down_write(&listeners->sem); | |
326 | list_for_each_entry_safe(s, tmp, &listeners->list, list) { | |
327 | if (s->pid == pid) { | |
328 | list_del(&s->list); | |
329 | kfree(s); | |
330 | break; | |
331 | } | |
332 | } | |
333 | up_write(&listeners->sem); | |
334 | } | |
335 | return ret; | |
336 | } | |
337 | ||
338 | static int parse(struct nlattr *na, struct cpumask *mask) | |
339 | { | |
340 | char *data; | |
341 | int len; | |
342 | int ret; | |
343 | ||
344 | if (na == NULL) | |
345 | return 1; | |
346 | len = nla_len(na); | |
347 | if (len > TASKSTATS_CPUMASK_MAXLEN) | |
348 | return -E2BIG; | |
349 | if (len < 1) | |
350 | return -EINVAL; | |
351 | data = kmalloc(len, GFP_KERNEL); | |
352 | if (!data) | |
353 | return -ENOMEM; | |
354 | nla_strlcpy(data, na, len); | |
355 | ret = cpulist_parse(data, mask); | |
356 | kfree(data); | |
357 | return ret; | |
358 | } | |
359 | ||
360 | static struct taskstats *mk_reply(struct sk_buff *skb, int type, u32 pid) | |
361 | { | |
362 | struct nlattr *na, *ret; | |
363 | int aggr; | |
364 | ||
365 | aggr = (type == TASKSTATS_TYPE_PID) | |
366 | ? TASKSTATS_TYPE_AGGR_PID | |
367 | : TASKSTATS_TYPE_AGGR_TGID; | |
368 | ||
369 | na = nla_nest_start(skb, aggr); | |
370 | if (!na) | |
371 | goto err; | |
372 | ||
373 | if (nla_put(skb, type, sizeof(pid), &pid) < 0) { | |
374 | nla_nest_cancel(skb, na); | |
375 | goto err; | |
376 | } | |
377 | ret = nla_reserve_64bit(skb, TASKSTATS_TYPE_STATS, | |
378 | sizeof(struct taskstats), TASKSTATS_TYPE_NULL); | |
379 | if (!ret) { | |
380 | nla_nest_cancel(skb, na); | |
381 | goto err; | |
382 | } | |
383 | nla_nest_end(skb, na); | |
384 | ||
385 | return nla_data(ret); | |
386 | err: | |
387 | return NULL; | |
388 | } | |
389 | ||
390 | static int cgroupstats_user_cmd(struct sk_buff *skb, struct genl_info *info) | |
391 | { | |
392 | int rc = 0; | |
393 | struct sk_buff *rep_skb; | |
394 | struct cgroupstats *stats; | |
395 | struct nlattr *na; | |
396 | size_t size; | |
397 | u32 fd; | |
398 | struct fd f; | |
399 | ||
400 | na = info->attrs[CGROUPSTATS_CMD_ATTR_FD]; | |
401 | if (!na) | |
402 | return -EINVAL; | |
403 | ||
404 | fd = nla_get_u32(info->attrs[CGROUPSTATS_CMD_ATTR_FD]); | |
405 | f = fdget(fd); | |
406 | if (!f.file) | |
407 | return 0; | |
408 | ||
409 | size = nla_total_size(sizeof(struct cgroupstats)); | |
410 | ||
411 | rc = prepare_reply(info, CGROUPSTATS_CMD_NEW, &rep_skb, | |
412 | size); | |
413 | if (rc < 0) | |
414 | goto err; | |
415 | ||
416 | na = nla_reserve(rep_skb, CGROUPSTATS_TYPE_CGROUP_STATS, | |
417 | sizeof(struct cgroupstats)); | |
418 | if (na == NULL) { | |
419 | nlmsg_free(rep_skb); | |
420 | rc = -EMSGSIZE; | |
421 | goto err; | |
422 | } | |
423 | ||
424 | stats = nla_data(na); | |
425 | memset(stats, 0, sizeof(*stats)); | |
426 | ||
427 | rc = cgroupstats_build(stats, f.file->f_path.dentry); | |
428 | if (rc < 0) { | |
429 | nlmsg_free(rep_skb); | |
430 | goto err; | |
431 | } | |
432 | ||
433 | rc = send_reply(rep_skb, info); | |
434 | ||
435 | err: | |
436 | fdput(f); | |
437 | return rc; | |
438 | } | |
439 | ||
440 | static int cmd_attr_register_cpumask(struct genl_info *info) | |
441 | { | |
442 | cpumask_var_t mask; | |
443 | int rc; | |
444 | ||
445 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) | |
446 | return -ENOMEM; | |
447 | rc = parse(info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK], mask); | |
448 | if (rc < 0) | |
449 | goto out; | |
450 | rc = add_del_listener(info->snd_portid, mask, REGISTER); | |
451 | out: | |
452 | free_cpumask_var(mask); | |
453 | return rc; | |
454 | } | |
455 | ||
456 | static int cmd_attr_deregister_cpumask(struct genl_info *info) | |
457 | { | |
458 | cpumask_var_t mask; | |
459 | int rc; | |
460 | ||
461 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) | |
462 | return -ENOMEM; | |
463 | rc = parse(info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK], mask); | |
464 | if (rc < 0) | |
465 | goto out; | |
466 | rc = add_del_listener(info->snd_portid, mask, DEREGISTER); | |
467 | out: | |
468 | free_cpumask_var(mask); | |
469 | return rc; | |
470 | } | |
471 | ||
472 | static size_t taskstats_packet_size(void) | |
473 | { | |
474 | size_t size; | |
475 | ||
476 | size = nla_total_size(sizeof(u32)) + | |
477 | nla_total_size_64bit(sizeof(struct taskstats)) + | |
478 | nla_total_size(0); | |
479 | ||
480 | return size; | |
481 | } | |
482 | ||
483 | static int cmd_attr_pid(struct genl_info *info) | |
484 | { | |
485 | struct taskstats *stats; | |
486 | struct sk_buff *rep_skb; | |
487 | size_t size; | |
488 | u32 pid; | |
489 | int rc; | |
490 | ||
491 | size = taskstats_packet_size(); | |
492 | ||
493 | rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size); | |
494 | if (rc < 0) | |
495 | return rc; | |
496 | ||
497 | rc = -EINVAL; | |
498 | pid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_PID]); | |
499 | stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID, pid); | |
500 | if (!stats) | |
501 | goto err; | |
502 | ||
503 | rc = fill_stats_for_pid(pid, stats); | |
504 | if (rc < 0) | |
505 | goto err; | |
506 | return send_reply(rep_skb, info); | |
507 | err: | |
508 | nlmsg_free(rep_skb); | |
509 | return rc; | |
510 | } | |
511 | ||
512 | static int cmd_attr_tgid(struct genl_info *info) | |
513 | { | |
514 | struct taskstats *stats; | |
515 | struct sk_buff *rep_skb; | |
516 | size_t size; | |
517 | u32 tgid; | |
518 | int rc; | |
519 | ||
520 | size = taskstats_packet_size(); | |
521 | ||
522 | rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size); | |
523 | if (rc < 0) | |
524 | return rc; | |
525 | ||
526 | rc = -EINVAL; | |
527 | tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]); | |
528 | stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tgid); | |
529 | if (!stats) | |
530 | goto err; | |
531 | ||
532 | rc = fill_stats_for_tgid(tgid, stats); | |
533 | if (rc < 0) | |
534 | goto err; | |
535 | return send_reply(rep_skb, info); | |
536 | err: | |
537 | nlmsg_free(rep_skb); | |
538 | return rc; | |
539 | } | |
540 | ||
541 | static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info) | |
542 | { | |
543 | if (info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK]) | |
544 | return cmd_attr_register_cpumask(info); | |
545 | else if (info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK]) | |
546 | return cmd_attr_deregister_cpumask(info); | |
547 | else if (info->attrs[TASKSTATS_CMD_ATTR_PID]) | |
548 | return cmd_attr_pid(info); | |
549 | else if (info->attrs[TASKSTATS_CMD_ATTR_TGID]) | |
550 | return cmd_attr_tgid(info); | |
551 | else | |
552 | return -EINVAL; | |
553 | } | |
554 | ||
555 | static struct taskstats *taskstats_tgid_alloc(struct task_struct *tsk) | |
556 | { | |
557 | struct signal_struct *sig = tsk->signal; | |
558 | struct taskstats *stats; | |
559 | ||
560 | if (sig->stats || thread_group_empty(tsk)) | |
561 | goto ret; | |
562 | ||
563 | /* No problem if kmem_cache_zalloc() fails */ | |
564 | stats = kmem_cache_zalloc(taskstats_cache, GFP_KERNEL); | |
565 | ||
566 | spin_lock_irq(&tsk->sighand->siglock); | |
567 | if (!sig->stats) { | |
568 | sig->stats = stats; | |
569 | stats = NULL; | |
570 | } | |
571 | spin_unlock_irq(&tsk->sighand->siglock); | |
572 | ||
573 | if (stats) | |
574 | kmem_cache_free(taskstats_cache, stats); | |
575 | ret: | |
576 | return sig->stats; | |
577 | } | |
578 | ||
579 | /* Send pid data out on exit */ | |
580 | void taskstats_exit(struct task_struct *tsk, int group_dead) | |
581 | { | |
582 | int rc; | |
583 | struct listener_list *listeners; | |
584 | struct taskstats *stats; | |
585 | struct sk_buff *rep_skb; | |
586 | size_t size; | |
587 | int is_thread_group; | |
588 | ||
589 | if (!family_registered) | |
590 | return; | |
591 | ||
592 | /* | |
593 | * Size includes space for nested attributes | |
594 | */ | |
595 | size = taskstats_packet_size(); | |
596 | ||
597 | is_thread_group = !!taskstats_tgid_alloc(tsk); | |
598 | if (is_thread_group) { | |
599 | /* PID + STATS + TGID + STATS */ | |
600 | size = 2 * size; | |
601 | /* fill the tsk->signal->stats structure */ | |
602 | fill_tgid_exit(tsk); | |
603 | } | |
604 | ||
605 | listeners = raw_cpu_ptr(&listener_array); | |
606 | if (list_empty(&listeners->list)) | |
607 | return; | |
608 | ||
609 | rc = prepare_reply(NULL, TASKSTATS_CMD_NEW, &rep_skb, size); | |
610 | if (rc < 0) | |
611 | return; | |
612 | ||
613 | stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID, | |
614 | task_pid_nr_ns(tsk, &init_pid_ns)); | |
615 | if (!stats) | |
616 | goto err; | |
617 | ||
618 | fill_stats(&init_user_ns, &init_pid_ns, tsk, stats); | |
619 | ||
620 | /* | |
621 | * Doesn't matter if tsk is the leader or the last group member leaving | |
622 | */ | |
623 | if (!is_thread_group || !group_dead) | |
624 | goto send; | |
625 | ||
626 | stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID, | |
627 | task_tgid_nr_ns(tsk, &init_pid_ns)); | |
628 | if (!stats) | |
629 | goto err; | |
630 | ||
631 | memcpy(stats, tsk->signal->stats, sizeof(*stats)); | |
632 | ||
633 | send: | |
634 | send_cpu_listeners(rep_skb, listeners); | |
635 | return; | |
636 | err: | |
637 | nlmsg_free(rep_skb); | |
638 | } | |
639 | ||
640 | static const struct genl_ops taskstats_ops[] = { | |
641 | { | |
642 | .cmd = TASKSTATS_CMD_GET, | |
643 | .doit = taskstats_user_cmd, | |
644 | .policy = taskstats_cmd_get_policy, | |
645 | .flags = GENL_ADMIN_PERM, | |
646 | }, | |
647 | { | |
648 | .cmd = CGROUPSTATS_CMD_GET, | |
649 | .doit = cgroupstats_user_cmd, | |
650 | .policy = cgroupstats_cmd_get_policy, | |
651 | }, | |
652 | }; | |
653 | ||
654 | /* Needed early in initialization */ | |
655 | void __init taskstats_init_early(void) | |
656 | { | |
657 | unsigned int i; | |
658 | ||
659 | taskstats_cache = KMEM_CACHE(taskstats, SLAB_PANIC); | |
660 | for_each_possible_cpu(i) { | |
661 | INIT_LIST_HEAD(&(per_cpu(listener_array, i).list)); | |
662 | init_rwsem(&(per_cpu(listener_array, i).sem)); | |
663 | } | |
664 | } | |
665 | ||
666 | static int __init taskstats_init(void) | |
667 | { | |
668 | int rc; | |
669 | ||
670 | rc = genl_register_family_with_ops(&family, taskstats_ops); | |
671 | if (rc) | |
672 | return rc; | |
673 | ||
674 | family_registered = 1; | |
675 | pr_info("registered taskstats version %d\n", TASKSTATS_GENL_VERSION); | |
676 | return 0; | |
677 | } | |
678 | ||
679 | /* | |
680 | * late initcall ensures initialization of statistics collection | |
681 | * mechanisms precedes initialization of the taskstats interface | |
682 | */ | |
683 | late_initcall(taskstats_init); |