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