src/bin/lttng-sessiond/jul.c

   1 /*
   2  * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License, version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 51
  15  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <assert.h>
  20 #include <urcu/uatomic.h>
  21
  22 #include <common/common.h>
  23 #include <common/sessiond-comm/jul.h>
  24
  25 #include "jul.h"
  26 #include "ust-app.h"
  27 #include "utils.h"
  28
  29 /*
  30  * URCU delayed JUL event reclaim.
  31  */
  32 static void destroy_event_jul_rcu(struct rcu_head *head)
  33 {
  34         struct lttng_ht_node_str *node =
  35                 caa_container_of(head, struct lttng_ht_node_str, head);
  36         struct jul_event *event =
  37                 caa_container_of(node, struct jul_event, node);
  38
  39         free(event);
  40 }
  41
  42 /*
  43  * URCU delayed JUL app reclaim.
  44  */
  45 static void destroy_app_jul_rcu(struct rcu_head *head)
  46 {
  47         struct lttng_ht_node_ulong *node =
  48                 caa_container_of(head, struct lttng_ht_node_ulong, head);
  49         struct jul_app *app =
  50                 caa_container_of(node, struct jul_app, node);
  51
  52         free(app);
  53 }
  54
  55 /*
  56  * Communication with Java agent. Send the message header to the given
  57  * socket in big endian.
  58  *
  59  * Return 0 on success or else a negative errno message of sendmsg() op.
  60  */
  61 static int send_header(struct lttcomm_sock *sock, uint64_t data_size,
  62                 uint32_t cmd, uint32_t cmd_version)
  63 {
  64         int ret;
  65         ssize_t size;
  66         struct lttcomm_jul_hdr msg;
  67
  68         assert(sock);
  69
  70         memset(&msg, 0, sizeof(msg));
  71         msg.data_size = htobe64(data_size);
  72         msg.cmd = htobe32(cmd);
  73         msg.cmd_version = htobe32(cmd_version);
  74
  75         size = sock->ops->sendmsg(sock, &msg, sizeof(msg), 0);
  76         if (size < sizeof(msg)) {
  77                 ret = -errno;
  78                 goto error;
  79         }
  80         ret = 0;
  81
  82 error:
  83         return ret;
  84 }
  85
  86 /*
  87  * Communication call with the Java agent. Send the payload to the given
  88  * socket. The header MUST be sent prior to this call.
  89  *
  90  * Return 0 on success or else a negative errno value of sendmsg() op.
  91  */
  92 static int send_payload(struct lttcomm_sock *sock, void *data,
  93                 size_t size)
  94 {
  95         int ret;
  96         ssize_t len;
  97
  98         assert(sock);
  99         assert(data);
 100
 101         len = sock->ops->sendmsg(sock, data, size, 0);
 102         if (len < size) {
 103                 ret = -errno;
 104                 goto error;
 105         }
 106         ret = 0;
 107
 108 error:
 109         return ret;
 110 }
 111
 112 /*
 113  * Communication call with the Java agent. Receive reply from the agent using
 114  * the given socket.
 115  *
 116  * Return 0 on success or else a negative errno value from recvmsg() op.
 117  */
 118 static int recv_reply(struct lttcomm_sock *sock, void *buf, size_t size)
 119 {
 120         int ret;
 121         ssize_t len;
 122
 123         assert(sock);
 124         assert(buf);
 125
 126         len = sock->ops->recvmsg(sock, buf, size, 0);
 127         if (len < size) {
 128                 ret = -errno;
 129                 goto error;
 130         }
 131         ret = 0;
 132
 133 error:
 134         return ret;
 135 }
 136
 137
 138 /*
 139  * Internal event listing for a given app. Populate events.
 140  *
 141  * Return number of element in the list or else a negative LTTNG_ERR* code.
 142  * On success, the caller is responsible for freeing the memory
 143  * allocated for "events".
 144  */
 145 static ssize_t list_events(struct jul_app *app, struct lttng_event **events)
 146 {
 147         int ret, i, len = 0, offset = 0;
 148         uint32_t nb_event;
 149         size_t data_size;
 150         struct lttng_event *tmp_events = NULL;
 151         struct lttcomm_jul_list_reply *reply = NULL;
 152         struct lttcomm_jul_list_reply_hdr reply_hdr;
 153
 154         assert(app);
 155         assert(app->sock);
 156         assert(events);
 157
 158         DBG2("JUL listing events for app pid: %d and socket %d", app->pid,
 159                         app->sock->fd);
 160
 161         ret = send_header(app->sock, 0, JUL_CMD_LIST, 0);
 162         if (ret < 0) {
 163                 goto error_io;
 164         }
 165
 166         /* Get list header so we know how much we'll receive. */
 167         ret = recv_reply(app->sock, &reply_hdr, sizeof(reply_hdr));
 168         if (ret < 0) {
 169                 goto error_io;
 170         }
 171
 172         switch (be32toh(reply_hdr.ret_code)) {
 173         case JUL_RET_CODE_SUCCESS:
 174                 data_size = be32toh(reply_hdr.data_size) + sizeof(*reply);
 175                 break;
 176         default:
 177                 ERR("Java agent returned an unknown code: %" PRIu32,
 178                                 be32toh(reply_hdr.ret_code));
 179                 ret = LTTNG_ERR_FATAL;
 180                 goto error;
 181         }
 182
 183         reply = zmalloc(data_size);
 184         if (!reply) {
 185                 ret = LTTNG_ERR_NOMEM;
 186                 goto error;
 187         }
 188
 189         /* Get the list with the appropriate data size. */
 190         ret = recv_reply(app->sock, reply, data_size);
 191         if (ret < 0) {
 192                 goto error_io;
 193         }
 194
 195         nb_event = be32toh(reply->nb_event);
 196         tmp_events = zmalloc(sizeof(*tmp_events) * nb_event);
 197         if (!tmp_events) {
 198                 ret = LTTNG_ERR_NOMEM;
 199                 goto error;
 200         }
 201
 202         for (i = 0; i < nb_event; i++) {
 203                 offset += len;
 204                 strncpy(tmp_events[i].name, reply->payload + offset,
 205                                 sizeof(tmp_events[i].name));
 206                 tmp_events[i].pid = app->pid;
 207                 tmp_events[i].enabled = -1;
 208                 len = strlen(reply->payload + offset) + 1;
 209         }
 210
 211         *events = tmp_events;
 212
 213         free(reply);
 214         return nb_event;
 215
 216 error_io:
 217         ret = LTTNG_ERR_UST_LIST_FAIL;
 218 error:
 219         free(reply);
 220         free(tmp_events);
 221         return -ret;
 222
 223 }
 224
 225 /*
 226  * Internal enable JUL event on a JUL application. This function
 227  * communicates with the Java agent to enable a given event (Logger name).
 228  *
 229  * Return LTTNG_OK on success or else a LTTNG_ERR* code.
 230  */
 231 static int enable_event(struct jul_app *app, struct jul_event *event)
 232 {
 233         int ret;
 234         uint64_t data_size;
 235         struct lttcomm_jul_enable msg;
 236         struct lttcomm_jul_generic_reply reply;
 237
 238         assert(app);
 239         assert(app->sock);
 240         assert(event);
 241
 242         DBG2("JUL enabling event %s for app pid: %d and socket %d", event->name,
 243                         app->pid, app->sock->fd);
 244
 245         data_size = sizeof(msg);
 246
 247         ret = send_header(app->sock, data_size, JUL_CMD_ENABLE, 0);
 248         if (ret < 0) {
 249                 goto error_io;
 250         }
 251
 252         memset(&msg, 0, sizeof(msg));
 253         msg.loglevel = event->loglevel;
 254         msg.loglevel_type = event->loglevel_type;
 255         strncpy(msg.name, event->name, sizeof(msg.name));
 256         ret = send_payload(app->sock, &msg, sizeof(msg));
 257         if (ret < 0) {
 258                 goto error_io;
 259         }
 260
 261         ret = recv_reply(app->sock, &reply, sizeof(reply));
 262         if (ret < 0) {
 263                 goto error_io;
 264         }
 265
 266         switch (be32toh(reply.ret_code)) {
 267         case JUL_RET_CODE_SUCCESS:
 268                 break;
 269         case JUL_RET_CODE_UNKNOWN_NAME:
 270                 ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
 271                 goto error;
 272         default:
 273                 ERR("Java agent returned an unknown code: %" PRIu32,
 274                                 be32toh(reply.ret_code));
 275                 ret = LTTNG_ERR_FATAL;
 276                 goto error;
 277         }
 278
 279         return LTTNG_OK;
 280
 281 error_io:
 282         ret = LTTNG_ERR_UST_ENABLE_FAIL;
 283 error:
 284         return ret;
 285 }
 286
 287 /*
 288  * Internal disable JUL event call on a JUL application. This function
 289  * communicates with the Java agent to disable a given event (Logger name).
 290  *
 291  * Return LTTNG_OK on success or else a LTTNG_ERR* code.
 292  */
 293 static int disable_event(struct jul_app *app, struct jul_event *event)
 294 {
 295         int ret;
 296         uint64_t data_size;
 297         struct lttcomm_jul_disable msg;
 298         struct lttcomm_jul_generic_reply reply;
 299
 300         assert(app);
 301         assert(app->sock);
 302         assert(event);
 303
 304         DBG2("JUL disabling event %s for app pid: %d and socket %d", event->name,
 305                         app->pid, app->sock->fd);
 306
 307         data_size = sizeof(msg);
 308
 309         ret = send_header(app->sock, data_size, JUL_CMD_DISABLE, 0);
 310         if (ret < 0) {
 311                 goto error_io;
 312         }
 313
 314         memset(&msg, 0, sizeof(msg));
 315         strncpy(msg.name, event->name, sizeof(msg.name));
 316         ret = send_payload(app->sock, &msg, sizeof(msg));
 317         if (ret < 0) {
 318                 goto error_io;
 319         }
 320
 321         ret = recv_reply(app->sock, &reply, sizeof(reply));
 322         if (ret < 0) {
 323                 goto error_io;
 324         }
 325
 326         switch (be32toh(reply.ret_code)) {
 327                 case JUL_RET_CODE_SUCCESS:
 328                         break;
 329                 case JUL_RET_CODE_UNKNOWN_NAME:
 330                         ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
 331                         goto error;
 332                 default:
 333                         ERR("Java agent returned an unknown code: %" PRIu32,
 334                                         be32toh(reply.ret_code));
 335                         ret = LTTNG_ERR_FATAL;
 336                         goto error;
 337         }
 338
 339         return LTTNG_OK;
 340
 341 error_io:
 342         ret = LTTNG_ERR_UST_DISABLE_FAIL;
 343 error:
 344         return ret;
 345 }
 346
 347 /*
 348  * Enable JUL event on every JUL applications registered with the session
 349  * daemon.
 350  *
 351  * Return LTTNG_OK on success or else a LTTNG_ERR* code.
 352  */
 353 int jul_enable_event(struct jul_event *event)
 354 {
 355         int ret;
 356         struct jul_app *app;
 357         struct lttng_ht_iter iter;
 358
 359         assert(event);
 360
 361         rcu_read_lock();
 362
 363         cds_lfht_for_each_entry(jul_apps_ht_by_sock->ht, &iter.iter, app,
 364                         node.node) {
 365                 /* Enable event on JUL application through TCP socket. */
 366                 ret = enable_event(app, event);
 367                 if (ret != LTTNG_OK) {
 368                         goto error;
 369                 }
 370         }
 371
 372         event->enabled = 1;
 373         ret = LTTNG_OK;
 374
 375 error:
 376         rcu_read_unlock();
 377         return ret;
 378 }
 379
 380 /*
 381  * Disable JUL event on every JUL applications registered with the session
 382  * daemon.
 383  *
 384  * Return LTTNG_OK on success or else a LTTNG_ERR* code.
 385  */
 386 int jul_disable_event(struct jul_event *event)
 387 {
 388         int ret;
 389         struct jul_app *app;
 390         struct lttng_ht_iter iter;
 391
 392         assert(event);
 393
 394         rcu_read_lock();
 395
 396         cds_lfht_for_each_entry(jul_apps_ht_by_sock->ht, &iter.iter, app,
 397                         node.node) {
 398                 /* Enable event on JUL application through TCP socket. */
 399                 ret = disable_event(app, event);
 400                 if (ret != LTTNG_OK) {
 401                         goto error;
 402                 }
 403         }
 404
 405         event->enabled = 0;
 406         ret = LTTNG_OK;
 407
 408 error:
 409         rcu_read_unlock();
 410         return ret;
 411 }
 412
 413 /*
 414  * Ask every java agent for the list of possible event (logger name). Events is
 415  * allocated with the events of every JUL application.
 416  *
 417  * Return the number of events or else a negative value.
 418  */
 419 int jul_list_events(struct lttng_event **events)
 420 {
 421         int ret;
 422         size_t nbmem, count = 0;
 423         struct jul_app *app;
 424         struct lttng_event *tmp_events = NULL;
 425         struct lttng_ht_iter iter;
 426
 427         assert(events);
 428
 429         nbmem = UST_APP_EVENT_LIST_SIZE;
 430         tmp_events = zmalloc(nbmem * sizeof(*tmp_events));
 431         if (!tmp_events) {
 432                 PERROR("zmalloc jul list events");
 433                 ret = -ENOMEM;
 434                 goto error;
 435         }
 436
 437         rcu_read_lock();
 438         cds_lfht_for_each_entry(jul_apps_ht_by_sock->ht, &iter.iter, app,
 439                         node.node) {
 440                 ssize_t nb_ev;
 441                 struct lttng_event *jul_events;
 442
 443                 nb_ev = list_events(app, &jul_events);
 444                 if (nb_ev < 0) {
 445                         ret = nb_ev;
 446                         goto error_unlock;
 447                 }
 448
 449                 if (count + nb_ev > nbmem) {
 450                         /* In case the realloc fails, we free the memory */
 451                         struct lttng_event *new_tmp_events;
 452                         size_t new_nbmem;
 453
 454                         new_nbmem = max_t(size_t, count + nb_ev, nbmem << 1);
 455                         DBG2("Reallocating JUL event list from %zu to %zu entries",
 456                                         nbmem, new_nbmem);
 457                         new_tmp_events = realloc(tmp_events,
 458                                 new_nbmem * sizeof(*new_tmp_events));
 459                         if (!new_tmp_events) {
 460                                 PERROR("realloc JUL events");
 461                                 ret = -ENOMEM;
 462                                 free(jul_events);
 463                                 goto error_unlock;
 464                         }
 465                         /* Zero the new memory */
 466                         memset(new_tmp_events + nbmem, 0,
 467                                 (new_nbmem - nbmem) * sizeof(*new_tmp_events));
 468                         nbmem = new_nbmem;
 469                         tmp_events = new_tmp_events;
 470                 }
 471                 memcpy(tmp_events + count, jul_events,
 472                         nb_ev * sizeof(*tmp_events));
 473                 free(jul_events);
 474                 count += nb_ev;
 475         }
 476         rcu_read_unlock();
 477
 478         ret = count;
 479         *events = tmp_events;
 480         return ret;
 481
 482 error_unlock:
 483         rcu_read_unlock();
 484 error:
 485         free(tmp_events);
 486         return ret;
 487 }
 488
 489 /*
 490  * Create a JUL app object using the given PID.
 491  *
 492  * Return newly allocated object or else NULL on error.
 493  */
 494 struct jul_app *jul_create_app(pid_t pid, struct lttcomm_sock *sock)
 495 {
 496         struct jul_app *app;
 497
 498         assert(sock);
 499
 500         app = zmalloc(sizeof(*app));
 501         if (!app) {
 502                 PERROR("zmalloc JUL create");
 503                 goto error;
 504         }
 505
 506         app->pid = pid;
 507         app->sock = sock;
 508         lttng_ht_node_init_ulong(&app->node, (unsigned long) app->sock->fd);
 509
 510 error:
 511         return app;
 512 }
 513
 514 /*
 515  * Lookup JUL app by socket in the global hash table.
 516  *
 517  * RCU read side lock MUST be acquired.
 518  *
 519  * Return object if found else NULL.
 520  */
 521 struct jul_app *jul_find_app_by_sock(int sock)
 522 {
 523         struct lttng_ht_node_ulong *node;
 524         struct lttng_ht_iter iter;
 525         struct jul_app *app;
 526
 527         assert(sock >= 0);
 528
 529         lttng_ht_lookup(jul_apps_ht_by_sock, (void *)((unsigned long) sock), &iter);
 530         node = lttng_ht_iter_get_node_ulong(&iter);
 531         if (node == NULL) {
 532                 goto error;
 533         }
 534         app = caa_container_of(node, struct jul_app, node);
 535
 536         DBG3("JUL app pid %d found by sock %d.", app->pid, sock);
 537         return app;
 538
 539 error:
 540         DBG3("JUL app NOT found by sock %d.", sock);
 541         return NULL;
 542 }
 543
 544 /*
 545  * Add JUL application object to a given hash table.
 546  */
 547 void jul_add_app(struct jul_app *app)
 548 {
 549         assert(app);
 550
 551         DBG3("JUL adding app sock: %d and pid: %d to ht", app->sock->fd, app->pid);
 552
 553         rcu_read_lock();
 554         lttng_ht_add_unique_ulong(jul_apps_ht_by_sock, &app->node);
 555         rcu_read_unlock();
 556 }
 557
 558 /*
 559  * Delete JUL application from the global hash table.
 560  */
 561 void jul_delete_app(struct jul_app *app)
 562 {
 563         int ret;
 564         struct lttng_ht_iter iter;
 565
 566         assert(app);
 567
 568         DBG3("JUL deleting app pid: %d and sock: %d", app->pid, app->sock->fd);
 569
 570         iter.iter.node = &app->node.node;
 571         rcu_read_lock();
 572         ret = lttng_ht_del(jul_apps_ht_by_sock, &iter);
 573         rcu_read_unlock();
 574         assert(!ret);
 575 }
 576
 577 /*
 578  * Destroy a JUL application object by detaching it from its corresponding UST
 579  * app if one is connected by closing the socket. Finally, perform a
 580  * delayed memory reclaim.
 581  */
 582 void jul_destroy_app(struct jul_app *app)
 583 {
 584         assert(app);
 585
 586         if (app->sock) {
 587                 app->sock->ops->close(app->sock);
 588                 lttcomm_destroy_sock(app->sock);
 589         }
 590
 591         call_rcu(&app->node.head, destroy_app_jul_rcu);
 592 }
 593
 594 /*
 595  * Initialize an already allocated JUL domain object.
 596  *
 597  * Return 0 on success or else a negative errno value.
 598  */
 599 int jul_init_domain(struct jul_domain *dom)
 600 {
 601         int ret;
 602
 603         assert(dom);
 604
 605         dom->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 606         if (!dom->events) {
 607                 ret = -ENOMEM;
 608                 goto error;
 609         }
 610
 611         return 0;
 612
 613 error:
 614         return ret;
 615 }
 616
 617 /*
 618  * Create a newly allocated JUL event data structure. If name is valid, it's
 619  * copied into the created event.
 620  *
 621  * Return a new object else NULL on error.
 622  */
 623 struct jul_event *jul_create_event(const char *name)
 624 {
 625         struct jul_event *event;
 626
 627         DBG3("JUL create new event with name %s", name);
 628
 629         event = zmalloc(sizeof(*event));
 630         if (!event) {
 631                 goto error;
 632         }
 633
 634         if (name) {
 635                 strncpy(event->name, name, sizeof(event->name));
 636                 event->name[sizeof(event->name) - 1] = '\0';
 637                 lttng_ht_node_init_str(&event->node, event->name);
 638         }
 639
 640 error:
 641         return event;
 642 }
 643
 644 /*
 645  * Unique add of a JUL event to a given domain.
 646  */
 647 void jul_add_event(struct jul_event *event, struct jul_domain *dom)
 648 {
 649         assert(event);
 650         assert(dom);
 651         assert(dom->events);
 652
 653         DBG3("JUL adding event %s to domain", event->name);
 654
 655         rcu_read_lock();
 656         lttng_ht_add_unique_str(dom->events, &event->node);
 657         rcu_read_unlock();
 658         dom->being_used = 1;
 659 }
 660
 661 /*
 662  * Find a JUL event in the given domain using name.
 663  *
 664  * RCU read side lock MUST be acquired.
 665  *
 666  * Return object if found else NULL.
 667  */
 668 struct jul_event *jul_find_by_name(const char *name, struct jul_domain *dom)
 669 {
 670         struct lttng_ht_node_str *node;
 671         struct lttng_ht_iter iter;
 672
 673         assert(name);
 674         assert(dom);
 675         assert(dom->events);
 676
 677         lttng_ht_lookup(dom->events, (void *)name, &iter);
 678         node = lttng_ht_iter_get_node_str(&iter);
 679         if (node == NULL) {
 680                 goto error;
 681         }
 682
 683         DBG3("JUL found by name %s in domain.", name);
 684         return caa_container_of(node, struct jul_event, node);
 685
 686 error:
 687         DBG3("JUL NOT found by name %s in domain.", name);
 688         return NULL;
 689 }
 690
 691 /*
 692  * Free given JUL event. This event must not be globally visible at this
 693  * point (only expected to be used on failure just after event
 694  * creation). After this call, the pointer is not usable anymore.
 695  */
 696 void jul_destroy_event(struct jul_event *event)
 697 {
 698         assert(event);
 699
 700         free(event);
 701 }
 702
 703 /*
 704  * Destroy a JUL domain completely. Note that the given pointer is NOT freed
 705  * thus a reference to static or stack data can be passed to this function.
 706  */
 707 void jul_destroy_domain(struct jul_domain *dom)
 708 {
 709         struct lttng_ht_node_str *node;
 710         struct lttng_ht_iter iter;
 711
 712         assert(dom);
 713
 714         DBG3("JUL destroy domain");
 715
 716         /*
 717          * Just ignore if no events hash table exists. This is possible if for
 718          * instance a JUL domain object was allocated but not initialized.
 719          */
 720         if (!dom->events) {
 721                 return;
 722         }
 723
 724         rcu_read_lock();
 725         cds_lfht_for_each_entry(dom->events->ht, &iter.iter, node, node) {
 726                 int ret;
 727
 728                 ret = lttng_ht_del(dom->events, &iter);
 729                 assert(!ret);
 730                 call_rcu(&node->head, destroy_event_jul_rcu);
 731         }
 732         rcu_read_unlock();
 733
 734         lttng_ht_destroy(dom->events);
 735 }
 736
 737 /*
 738  * Initialize JUL subsystem.
 739  */
 740 int jul_init(void)
 741 {
 742         jul_apps_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 743         if (!jul_apps_ht_by_sock) {
 744                 return -1;
 745         }
 746
 747         return 0;
 748 }
 749
 750 /*
 751  * Update a JUL application (given socket) using the given domain.
 752  *
 753  * Note that this function is most likely to be used with a tracing session
 754  * thus the caller should make sure to hold the appropriate lock(s).
 755  */
 756 void jul_update(struct jul_domain *domain, int sock)
 757 {
 758         int ret;
 759         struct jul_app *app;
 760         struct jul_event *event;
 761         struct lttng_ht_iter iter;
 762
 763         assert(domain);
 764         assert(sock >= 0);
 765
 766         DBG("JUL updating app socket %d", sock);
 767
 768         rcu_read_lock();
 769         cds_lfht_for_each_entry(domain->events->ht, &iter.iter, event, node.node) {
 770                 /* Skip event if disabled. */
 771                 if (!event->enabled) {
 772                         continue;
 773                 }
 774
 775                 app = jul_find_app_by_sock(sock);
 776                 /*
 777                  * We are in the registration path thus if the application is gone,
 778                  * there is a serious code flow error.
 779                  */
 780                 assert(app);
 781
 782                 ret = enable_event(app, event);
 783                 if (ret != LTTNG_OK) {
 784                         DBG2("JUL update unable to enable event %s on app pid: %d sock %d",
 785                                         event->name, app->pid, app->sock->fd);
 786                         /* Let's try the others here and don't assume the app is dead. */
 787                         continue;
 788                 }
 789         }
 790         rcu_read_unlock();
 791 }