src/bin/lttng-sessiond/event.c

   1 /*
   2  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   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 as published by the Free
   6  * Software Foundation; only version 2 of the License.
   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., 59 Temple
  15  * Place - Suite 330, Boston, MA  02111-1307, USA.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <errno.h>
  20 #include <urcu/list.h>
  21 #include <string.h>
  22
  23 #include <lttng/lttng.h>
  24 #include <common/sessiond-comm/sessiond-comm.h>
  25 #include <common/lttngerr.h>
  26
  27 #include "channel.h"
  28 #include "event.h"
  29 #include "kernel.h"
  30 #include "ust-ctl.h"
  31 #include "ust-app.h"
  32 #include "trace-kernel.h"
  33 #include "trace-ust.h"
  34
  35 /*
  36  * Setup a lttng_event used to enable *all* syscall tracing.
  37  */
  38 static void init_syscalls_kernel_event(struct lttng_event *event)
  39 {
  40         event->name[0] = '\0';
  41         /*
  42          * We use LTTNG_EVENT* here since the trace kernel creation will make the
  43          * right changes for the kernel.
  44          */
  45         event->type = LTTNG_EVENT_SYSCALL;
  46 }
  47
  48 /*
  49  * Disable kernel tracepoint event for a channel from the kernel session.
  50  */
  51 int event_kernel_disable_tracepoint(struct ltt_kernel_session *ksession,
  52                 struct ltt_kernel_channel *kchan, char *event_name)
  53 {
  54         int ret;
  55         struct ltt_kernel_event *kevent;
  56
  57         kevent = trace_kernel_get_event_by_name(event_name, kchan);
  58         if (kevent == NULL) {
  59                 ret = LTTCOMM_NO_EVENT;
  60                 goto error;
  61         }
  62
  63         ret = kernel_disable_event(kevent);
  64         if (ret < 0) {
  65                 ret = LTTCOMM_KERN_DISABLE_FAIL;
  66                 goto error;
  67         }
  68
  69         DBG("Kernel event %s disable for channel %s.",
  70                         kevent->event->name, kchan->channel->name);
  71
  72         ret = LTTCOMM_OK;
  73
  74 error:
  75         return ret;
  76 }
  77
  78 /*
  79  * Disable kernel tracepoint events for a channel from the kernel session.
  80  */
  81 int event_kernel_disable_all_tracepoints(struct ltt_kernel_session *ksession,
  82                 struct ltt_kernel_channel *kchan)
  83 {
  84         int ret;
  85         struct ltt_kernel_event *kevent;
  86
  87         /* For each event in the kernel session */
  88         cds_list_for_each_entry(kevent, &kchan->events_list.head, list) {
  89                 ret = kernel_disable_event(kevent);
  90                 if (ret < 0) {
  91                         /* We continue disabling the rest */
  92                         continue;
  93                 }
  94         }
  95         ret = LTTCOMM_OK;
  96         return ret;
  97 }
  98
  99 /*
 100  * Disable kernel syscall events for a channel from the kernel session.
 101  */
 102 int event_kernel_disable_all_syscalls(struct ltt_kernel_session *ksession,
 103                 struct ltt_kernel_channel *kchan)
 104 {
 105         ERR("Cannot disable syscall tracing for existing session. Please destroy session instead.");
 106         return LTTCOMM_OK;      /* Return OK so disable all succeeds */
 107 }
 108
 109 /*
 110  * Disable all kernel event for a channel from the kernel session.
 111  */
 112 int event_kernel_disable_all(struct ltt_kernel_session *ksession,
 113                 struct ltt_kernel_channel *kchan)
 114 {
 115         int ret;
 116
 117         ret = event_kernel_disable_all_tracepoints(ksession, kchan);
 118         if (ret != LTTCOMM_OK)
 119                 return ret;
 120         ret = event_kernel_disable_all_syscalls(ksession, kchan);
 121         return ret;
 122 }
 123
 124 /*
 125  * Enable kernel tracepoint event for a channel from the kernel session.
 126  */
 127 int event_kernel_enable_tracepoint(struct ltt_kernel_session *ksession,
 128                 struct ltt_kernel_channel *kchan, struct lttng_event *event)
 129 {
 130         int ret;
 131         struct ltt_kernel_event *kevent;
 132
 133         kevent = trace_kernel_get_event_by_name(event->name, kchan);
 134         if (kevent == NULL) {
 135                 ret = kernel_create_event(event, kchan);
 136                 if (ret < 0) {
 137                         if (ret == -EEXIST) {
 138                                 ret = LTTCOMM_KERN_EVENT_EXIST;
 139                         } else {
 140                                 ret = LTTCOMM_KERN_ENABLE_FAIL;
 141                         }
 142                         goto end;
 143                 }
 144         } else if (kevent->enabled == 0) {
 145                 ret = kernel_enable_event(kevent);
 146                 if (ret < 0) {
 147                         ret = LTTCOMM_KERN_ENABLE_FAIL;
 148                         goto end;
 149                 }
 150         }
 151         ret = LTTCOMM_OK;
 152 end:
 153         return ret;
 154 }
 155
 156 /*
 157  * Enable all kernel tracepoint events of a channel of the kernel session.
 158  */
 159 int event_kernel_enable_all_tracepoints(struct ltt_kernel_session *ksession,
 160                 struct ltt_kernel_channel *kchan, int kernel_tracer_fd)
 161 {
 162         int size, i, ret;
 163         struct ltt_kernel_event *kevent;
 164         struct lttng_event *event_list = NULL;
 165
 166         /* For each event in the kernel session */
 167         cds_list_for_each_entry(kevent, &kchan->events_list.head, list) {
 168                 if (kevent->enabled == 0) {
 169                         ret = kernel_enable_event(kevent);
 170                         if (ret < 0) {
 171                                 /* Enable failed but still continue */
 172                                 continue;
 173                         }
 174                 }
 175         }
 176
 177         size = kernel_list_events(kernel_tracer_fd, &event_list);
 178         if (size < 0) {
 179                 ret = LTTCOMM_KERN_LIST_FAIL;
 180                 goto end;
 181         }
 182
 183         for (i = 0; i < size; i++) {
 184                 kevent = trace_kernel_get_event_by_name(event_list[i].name, kchan);
 185                 if (kevent == NULL) {
 186                         /* Default event type for enable all */
 187                         event_list[i].type = LTTNG_EVENT_TRACEPOINT;
 188                         /* Enable each single tracepoint event */
 189                         ret = kernel_create_event(&event_list[i], kchan);
 190                         if (ret < 0) {
 191                                 /* Ignore error here and continue */
 192                         }
 193                 }
 194         }
 195         free(event_list);
 196
 197         ret = LTTCOMM_OK;
 198 end:
 199         return ret;
 200
 201 }
 202
 203 /*
 204  * Enable all kernel tracepoint events of a channel of the kernel session.
 205  */
 206 int event_kernel_enable_all_syscalls(struct ltt_kernel_session *ksession,
 207                 struct ltt_kernel_channel *kchan, int kernel_tracer_fd)
 208 {
 209         int ret;
 210         struct lttng_event event;
 211
 212         init_syscalls_kernel_event(&event);
 213
 214         DBG("Enabling all syscall tracing");
 215
 216         ret = kernel_create_event(&event, kchan);
 217         if (ret < 0) {
 218                 if (ret == -EEXIST) {
 219                         ret = LTTCOMM_KERN_EVENT_EXIST;
 220                 } else {
 221                         ret = LTTCOMM_KERN_ENABLE_FAIL;
 222                 }
 223                 goto end;
 224         }
 225
 226         ret = LTTCOMM_OK;
 227 end:
 228         return ret;
 229 }
 230
 231 /*
 232  * Enable all kernel events of a channel of the kernel session.
 233  */
 234 int event_kernel_enable_all(struct ltt_kernel_session *ksession,
 235                 struct ltt_kernel_channel *kchan, int kernel_tracer_fd)
 236 {
 237         int ret;
 238
 239         ret = event_kernel_enable_all_tracepoints(ksession, kchan, kernel_tracer_fd);
 240         if (ret != LTTCOMM_OK) {
 241                 goto end;
 242         }
 243         ret = event_kernel_enable_all_syscalls(ksession, kchan, kernel_tracer_fd);
 244 end:
 245         return ret;
 246 }
 247
 248 /*
 249  * ============================
 250  * UST : The Ultimate Frontier!
 251  * ============================
 252  */
 253
 254 /*
 255  * Enable all UST tracepoints for a channel from a UST session.
 256  */
 257 int event_ust_enable_all_tracepoints(struct ltt_ust_session *usess, int domain,
 258                 struct ltt_ust_channel *uchan)
 259 {
 260         int ret, i;
 261         size_t size;
 262         struct lttng_ht_iter iter;
 263         struct ltt_ust_event *uevent = NULL;
 264         struct lttng_event *events = NULL;
 265
 266         switch (domain) {
 267         case LTTNG_DOMAIN_UST:
 268         {
 269                 /* Enable existing events */
 270                 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent,
 271                                 node.node) {
 272                         if (uevent->enabled == 0) {
 273                                 ret = ust_app_enable_event_glb(usess, uchan, uevent);
 274                                 if (ret < 0) {
 275                                         continue;
 276                                 }
 277                                 uevent->enabled = 1;
 278                         }
 279                 }
 280
 281                 /* Get all UST available events */
 282                 size = ust_app_list_events(&events);
 283                 if (size < 0) {
 284                         ret = LTTCOMM_UST_LIST_FAIL;
 285                         goto error;
 286                 }
 287
 288                 for (i = 0; i < size; i++) {
 289                         /*
 290                          * Check if event exist and if so, continue since it was enable
 291                          * previously.
 292                          */
 293                         uevent = trace_ust_find_event_by_name(uchan->events,
 294                                         events[i].name);
 295                         if (uevent != NULL) {
 296                                 ret = ust_app_enable_event_pid(usess, uchan, uevent,
 297                                                 events[i].pid);
 298                                 if (ret < 0) {
 299                                         if (ret != -EEXIST) {
 300                                                 ret = LTTCOMM_UST_ENABLE_FAIL;
 301                                                 goto error;
 302                                         }
 303                                 }
 304                                 continue;
 305                         }
 306
 307                         /* Create ust event */
 308                         uevent = trace_ust_create_event(&events[i]);
 309                         if (uevent == NULL) {
 310                                 ret = LTTCOMM_FATAL;
 311                                 goto error_destroy;
 312                         }
 313
 314                         /* Create event for the specific PID */
 315                         ret = ust_app_enable_event_pid(usess, uchan, uevent,
 316                                         events[i].pid);
 317                         if (ret < 0) {
 318                                 if (ret == -EEXIST) {
 319                                         ret = LTTCOMM_UST_EVENT_EXIST;
 320                                         goto error;
 321                                 } else {
 322                                         ret = LTTCOMM_UST_ENABLE_FAIL;
 323                                         goto error_destroy;
 324                                 }
 325                         }
 326
 327                         uevent->enabled = 1;
 328                         /* Add ltt ust event to channel */
 329                         rcu_read_lock();
 330                         lttng_ht_add_unique_str(uchan->events, &uevent->node);
 331                         rcu_read_unlock();
 332                 }
 333
 334                 free(events);
 335                 break;
 336         }
 337         case LTTNG_DOMAIN_UST_EXEC_NAME:
 338         case LTTNG_DOMAIN_UST_PID:
 339         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 340         default:
 341                 ret = LTTCOMM_NOT_IMPLEMENTED;
 342                 goto error;
 343         }
 344
 345         return LTTCOMM_OK;
 346
 347 error_destroy:
 348         trace_ust_destroy_event(uevent);
 349
 350 error:
 351         free(events);
 352         return ret;
 353 }
 354
 355 /*
 356  * Enable UST tracepoint event for a channel from a UST session.
 357  */
 358 int event_ust_enable_tracepoint(struct ltt_ust_session *usess, int domain,
 359                 struct ltt_ust_channel *uchan, struct lttng_event *event)
 360 {
 361         int ret = LTTCOMM_OK, to_create = 0;
 362         struct ltt_ust_event *uevent;
 363
 364         uevent = trace_ust_find_event_by_name(uchan->events, event->name);
 365         if (uevent == NULL) {
 366                 uevent = trace_ust_create_event(event);
 367                 if (uevent == NULL) {
 368                         ret = LTTCOMM_FATAL;
 369                         goto error;
 370                 }
 371                 /* Valid to set it after the goto error since uevent is still NULL */
 372                 to_create = 1;
 373         }
 374
 375         if (uevent->enabled) {
 376                 /* It's already enabled so everything is OK */
 377                 goto end;
 378         }
 379
 380         uevent->enabled = 1;
 381
 382         switch (domain) {
 383         case LTTNG_DOMAIN_UST:
 384         {
 385                 if (to_create) {
 386                         /* Create event on all UST registered apps for session */
 387                         ret = ust_app_create_event_glb(usess, uchan, uevent);
 388                 } else {
 389                         /* Enable event on all UST registered apps for session */
 390                         ret = ust_app_enable_event_glb(usess, uchan, uevent);
 391                 }
 392
 393                 if (ret < 0) {
 394                         if (ret == -EEXIST) {
 395                                 ret = LTTCOMM_UST_EVENT_EXIST;
 396                                 goto end;
 397                         } else {
 398                                 ret = LTTCOMM_UST_ENABLE_FAIL;
 399                                 goto error;
 400                         }
 401                 }
 402                 break;
 403         }
 404         case LTTNG_DOMAIN_UST_EXEC_NAME:
 405         case LTTNG_DOMAIN_UST_PID:
 406         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 407         default:
 408                 ret = LTTCOMM_NOT_IMPLEMENTED;
 409                 goto end;
 410         }
 411
 412         if (to_create) {
 413                 rcu_read_lock();
 414                 /* Add ltt ust event to channel */
 415                 lttng_ht_add_unique_str(uchan->events, &uevent->node);
 416                 rcu_read_unlock();
 417         }
 418
 419         DBG("Event UST %s %s in channel %s", uevent->attr.name,
 420                         to_create ? "created" : "enabled", uchan->name);
 421
 422         ret = LTTCOMM_OK;
 423
 424 end:
 425         return ret;
 426
 427 error:
 428         /*
 429          * Only destroy event on creation time (not enabling time) because if the
 430          * event is found in the channel (to_create == 0), it means that at some
 431          * point the enable_event worked and it's thus valid to keep it alive.
 432          * Destroying it also implies that we also destroy it's shadow copy to sync
 433          * everyone up.
 434          */
 435         if (to_create) {
 436                 /* In this code path, the uevent was not added to the hash table */
 437                 trace_ust_destroy_event(uevent);
 438         }
 439         return ret;
 440 }
 441
 442 /*
 443  * Disable UST tracepoint of a channel from a UST session.
 444  */
 445 int event_ust_disable_tracepoint(struct ltt_ust_session *usess, int domain,
 446                 struct ltt_ust_channel *uchan, char *event_name)
 447 {
 448         int ret;
 449         struct ltt_ust_event *uevent;
 450
 451         uevent = trace_ust_find_event_by_name(uchan->events, event_name);
 452         if (uevent == NULL) {
 453                 ret = LTTCOMM_UST_EVENT_NOT_FOUND;
 454                 goto error;
 455         }
 456
 457         if (uevent->enabled == 0) {
 458                 /* It's already enabled so everything is OK */
 459                 ret = LTTCOMM_OK;
 460                 goto end;
 461         }
 462
 463         switch (domain) {
 464         case LTTNG_DOMAIN_UST:
 465                 ret = ust_app_disable_event_glb(usess, uchan, uevent);
 466                 if (ret < 0 && ret != -EEXIST) {
 467                         ret = LTTCOMM_UST_DISABLE_FAIL;
 468                         goto error;
 469                 }
 470                 break;
 471         case LTTNG_DOMAIN_UST_EXEC_NAME:
 472         case LTTNG_DOMAIN_UST_PID:
 473         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 474         default:
 475                 ret = LTTCOMM_NOT_IMPLEMENTED;
 476                 goto error;
 477         }
 478
 479         uevent->enabled = 0;
 480         ret = LTTCOMM_OK;
 481
 482 end:
 483         DBG2("Event UST %s disabled in channel %s", uevent->attr.name,
 484                         uchan->name);
 485
 486 error:
 487         return ret;
 488 }
 489
 490 /*
 491  * Disable all UST tracepoints for a channel from a UST session.
 492  */
 493 int event_ust_disable_all_tracepoints(struct ltt_ust_session *usess, int domain,
 494                 struct ltt_ust_channel *uchan)
 495 {
 496         int ret, i;
 497         size_t size;
 498         struct lttng_ht_iter iter;
 499         struct ltt_ust_event *uevent = NULL;
 500         struct lttng_event *events = NULL;
 501
 502         switch (domain) {
 503         case LTTNG_DOMAIN_UST:
 504         {
 505                 /* Disabling existing events */
 506                 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent,
 507                                 node.node) {
 508                         if (uevent->enabled == 1) {
 509                                 ret = ust_app_disable_event_glb(usess, uchan, uevent);
 510                                 if (ret < 0) {
 511                                         continue;
 512                                 }
 513                                 uevent->enabled = 0;
 514                         }
 515                 }
 516
 517                 /* Get all UST available events */
 518                 size = ust_app_list_events(&events);
 519                 if (size < 0) {
 520                         ret = LTTCOMM_UST_LIST_FAIL;
 521                         goto error;
 522                 }
 523
 524                 for (i = 0; i < size; i++) {
 525                         uevent = trace_ust_find_event_by_name(uchan->events,
 526                                         events[i].name);
 527                         if (uevent != NULL && uevent->enabled == 1) {
 528                                 ret = ust_app_disable_event_pid(usess, uchan, uevent,
 529                                                 events[i].pid);
 530                                 if (ret < 0 && ret != -EEXIST) {
 531                                         ret = LTTCOMM_UST_DISABLE_FAIL;
 532                                         goto error;
 533                                 }
 534                                 uevent->enabled = 0;
 535                                 continue;
 536                         }
 537                 }
 538
 539                 free(events);
 540                 break;
 541         }
 542         case LTTNG_DOMAIN_UST_EXEC_NAME:
 543         case LTTNG_DOMAIN_UST_PID:
 544         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 545         default:
 546                 ret = LTTCOMM_NOT_IMPLEMENTED;
 547                 goto error;
 548         }
 549
 550         return LTTCOMM_OK;
 551
 552 error:
 553         free(events);
 554         return ret;
 555 }