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/error.h>
  25 #include <common/sessiond-comm/sessiond-comm.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 #if 0
 338         case LTTNG_DOMAIN_UST_EXEC_NAME:
 339         case LTTNG_DOMAIN_UST_PID:
 340         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 341 #endif
 342         default:
 343                 ret = LTTCOMM_UND;
 344                 goto error;
 345         }
 346
 347         return LTTCOMM_OK;
 348
 349 error_destroy:
 350         trace_ust_destroy_event(uevent);
 351
 352 error:
 353         free(events);
 354         return ret;
 355 }
 356
 357 /*
 358  * Enable UST tracepoint event for a channel from a UST session.
 359  */
 360 int event_ust_enable_tracepoint(struct ltt_ust_session *usess, int domain,
 361                 struct ltt_ust_channel *uchan, struct lttng_event *event)
 362 {
 363         int ret = LTTCOMM_OK, to_create = 0;
 364         struct ltt_ust_event *uevent;
 365
 366         uevent = trace_ust_find_event_by_name(uchan->events, event->name);
 367         if (uevent == NULL) {
 368                 uevent = trace_ust_create_event(event);
 369                 if (uevent == NULL) {
 370                         ret = LTTCOMM_FATAL;
 371                         goto error;
 372                 }
 373                 /* Valid to set it after the goto error since uevent is still NULL */
 374                 to_create = 1;
 375         }
 376
 377         if (uevent->enabled) {
 378                 /* It's already enabled so everything is OK */
 379                 goto end;
 380         }
 381
 382         uevent->enabled = 1;
 383
 384         switch (domain) {
 385         case LTTNG_DOMAIN_UST:
 386         {
 387                 if (to_create) {
 388                         /* Create event on all UST registered apps for session */
 389                         ret = ust_app_create_event_glb(usess, uchan, uevent);
 390                 } else {
 391                         /* Enable event on all UST registered apps for session */
 392                         ret = ust_app_enable_event_glb(usess, uchan, uevent);
 393                 }
 394
 395                 if (ret < 0) {
 396                         if (ret == -EEXIST) {
 397                                 ret = LTTCOMM_UST_EVENT_EXIST;
 398                                 goto end;
 399                         } else {
 400                                 ret = LTTCOMM_UST_ENABLE_FAIL;
 401                                 goto error;
 402                         }
 403                 }
 404                 break;
 405         }
 406 #if 0
 407         case LTTNG_DOMAIN_UST_EXEC_NAME:
 408         case LTTNG_DOMAIN_UST_PID:
 409         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 410 #endif
 411         default:
 412                 ret = LTTCOMM_UND;
 413                 goto end;
 414         }
 415
 416         if (to_create) {
 417                 rcu_read_lock();
 418                 /* Add ltt ust event to channel */
 419                 lttng_ht_add_unique_str(uchan->events, &uevent->node);
 420                 rcu_read_unlock();
 421         }
 422
 423         DBG("Event UST %s %s in channel %s", uevent->attr.name,
 424                         to_create ? "created" : "enabled", uchan->name);
 425
 426         ret = LTTCOMM_OK;
 427
 428 end:
 429         return ret;
 430
 431 error:
 432         /*
 433          * Only destroy event on creation time (not enabling time) because if the
 434          * event is found in the channel (to_create == 0), it means that at some
 435          * point the enable_event worked and it's thus valid to keep it alive.
 436          * Destroying it also implies that we also destroy it's shadow copy to sync
 437          * everyone up.
 438          */
 439         if (to_create) {
 440                 /* In this code path, the uevent was not added to the hash table */
 441                 trace_ust_destroy_event(uevent);
 442         }
 443         return ret;
 444 }
 445
 446 /*
 447  * Disable UST tracepoint of a channel from a UST session.
 448  */
 449 int event_ust_disable_tracepoint(struct ltt_ust_session *usess, int domain,
 450                 struct ltt_ust_channel *uchan, char *event_name)
 451 {
 452         int ret;
 453         struct ltt_ust_event *uevent;
 454
 455         uevent = trace_ust_find_event_by_name(uchan->events, event_name);
 456         if (uevent == NULL) {
 457                 ret = LTTCOMM_UST_EVENT_NOT_FOUND;
 458                 goto error;
 459         }
 460
 461         if (uevent->enabled == 0) {
 462                 /* It's already enabled so everything is OK */
 463                 ret = LTTCOMM_OK;
 464                 goto end;
 465         }
 466
 467         switch (domain) {
 468         case LTTNG_DOMAIN_UST:
 469                 ret = ust_app_disable_event_glb(usess, uchan, uevent);
 470                 if (ret < 0 && ret != -EEXIST) {
 471                         ret = LTTCOMM_UST_DISABLE_FAIL;
 472                         goto error;
 473                 }
 474                 break;
 475 #if 0
 476         case LTTNG_DOMAIN_UST_EXEC_NAME:
 477         case LTTNG_DOMAIN_UST_PID:
 478         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 479 #endif
 480         default:
 481                 ret = LTTCOMM_UND;
 482                 goto error;
 483         }
 484
 485         uevent->enabled = 0;
 486         ret = LTTCOMM_OK;
 487
 488 end:
 489         DBG2("Event UST %s disabled in channel %s", uevent->attr.name,
 490                         uchan->name);
 491
 492 error:
 493         return ret;
 494 }
 495
 496 /*
 497  * Disable all UST tracepoints for a channel from a UST session.
 498  */
 499 int event_ust_disable_all_tracepoints(struct ltt_ust_session *usess, int domain,
 500                 struct ltt_ust_channel *uchan)
 501 {
 502         int ret, i;
 503         size_t size;
 504         struct lttng_ht_iter iter;
 505         struct ltt_ust_event *uevent = NULL;
 506         struct lttng_event *events = NULL;
 507
 508         switch (domain) {
 509         case LTTNG_DOMAIN_UST:
 510         {
 511                 /* Disabling existing events */
 512                 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent,
 513                                 node.node) {
 514                         if (uevent->enabled == 1) {
 515                                 ret = ust_app_disable_event_glb(usess, uchan, uevent);
 516                                 if (ret < 0) {
 517                                         continue;
 518                                 }
 519                                 uevent->enabled = 0;
 520                         }
 521                 }
 522
 523                 /* Get all UST available events */
 524                 size = ust_app_list_events(&events);
 525                 if (size < 0) {
 526                         ret = LTTCOMM_UST_LIST_FAIL;
 527                         goto error;
 528                 }
 529
 530                 for (i = 0; i < size; i++) {
 531                         uevent = trace_ust_find_event_by_name(uchan->events,
 532                                         events[i].name);
 533                         if (uevent != NULL && uevent->enabled == 1) {
 534                                 ret = ust_app_disable_event_pid(usess, uchan, uevent,
 535                                                 events[i].pid);
 536                                 if (ret < 0 && ret != -EEXIST) {
 537                                         ret = LTTCOMM_UST_DISABLE_FAIL;
 538                                         goto error;
 539                                 }
 540                                 uevent->enabled = 0;
 541                                 continue;
 542                         }
 543                 }
 544
 545                 free(events);
 546                 break;
 547         }
 548 #if 0
 549         case LTTNG_DOMAIN_UST_EXEC_NAME:
 550         case LTTNG_DOMAIN_UST_PID:
 551         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 552 #endif
 553         default:
 554                 ret = LTTCOMM_UND;
 555                 goto error;
 556         }
 557
 558         return LTTCOMM_OK;
 559
 560 error:
 561         free(events);
 562         return ret;
 563 }