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