src/bin/lttng-sessiond/trace-ust.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 <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23
  24 #include <common/common.h>
  25 #include <common/defaults.h>
  26
  27 #include "trace-ust.h"
  28
  29 /*
  30  * Find the channel in the hashtable.
  31  */
  32 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
  33                 char *name)
  34 {
  35         struct lttng_ht_node_str *node;
  36         struct lttng_ht_iter iter;
  37
  38         rcu_read_lock();
  39         lttng_ht_lookup(ht, (void *)name, &iter);
  40         node = lttng_ht_iter_get_node_str(&iter);
  41         if (node == NULL) {
  42                 rcu_read_unlock();
  43                 goto error;
  44         }
  45         rcu_read_unlock();
  46
  47         DBG2("Trace UST channel %s found by name", name);
  48
  49         return caa_container_of(node, struct ltt_ust_channel, node);
  50
  51 error:
  52         DBG2("Trace UST channel %s not found by name", name);
  53         return NULL;
  54 }
  55
  56 /*
  57  * Find the event in the hashtable.
  58  */
  59 struct ltt_ust_event *trace_ust_find_event_by_name(struct lttng_ht *ht,
  60                 char *name)
  61 {
  62         struct lttng_ht_node_str *node;
  63         struct lttng_ht_iter iter;
  64
  65         rcu_read_lock();
  66         lttng_ht_lookup(ht, (void *) name, &iter);
  67         node = lttng_ht_iter_get_node_str(&iter);
  68         if (node == NULL) {
  69                 rcu_read_unlock();
  70                 goto error;
  71         }
  72         rcu_read_unlock();
  73
  74         DBG2("Trace UST event found by name %s", name);
  75
  76         return caa_container_of(node, struct ltt_ust_event, node);
  77
  78 error:
  79         DBG2("Trace UST event NOT found by name %s", name);
  80         return NULL;
  81 }
  82
  83 /*
  84  * Allocate and initialize a ust session data structure.
  85  *
  86  * Return pointer to structure or NULL.
  87  */
  88 struct ltt_ust_session *trace_ust_create_session(char *path, int session_id,
  89                 struct lttng_domain *domain)
  90 {
  91         int ret;
  92         struct ltt_ust_session *lus;
  93
  94         /* Allocate a new ltt ust session */
  95         lus = zmalloc(sizeof(struct ltt_ust_session));
  96         if (lus == NULL) {
  97                 PERROR("create ust session zmalloc");
  98                 goto error;
  99         }
 100
 101         /* Init data structure */
 102         lus->id = session_id;
 103         lus->start_trace = 0;
 104
 105         /* Alloc UST domain hash tables */
 106         lus->domain_pid = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 107         lus->domain_exec = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 108
 109         /* Alloc UST global domain channels' HT */
 110         lus->domain_global.channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 111
 112         /* Set session path */
 113         ret = snprintf(lus->pathname, PATH_MAX, "%s/ust", path);
 114         if (ret < 0) {
 115                 PERROR("snprintf kernel traces path");
 116                 goto error_free_session;
 117         }
 118
 119         DBG2("UST trace session create successful");
 120
 121         return lus;
 122
 123 error_free_session:
 124         free(lus);
 125 error:
 126         return NULL;
 127 }
 128
 129 /*
 130  * Allocate and initialize a ust channel data structure.
 131  *
 132  * Return pointer to structure or NULL.
 133  */
 134 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
 135                 char *path)
 136 {
 137         int ret;
 138         struct ltt_ust_channel *luc;
 139
 140         luc = zmalloc(sizeof(struct ltt_ust_channel));
 141         if (luc == NULL) {
 142                 perror("ltt_ust_channel zmalloc");
 143                 goto error;
 144         }
 145
 146         /* Copy UST channel attributes */
 147         luc->attr.overwrite = chan->attr.overwrite;
 148         luc->attr.subbuf_size = chan->attr.subbuf_size;
 149         luc->attr.num_subbuf = chan->attr.num_subbuf;
 150         luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
 151         luc->attr.read_timer_interval = chan->attr.read_timer_interval;
 152         luc->attr.output = chan->attr.output;
 153
 154         /* Translate to UST output enum */
 155         switch (luc->attr.output) {
 156         default:
 157                 luc->attr.output = LTTNG_UST_MMAP;
 158                 break;
 159         }
 160
 161         /* Copy channel name */
 162         strncpy(luc->name, chan->name, sizeof(luc->name));
 163         luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 164
 165         /* Init node */
 166         lttng_ht_node_init_str(&luc->node, luc->name);
 167         /* Alloc hash tables */
 168         luc->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 169         luc->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 170
 171         /* Set trace output path */
 172         ret = snprintf(luc->pathname, PATH_MAX, "%s", path);
 173         if (ret < 0) {
 174                 perror("asprintf ust create channel");
 175                 goto error_free_channel;
 176         }
 177
 178         DBG2("Trace UST channel %s created", luc->name);
 179
 180         return luc;
 181
 182 error_free_channel:
 183         free(luc);
 184 error:
 185         return NULL;
 186 }
 187
 188 /*
 189  * Allocate and initialize a ust event. Set name and event type.
 190  *
 191  * Return pointer to structure or NULL.
 192  */
 193 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev)
 194 {
 195         struct ltt_ust_event *lue;
 196
 197         lue = zmalloc(sizeof(struct ltt_ust_event));
 198         if (lue == NULL) {
 199                 PERROR("ust event zmalloc");
 200                 goto error;
 201         }
 202
 203         switch (ev->type) {
 204         case LTTNG_EVENT_PROBE:
 205                 lue->attr.instrumentation = LTTNG_UST_PROBE;
 206                 break;
 207         case LTTNG_EVENT_FUNCTION:
 208                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 209                 break;
 210         case LTTNG_EVENT_FUNCTION_ENTRY:
 211                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 212                 break;
 213         case LTTNG_EVENT_TRACEPOINT:
 214                 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
 215                 break;
 216         case LTTNG_EVENT_TRACEPOINT_LOGLEVEL:
 217                 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT_LOGLEVEL;
 218                 break;
 219         default:
 220                 ERR("Unknown ust instrumentation type (%d)", ev->type);
 221                 goto error_free_event;
 222         }
 223
 224         /* Copy event name */
 225         strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
 226         lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 227
 228         /* Init node */
 229         lttng_ht_node_init_str(&lue->node, lue->attr.name);
 230         /* Alloc context hash tables */
 231         lue->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 232
 233         DBG2("Trace UST event %s created", lue->attr.name);
 234
 235         return lue;
 236
 237 error_free_event:
 238         free(lue);
 239 error:
 240         return NULL;
 241 }
 242
 243 /*
 244  * Allocate and initialize a ust metadata.
 245  *
 246  * Return pointer to structure or NULL.
 247  */
 248 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
 249 {
 250         int ret;
 251         struct ltt_ust_metadata *lum;
 252
 253         lum = zmalloc(sizeof(struct ltt_ust_metadata));
 254         if (lum == NULL) {
 255                 perror("ust metadata zmalloc");
 256                 goto error;
 257         }
 258
 259         /* Set default attributes */
 260         lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 261         lum->attr.subbuf_size = DEFAULT_METADATA_SUBBUF_SIZE;
 262         lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 263         lum->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 264         lum->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 265         lum->attr.output = LTTNG_UST_MMAP;
 266
 267         lum->handle = -1;
 268         /* Set metadata trace path */
 269         ret = snprintf(lum->pathname, PATH_MAX, "%s/metadata", path);
 270         if (ret < 0) {
 271                 perror("asprintf ust metadata");
 272                 goto error_free_metadata;
 273         }
 274
 275         return lum;
 276
 277 error_free_metadata:
 278         free(lum);
 279 error:
 280         return NULL;
 281 }
 282
 283 /*
 284  * Allocate and initialize an UST context.
 285  *
 286  * Return pointer to structure or NULL.
 287  */
 288 struct ltt_ust_context *trace_ust_create_context(
 289                 struct lttng_event_context *ctx)
 290 {
 291         struct ltt_ust_context *uctx;
 292
 293         uctx = zmalloc(sizeof(struct ltt_ust_context));
 294         if (uctx == NULL) {
 295                 PERROR("zmalloc ltt_ust_context");
 296                 goto error;
 297         }
 298
 299         uctx->ctx.ctx = ctx->ctx;
 300         lttng_ht_node_init_ulong(&uctx->node, (unsigned long) uctx->ctx.ctx);
 301
 302         return uctx;
 303
 304 error:
 305         return NULL;
 306 }
 307
 308 /*
 309  * RCU safe free context structure.
 310  */
 311 static void destroy_context_rcu(struct rcu_head *head)
 312 {
 313         struct lttng_ht_node_ulong *node =
 314                 caa_container_of(head, struct lttng_ht_node_ulong, head);
 315         struct ltt_ust_context *ctx =
 316                 caa_container_of(node, struct ltt_ust_context, node);
 317
 318         free(ctx);
 319 }
 320
 321 /*
 322  * Cleanup UST context hash table.
 323  */
 324 static void destroy_contexts(struct lttng_ht *ht)
 325 {
 326         int ret;
 327         struct lttng_ht_node_ulong *node;
 328         struct lttng_ht_iter iter;
 329
 330         cds_lfht_for_each_entry(ht->ht, &iter.iter, node, node) {
 331                 ret = lttng_ht_del(ht, &iter);
 332                 if (!ret) {
 333                         call_rcu(&node->head, destroy_context_rcu);
 334                 }
 335         }
 336
 337         lttng_ht_destroy(ht);
 338 }
 339
 340 /*
 341  * Cleanup ust event structure.
 342  */
 343 void trace_ust_destroy_event(struct ltt_ust_event *event)
 344 {
 345         DBG2("Trace destroy UST event %s", event->attr.name);
 346         destroy_contexts(event->ctx);
 347
 348         free(event);
 349 }
 350
 351 /*
 352  * URCU intermediate call to complete destroy event.
 353  */
 354 static void destroy_event_rcu(struct rcu_head *head)
 355 {
 356         struct lttng_ht_node_str *node =
 357                 caa_container_of(head, struct lttng_ht_node_str, head);
 358         struct ltt_ust_event *event =
 359                 caa_container_of(node, struct ltt_ust_event, node);
 360
 361         trace_ust_destroy_event(event);
 362 }
 363
 364 /*
 365  * Cleanup UST events hashtable.
 366  */
 367 static void destroy_events(struct lttng_ht *events)
 368 {
 369         int ret;
 370         struct lttng_ht_node_str *node;
 371         struct lttng_ht_iter iter;
 372
 373         cds_lfht_for_each_entry(events->ht, &iter.iter, node, node) {
 374                 ret = lttng_ht_del(events, &iter);
 375                 assert(!ret);
 376                 call_rcu(&node->head, destroy_event_rcu);
 377         }
 378
 379         lttng_ht_destroy(events);
 380 }
 381
 382 /*
 383  * Cleanup ust channel structure.
 384  */
 385 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 386 {
 387         DBG2("Trace destroy UST channel %s", channel->name);
 388
 389         rcu_read_lock();
 390
 391         /* Destroying all events of the channel */
 392         destroy_events(channel->events);
 393         /* Destroying all context of the channel */
 394         destroy_contexts(channel->ctx);
 395
 396         free(channel);
 397
 398         rcu_read_unlock();
 399 }
 400
 401 /*
 402  * URCU intermediate call to complete destroy channel.
 403  */
 404 static void destroy_channel_rcu(struct rcu_head *head)
 405 {
 406         struct lttng_ht_node_str *node =
 407                 caa_container_of(head, struct lttng_ht_node_str, head);
 408         struct ltt_ust_channel *channel =
 409                 caa_container_of(node, struct ltt_ust_channel, node);
 410
 411         trace_ust_destroy_channel(channel);
 412 }
 413
 414 /*
 415  * Cleanup ust metadata structure.
 416  */
 417 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 418 {
 419         DBG2("Trace UST destroy metadata %d", metadata->handle);
 420
 421         free(metadata);
 422 }
 423
 424 /*
 425  * Iterate over a hash table containing channels and cleanup safely.
 426  */
 427 static void destroy_channels(struct lttng_ht *channels)
 428 {
 429         int ret;
 430         struct lttng_ht_node_str *node;
 431         struct lttng_ht_iter iter;
 432
 433         rcu_read_lock();
 434
 435         cds_lfht_for_each_entry(channels->ht, &iter.iter, node, node) {
 436                 ret = lttng_ht_del(channels, &iter);
 437                 assert(!ret);
 438                 call_rcu(&node->head, destroy_channel_rcu);
 439         }
 440
 441         lttng_ht_destroy(channels);
 442
 443         rcu_read_unlock();
 444 }
 445
 446 /*
 447  * Cleanup UST pid domain.
 448  */
 449 static void destroy_domain_pid(struct lttng_ht *ht)
 450 {
 451         int ret;
 452         struct lttng_ht_iter iter;
 453         struct ltt_ust_domain_pid *dpid;
 454
 455         cds_lfht_for_each_entry(ht->ht, &iter.iter, dpid, node.node) {
 456                 ret = lttng_ht_del(ht , &iter);
 457                 assert(!ret);
 458                 destroy_channels(dpid->channels);
 459         }
 460
 461         lttng_ht_destroy(ht);
 462 }
 463
 464 /*
 465  * Cleanup UST exec name domain.
 466  */
 467 static void destroy_domain_exec(struct lttng_ht *ht)
 468 {
 469         int ret;
 470         struct lttng_ht_iter iter;
 471         struct ltt_ust_domain_exec *dexec;
 472
 473         cds_lfht_for_each_entry(ht->ht, &iter.iter, dexec, node.node) {
 474                 ret = lttng_ht_del(ht , &iter);
 475                 assert(!ret);
 476                 destroy_channels(dexec->channels);
 477         }
 478
 479         lttng_ht_destroy(ht);
 480 }
 481
 482 /*
 483  * Cleanup UST global domain.
 484  */
 485 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
 486 {
 487         destroy_channels(dom->channels);
 488 }
 489
 490 /*
 491  * Cleanup ust session structure
 492  */
 493 void trace_ust_destroy_session(struct ltt_ust_session *session)
 494 {
 495         /* Extra protection */
 496         if (session == NULL) {
 497                 return;
 498         }
 499
 500         rcu_read_lock();
 501
 502         DBG2("Trace UST destroy session %d", session->id);
 503
 504         /* Cleaning up UST domain */
 505         destroy_domain_global(&session->domain_global);
 506         destroy_domain_pid(session->domain_pid);
 507         destroy_domain_exec(session->domain_exec);
 508
 509         free(session);
 510
 511         rcu_read_unlock();
 512 }