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 <lttngerr.h>
  25 #include <lttng-share.h>
  26
  27 #include "hashtable.h"
  28 #include "trace-ust.h"
  29
  30 /*
  31  * Find the channel in the hashtable.
  32  */
  33 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct cds_lfht *ht,
  34                 char *name)
  35 {
  36         struct cds_lfht_node *node;
  37         struct cds_lfht_iter iter;
  38
  39         rcu_read_lock();
  40         node = hashtable_lookup(ht, (void *) name, strlen(name), &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 cds_lfht *ht,
  60                 char *name)
  61 {
  62         struct cds_lfht_node *node;
  63         struct cds_lfht_iter iter;
  64
  65         rcu_read_lock();
  66         node = hashtable_lookup(ht, (void *) name, strlen(name), &iter);
  67         if (node == NULL) {
  68                 rcu_read_unlock();
  69                 goto error;
  70         }
  71         rcu_read_unlock();
  72
  73         DBG2("Trace UST event found by name %s", name);
  74
  75         return caa_container_of(node, struct ltt_ust_event, node);
  76
  77 error:
  78         DBG2("Trace UST event NOT found by name %s", name);
  79         return NULL;
  80 }
  81
  82 /*
  83  * Allocate and initialize a ust session data structure.
  84  *
  85  * Return pointer to structure or NULL.
  86  */
  87 struct ltt_ust_session *trace_ust_create_session(char *path, unsigned int uid,
  88                 struct lttng_domain *domain)
  89 {
  90         int ret;
  91         struct ltt_ust_session *lus;
  92
  93         /* Allocate a new ltt ust session */
  94         lus = zmalloc(sizeof(struct ltt_ust_session));
  95         if (lus == NULL) {
  96                 PERROR("create ust session zmalloc");
  97                 goto error;
  98         }
  99
 100         /* Init data structure */
 101         lus->uid = uid;
 102         lus->start_trace = 0;
 103
 104         /* Alloc UST domain hash tables */
 105         lus->domain_pid = hashtable_new(0);
 106         lus->domain_exec = hashtable_new_str(0);
 107
 108         /* Alloc UST global domain channels' HT */
 109         lus->domain_global.channels = hashtable_new_str(0);
 110
 111         /* Set session path */
 112         ret = snprintf(lus->pathname, PATH_MAX, "%s/ust", path);
 113         if (ret < 0) {
 114                 PERROR("snprintf kernel traces path");
 115                 goto error_free_session;
 116         }
 117
 118         DBG2("UST trace session create successful");
 119
 120         return lus;
 121
 122 error_free_session:
 123         free(lus);
 124 error:
 125         return NULL;
 126 }
 127
 128 /*
 129  * Allocate and initialize a ust channel data structure.
 130  *
 131  * Return pointer to structure or NULL.
 132  */
 133 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
 134                 char *path)
 135 {
 136         int ret;
 137         struct ltt_ust_channel *luc;
 138
 139         luc = zmalloc(sizeof(struct ltt_ust_channel));
 140         if (luc == NULL) {
 141                 perror("ltt_ust_channel zmalloc");
 142                 goto error;
 143         }
 144
 145         /* Copy UST channel attributes */
 146         luc->attr.overwrite = chan->attr.overwrite;
 147         luc->attr.subbuf_size = chan->attr.subbuf_size;
 148         luc->attr.num_subbuf = chan->attr.num_subbuf;
 149         luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
 150         luc->attr.read_timer_interval = chan->attr.read_timer_interval;
 151         luc->attr.output = chan->attr.output;
 152
 153         /* Translate to UST output enum */
 154         switch (luc->attr.output) {
 155         default:
 156                 luc->attr.output = LTTNG_UST_MMAP;
 157                 break;
 158         }
 159
 160         /* Copy channel name */
 161         strncpy(luc->name, chan->name, sizeof(&luc->name));
 162         luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 163
 164         /* Init node */
 165         hashtable_node_init(&luc->node, (void *) luc->name, strlen(luc->name));
 166         /* Alloc hash tables */
 167         luc->events = hashtable_new_str(0);
 168         luc->ctx = hashtable_new(0);
 169
 170         /* Set trace output path */
 171         ret = snprintf(luc->pathname, PATH_MAX, "%s", path);
 172         if (ret < 0) {
 173                 perror("asprintf ust create channel");
 174                 goto error_free_channel;
 175         }
 176
 177         DBG2("Trace UST channel %s created", luc->name);
 178
 179         return luc;
 180
 181 error_free_channel:
 182         free(luc);
 183 error:
 184         return NULL;
 185 }
 186
 187 /*
 188  * Allocate and initialize a ust event. Set name and event type.
 189  *
 190  * Return pointer to structure or NULL.
 191  */
 192 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev)
 193 {
 194         struct ltt_ust_event *lue;
 195
 196         lue = zmalloc(sizeof(struct ltt_ust_event));
 197         if (lue == NULL) {
 198                 PERROR("ust event zmalloc");
 199                 goto error;
 200         }
 201
 202         switch (ev->type) {
 203         case LTTNG_EVENT_PROBE:
 204                 lue->attr.instrumentation = LTTNG_UST_PROBE;
 205                 break;
 206         case LTTNG_EVENT_FUNCTION:
 207                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 208                 break;
 209         case LTTNG_EVENT_FUNCTION_ENTRY:
 210                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 211                 break;
 212         case LTTNG_EVENT_TRACEPOINT:
 213                 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
 214                 break;
 215         default:
 216                 ERR("Unknown ust instrumentation type (%d)", ev->type);
 217                 goto error_free_event;
 218         }
 219
 220         /* Copy event name */
 221         strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
 222         lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 223
 224         /* Init node */
 225         hashtable_node_init(&lue->node, (void *) lue->attr.name,
 226                         strlen(lue->attr.name));
 227         /* Alloc context hash tables */
 228         lue->ctx = hashtable_new(0);
 229
 230         DBG2("Trace UST event %s created", lue->attr.name);
 231
 232         return lue;
 233
 234 error_free_event:
 235         free(lue);
 236 error:
 237         return NULL;
 238 }
 239
 240 /*
 241  * Allocate and initialize a ust metadata.
 242  *
 243  * Return pointer to structure or NULL.
 244  */
 245 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
 246 {
 247         int ret;
 248         struct ltt_ust_metadata *lum;
 249
 250         lum = zmalloc(sizeof(struct ltt_ust_metadata));
 251         if (lum == NULL) {
 252                 perror("ust metadata zmalloc");
 253                 goto error;
 254         }
 255
 256         /* Set default attributes */
 257         lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 258         lum->attr.subbuf_size = DEFAULT_METADATA_SUBBUF_SIZE;
 259         lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 260         lum->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 261         lum->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 262         lum->attr.output = LTTNG_UST_MMAP;
 263
 264         lum->handle = -1;
 265         /* Set metadata trace path */
 266         ret = snprintf(lum->pathname, PATH_MAX, "%s/metadata", path);
 267         if (ret < 0) {
 268                 perror("asprintf ust metadata");
 269                 goto error_free_metadata;
 270         }
 271
 272         return lum;
 273
 274 error_free_metadata:
 275         free(lum);
 276 error:
 277         return NULL;
 278 }
 279
 280 /*
 281  * Allocate and initialize an UST context.
 282  *
 283  * Return pointer to structure or NULL.
 284  */
 285 struct ltt_ust_context *trace_ust_create_context(
 286                 struct lttng_event_context *ctx)
 287 {
 288         struct ltt_ust_context *uctx;
 289
 290         uctx = zmalloc(sizeof(struct ltt_ust_context));
 291         if (uctx == NULL) {
 292                 PERROR("zmalloc ltt_ust_context");
 293                 goto error;
 294         }
 295
 296         uctx->ctx.ctx = ctx->ctx;
 297         hashtable_node_init(&uctx->node, (void *)((unsigned long) uctx->ctx.ctx),
 298                                 sizeof(void *));
 299
 300         return uctx;
 301
 302 error:
 303         return NULL;
 304 }
 305
 306 /*
 307  * RCU safe free context structure.
 308  */
 309 static void destroy_context_rcu(struct rcu_head *head)
 310 {
 311         struct cds_lfht_node *node =
 312                 caa_container_of(head, struct cds_lfht_node, head);
 313         struct ltt_ust_context *ctx =
 314                 caa_container_of(node, struct ltt_ust_context, node);
 315
 316         free(ctx);
 317 }
 318
 319 /*
 320  * Cleanup UST context hash table.
 321  */
 322 static void destroy_context(struct cds_lfht *ht)
 323 {
 324         int ret;
 325         struct cds_lfht_node *node;
 326         struct cds_lfht_iter iter;
 327
 328         cds_lfht_for_each(ht, &iter, node) {
 329                 ret = hashtable_del(ht, &iter);
 330                 if (!ret) {
 331                         call_rcu(&node->head, destroy_context_rcu);
 332                 }
 333         }
 334
 335         hashtable_destroy(ht);
 336 }
 337
 338 /*
 339  * Cleanup ust event structure.
 340  */
 341 void trace_ust_destroy_event(struct ltt_ust_event *event)
 342 {
 343         DBG2("Trace destroy UST event %s", event->attr.name);
 344         destroy_context(event->ctx);
 345
 346         free(event);
 347 }
 348
 349 /*
 350  * URCU intermediate call to complete destroy event.
 351  */
 352 static void destroy_event_rcu(struct rcu_head *head)
 353 {
 354         struct cds_lfht_node *node =
 355                 caa_container_of(head, struct cds_lfht_node, head);
 356         struct ltt_ust_event *event =
 357                 caa_container_of(node, struct ltt_ust_event, node);
 358
 359         trace_ust_destroy_event(event);
 360 }
 361
 362 /*
 363  * Cleanup UST events hashtable.
 364  */
 365 static void destroy_event(struct cds_lfht *events)
 366 {
 367         int ret;
 368         struct cds_lfht_node *node;
 369         struct cds_lfht_iter iter;
 370
 371         cds_lfht_for_each(events, &iter, node) {
 372                 ret = hashtable_del(events, &iter);
 373                 if (!ret) {
 374                         call_rcu(&node->head, destroy_event_rcu);
 375                 }
 376         }
 377
 378         hashtable_destroy(events);
 379 }
 380
 381 /*
 382  * Cleanup ust channel structure.
 383  */
 384 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 385 {
 386         int ret;
 387         struct cds_lfht_node *node;
 388         struct cds_lfht_iter iter;
 389
 390         DBG2("Trace destroy UST channel %s", channel->name);
 391
 392         rcu_read_lock();
 393
 394         cds_lfht_for_each(channel->events, &iter, node) {
 395                 ret = hashtable_del(channel->events, &iter);
 396                 if (!ret) {
 397                         destroy_event(channel->events);
 398                 }
 399         }
 400
 401         destroy_context(channel->ctx);
 402         free(channel);
 403
 404         rcu_read_unlock();
 405 }
 406
 407 /*
 408  * URCU intermediate call to complete destroy channel.
 409  */
 410 static void destroy_channel_rcu(struct rcu_head *head)
 411 {
 412         struct cds_lfht_node *node =
 413                 caa_container_of(head, struct cds_lfht_node, head);
 414         struct ltt_ust_channel *channel =
 415                 caa_container_of(node, struct ltt_ust_channel, node);
 416
 417         trace_ust_destroy_channel(channel);
 418 }
 419
 420 /*
 421  * Cleanup ust metadata structure.
 422  */
 423 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 424 {
 425         DBG2("Trace UST destroy metadata %d", metadata->handle);
 426
 427         free(metadata);
 428 }
 429
 430 /*
 431  * Iterate over a hash table containing channels and cleanup safely.
 432  */
 433 static void destroy_channels(struct cds_lfht *channels)
 434 {
 435         int ret;
 436         struct cds_lfht_node *node;
 437         struct cds_lfht_iter iter;
 438
 439         cds_lfht_for_each(channels, &iter, node) {
 440                 ret = hashtable_del(channels, &iter);
 441                 if (!ret) {
 442                         call_rcu(&node->head, destroy_channel_rcu);
 443                 }
 444         }
 445
 446         hashtable_destroy(channels);
 447 }
 448
 449 /*
 450  * Cleanup UST pid domain.
 451  */
 452 static void destroy_domain_pid(struct cds_lfht *ht)
 453 {
 454         int ret;
 455         struct cds_lfht_iter iter;
 456         struct ltt_ust_domain_pid *dpid;
 457
 458         cds_lfht_for_each_entry(ht, &iter, dpid, node) {
 459                 ret = hashtable_del(ht , &iter);
 460                 if (!ret) {
 461                         destroy_channels(dpid->channels);
 462                 }
 463         }
 464
 465         hashtable_destroy(ht);
 466 }
 467
 468 /*
 469  * Cleanup UST exec name domain.
 470  */
 471 static void destroy_domain_exec(struct cds_lfht *ht)
 472 {
 473         int ret;
 474         struct cds_lfht_iter iter;
 475         struct ltt_ust_domain_exec *dexec;
 476
 477         cds_lfht_for_each_entry(ht, &iter, dexec, node) {
 478                 ret = hashtable_del(ht , &iter);
 479                 if (!ret) {
 480                         destroy_channels(dexec->channels);
 481                 }
 482         }
 483
 484         hashtable_destroy(ht);
 485 }
 486
 487 /*
 488  * Cleanup UST global domain.
 489  */
 490 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
 491 {
 492         destroy_channels(dom->channels);
 493 }
 494
 495 /*
 496  * Cleanup ust session structure
 497  */
 498 void trace_ust_destroy_session(struct ltt_ust_session *session)
 499 {
 500         /* Extra protection */
 501         if (session == NULL) {
 502                 return;
 503         }
 504
 505         rcu_read_lock();
 506
 507         DBG2("Trace UST destroy session %d", session->uid);
 508
 509         /* Cleaning up UST domain */
 510         destroy_domain_global(&session->domain_global);
 511         destroy_domain_pid(session->domain_pid);
 512         destroy_domain_exec(session->domain_exec);
 513
 514         free(session);
 515
 516         rcu_read_unlock();
 517 }