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_str(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_str(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  * RCU safe free context structure.
 282  */
 283 static void destroy_context_rcu(struct rcu_head *head)
 284 {
 285         struct cds_lfht_node *node =
 286                 caa_container_of(head, struct cds_lfht_node, head);
 287         struct ltt_ust_context *ctx =
 288                 caa_container_of(node, struct ltt_ust_context, node);
 289
 290         free(ctx);
 291 }
 292
 293 /*
 294  * Cleanup UST context hash table.
 295  */
 296 static void destroy_context(struct cds_lfht *ht)
 297 {
 298         int ret;
 299         struct cds_lfht_node *node;
 300         struct cds_lfht_iter iter;
 301
 302         cds_lfht_for_each(ht, &iter, node) {
 303                 ret = hashtable_del(ht, &iter);
 304                 if (!ret) {
 305                         call_rcu(&node->head, destroy_context_rcu);
 306                 }
 307         }
 308
 309         hashtable_destroy(ht);
 310 }
 311
 312 /*
 313  * Cleanup ust event structure.
 314  */
 315 void trace_ust_destroy_event(struct ltt_ust_event *event)
 316 {
 317         DBG2("Trace destroy UST event %s", event->attr.name);
 318         destroy_context(event->ctx);
 319
 320         free(event);
 321 }
 322
 323 /*
 324  * URCU intermediate call to complete destroy event.
 325  */
 326 static void destroy_event_rcu(struct rcu_head *head)
 327 {
 328         struct cds_lfht_node *node =
 329                 caa_container_of(head, struct cds_lfht_node, head);
 330         struct ltt_ust_event *event =
 331                 caa_container_of(node, struct ltt_ust_event, node);
 332
 333         trace_ust_destroy_event(event);
 334 }
 335
 336 /*
 337  * Cleanup UST events hashtable.
 338  */
 339 static void destroy_event(struct cds_lfht *events)
 340 {
 341         int ret;
 342         struct cds_lfht_node *node;
 343         struct cds_lfht_iter iter;
 344
 345         cds_lfht_for_each(events, &iter, node) {
 346                 ret = hashtable_del(events, &iter);
 347                 if (!ret) {
 348                         call_rcu(&node->head, destroy_event_rcu);
 349                 }
 350         }
 351
 352         hashtable_destroy(events);
 353 }
 354
 355 /*
 356  * Cleanup ust channel structure.
 357  */
 358 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 359 {
 360         int ret;
 361         struct cds_lfht_node *node;
 362         struct cds_lfht_iter iter;
 363
 364         DBG2("Trace destroy UST channel %s", channel->name);
 365
 366         rcu_read_lock();
 367
 368         cds_lfht_for_each(channel->events, &iter, node) {
 369                 ret = hashtable_del(channel->events, &iter);
 370                 if (!ret) {
 371                         destroy_event(channel->events);
 372                 }
 373         }
 374
 375         destroy_context(channel->ctx);
 376         free(channel);
 377
 378         rcu_read_unlock();
 379 }
 380
 381 /*
 382  * URCU intermediate call to complete destroy channel.
 383  */
 384 static void destroy_channel_rcu(struct rcu_head *head)
 385 {
 386         struct cds_lfht_node *node =
 387                 caa_container_of(head, struct cds_lfht_node, head);
 388         struct ltt_ust_channel *channel =
 389                 caa_container_of(node, struct ltt_ust_channel, node);
 390
 391         trace_ust_destroy_channel(channel);
 392 }
 393
 394 /*
 395  * Cleanup ust metadata structure.
 396  */
 397 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 398 {
 399         DBG2("Trace UST destroy metadata %d", metadata->handle);
 400
 401         free(metadata);
 402 }
 403
 404 /*
 405  * Iterate over a hash table containing channels and cleanup safely.
 406  */
 407 static void destroy_channels(struct cds_lfht *channels)
 408 {
 409         int ret;
 410         struct cds_lfht_node *node;
 411         struct cds_lfht_iter iter;
 412
 413         cds_lfht_for_each(channels, &iter, node) {
 414                 ret = hashtable_del(channels, &iter);
 415                 if (!ret) {
 416                         call_rcu(&node->head, destroy_channel_rcu);
 417                 }
 418         }
 419
 420         hashtable_destroy(channels);
 421 }
 422
 423 /*
 424  * Cleanup UST pid domain.
 425  */
 426 static void destroy_domain_pid(struct cds_lfht *ht)
 427 {
 428         int ret;
 429         struct cds_lfht_iter iter;
 430         struct ltt_ust_domain_pid *dpid;
 431
 432         cds_lfht_for_each_entry(ht, &iter, dpid, node) {
 433                 ret = hashtable_del(ht , &iter);
 434                 if (!ret) {
 435                         destroy_channels(dpid->channels);
 436                 }
 437         }
 438
 439         hashtable_destroy(ht);
 440 }
 441
 442 /*
 443  * Cleanup UST exec name domain.
 444  */
 445 static void destroy_domain_exec(struct cds_lfht *ht)
 446 {
 447         int ret;
 448         struct cds_lfht_iter iter;
 449         struct ltt_ust_domain_exec *dexec;
 450
 451         cds_lfht_for_each_entry(ht, &iter, dexec, node) {
 452                 ret = hashtable_del(ht , &iter);
 453                 if (!ret) {
 454                         destroy_channels(dexec->channels);
 455                 }
 456         }
 457
 458         hashtable_destroy(ht);
 459 }
 460
 461 /*
 462  * Cleanup UST global domain.
 463  */
 464 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
 465 {
 466         destroy_channels(dom->channels);
 467 }
 468
 469 /*
 470  * Cleanup ust session structure
 471  */
 472 void trace_ust_destroy_session(struct ltt_ust_session *session)
 473 {
 474         /* Extra protection */
 475         if (session == NULL) {
 476                 return;
 477         }
 478
 479         rcu_read_lock();
 480
 481         DBG2("Trace UST destroy session %d", session->uid);
 482
 483         /* Cleaning up UST domain */
 484         destroy_domain_global(&session->domain_global);
 485         destroy_domain_pid(session->domain_pid);
 486         destroy_domain_exec(session->domain_exec);
 487
 488         free(session);
 489
 490         rcu_read_unlock();
 491 }