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->consumer_fds_sent = 0;
 102         lus->uid = uid;
 103         lus->start_trace = 0;
 104
 105         /* Alloc UST domain hash tables */
 106         lus->domain_pid = hashtable_new(0);
 107         lus->domain_exec = hashtable_new_str(0);
 108
 109         /* Alloc UST global domain channels' HT */
 110         lus->domain_global.channels = hashtable_new_str(0);
 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         hashtable_node_init(&luc->node, (void *) luc->name, strlen(luc->name));
 167         /* Alloc hash tables */
 168         luc->events = hashtable_new_str(0);
 169         luc->ctx = hashtable_new_str(0);
 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         default:
 217                 ERR("Unknown ust instrumentation type (%d)", ev->type);
 218                 goto error_free_event;
 219         }
 220
 221         /* Copy event name */
 222         strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
 223         lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 224
 225         /* Init node */
 226         hashtable_node_init(&lue->node, (void *) lue->attr.name,
 227                         strlen(lue->attr.name));
 228         /* Alloc context hash tables */
 229         lue->ctx = hashtable_new_str(0);
 230
 231         DBG2("Trace UST event %s created", lue->attr.name);
 232
 233         return lue;
 234
 235 error_free_event:
 236         free(lue);
 237 error:
 238         return NULL;
 239 }
 240
 241 /*
 242  * Allocate and initialize a ust metadata.
 243  *
 244  * Return pointer to structure or NULL.
 245  */
 246 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
 247 {
 248         int ret;
 249         struct ltt_ust_metadata *lum;
 250
 251         lum = zmalloc(sizeof(struct ltt_ust_metadata));
 252         if (lum == NULL) {
 253                 perror("ust metadata zmalloc");
 254                 goto error;
 255         }
 256
 257         /* Set default attributes */
 258         lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 259         lum->attr.subbuf_size = DEFAULT_METADATA_SUBBUF_SIZE;
 260         lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 261         lum->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 262         lum->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 263         lum->attr.output = LTTNG_UST_MMAP;
 264
 265         lum->handle = -1;
 266         /* Set metadata trace path */
 267         ret = snprintf(lum->pathname, PATH_MAX, "%s/metadata", path);
 268         if (ret < 0) {
 269                 perror("asprintf ust metadata");
 270                 goto error_free_metadata;
 271         }
 272
 273         return lum;
 274
 275 error_free_metadata:
 276         free(lum);
 277 error:
 278         return NULL;
 279 }
 280
 281 /*
 282  * RCU safe free context structure.
 283  */
 284 static void destroy_context_rcu(struct rcu_head *head)
 285 {
 286         struct cds_lfht_node *node =
 287                 caa_container_of(head, struct cds_lfht_node, head);
 288         struct ltt_ust_context *ctx =
 289                 caa_container_of(node, struct ltt_ust_context, node);
 290
 291         free(ctx);
 292 }
 293
 294 /*
 295  * Cleanup UST context hash table.
 296  */
 297 static void destroy_context(struct cds_lfht *ht)
 298 {
 299         int ret;
 300         struct cds_lfht_node *node;
 301         struct cds_lfht_iter iter;
 302
 303         cds_lfht_for_each(ht, &iter, node) {
 304                 ret = hashtable_del(ht, &iter);
 305                 if (!ret) {
 306                         call_rcu(&node->head, destroy_context_rcu);
 307                 }
 308         }
 309
 310         hashtable_destroy(ht);
 311 }
 312
 313 /*
 314  * Cleanup ust event structure.
 315  */
 316 void trace_ust_destroy_event(struct ltt_ust_event *event)
 317 {
 318         DBG2("Trace destroy UST event %s", event->attr.name);
 319         destroy_context(event->ctx);
 320
 321         free(event);
 322 }
 323
 324 /*
 325  * URCU intermediate call to complete destroy event.
 326  */
 327 static void destroy_event_rcu(struct rcu_head *head)
 328 {
 329         struct cds_lfht_node *node =
 330                 caa_container_of(head, struct cds_lfht_node, head);
 331         struct ltt_ust_event *event =
 332                 caa_container_of(node, struct ltt_ust_event, node);
 333
 334         trace_ust_destroy_event(event);
 335 }
 336
 337 /*
 338  * Cleanup UST events hashtable.
 339  */
 340 static void destroy_event(struct cds_lfht *events)
 341 {
 342         int ret;
 343         struct cds_lfht_node *node;
 344         struct cds_lfht_iter iter;
 345
 346         cds_lfht_for_each(events, &iter, node) {
 347                 ret = hashtable_del(events, &iter);
 348                 if (!ret) {
 349                         call_rcu(&node->head, destroy_event_rcu);
 350                 }
 351         }
 352
 353         hashtable_destroy(events);
 354 }
 355
 356 /*
 357  * Cleanup ust channel structure.
 358  */
 359 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 360 {
 361         int ret;
 362         struct cds_lfht_node *node;
 363         struct cds_lfht_iter iter;
 364
 365         DBG2("Trace destroy UST channel %s", channel->name);
 366
 367         rcu_read_lock();
 368
 369         cds_lfht_for_each(channel->events, &iter, node) {
 370                 ret = hashtable_del(channel->events, &iter);
 371                 if (!ret) {
 372                         destroy_event(channel->events);
 373                 }
 374         }
 375
 376         destroy_context(channel->ctx);
 377         free(channel);
 378
 379         rcu_read_unlock();
 380 }
 381
 382 /*
 383  * URCU intermediate call to complete destroy channel.
 384  */
 385 static void destroy_channel_rcu(struct rcu_head *head)
 386 {
 387         struct cds_lfht_node *node =
 388                 caa_container_of(head, struct cds_lfht_node, head);
 389         struct ltt_ust_channel *channel =
 390                 caa_container_of(node, struct ltt_ust_channel, node);
 391
 392         trace_ust_destroy_channel(channel);
 393 }
 394
 395 /*
 396  * Cleanup ust metadata structure.
 397  */
 398 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 399 {
 400         DBG2("Trace UST destroy metadata %d", metadata->handle);
 401
 402         free(metadata);
 403 }
 404
 405 /*
 406  * Iterate over a hash table containing channels and cleanup safely.
 407  */
 408 static void destroy_channels(struct cds_lfht *channels)
 409 {
 410         int ret;
 411         struct cds_lfht_node *node;
 412         struct cds_lfht_iter iter;
 413
 414         cds_lfht_for_each(channels, &iter, node) {
 415                 ret = hashtable_del(channels, &iter);
 416                 if (!ret) {
 417                         call_rcu(&node->head, destroy_channel_rcu);
 418                 }
 419         }
 420
 421         hashtable_destroy(channels);
 422 }
 423
 424 /*
 425  * Cleanup UST pid domain.
 426  */
 427 static void destroy_domain_pid(struct cds_lfht *ht)
 428 {
 429         int ret;
 430         struct cds_lfht_iter iter;
 431         struct ltt_ust_domain_pid *dpid;
 432
 433         cds_lfht_for_each_entry(ht, &iter, dpid, node) {
 434                 ret = hashtable_del(ht , &iter);
 435                 if (!ret) {
 436                         destroy_channels(dpid->channels);
 437                 }
 438         }
 439
 440         hashtable_destroy(ht);
 441 }
 442
 443 /*
 444  * Cleanup UST exec name domain.
 445  */
 446 static void destroy_domain_exec(struct cds_lfht *ht)
 447 {
 448         int ret;
 449         struct cds_lfht_iter iter;
 450         struct ltt_ust_domain_exec *dexec;
 451
 452         cds_lfht_for_each_entry(ht, &iter, dexec, node) {
 453                 ret = hashtable_del(ht , &iter);
 454                 if (!ret) {
 455                         destroy_channels(dexec->channels);
 456                 }
 457         }
 458
 459         hashtable_destroy(ht);
 460 }
 461
 462 /*
 463  * Cleanup UST global domain.
 464  */
 465 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
 466 {
 467         destroy_channels(dom->channels);
 468 }
 469
 470 /*
 471  * Cleanup ust session structure
 472  */
 473 void trace_ust_destroy_session(struct ltt_ust_session *session)
 474 {
 475         /* Extra protection */
 476         if (session == NULL) {
 477                 return;
 478         }
 479
 480         rcu_read_lock();
 481
 482         DBG2("Trace UST destroy session %d", session->uid);
 483
 484         /* Cleaning up UST domain */
 485         destroy_domain_global(&session->domain_global);
 486         destroy_domain_pid(session->domain_pid);
 487         destroy_domain_exec(session->domain_exec);
 488
 489         free(session);
 490
 491         rcu_read_unlock();
 492 }