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("Found UST event by name %s", name);
  74
  75         return caa_container_of(node, struct ltt_ust_event, node);
  76
  77 error:
  78         return NULL;
  79 }
  80
  81 /*
  82  * Allocate and initialize a ust session data structure.
  83  *
  84  * Return pointer to structure or NULL.
  85  */
  86 struct ltt_ust_session *trace_ust_create_session(char *path, unsigned int uid,
  87                 struct lttng_domain *domain)
  88 {
  89         int ret;
  90         struct ltt_ust_session *lus;
  91
  92         /* Allocate a new ltt ust session */
  93         lus = malloc(sizeof(struct ltt_ust_session));
  94         if (lus == NULL) {
  95                 PERROR("create ust session malloc");
  96                 goto error;
  97         }
  98
  99         /* Init data structure */
 100         lus->consumer_fds_sent = 0;
 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 = malloc(sizeof(struct ltt_ust_channel));
 140         if (luc == NULL) {
 141                 perror("ltt_ust_channel malloc");
 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 = malloc(sizeof(struct ltt_ust_event));
 197         if (lue == NULL) {
 198                 PERROR("ust event malloc");
 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         return lue;
 231
 232 error_free_event:
 233         free(lue);
 234 error:
 235         return NULL;
 236 }
 237
 238 /*
 239  * Allocate and initialize a ust metadata.
 240  *
 241  * Return pointer to structure or NULL.
 242  */
 243 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
 244 {
 245         int ret;
 246         struct ltt_ust_metadata *lum;
 247
 248         lum = zmalloc(sizeof(struct ltt_ust_metadata));
 249         if (lum == NULL) {
 250                 perror("ust metadata malloc");
 251                 goto error;
 252         }
 253
 254         /* Set default attributes */
 255         lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 256         lum->attr.subbuf_size = DEFAULT_METADATA_SUBBUF_SIZE;
 257         lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 258         lum->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 259         lum->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 260         lum->attr.output = LTTNG_UST_MMAP;
 261
 262         lum->handle = -1;
 263         /* Set metadata trace path */
 264         ret = snprintf(lum->pathname, PATH_MAX, "%s/metadata", path);
 265         if (ret < 0) {
 266                 perror("asprintf ust metadata");
 267                 goto error_free_metadata;
 268         }
 269
 270         return lum;
 271
 272 error_free_metadata:
 273         free(lum);
 274 error:
 275         return NULL;
 276 }
 277
 278 /*
 279  * RCU safe free context structure.
 280  */
 281 static void destroy_context_rcu(struct rcu_head *head)
 282 {
 283         struct cds_lfht_node *node =
 284                 caa_container_of(head, struct cds_lfht_node, head);
 285         struct ltt_ust_context *ctx =
 286                 caa_container_of(node, struct ltt_ust_context, node);
 287
 288         free(ctx);
 289 }
 290
 291 /*
 292  * Cleanup UST context hash table.
 293  */
 294 static void destroy_context(struct cds_lfht *ht)
 295 {
 296         int ret;
 297         struct cds_lfht_node *node;
 298         struct cds_lfht_iter iter;
 299
 300         cds_lfht_for_each(ht, &iter, node) {
 301                 ret = hashtable_del(ht, &iter);
 302                 if (!ret) {
 303                         call_rcu(&node->head, destroy_context_rcu);
 304                 }
 305         }
 306
 307         hashtable_destroy(ht);
 308 }
 309
 310 /*
 311  * Cleanup ust event structure.
 312  */
 313 void trace_ust_destroy_event(struct ltt_ust_event *event)
 314 {
 315         DBG2("Trace destroy UST event %s", event->attr.name);
 316         destroy_context(event->ctx);
 317
 318         free(event);
 319 }
 320
 321 /*
 322  * URCU intermediate call to complete destroy event.
 323  */
 324 static void destroy_event_rcu(struct rcu_head *head)
 325 {
 326         struct cds_lfht_node *node =
 327                 caa_container_of(head, struct cds_lfht_node, head);
 328         struct ltt_ust_event *event =
 329                 caa_container_of(node, struct ltt_ust_event, node);
 330
 331         trace_ust_destroy_event(event);
 332 }
 333
 334 static void destroy_event(struct cds_lfht *ht)
 335 {
 336         int ret;
 337         struct cds_lfht_node *node;
 338         struct cds_lfht_iter iter;
 339
 340         cds_lfht_for_each(ht, &iter, node) {
 341                 ret = hashtable_del(ht, &iter);
 342                 if (!ret) {
 343                         call_rcu(&node->head, destroy_event_rcu);
 344                 }
 345         }
 346
 347         hashtable_destroy(ht);
 348 }
 349
 350 /*
 351  * Cleanup ust channel structure.
 352  */
 353 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 354 {
 355         int ret;
 356         struct cds_lfht_node *node;
 357         struct cds_lfht_iter iter;
 358
 359         DBG2("Trace destroy UST channel %s", channel->name);
 360
 361         rcu_read_lock();
 362
 363         cds_lfht_for_each(channel->events, &iter, node) {
 364                 ret = hashtable_del(channel->events, &iter);
 365                 if (!ret) {
 366                         destroy_event(channel->events);
 367                 }
 368         }
 369
 370         destroy_context(channel->ctx);
 371         free(channel);
 372
 373         rcu_read_unlock();
 374 }
 375
 376 /*
 377  * URCU intermediate call to complete destroy channel.
 378  */
 379 static void destroy_channel_rcu(struct rcu_head *head)
 380 {
 381         struct cds_lfht_node *node =
 382                 caa_container_of(head, struct cds_lfht_node, head);
 383         struct ltt_ust_channel *channel =
 384                 caa_container_of(node, struct ltt_ust_channel, node);
 385
 386         trace_ust_destroy_channel(channel);
 387 }
 388
 389 /*
 390  * Cleanup ust metadata structure.
 391  */
 392 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 393 {
 394         DBG2("Trace UST destroy metadata %d", metadata->handle);
 395
 396         free(metadata);
 397 }
 398
 399 /*
 400  * Iterate over a hash table containing channels and cleanup safely.
 401  */
 402 static void destroy_channels(struct cds_lfht *channels)
 403 {
 404         int ret;
 405         struct cds_lfht_node *node;
 406         struct cds_lfht_iter iter;
 407
 408         cds_lfht_for_each(channels, &iter, node) {
 409                 ret = hashtable_del(channels, &iter);
 410                 if (!ret) {
 411                         call_rcu(&node->head, destroy_channel_rcu);
 412                 }
 413         }
 414
 415         hashtable_destroy(channels);
 416 }
 417
 418 /*
 419  * Cleanup UST pid domain.
 420  */
 421 static void destroy_domain_pid(struct cds_lfht *ht)
 422 {
 423         int ret;
 424         struct cds_lfht_iter iter;
 425         struct ltt_ust_domain_pid *dpid;
 426
 427         cds_lfht_for_each_entry(ht, &iter, dpid, node) {
 428                 ret = hashtable_del(ht , &iter);
 429                 if (!ret) {
 430                         destroy_channels(dpid->channels);
 431                 }
 432         }
 433
 434         hashtable_destroy(ht);
 435 }
 436
 437 /*
 438  * Cleanup UST exec name domain.
 439  */
 440 static void destroy_domain_exec(struct cds_lfht *ht)
 441 {
 442         int ret;
 443         struct cds_lfht_iter iter;
 444         struct ltt_ust_domain_exec *dexec;
 445
 446         cds_lfht_for_each_entry(ht, &iter, dexec, node) {
 447                 ret = hashtable_del(ht , &iter);
 448                 if (!ret) {
 449                         destroy_channels(dexec->channels);
 450                 }
 451         }
 452
 453         hashtable_destroy(ht);
 454 }
 455
 456 /*
 457  * Cleanup UST global domain.
 458  */
 459 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
 460 {
 461         destroy_channels(dom->channels);
 462 }
 463
 464 /*
 465  * Cleanup ust session structure
 466  */
 467 void trace_ust_destroy_session(struct ltt_ust_session *session)
 468 {
 469         /* Extra protection */
 470         if (session == NULL) {
 471                 return;
 472         }
 473
 474         rcu_read_lock();
 475
 476         DBG2("Trace UST destroy session %d", session->uid);
 477
 478         /* Cleaning up UST domain */
 479         destroy_domain_global(&session->domain_global);
 480         destroy_domain_pid(session->domain_pid);
 481         destroy_domain_exec(session->domain_exec);
 482
 483         free(session);
 484
 485         rcu_read_unlock();
 486 }