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
 103         /* Alloc UST domain hash tables */
 104         lus->domain_pid = hashtable_new(0);
 105         lus->domain_exec = hashtable_new_str(0);
 106
 107         /* Alloc UST global domain channels' HT */
 108         lus->domain_global.channels = hashtable_new_str(0);
 109
 110         /* Set session path */
 111         ret = snprintf(lus->pathname, PATH_MAX, "%s/ust", path);
 112         if (ret < 0) {
 113                 PERROR("snprintf kernel traces path");
 114                 goto error;
 115         }
 116
 117         DBG2("UST trace session create successful");
 118
 119         return lus;
 120
 121 error:
 122         return NULL;
 123 }
 124
 125 /*
 126  * Allocate and initialize a ust channel data structure.
 127  *
 128  * Return pointer to structure or NULL.
 129  */
 130 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
 131                 char *path)
 132 {
 133         int ret;
 134         struct ltt_ust_channel *luc;
 135
 136         luc = malloc(sizeof(struct ltt_ust_channel));
 137         if (luc == NULL) {
 138                 perror("ltt_ust_channel malloc");
 139                 goto error;
 140         }
 141
 142         /* Copy UST channel attributes */
 143         luc->attr.overwrite = chan->attr.overwrite;
 144         luc->attr.subbuf_size = chan->attr.subbuf_size;
 145         luc->attr.num_subbuf = chan->attr.num_subbuf;
 146         luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
 147         luc->attr.read_timer_interval = chan->attr.read_timer_interval;
 148         luc->attr.output = chan->attr.output;
 149
 150         /* Translate to UST output enum */
 151         switch (luc->attr.output) {
 152         default:
 153                 luc->attr.output = LTTNG_UST_MMAP;
 154                 break;
 155         }
 156
 157         /* Copy channel name */
 158         strncpy(luc->name, chan->name, sizeof(&luc->name));
 159         luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 160
 161         /* Init node */
 162         hashtable_node_init(&luc->node, (void *) luc->name, strlen(luc->name));
 163         /* Alloc hash tables */
 164         luc->events = hashtable_new_str(0);
 165         luc->ctx = hashtable_new_str(0);
 166
 167         /* Set trace output path */
 168         ret = snprintf(luc->pathname, PATH_MAX, "%s", path);
 169         if (ret < 0) {
 170                 perror("asprintf ust create channel");
 171                 goto error;
 172         }
 173
 174         DBG2("Trace UST channel %s created", luc->name);
 175
 176         return luc;
 177
 178 error:
 179         return NULL;
 180 }
 181
 182 /*
 183  * Allocate and initialize a ust event. Set name and event type.
 184  *
 185  * Return pointer to structure or NULL.
 186  */
 187 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev)
 188 {
 189         struct ltt_ust_event *lue;
 190
 191         lue = malloc(sizeof(struct ltt_ust_event));
 192         if (lue == NULL) {
 193                 PERROR("ust event malloc");
 194                 goto error;
 195         }
 196
 197         switch (ev->type) {
 198         case LTTNG_EVENT_PROBE:
 199                 lue->attr.instrumentation = LTTNG_UST_PROBE;
 200                 break;
 201         case LTTNG_EVENT_FUNCTION:
 202                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 203                 break;
 204         case LTTNG_EVENT_FUNCTION_ENTRY:
 205                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 206                 break;
 207         case LTTNG_EVENT_TRACEPOINT:
 208                 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
 209                 break;
 210         default:
 211                 ERR("Unknown ust instrumentation type (%d)", ev->type);
 212                 goto error;
 213         }
 214
 215         /* Copy event name */
 216         strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
 217         lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 218
 219         /* Init node */
 220         hashtable_node_init(&lue->node, (void *) lue->attr.name,
 221                         strlen(lue->attr.name));
 222         /* Alloc context hash tables */
 223         lue->ctx = hashtable_new_str(5);
 224
 225         return lue;
 226
 227 error:
 228         return NULL;
 229 }
 230
 231 /*
 232  * Allocate and initialize a ust metadata.
 233  *
 234  * Return pointer to structure or NULL.
 235  */
 236 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
 237 {
 238         int ret;
 239         struct ltt_ust_metadata *lum;
 240
 241         lum = malloc(sizeof(struct ltt_ust_metadata));
 242         if (lum == NULL) {
 243                 perror("ust metadata malloc");
 244                 goto error;
 245         }
 246
 247         /* Set default attributes */
 248         lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 249         lum->attr.subbuf_size = DEFAULT_METADATA_SUBBUF_SIZE;
 250         lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 251         lum->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 252         lum->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 253         lum->attr.output = DEFAULT_UST_CHANNEL_OUTPUT;
 254
 255         lum->handle = -1;
 256         /* Set metadata trace path */
 257         ret = snprintf(lum->pathname, PATH_MAX, "%s/metadata", path);
 258         if (ret < 0) {
 259                 perror("asprintf ust metadata");
 260                 goto error;
 261         }
 262
 263         return lum;
 264
 265 error:
 266         return NULL;
 267 }
 268
 269 /*
 270  * RCU safe free context structure.
 271  */
 272 static void destroy_context_rcu(struct rcu_head *head)
 273 {
 274         struct cds_lfht_node *node =
 275                 caa_container_of(head, struct cds_lfht_node, head);
 276         struct ltt_ust_context *ctx =
 277                 caa_container_of(node, struct ltt_ust_context, node);
 278
 279         free(ctx);
 280 }
 281
 282 /*
 283  * Cleanup UST context hash table.
 284  */
 285 static void destroy_context(struct cds_lfht *ht)
 286 {
 287         int ret;
 288         struct cds_lfht_node *node;
 289         struct cds_lfht_iter iter;
 290
 291         hashtable_get_first(ht, &iter);
 292         while ((node = hashtable_iter_get_node(&iter)) != NULL) {
 293                 ret = hashtable_del(ht, &iter);
 294                 if (!ret) {
 295                         call_rcu(&node->head, destroy_context_rcu);
 296                 }
 297                 hashtable_get_next(ht, &iter);
 298         }
 299 }
 300
 301 /*
 302  * Cleanup ust event structure.
 303  */
 304 void trace_ust_destroy_event(struct ltt_ust_event *event)
 305 {
 306         DBG2("Trace destroy UST event %s", event->attr.name);
 307         destroy_context(event->ctx);
 308         free(event);
 309 }
 310
 311 /*
 312  * URCU intermediate call to complete destroy event.
 313  */
 314 static void destroy_event_rcu(struct rcu_head *head)
 315 {
 316         struct cds_lfht_node *node =
 317                 caa_container_of(head, struct cds_lfht_node, head);
 318         struct ltt_ust_event *event =
 319                 caa_container_of(node, struct ltt_ust_event, node);
 320
 321         trace_ust_destroy_event(event);
 322 }
 323
 324 /*
 325  * Cleanup ust channel structure.
 326  */
 327 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 328 {
 329         int ret;
 330         struct cds_lfht_node *node;
 331         struct cds_lfht_iter iter;
 332
 333         DBG2("Trace destroy UST channel %s", channel->name);
 334
 335         rcu_read_lock();
 336
 337         hashtable_get_first(channel->events, &iter);
 338         while ((node = hashtable_iter_get_node(&iter)) != NULL) {
 339                 ret = hashtable_del(channel->events, &iter);
 340                 if (!ret) {
 341                         call_rcu(&node->head, destroy_event_rcu);
 342                 }
 343                 hashtable_get_next(channel->events, &iter);
 344         }
 345
 346         free(channel->events);
 347         destroy_context(channel->ctx);
 348         free(channel);
 349
 350         rcu_read_unlock();
 351 }
 352
 353 /*
 354  * URCU intermediate call to complete destroy channel.
 355  */
 356 static void destroy_channel_rcu(struct rcu_head *head)
 357 {
 358         struct cds_lfht_node *node =
 359                 caa_container_of(head, struct cds_lfht_node, head);
 360         struct ltt_ust_channel *channel =
 361                 caa_container_of(node, struct ltt_ust_channel, node);
 362
 363         trace_ust_destroy_channel(channel);
 364 }
 365
 366 /*
 367  * Cleanup ust metadata structure.
 368  */
 369 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 370 {
 371         DBG2("Trace UST destroy metadata %d", metadata->handle);
 372
 373         free(metadata);
 374 }
 375
 376 /*
 377  * Iterate over a hash table containing channels and cleanup safely.
 378  */
 379 static void destroy_channels(struct cds_lfht *channels)
 380 {
 381         int ret;
 382         struct cds_lfht_node *node;
 383         struct cds_lfht_iter iter;
 384
 385         hashtable_get_first(channels, &iter);
 386         while ((node = hashtable_iter_get_node(&iter)) != NULL) {
 387                 ret = hashtable_del(channels, &iter);
 388                 if (!ret) {
 389                         call_rcu(&node->head, destroy_channel_rcu);
 390                 }
 391                 hashtable_get_next(channels, &iter);
 392         }
 393 }
 394
 395 /*
 396  * Cleanup UST pid domain.
 397  */
 398 static void destroy_domain_pid(struct cds_lfht *ht)
 399 {
 400         int ret;
 401         struct cds_lfht_node *node;
 402         struct cds_lfht_iter iter;
 403         struct ltt_ust_domain_pid *d;
 404
 405         hashtable_get_first(ht, &iter);
 406         while ((node = hashtable_iter_get_node(&iter)) != NULL) {
 407                 ret = hashtable_del(ht , &iter);
 408                 if (!ret) {
 409                         d = caa_container_of(node, struct ltt_ust_domain_pid, node);
 410                         destroy_channels(d->channels);
 411                 }
 412                 hashtable_get_next(ht, &iter);
 413         }
 414 }
 415
 416 /*
 417  * Cleanup UST exec name domain.
 418  */
 419 static void destroy_domain_exec(struct cds_lfht *ht)
 420 {
 421         int ret;
 422         struct cds_lfht_node *node;
 423         struct cds_lfht_iter iter;
 424         struct ltt_ust_domain_exec *d;
 425
 426         hashtable_get_first(ht, &iter);
 427         while ((node = hashtable_iter_get_node(&iter)) != NULL) {
 428                 ret = hashtable_del(ht , &iter);
 429                 if (!ret) {
 430                         d = caa_container_of(node, struct ltt_ust_domain_exec, node);
 431                         destroy_channels(d->channels);
 432                 }
 433                 hashtable_get_next(ht, &iter);
 434         }
 435 }
 436
 437 /*
 438  * Cleanup UST global domain.
 439  */
 440 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
 441 {
 442         destroy_channels(dom->channels);
 443 }
 444
 445 /*
 446  * Cleanup ust session structure
 447  */
 448 void trace_ust_destroy_session(struct ltt_ust_session *session)
 449 {
 450         /* Extra safety */
 451         if (session == NULL) {
 452                 return;
 453         }
 454
 455         rcu_read_lock();
 456
 457         DBG2("Trace UST destroy session %d", session->uid);
 458
 459         //if (session->metadata != NULL) {
 460         //      trace_ust_destroy_metadata(session->metadata);
 461         //}
 462
 463         /* Cleaning up UST domain */
 464         destroy_domain_global(&session->domain_global);
 465         destroy_domain_pid(session->domain_pid);
 466         destroy_domain_exec(session->domain_exec);
 467
 468         free(session);
 469
 470         rcu_read_unlock();
 471 }