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-ht.h>
  26 #include <lttng-share.h>
  27
  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 lttng_ht *ht,
  34                 char *name)
  35 {
  36         struct lttng_ht_node_str *node;
  37         struct lttng_ht_iter iter;
  38
  39         rcu_read_lock();
  40         lttng_ht_lookup(ht, (void *)name, &iter);
  41         node = lttng_ht_iter_get_node_str(&iter);
  42         if (node == NULL) {
  43                 rcu_read_unlock();
  44                 goto error;
  45         }
  46         rcu_read_unlock();
  47
  48         DBG2("Trace UST channel %s found by name", name);
  49
  50         return caa_container_of(node, struct ltt_ust_channel, node);
  51
  52 error:
  53         DBG2("Trace UST channel %s not found by name", name);
  54         return NULL;
  55 }
  56
  57 /*
  58  * Find the event in the hashtable.
  59  */
  60 struct ltt_ust_event *trace_ust_find_event_by_name(struct lttng_ht *ht,
  61                 char *name)
  62 {
  63         struct lttng_ht_node_str *node;
  64         struct lttng_ht_iter iter;
  65
  66         rcu_read_lock();
  67         lttng_ht_lookup(ht, (void *) name, &iter);
  68         node = lttng_ht_iter_get_node_str(&iter);
  69         if (node == NULL) {
  70                 rcu_read_unlock();
  71                 goto error;
  72         }
  73         rcu_read_unlock();
  74
  75         DBG2("Trace UST event found by name %s", name);
  76
  77         return caa_container_of(node, struct ltt_ust_event, node);
  78
  79 error:
  80         DBG2("Trace UST event NOT found by name %s", name);
  81         return NULL;
  82 }
  83
  84 /*
  85  * Allocate and initialize a ust session data structure.
  86  *
  87  * Return pointer to structure or NULL.
  88  */
  89 struct ltt_ust_session *trace_ust_create_session(char *path, int session_id,
  90                 struct lttng_domain *domain)
  91 {
  92         int ret;
  93         struct ltt_ust_session *lus;
  94
  95         /* Allocate a new ltt ust session */
  96         lus = zmalloc(sizeof(struct ltt_ust_session));
  97         if (lus == NULL) {
  98                 PERROR("create ust session zmalloc");
  99                 goto error;
 100         }
 101
 102         /* Init data structure */
 103         lus->id = session_id;
 104         lus->start_trace = 0;
 105
 106         /* Alloc UST domain hash tables */
 107         lus->domain_pid = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 108         lus->domain_exec = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 109
 110         /* Alloc UST global domain channels' HT */
 111         lus->domain_global.channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 112
 113         /* Set session path */
 114         ret = snprintf(lus->pathname, PATH_MAX, "%s/ust", path);
 115         if (ret < 0) {
 116                 PERROR("snprintf kernel traces path");
 117                 goto error_free_session;
 118         }
 119
 120         DBG2("UST trace session create successful");
 121
 122         return lus;
 123
 124 error_free_session:
 125         free(lus);
 126 error:
 127         return NULL;
 128 }
 129
 130 /*
 131  * Allocate and initialize a ust channel data structure.
 132  *
 133  * Return pointer to structure or NULL.
 134  */
 135 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
 136                 char *path)
 137 {
 138         int ret;
 139         struct ltt_ust_channel *luc;
 140
 141         luc = zmalloc(sizeof(struct ltt_ust_channel));
 142         if (luc == NULL) {
 143                 perror("ltt_ust_channel zmalloc");
 144                 goto error;
 145         }
 146
 147         /* Copy UST channel attributes */
 148         luc->attr.overwrite = chan->attr.overwrite;
 149         luc->attr.subbuf_size = chan->attr.subbuf_size;
 150         luc->attr.num_subbuf = chan->attr.num_subbuf;
 151         luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
 152         luc->attr.read_timer_interval = chan->attr.read_timer_interval;
 153         luc->attr.output = chan->attr.output;
 154
 155         /* Translate to UST output enum */
 156         switch (luc->attr.output) {
 157         default:
 158                 luc->attr.output = LTTNG_UST_MMAP;
 159                 break;
 160         }
 161
 162         /* Copy channel name */
 163         strncpy(luc->name, chan->name, sizeof(luc->name));
 164         luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 165
 166         /* Init node */
 167         lttng_ht_node_init_str(&luc->node, luc->name);
 168         /* Alloc hash tables */
 169         luc->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
 170         luc->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 171
 172         /* Set trace output path */
 173         ret = snprintf(luc->pathname, PATH_MAX, "%s", path);
 174         if (ret < 0) {
 175                 perror("asprintf ust create channel");
 176                 goto error_free_channel;
 177         }
 178
 179         DBG2("Trace UST channel %s created", luc->name);
 180
 181         return luc;
 182
 183 error_free_channel:
 184         free(luc);
 185 error:
 186         return NULL;
 187 }
 188
 189 /*
 190  * Allocate and initialize a ust event. Set name and event type.
 191  *
 192  * Return pointer to structure or NULL.
 193  */
 194 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev)
 195 {
 196         struct ltt_ust_event *lue;
 197
 198         lue = zmalloc(sizeof(struct ltt_ust_event));
 199         if (lue == NULL) {
 200                 PERROR("ust event zmalloc");
 201                 goto error;
 202         }
 203
 204         switch (ev->type) {
 205         case LTTNG_EVENT_PROBE:
 206                 lue->attr.instrumentation = LTTNG_UST_PROBE;
 207                 break;
 208         case LTTNG_EVENT_FUNCTION:
 209                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 210                 break;
 211         case LTTNG_EVENT_FUNCTION_ENTRY:
 212                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 213                 break;
 214         case LTTNG_EVENT_TRACEPOINT:
 215                 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
 216                 break;
 217         case LTTNG_EVENT_TRACEPOINT_LOGLEVEL:
 218                 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT_LOGLEVEL;
 219                 break;
 220         default:
 221                 ERR("Unknown ust instrumentation type (%d)", ev->type);
 222                 goto error_free_event;
 223         }
 224
 225         /* Copy event name */
 226         strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
 227         lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 228
 229         /* Init node */
 230         lttng_ht_node_init_str(&lue->node, lue->attr.name);
 231         /* Alloc context hash tables */
 232         lue->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 233
 234         DBG2("Trace UST event %s created", lue->attr.name);
 235
 236         return lue;
 237
 238 error_free_event:
 239         free(lue);
 240 error:
 241         return NULL;
 242 }
 243
 244 /*
 245  * Allocate and initialize a ust metadata.
 246  *
 247  * Return pointer to structure or NULL.
 248  */
 249 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
 250 {
 251         int ret;
 252         struct ltt_ust_metadata *lum;
 253
 254         lum = zmalloc(sizeof(struct ltt_ust_metadata));
 255         if (lum == NULL) {
 256                 perror("ust metadata zmalloc");
 257                 goto error;
 258         }
 259
 260         /* Set default attributes */
 261         lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 262         lum->attr.subbuf_size = DEFAULT_METADATA_SUBBUF_SIZE;
 263         lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 264         lum->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 265         lum->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 266         lum->attr.output = LTTNG_UST_MMAP;
 267
 268         lum->handle = -1;
 269         /* Set metadata trace path */
 270         ret = snprintf(lum->pathname, PATH_MAX, "%s/metadata", path);
 271         if (ret < 0) {
 272                 perror("asprintf ust metadata");
 273                 goto error_free_metadata;
 274         }
 275
 276         return lum;
 277
 278 error_free_metadata:
 279         free(lum);
 280 error:
 281         return NULL;
 282 }
 283
 284 /*
 285  * Allocate and initialize an UST context.
 286  *
 287  * Return pointer to structure or NULL.
 288  */
 289 struct ltt_ust_context *trace_ust_create_context(
 290                 struct lttng_event_context *ctx)
 291 {
 292         struct ltt_ust_context *uctx;
 293
 294         uctx = zmalloc(sizeof(struct ltt_ust_context));
 295         if (uctx == NULL) {
 296                 PERROR("zmalloc ltt_ust_context");
 297                 goto error;
 298         }
 299
 300         uctx->ctx.ctx = ctx->ctx;
 301         lttng_ht_node_init_ulong(&uctx->node, (unsigned long) uctx->ctx.ctx);
 302
 303         return uctx;
 304
 305 error:
 306         return NULL;
 307 }
 308
 309 /*
 310  * RCU safe free context structure.
 311  */
 312 static void destroy_context_rcu(struct rcu_head *head)
 313 {
 314         struct lttng_ht_node_ulong *node =
 315                 caa_container_of(head, struct lttng_ht_node_ulong, head);
 316         struct ltt_ust_context *ctx =
 317                 caa_container_of(node, struct ltt_ust_context, node);
 318
 319         free(ctx);
 320 }
 321
 322 /*
 323  * Cleanup UST context hash table.
 324  */
 325 static void destroy_context(struct lttng_ht *ht)
 326 {
 327         int ret;
 328         struct lttng_ht_node_ulong *node;
 329         struct lttng_ht_iter iter;
 330
 331         cds_lfht_for_each_entry(ht->ht, &iter.iter, node, node) {
 332                 ret = lttng_ht_del(ht, &iter);
 333                 if (!ret) {
 334                         call_rcu(&node->head, destroy_context_rcu);
 335                 }
 336         }
 337
 338         lttng_ht_destroy(ht);
 339 }
 340
 341 /*
 342  * Cleanup ust event structure.
 343  */
 344 void trace_ust_destroy_event(struct ltt_ust_event *event)
 345 {
 346         DBG2("Trace destroy UST event %s", event->attr.name);
 347         destroy_context(event->ctx);
 348
 349         free(event);
 350 }
 351
 352 /*
 353  * URCU intermediate call to complete destroy event.
 354  */
 355 static void destroy_event_rcu(struct rcu_head *head)
 356 {
 357         struct lttng_ht_node_str *node =
 358                 caa_container_of(head, struct lttng_ht_node_str, head);
 359         struct ltt_ust_event *event =
 360                 caa_container_of(node, struct ltt_ust_event, node);
 361
 362         trace_ust_destroy_event(event);
 363 }
 364
 365 /*
 366  * Cleanup UST events hashtable.
 367  */
 368 static void destroy_event(struct lttng_ht *events)
 369 {
 370         int ret;
 371         struct lttng_ht_node_str *node;
 372         struct lttng_ht_iter iter;
 373
 374         cds_lfht_for_each_entry(events->ht, &iter.iter, node, node) {
 375                 ret = lttng_ht_del(events, &iter);
 376                 if (!ret) {
 377                         call_rcu(&node->head, destroy_event_rcu);
 378                 }
 379         }
 380
 381         lttng_ht_destroy(events);
 382 }
 383
 384 /*
 385  * Cleanup ust channel structure.
 386  */
 387 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 388 {
 389         int ret;
 390         struct lttng_ht_node_str *node;
 391         struct lttng_ht_iter iter;
 392
 393         DBG2("Trace destroy UST channel %s", channel->name);
 394
 395         rcu_read_lock();
 396
 397         cds_lfht_for_each_entry(channel->events->ht, &iter.iter, node, node) {
 398                 ret = lttng_ht_del(channel->events, &iter);
 399                 if (!ret) {
 400                         destroy_event(channel->events);
 401                 }
 402         }
 403
 404         destroy_context(channel->ctx);
 405         free(channel);
 406
 407         rcu_read_unlock();
 408 }
 409
 410 /*
 411  * URCU intermediate call to complete destroy channel.
 412  */
 413 static void destroy_channel_rcu(struct rcu_head *head)
 414 {
 415         struct lttng_ht_node_str *node =
 416                 caa_container_of(head, struct lttng_ht_node_str, head);
 417         struct ltt_ust_channel *channel =
 418                 caa_container_of(node, struct ltt_ust_channel, node);
 419
 420         trace_ust_destroy_channel(channel);
 421 }
 422
 423 /*
 424  * Cleanup ust metadata structure.
 425  */
 426 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 427 {
 428         DBG2("Trace UST destroy metadata %d", metadata->handle);
 429
 430         free(metadata);
 431 }
 432
 433 /*
 434  * Iterate over a hash table containing channels and cleanup safely.
 435  */
 436 static void destroy_channels(struct lttng_ht *channels)
 437 {
 438         int ret;
 439         struct lttng_ht_node_str *node;
 440         struct lttng_ht_iter iter;
 441
 442         cds_lfht_for_each_entry(channels->ht, &iter.iter, node, node) {
 443                 ret = lttng_ht_del(channels, &iter);
 444                 if (!ret) {
 445                         call_rcu(&node->head, destroy_channel_rcu);
 446                 }
 447         }
 448
 449         lttng_ht_destroy(channels);
 450 }
 451
 452 /*
 453  * Cleanup UST pid domain.
 454  */
 455 static void destroy_domain_pid(struct lttng_ht *ht)
 456 {
 457         int ret;
 458         struct lttng_ht_iter iter;
 459         struct ltt_ust_domain_pid *dpid;
 460
 461         cds_lfht_for_each_entry(ht->ht, &iter.iter, dpid, node.node) {
 462                 ret = lttng_ht_del(ht , &iter);
 463                 if (!ret) {
 464                         destroy_channels(dpid->channels);
 465                 }
 466         }
 467
 468         lttng_ht_destroy(ht);
 469 }
 470
 471 /*
 472  * Cleanup UST exec name domain.
 473  */
 474 static void destroy_domain_exec(struct lttng_ht *ht)
 475 {
 476         int ret;
 477         struct lttng_ht_iter iter;
 478         struct ltt_ust_domain_exec *dexec;
 479
 480         cds_lfht_for_each_entry(ht->ht, &iter.iter, dexec, node.node) {
 481                 ret = lttng_ht_del(ht , &iter);
 482                 if (!ret) {
 483                         destroy_channels(dexec->channels);
 484                 }
 485         }
 486
 487         lttng_ht_destroy(ht);
 488 }
 489
 490 /*
 491  * Cleanup UST global domain.
 492  */
 493 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
 494 {
 495         destroy_channels(dom->channels);
 496 }
 497
 498 /*
 499  * Cleanup ust session structure
 500  */
 501 void trace_ust_destroy_session(struct ltt_ust_session *session)
 502 {
 503         /* Extra protection */
 504         if (session == NULL) {
 505                 return;
 506         }
 507
 508         rcu_read_lock();
 509
 510         DBG2("Trace UST destroy session %d", session->id);
 511
 512         /* Cleaning up UST domain */
 513         destroy_domain_global(&session->domain_global);
 514         destroy_domain_pid(session->domain_pid);
 515         destroy_domain_exec(session->domain_exec);
 516
 517         free(session);
 518
 519         rcu_read_unlock();
 520 }