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;
 116         }
 117
 118         DBG2("UST trace session create successful");
 119
 120         return lus;
 121
 122 error:
 123         return NULL;
 124 }
 125
 126 /*
 127  * Allocate and initialize a ust channel data structure.
 128  *
 129  * Return pointer to structure or NULL.
 130  */
 131 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
 132                 char *path)
 133 {
 134         int ret;
 135         struct ltt_ust_channel *luc;
 136
 137         luc = malloc(sizeof(struct ltt_ust_channel));
 138         if (luc == NULL) {
 139                 perror("ltt_ust_channel malloc");
 140                 goto error;
 141         }
 142
 143         /* Copy UST channel attributes */
 144         luc->attr.overwrite = chan->attr.overwrite;
 145         luc->attr.subbuf_size = chan->attr.subbuf_size;
 146         luc->attr.num_subbuf = chan->attr.num_subbuf;
 147         luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
 148         luc->attr.read_timer_interval = chan->attr.read_timer_interval;
 149         luc->attr.output = chan->attr.output;
 150
 151         /* Translate to UST output enum */
 152         switch (luc->attr.output) {
 153         default:
 154                 luc->attr.output = LTTNG_UST_MMAP;
 155                 break;
 156         }
 157
 158         /* Copy channel name */
 159         strncpy(luc->name, chan->name, sizeof(&luc->name));
 160         luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 161
 162         /* Init node */
 163         hashtable_node_init(&luc->node, (void *) luc->name, strlen(luc->name));
 164         /* Alloc hash tables */
 165         luc->events = hashtable_new_str(0);
 166         luc->ctx = hashtable_new_str(0);
 167
 168         /* Set trace output path */
 169         ret = snprintf(luc->pathname, PATH_MAX, "%s", path);
 170         if (ret < 0) {
 171                 perror("asprintf ust create channel");
 172                 goto error;
 173         }
 174
 175         DBG2("Trace UST channel %s created", luc->name);
 176
 177         return luc;
 178
 179 error:
 180         return NULL;
 181 }
 182
 183 /*
 184  * Allocate and initialize a ust event. Set name and event type.
 185  *
 186  * Return pointer to structure or NULL.
 187  */
 188 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev)
 189 {
 190         struct ltt_ust_event *lue;
 191
 192         lue = malloc(sizeof(struct ltt_ust_event));
 193         if (lue == NULL) {
 194                 PERROR("ust event malloc");
 195                 goto error;
 196         }
 197
 198         switch (ev->type) {
 199         case LTTNG_EVENT_PROBE:
 200                 lue->attr.instrumentation = LTTNG_UST_PROBE;
 201                 break;
 202         case LTTNG_EVENT_FUNCTION:
 203                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 204                 break;
 205         case LTTNG_EVENT_FUNCTION_ENTRY:
 206                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 207                 break;
 208         case LTTNG_EVENT_TRACEPOINT:
 209                 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
 210                 break;
 211         default:
 212                 ERR("Unknown ust instrumentation type (%d)", ev->type);
 213                 goto error;
 214         }
 215
 216         /* Copy event name */
 217         strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
 218         lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 219
 220         /* Init node */
 221         hashtable_node_init(&lue->node, (void *) lue->attr.name,
 222                         strlen(lue->attr.name));
 223         /* Alloc context hash tables */
 224         lue->ctx = hashtable_new_str(5);
 225
 226         return lue;
 227
 228 error:
 229         return NULL;
 230 }
 231
 232 /*
 233  * Allocate and initialize a ust metadata.
 234  *
 235  * Return pointer to structure or NULL.
 236  */
 237 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
 238 {
 239         int ret;
 240         struct ltt_ust_metadata *lum;
 241
 242         lum = malloc(sizeof(struct ltt_ust_metadata));
 243         if (lum == NULL) {
 244                 perror("ust metadata malloc");
 245                 goto error;
 246         }
 247
 248         /* Set default attributes */
 249         lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 250         lum->attr.subbuf_size = DEFAULT_METADATA_SUBBUF_SIZE;
 251         lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 252         lum->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 253         lum->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 254         lum->attr.output = LTTNG_UST_MMAP;
 255
 256         lum->handle = -1;
 257         /* Set metadata trace path */
 258         ret = snprintf(lum->pathname, PATH_MAX, "%s/metadata", path);
 259         if (ret < 0) {
 260                 perror("asprintf ust metadata");
 261                 goto error;
 262         }
 263
 264         return lum;
 265
 266 error:
 267         return NULL;
 268 }
 269
 270 /*
 271  * RCU safe free context structure.
 272  */
 273 static void destroy_context_rcu(struct rcu_head *head)
 274 {
 275         struct cds_lfht_node *node =
 276                 caa_container_of(head, struct cds_lfht_node, head);
 277         struct ltt_ust_context *ctx =
 278                 caa_container_of(node, struct ltt_ust_context, node);
 279
 280         free(ctx);
 281 }
 282
 283 /*
 284  * Cleanup UST context hash table.
 285  */
 286 static void destroy_context(struct cds_lfht *ht)
 287 {
 288         int ret;
 289         struct cds_lfht_node *node;
 290         struct cds_lfht_iter iter;
 291
 292         hashtable_get_first(ht, &iter);
 293         while ((node = hashtable_iter_get_node(&iter)) != NULL) {
 294                 ret = hashtable_del(ht, &iter);
 295                 if (!ret) {
 296                         call_rcu(&node->head, destroy_context_rcu);
 297                 }
 298                 hashtable_get_next(ht, &iter);
 299         }
 300 }
 301
 302 /*
 303  * Cleanup ust event structure.
 304  */
 305 void trace_ust_destroy_event(struct ltt_ust_event *event)
 306 {
 307         DBG2("Trace destroy UST event %s", event->attr.name);
 308         destroy_context(event->ctx);
 309         free(event);
 310 }
 311
 312 /*
 313  * URCU intermediate call to complete destroy event.
 314  */
 315 static void destroy_event_rcu(struct rcu_head *head)
 316 {
 317         struct cds_lfht_node *node =
 318                 caa_container_of(head, struct cds_lfht_node, head);
 319         struct ltt_ust_event *event =
 320                 caa_container_of(node, struct ltt_ust_event, node);
 321
 322         trace_ust_destroy_event(event);
 323 }
 324
 325 /*
 326  * Cleanup ust channel structure.
 327  */
 328 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 329 {
 330         int ret;
 331         struct cds_lfht_node *node;
 332         struct cds_lfht_iter iter;
 333
 334         DBG2("Trace destroy UST channel %s", channel->name);
 335
 336         rcu_read_lock();
 337
 338         hashtable_get_first(channel->events, &iter);
 339         while ((node = hashtable_iter_get_node(&iter)) != NULL) {
 340                 ret = hashtable_del(channel->events, &iter);
 341                 if (!ret) {
 342                         call_rcu(&node->head, destroy_event_rcu);
 343                 }
 344                 hashtable_get_next(channel->events, &iter);
 345         }
 346
 347         free(channel->events);
 348         destroy_context(channel->ctx);
 349         free(channel);
 350
 351         rcu_read_unlock();
 352 }
 353
 354 /*
 355  * URCU intermediate call to complete destroy channel.
 356  */
 357 static void destroy_channel_rcu(struct rcu_head *head)
 358 {
 359         struct cds_lfht_node *node =
 360                 caa_container_of(head, struct cds_lfht_node, head);
 361         struct ltt_ust_channel *channel =
 362                 caa_container_of(node, struct ltt_ust_channel, node);
 363
 364         trace_ust_destroy_channel(channel);
 365 }
 366
 367 /*
 368  * Cleanup ust metadata structure.
 369  */
 370 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 371 {
 372         DBG2("Trace UST destroy metadata %d", metadata->handle);
 373
 374         free(metadata);
 375 }
 376
 377 /*
 378  * Iterate over a hash table containing channels and cleanup safely.
 379  */
 380 static void destroy_channels(struct cds_lfht *channels)
 381 {
 382         int ret;
 383         struct cds_lfht_node *node;
 384         struct cds_lfht_iter iter;
 385
 386         hashtable_get_first(channels, &iter);
 387         while ((node = hashtable_iter_get_node(&iter)) != NULL) {
 388                 ret = hashtable_del(channels, &iter);
 389                 if (!ret) {
 390                         call_rcu(&node->head, destroy_channel_rcu);
 391                 }
 392                 hashtable_get_next(channels, &iter);
 393         }
 394 }
 395
 396 /*
 397  * Cleanup UST pid domain.
 398  */
 399 static void destroy_domain_pid(struct cds_lfht *ht)
 400 {
 401         int ret;
 402         struct cds_lfht_node *node;
 403         struct cds_lfht_iter iter;
 404         struct ltt_ust_domain_pid *d;
 405
 406         hashtable_get_first(ht, &iter);
 407         while ((node = hashtable_iter_get_node(&iter)) != NULL) {
 408                 ret = hashtable_del(ht , &iter);
 409                 if (!ret) {
 410                         d = caa_container_of(node, struct ltt_ust_domain_pid, node);
 411                         destroy_channels(d->channels);
 412                 }
 413                 hashtable_get_next(ht, &iter);
 414         }
 415 }
 416
 417 /*
 418  * Cleanup UST exec name domain.
 419  */
 420 static void destroy_domain_exec(struct cds_lfht *ht)
 421 {
 422         int ret;
 423         struct cds_lfht_node *node;
 424         struct cds_lfht_iter iter;
 425         struct ltt_ust_domain_exec *d;
 426
 427         hashtable_get_first(ht, &iter);
 428         while ((node = hashtable_iter_get_node(&iter)) != NULL) {
 429                 ret = hashtable_del(ht , &iter);
 430                 if (!ret) {
 431                         d = caa_container_of(node, struct ltt_ust_domain_exec, node);
 432                         destroy_channels(d->channels);
 433                 }
 434                 hashtable_get_next(ht, &iter);
 435         }
 436 }
 437
 438 /*
 439  * Cleanup UST global domain.
 440  */
 441 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
 442 {
 443         destroy_channels(dom->channels);
 444 }
 445
 446 /*
 447  * Cleanup ust session structure
 448  */
 449 void trace_ust_destroy_session(struct ltt_ust_session *session)
 450 {
 451         /* Extra safety */
 452         if (session == NULL) {
 453                 return;
 454         }
 455
 456         rcu_read_lock();
 457
 458         DBG2("Trace UST destroy session %d", session->uid);
 459
 460         //if (session->metadata != NULL) {
 461         //      trace_ust_destroy_metadata(session->metadata);
 462         //}
 463
 464         /* Cleaning up UST domain */
 465         destroy_domain_global(&session->domain_global);
 466         destroy_domain_pid(session->domain_pid);
 467         destroy_domain_exec(session->domain_exec);
 468
 469         free(session);
 470
 471         rcu_read_unlock();
 472 }