src/bin/lttng-sessiond/trace-kernel.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
   5  * it under the terms of the GNU General Public License, version 2 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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 <common/common.h>
  25 #include <common/defaults.h>
  26
  27 #include "consumer.h"
  28 #include "trace-kernel.h"
  29
  30 /*
  31  * Find the channel name for the given kernel session.
  32  */
  33 struct ltt_kernel_channel *trace_kernel_get_channel_by_name(
  34                 char *name, struct ltt_kernel_session *session)
  35 {
  36         struct ltt_kernel_channel *chan;
  37
  38         assert(session);
  39         assert(name);
  40
  41         DBG("Trying to find channel %s", name);
  42
  43         cds_list_for_each_entry(chan, &session->channel_list.head, list) {
  44                 if (strcmp(name, chan->channel->name) == 0) {
  45                         DBG("Found channel by name %s", name);
  46                         return chan;
  47                 }
  48         }
  49
  50         return NULL;
  51 }
  52
  53 /*
  54  * Find the event name for the given channel.
  55  */
  56 struct ltt_kernel_event *trace_kernel_get_event_by_name(
  57                 char *name, struct ltt_kernel_channel *channel)
  58 {
  59         struct ltt_kernel_event *ev;
  60
  61         assert(name);
  62         assert(channel);
  63
  64         cds_list_for_each_entry(ev, &channel->events_list.head, list) {
  65                 if (strcmp(name, ev->event->name) == 0) {
  66                         DBG("Found event by name %s for channel %s", name,
  67                                         channel->channel->name);
  68                         return ev;
  69                 }
  70         }
  71
  72         return NULL;
  73 }
  74
  75 /*
  76  * Allocate and initialize a kernel session data structure.
  77  *
  78  * Return pointer to structure or NULL.
  79  */
  80 struct ltt_kernel_session *trace_kernel_create_session(char *path)
  81 {
  82         struct ltt_kernel_session *lks = NULL;
  83
  84         /* Allocate a new ltt kernel session */
  85         lks = zmalloc(sizeof(struct ltt_kernel_session));
  86         if (lks == NULL) {
  87                 PERROR("create kernel session zmalloc");
  88                 goto alloc_error;
  89         }
  90
  91         /* Init data structure */
  92         lks->fd = -1;
  93         lks->metadata_stream_fd = -1;
  94         lks->channel_count = 0;
  95         lks->stream_count_global = 0;
  96         lks->metadata = NULL;
  97         CDS_INIT_LIST_HEAD(&lks->channel_list.head);
  98
  99         lks->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
 100         if (lks->consumer == NULL) {
 101                 goto error;
 102         }
 103
 104         /*
 105          * The tmp_consumer stays NULL until a set_consumer_uri command is
 106          * executed. At this point, the consumer should be nullify until an
 107          * enable_consumer command. This assignment is symbolic since we've zmalloc
 108          * the struct.
 109          */
 110         lks->tmp_consumer = NULL;
 111
 112         if (*path != '\0') {
 113                 int ret;
 114
 115                 /* Use the default consumer output which is the tracing session path. */
 116                 ret = snprintf(lks->consumer->dst.trace_path, PATH_MAX,
 117                                 "%s" DEFAULT_KERNEL_TRACE_DIR, path);
 118                 if (ret < 0) {
 119                         PERROR("snprintf consumer trace path");
 120                         goto error;
 121                 }
 122
 123                 /* Set session path */
 124                 ret = asprintf(&lks->trace_path, "%s" DEFAULT_KERNEL_TRACE_DIR, path);
 125                 if (ret < 0) {
 126                         PERROR("asprintf kernel traces path");
 127                         goto error;
 128                 }
 129         }
 130
 131         return lks;
 132
 133 error:
 134         free(lks);
 135
 136 alloc_error:
 137         return NULL;
 138 }
 139
 140 /*
 141  * Allocate and initialize a kernel channel data structure.
 142  *
 143  * Return pointer to structure or NULL.
 144  */
 145 struct ltt_kernel_channel *trace_kernel_create_channel(
 146                 struct lttng_channel *chan)
 147 {
 148         struct ltt_kernel_channel *lkc;
 149
 150         assert(chan);
 151
 152         lkc = zmalloc(sizeof(struct ltt_kernel_channel));
 153         if (lkc == NULL) {
 154                 PERROR("ltt_kernel_channel zmalloc");
 155                 goto error;
 156         }
 157
 158         lkc->channel = zmalloc(sizeof(struct lttng_channel));
 159         if (lkc->channel == NULL) {
 160                 PERROR("lttng_channel zmalloc");
 161                 free(lkc);
 162                 goto error;
 163         }
 164         memcpy(lkc->channel, chan, sizeof(struct lttng_channel));
 165
 166         lkc->fd = -1;
 167         lkc->stream_count = 0;
 168         lkc->event_count = 0;
 169         lkc->enabled = 1;
 170         lkc->ctx = NULL;
 171         /* Init linked list */
 172         CDS_INIT_LIST_HEAD(&lkc->events_list.head);
 173         CDS_INIT_LIST_HEAD(&lkc->stream_list.head);
 174
 175         return lkc;
 176
 177 error:
 178         return NULL;
 179 }
 180
 181 /*
 182  * Allocate and initialize a kernel event. Set name and event type.
 183  *
 184  * Return pointer to structure or NULL.
 185  */
 186 struct ltt_kernel_event *trace_kernel_create_event(struct lttng_event *ev)
 187 {
 188         struct ltt_kernel_event *lke;
 189         struct lttng_kernel_event *attr;
 190
 191         assert(ev);
 192
 193         lke = zmalloc(sizeof(struct ltt_kernel_event));
 194         attr = zmalloc(sizeof(struct lttng_kernel_event));
 195         if (lke == NULL || attr == NULL) {
 196                 PERROR("kernel event zmalloc");
 197                 goto error;
 198         }
 199
 200         switch (ev->type) {
 201         case LTTNG_EVENT_PROBE:
 202                 attr->instrumentation = LTTNG_KERNEL_KPROBE;
 203                 attr->u.kprobe.addr = ev->attr.probe.addr;
 204                 attr->u.kprobe.offset = ev->attr.probe.offset;
 205                 strncpy(attr->u.kprobe.symbol_name,
 206                                 ev->attr.probe.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
 207                 attr->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 208                 break;
 209         case LTTNG_EVENT_FUNCTION:
 210                 attr->instrumentation = LTTNG_KERNEL_KRETPROBE;
 211                 attr->u.kretprobe.addr = ev->attr.probe.addr;
 212                 attr->u.kretprobe.offset = ev->attr.probe.offset;
 213                 attr->u.kretprobe.offset = ev->attr.probe.offset;
 214                 strncpy(attr->u.kretprobe.symbol_name,
 215                                 ev->attr.probe.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
 216                 attr->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 217                 break;
 218         case LTTNG_EVENT_FUNCTION_ENTRY:
 219                 attr->instrumentation = LTTNG_KERNEL_FUNCTION;
 220                 strncpy(attr->u.ftrace.symbol_name,
 221                                 ev->attr.ftrace.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
 222                 attr->u.ftrace.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 223                 break;
 224         case LTTNG_EVENT_TRACEPOINT:
 225                 attr->instrumentation = LTTNG_KERNEL_TRACEPOINT;
 226                 break;
 227         case LTTNG_EVENT_SYSCALL:
 228                 attr->instrumentation = LTTNG_KERNEL_SYSCALL;
 229                 break;
 230         case LTTNG_EVENT_ALL:
 231                 attr->instrumentation = LTTNG_KERNEL_ALL;
 232                 break;
 233         default:
 234                 ERR("Unknown kernel instrumentation type (%d)", ev->type);
 235                 goto error;
 236         }
 237
 238         /* Copy event name */
 239         strncpy(attr->name, ev->name, LTTNG_KERNEL_SYM_NAME_LEN);
 240         attr->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
 241
 242         /* Setting up a kernel event */
 243         lke->fd = -1;
 244         lke->event = attr;
 245         lke->enabled = 1;
 246
 247         return lke;
 248
 249 error:
 250         free(lke);
 251         free(attr);
 252         return NULL;
 253 }
 254
 255 /*
 256  * Allocate and initialize a kernel metadata.
 257  *
 258  * Return pointer to structure or NULL.
 259  */
 260 struct ltt_kernel_metadata *trace_kernel_create_metadata(void)
 261 {
 262         struct ltt_kernel_metadata *lkm;
 263         struct lttng_channel *chan;
 264
 265         lkm = zmalloc(sizeof(struct ltt_kernel_metadata));
 266         chan = zmalloc(sizeof(struct lttng_channel));
 267         if (lkm == NULL || chan == NULL) {
 268                 PERROR("kernel metadata zmalloc");
 269                 goto error;
 270         }
 271
 272         /* Set default attributes */
 273         chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 274         chan->attr.subbuf_size = default_get_metadata_subbuf_size();
 275         chan->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 276         chan->attr.switch_timer_interval = DEFAULT_KERNEL_CHANNEL_SWITCH_TIMER;
 277         chan->attr.read_timer_interval = DEFAULT_KERNEL_CHANNEL_READ_TIMER;
 278         chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
 279
 280         /* Init metadata */
 281         lkm->fd = -1;
 282         lkm->conf = chan;
 283
 284         return lkm;
 285
 286 error:
 287         free(lkm);
 288         free(chan);
 289         return NULL;
 290 }
 291
 292 /*
 293  * Allocate and initialize a kernel stream. The stream is set to ACTIVE_FD by
 294  * default.
 295  *
 296  * Return pointer to structure or NULL.
 297  */
 298 struct ltt_kernel_stream *trace_kernel_create_stream(const char *name,
 299                 unsigned int count)
 300 {
 301         int ret;
 302         struct ltt_kernel_stream *lks;
 303
 304         assert(name);
 305
 306         lks = zmalloc(sizeof(struct ltt_kernel_stream));
 307         if (lks == NULL) {
 308                 PERROR("kernel stream zmalloc");
 309                 goto error;
 310         }
 311
 312         /* Set name */
 313         ret = snprintf(lks->name, sizeof(lks->name), "%s_%d", name, count);
 314         if (ret < 0) {
 315                 PERROR("snprintf stream name");
 316                 goto error;
 317         }
 318         lks->name[sizeof(lks->name) - 1] = '\0';
 319
 320         /* Init stream */
 321         lks->fd = -1;
 322         lks->state = 0;
 323         lks->cpu = count;
 324
 325         return lks;
 326
 327 error:
 328         return NULL;
 329 }
 330
 331 /*
 332  * Cleanup kernel stream structure.
 333  */
 334 void trace_kernel_destroy_stream(struct ltt_kernel_stream *stream)
 335 {
 336         assert(stream);
 337
 338         DBG("[trace] Closing stream fd %d", stream->fd);
 339         /* Close kernel fd */
 340         if (stream->fd >= 0) {
 341                 int ret;
 342
 343                 ret = close(stream->fd);
 344                 if (ret) {
 345                         PERROR("close");
 346                 }
 347         }
 348         /* Remove from stream list */
 349         cds_list_del(&stream->list);
 350
 351         free(stream);
 352 }
 353
 354 /*
 355  * Cleanup kernel event structure.
 356  */
 357 void trace_kernel_destroy_event(struct ltt_kernel_event *event)
 358 {
 359         assert(event);
 360
 361         if (event->fd >= 0) {
 362                 int ret;
 363
 364                 DBG("[trace] Closing event fd %d", event->fd);
 365                 /* Close kernel fd */
 366                 ret = close(event->fd);
 367                 if (ret) {
 368                         PERROR("close");
 369                 }
 370         } else {
 371                 DBG("[trace] Tearing down event (no associated fd)");
 372         }
 373
 374         /* Remove from event list */
 375         cds_list_del(&event->list);
 376
 377         free(event->event);
 378         free(event);
 379 }
 380
 381 /*
 382  * Cleanup kernel channel structure.
 383  */
 384 void trace_kernel_destroy_channel(struct ltt_kernel_channel *channel)
 385 {
 386         struct ltt_kernel_stream *stream, *stmp;
 387         struct ltt_kernel_event *event, *etmp;
 388         int ret;
 389
 390         assert(channel);
 391
 392         DBG("[trace] Closing channel fd %d", channel->fd);
 393         /* Close kernel fd */
 394         if (channel->fd >= 0) {
 395                 ret = close(channel->fd);
 396                 if (ret) {
 397                         PERROR("close");
 398                 }
 399         }
 400
 401         /* For each stream in the channel list */
 402         cds_list_for_each_entry_safe(stream, stmp, &channel->stream_list.head, list) {
 403                 trace_kernel_destroy_stream(stream);
 404         }
 405
 406         /* For each event in the channel list */
 407         cds_list_for_each_entry_safe(event, etmp, &channel->events_list.head, list) {
 408                 trace_kernel_destroy_event(event);
 409         }
 410
 411         /* Remove from channel list */
 412         cds_list_del(&channel->list);
 413
 414         free(channel->channel);
 415         free(channel->ctx);
 416         free(channel);
 417 }
 418
 419 /*
 420  * Cleanup kernel metadata structure.
 421  */
 422 void trace_kernel_destroy_metadata(struct ltt_kernel_metadata *metadata)
 423 {
 424         assert(metadata);
 425
 426         DBG("[trace] Closing metadata fd %d", metadata->fd);
 427         /* Close kernel fd */
 428         if (metadata->fd >= 0) {
 429                 int ret;
 430
 431                 ret = close(metadata->fd);
 432                 if (ret) {
 433                         PERROR("close");
 434                 }
 435         }
 436
 437         free(metadata->conf);
 438         free(metadata);
 439 }
 440
 441 /*
 442  * Cleanup kernel session structure
 443  */
 444 void trace_kernel_destroy_session(struct ltt_kernel_session *session)
 445 {
 446         struct ltt_kernel_channel *channel, *ctmp;
 447         int ret;
 448
 449         assert(session);
 450
 451         DBG("[trace] Closing session fd %d", session->fd);
 452         /* Close kernel fds */
 453         if (session->fd >= 0) {
 454                 ret = close(session->fd);
 455                 if (ret) {
 456                         PERROR("close");
 457                 }
 458         }
 459
 460         if (session->metadata_stream_fd >= 0) {
 461                 DBG("[trace] Closing metadata stream fd %d", session->metadata_stream_fd);
 462                 ret = close(session->metadata_stream_fd);
 463                 if (ret) {
 464                         PERROR("close");
 465                 }
 466         }
 467
 468         if (session->metadata != NULL) {
 469                 trace_kernel_destroy_metadata(session->metadata);
 470         }
 471
 472         cds_list_for_each_entry_safe(channel, ctmp, &session->channel_list.head, list) {
 473                 trace_kernel_destroy_channel(channel);
 474         }
 475
 476         /* Wipe consumer output object */
 477         consumer_destroy_output(session->consumer);
 478         consumer_destroy_output(session->tmp_consumer);
 479
 480         free(session->trace_path);
 481         free(session);
 482 }