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         if (session == NULL) {
  39                 ERR("Undefine session");
  40                 goto error;
  41         }
  42
  43         DBG("Trying to find channel %s", name);
  44
  45         cds_list_for_each_entry(chan, &session->channel_list.head, list) {
  46                 if (strcmp(name, chan->channel->name) == 0) {
  47                         DBG("Found channel by name %s", name);
  48                         return chan;
  49                 }
  50         }
  51
  52 error:
  53         return NULL;
  54 }
  55
  56 /*
  57  * Find the event name for the given channel.
  58  */
  59 struct ltt_kernel_event *trace_kernel_get_event_by_name(
  60                 char *name, struct ltt_kernel_channel *channel)
  61 {
  62         struct ltt_kernel_event *ev;
  63
  64         if (channel == NULL) {
  65                 ERR("Undefine channel");
  66                 goto error;
  67         }
  68
  69         cds_list_for_each_entry(ev, &channel->events_list.head, list) {
  70                 if (strcmp(name, ev->event->name) == 0) {
  71                         DBG("Found event by name %s for channel %s", name,
  72                                         channel->channel->name);
  73                         return ev;
  74                 }
  75         }
  76
  77 error:
  78         return NULL;
  79 }
  80
  81 /*
  82  * Allocate and initialize a kernel session data structure.
  83  *
  84  * Return pointer to structure or NULL.
  85  */
  86 struct ltt_kernel_session *trace_kernel_create_session(char *path)
  87 {
  88         int ret;
  89         struct ltt_kernel_session *lks = NULL;
  90
  91         /* Allocate a new ltt kernel session */
  92         lks = zmalloc(sizeof(struct ltt_kernel_session));
  93         if (lks == NULL) {
  94                 PERROR("create kernel session zmalloc");
  95                 goto alloc_error;
  96         }
  97
  98         /* Init data structure */
  99         lks->fd = -1;
 100         lks->metadata_stream_fd = -1;
 101         lks->channel_count = 0;
 102         lks->stream_count_global = 0;
 103         lks->metadata = NULL;
 104         CDS_INIT_LIST_HEAD(&lks->channel_list.head);
 105
 106         lks->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
 107         if (lks->consumer == NULL) {
 108                 goto error;
 109         }
 110
 111         /*
 112          * The tmp_consumer stays NULL until a set_consumer_uri command is
 113          * executed. At this point, the consumer should be nullify until an
 114          * enable_consumer command. This assignment is symbolic since we've zmalloc
 115          * the struct.
 116          */
 117         lks->tmp_consumer = NULL;
 118
 119         if (path && strlen(path) > 0) {
 120                 /* Use the default consumer output which is the tracing session path. */
 121                 ret = snprintf(lks->consumer->dst.trace_path, PATH_MAX,
 122                                 "%s" DEFAULT_KERNEL_TRACE_DIR, path);
 123                 if (ret < 0) {
 124                         PERROR("snprintf consumer trace path");
 125                         goto error;
 126                 }
 127
 128                 /* Set session path */
 129                 ret = asprintf(&lks->trace_path, "%s" DEFAULT_KERNEL_TRACE_DIR, path);
 130                 if (ret < 0) {
 131                         PERROR("asprintf kernel traces path");
 132                         goto error;
 133                 }
 134         }
 135
 136         return lks;
 137
 138 error:
 139         free(lks);
 140
 141 alloc_error:
 142         return NULL;
 143 }
 144
 145 /*
 146  * Allocate and initialize a kernel channel data structure.
 147  *
 148  * Return pointer to structure or NULL.
 149  */
 150 struct ltt_kernel_channel *trace_kernel_create_channel(
 151                 struct lttng_channel *chan, char *path)
 152 {
 153         struct ltt_kernel_channel *lkc;
 154
 155         lkc = zmalloc(sizeof(struct ltt_kernel_channel));
 156         if (lkc == NULL) {
 157                 PERROR("ltt_kernel_channel zmalloc");
 158                 goto error;
 159         }
 160
 161         lkc->channel = zmalloc(sizeof(struct lttng_channel));
 162         if (lkc->channel == NULL) {
 163                 PERROR("lttng_channel zmalloc");
 164                 goto error;
 165         }
 166         memcpy(lkc->channel, chan, sizeof(struct lttng_channel));
 167
 168         lkc->fd = -1;
 169         lkc->stream_count = 0;
 170         lkc->event_count = 0;
 171         lkc->enabled = 1;
 172         lkc->ctx = NULL;
 173         /* Init linked list */
 174         CDS_INIT_LIST_HEAD(&lkc->events_list.head);
 175         CDS_INIT_LIST_HEAD(&lkc->stream_list.head);
 176
 177         return lkc;
 178
 179 error:
 180         return NULL;
 181 }
 182
 183 /*
 184  * Allocate and initialize a kernel event. Set name and event type.
 185  *
 186  * Return pointer to structure or NULL.
 187  */
 188 struct ltt_kernel_event *trace_kernel_create_event(struct lttng_event *ev)
 189 {
 190         struct ltt_kernel_event *lke;
 191         struct lttng_kernel_event *attr;
 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         lke->ctx = NULL;
 247
 248         return lke;
 249
 250 error:
 251         free(lke);
 252         free(attr);
 253         return NULL;
 254 }
 255
 256 /*
 257  * Allocate and initialize a kernel metadata.
 258  *
 259  * Return pointer to structure or NULL.
 260  */
 261 struct ltt_kernel_metadata *trace_kernel_create_metadata(void)
 262 {
 263         struct ltt_kernel_metadata *lkm;
 264         struct lttng_channel *chan;
 265
 266         lkm = zmalloc(sizeof(struct ltt_kernel_metadata));
 267         chan = zmalloc(sizeof(struct lttng_channel));
 268         if (lkm == NULL || chan == NULL) {
 269                 PERROR("kernel metadata zmalloc");
 270                 goto error;
 271         }
 272
 273         /* Set default attributes */
 274         chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 275         chan->attr.subbuf_size = default_get_metadata_subbuf_size();
 276         chan->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 277         chan->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 278         chan->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 279         chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
 280
 281         /* Init metadata */
 282         lkm->fd = -1;
 283         lkm->conf = chan;
 284
 285         return lkm;
 286
 287 error:
 288         free(lkm);
 289         free(chan);
 290         return NULL;
 291 }
 292
 293 /*
 294  * Allocate and initialize a kernel stream. The stream is set to ACTIVE_FD by
 295  * default.
 296  *
 297  * Return pointer to structure or NULL.
 298  */
 299 struct ltt_kernel_stream *trace_kernel_create_stream(const char *name,
 300                 unsigned int count)
 301 {
 302         int ret;
 303         struct ltt_kernel_stream *lks;
 304
 305         lks = zmalloc(sizeof(struct ltt_kernel_stream));
 306         if (lks == NULL) {
 307                 PERROR("kernel stream zmalloc");
 308                 goto error;
 309         }
 310
 311         /* Set name */
 312         ret = snprintf(lks->name, sizeof(lks->name), "%s_%d", name, count);
 313         if (ret < 0) {
 314                 PERROR("snprintf stream name");
 315                 goto error;
 316         }
 317         lks->name[sizeof(lks->name) - 1] = '\0';
 318
 319         /* Init stream */
 320         lks->fd = -1;
 321         lks->state = 0;
 322
 323         return lks;
 324
 325 error:
 326         return NULL;
 327 }
 328
 329 /*
 330  * Cleanup kernel stream structure.
 331  */
 332 void trace_kernel_destroy_stream(struct ltt_kernel_stream *stream)
 333 {
 334         int ret;
 335
 336         DBG("[trace] Closing stream fd %d", stream->fd);
 337         /* Close kernel fd */
 338         if (stream->fd >= 0) {
 339                 ret = close(stream->fd);
 340                 if (ret) {
 341                         PERROR("close");
 342                 }
 343         }
 344         /* Remove from stream list */
 345         cds_list_del(&stream->list);
 346
 347         free(stream);
 348 }
 349
 350 /*
 351  * Cleanup kernel event structure.
 352  */
 353 void trace_kernel_destroy_event(struct ltt_kernel_event *event)
 354 {
 355         int ret;
 356
 357         if (event->fd >= 0) {
 358                 DBG("[trace] Closing event fd %d", event->fd);
 359                 /* Close kernel fd */
 360                 ret = close(event->fd);
 361                 if (ret) {
 362                         PERROR("close");
 363                 }
 364         } else {
 365                 DBG("[trace] Tearing down event (no associated fd)");
 366         }
 367
 368         /* Remove from event list */
 369         cds_list_del(&event->list);
 370
 371         free(event->event);
 372         free(event->ctx);
 373         free(event);
 374 }
 375
 376 /*
 377  * Cleanup kernel channel structure.
 378  */
 379 void trace_kernel_destroy_channel(struct ltt_kernel_channel *channel)
 380 {
 381         struct ltt_kernel_stream *stream, *stmp;
 382         struct ltt_kernel_event *event, *etmp;
 383         int ret;
 384
 385         DBG("[trace] Closing channel fd %d", channel->fd);
 386         /* Close kernel fd */
 387         if (channel->fd >= 0) {
 388                 ret = close(channel->fd);
 389                 if (ret) {
 390                         PERROR("close");
 391                 }
 392         }
 393
 394         /* For each stream in the channel list */
 395         cds_list_for_each_entry_safe(stream, stmp, &channel->stream_list.head, list) {
 396                 trace_kernel_destroy_stream(stream);
 397         }
 398
 399         /* For each event in the channel list */
 400         cds_list_for_each_entry_safe(event, etmp, &channel->events_list.head, list) {
 401                 trace_kernel_destroy_event(event);
 402         }
 403
 404         /* Remove from channel list */
 405         cds_list_del(&channel->list);
 406
 407         free(channel->channel);
 408         free(channel->ctx);
 409         free(channel);
 410 }
 411
 412 /*
 413  * Cleanup kernel metadata structure.
 414  */
 415 void trace_kernel_destroy_metadata(struct ltt_kernel_metadata *metadata)
 416 {
 417         int ret;
 418
 419         DBG("[trace] Closing metadata fd %d", metadata->fd);
 420         /* Close kernel fd */
 421         if (metadata->fd >= 0) {
 422                 ret = close(metadata->fd);
 423                 if (ret) {
 424                         PERROR("close");
 425                 }
 426         }
 427
 428         free(metadata->conf);
 429         free(metadata);
 430 }
 431
 432 /*
 433  * Cleanup kernel session structure
 434  */
 435 void trace_kernel_destroy_session(struct ltt_kernel_session *session)
 436 {
 437         struct ltt_kernel_channel *channel, *ctmp;
 438         int ret;
 439
 440         DBG("[trace] Closing session fd %d", session->fd);
 441         /* Close kernel fds */
 442         if (session->fd >= 0) {
 443                 ret = close(session->fd);
 444                 if (ret) {
 445                         PERROR("close");
 446                 }
 447         }
 448
 449         if (session->metadata_stream_fd >= 0) {
 450                 DBG("[trace] Closing metadata stream fd %d", session->metadata_stream_fd);
 451                 ret = close(session->metadata_stream_fd);
 452                 if (ret) {
 453                         PERROR("close");
 454                 }
 455         }
 456
 457         if (session->metadata != NULL) {
 458                 trace_kernel_destroy_metadata(session->metadata);
 459         }
 460
 461         cds_list_for_each_entry_safe(channel, ctmp, &session->channel_list.head, list) {
 462                 trace_kernel_destroy_channel(channel);
 463         }
 464
 465         /* Wipe consumer output object */
 466         consumer_destroy_output(session->consumer);
 467         consumer_destroy_output(session->tmp_consumer);
 468
 469         free(session->trace_path);
 470         free(session);
 471 }