ltt-sessiond/trace.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
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; only version 2
   7  * of the License.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17  */
  18
  19 #define _GNU_SOURCE
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24 #include <urcu/list.h>
  25
  26 #include "lttngerr.h"
  27 #include "trace.h"
  28
  29 /*
  30  *  get_kernel_channel_by_name
  31  *
  32  *  Find the channel name for the given kernel session.
  33  */
  34 struct ltt_kernel_channel *get_kernel_channel_by_name(
  35                 char *name, struct ltt_kernel_session *session)
  36 {
  37         struct ltt_kernel_channel *chan;
  38
  39         if (session == NULL) {
  40                 ERR("Undefine session");
  41                 goto error;
  42         }
  43
  44         cds_list_for_each_entry(chan, &session->channel_list.head, list) {
  45                 if (strcmp(name, chan->channel->name) == 0) {
  46                         DBG("Found channel by name %s", name);
  47                         return chan;
  48                 }
  49         }
  50
  51 error:
  52         return NULL;
  53 }
  54
  55 /*
  56  *  get_kernel_event_by_name
  57  *
  58  *  Find the event name for the given channel.
  59  */
  60 struct ltt_kernel_event *get_kernel_event_by_name(
  61                 char *name, struct ltt_kernel_channel *channel)
  62 {
  63         struct ltt_kernel_event *ev;
  64
  65         if (channel == NULL) {
  66                 ERR("Undefine channel");
  67                 goto error;
  68         }
  69
  70         cds_list_for_each_entry(ev, &channel->events_list.head, list) {
  71                 if (strcmp(name, ev->event->name) == 0) {
  72                         DBG("Found event by name %s for channel %s", name,
  73                                         channel->channel->name);
  74                         return ev;
  75                 }
  76         }
  77
  78 error:
  79         return NULL;
  80 }
  81
  82 /*
  83  *  trace_create_kernel_session
  84  *
  85  *  Allocate and initialize a kernel session data structure.
  86  *
  87  *  Return pointer to structure or NULL.
  88  */
  89 struct ltt_kernel_session *trace_create_kernel_session(void)
  90 {
  91         struct ltt_kernel_session *lks;
  92
  93         /* Allocate a new ltt kernel session */
  94         lks = malloc(sizeof(struct ltt_kernel_session));
  95         if (lks == NULL) {
  96                 perror("create kernel session malloc");
  97                 goto error;
  98         }
  99
 100         /* Init data structure */
 101         lks->fd = 0;
 102         lks->metadata_stream_fd = 0;
 103         lks->channel_count = 0;
 104         lks->stream_count_global = 0;
 105         lks->metadata = NULL;
 106         CDS_INIT_LIST_HEAD(&lks->channel_list.head);
 107
 108         return lks;
 109
 110 error:
 111         return NULL;
 112 }
 113
 114 /*
 115  *  trace_create_kernel_channel
 116  *
 117  *  Allocate and initialize a kernel channel data structure.
 118  *
 119  *  Return pointer to structure or NULL.
 120  */
 121 struct ltt_kernel_channel *trace_create_kernel_channel(struct lttng_channel *chan, char *path)
 122 {
 123         int ret;
 124         struct ltt_kernel_channel *lkc;
 125
 126         lkc = malloc(sizeof(struct ltt_kernel_channel));
 127         if (lkc == NULL) {
 128                 perror("ltt_kernel_channel malloc");
 129                 goto error;
 130         }
 131
 132         lkc->channel = malloc(sizeof(struct lttng_channel));
 133         if (lkc->channel == NULL) {
 134                 perror("lttng_channel malloc");
 135                 goto error;
 136         }
 137         memcpy(lkc->channel, chan, sizeof(struct lttng_channel));
 138
 139         lkc->fd = 0;
 140         lkc->stream_count = 0;
 141         lkc->event_count = 0;
 142         lkc->enabled = 1;
 143         lkc->ctx = NULL;
 144         /* Init linked list */
 145         CDS_INIT_LIST_HEAD(&lkc->events_list.head);
 146         CDS_INIT_LIST_HEAD(&lkc->stream_list.head);
 147         /* Set default trace output path */
 148         ret = asprintf(&lkc->pathname, "%s", path);
 149         if (ret < 0) {
 150                 perror("asprintf kernel create channel");
 151                 goto error;
 152         }
 153
 154         return lkc;
 155
 156 error:
 157         return NULL;
 158 }
 159
 160 /*
 161  *  trace_create_kernel_event
 162  *
 163  *  Allocate and initialize a kernel event. Set name and event type.
 164  *
 165  *  Return pointer to structure or NULL.
 166  */
 167 struct ltt_kernel_event *trace_create_kernel_event(struct lttng_event *ev)
 168 {
 169         struct ltt_kernel_event *lke;
 170         struct lttng_kernel_event *attr;
 171
 172         lke = malloc(sizeof(struct ltt_kernel_event));
 173         attr = malloc(sizeof(struct lttng_kernel_event));
 174         if (lke == NULL || attr == NULL) {
 175                 perror("kernel event malloc");
 176                 goto error;
 177         }
 178
 179         switch (ev->type) {
 180         case LTTNG_EVENT_PROBE:
 181                 attr->instrumentation = LTTNG_KERNEL_KPROBE;
 182                 attr->u.kprobe.addr = ev->attr.probe.addr;
 183                 attr->u.kprobe.offset = ev->attr.probe.offset;
 184                 strncpy(attr->u.kprobe.symbol_name,
 185                                 ev->attr.probe.symbol_name, LTTNG_SYM_NAME_LEN);
 186                 attr->u.kprobe.symbol_name[LTTNG_SYM_NAME_LEN - 1] = '\0';
 187                 break;
 188         case LTTNG_EVENT_FUNCTION:
 189                 attr->instrumentation = LTTNG_KERNEL_KRETPROBE;
 190                 attr->u.kretprobe.addr = ev->attr.probe.addr;
 191                 attr->u.kretprobe.offset = ev->attr.probe.offset;
 192                 attr->u.kretprobe.offset = ev->attr.probe.offset;
 193                 strncpy(attr->u.kretprobe.symbol_name,
 194                                 ev->attr.probe.symbol_name, LTTNG_SYM_NAME_LEN);
 195                 attr->u.kretprobe.symbol_name[LTTNG_SYM_NAME_LEN - 1] = '\0';
 196                 break;
 197         case LTTNG_EVENT_FUNCTION_ENTRY:
 198                 attr->instrumentation = LTTNG_KERNEL_FUNCTION;
 199                 strncpy(attr->u.ftrace.symbol_name,
 200                                 ev->attr.ftrace.symbol_name, LTTNG_SYM_NAME_LEN);
 201                 attr->u.ftrace.symbol_name[LTTNG_SYM_NAME_LEN - 1] = '\0';
 202                 break;
 203         case LTTNG_EVENT_TRACEPOINT:
 204                 attr->instrumentation = LTTNG_KERNEL_TRACEPOINT;
 205                 break;
 206         default:
 207                 ERR("Unknown kernel instrumentation type (%d)", ev->type);
 208                 goto error;
 209         }
 210
 211         /* Copy event name */
 212         strncpy(attr->name, ev->name, LTTNG_SYM_NAME_LEN);
 213         attr->name[LTTNG_SYM_NAME_LEN - 1] = '\0';
 214
 215         /* Setting up a kernel event */
 216         lke->fd = 0;
 217         lke->event = attr;
 218         lke->enabled = 1;
 219         lke->ctx = NULL;
 220
 221         return lke;
 222
 223 error:
 224         return NULL;
 225 }
 226
 227 /*
 228  *  trace_create_kernel_metadata
 229  *
 230  *  Allocate and initialize a kernel metadata.
 231  *
 232  *  Return pointer to structure or NULL.
 233  */
 234 struct ltt_kernel_metadata *trace_create_kernel_metadata(char *path)
 235 {
 236         int ret;
 237         struct ltt_kernel_metadata *lkm;
 238         struct lttng_channel *chan;
 239
 240         lkm = malloc(sizeof(struct ltt_kernel_metadata));
 241         chan = malloc(sizeof(struct lttng_channel));
 242         if (lkm == NULL || chan == NULL) {
 243                 perror("kernel metadata malloc");
 244                 goto error;
 245         }
 246
 247         /* Set default attributes */
 248         chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 249         chan->attr.subbuf_size = DEFAULT_CHANNEL_SUBBUF_SIZE;
 250         chan->attr.num_subbuf = DEFAULT_CHANNEL_SUBBUF_NUM;
 251         chan->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 252         chan->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 253         chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
 254
 255         /* Init metadata */
 256         lkm->fd = 0;
 257         lkm->conf = chan;
 258         /* Set default metadata path */
 259         ret = asprintf(&lkm->pathname, "%s/metadata", path);
 260         if (ret < 0) {
 261                 perror("asprintf kernel metadata");
 262                 goto error;
 263         }
 264
 265         return lkm;
 266
 267 error:
 268         return NULL;
 269 }
 270
 271 /*
 272  *  trace_create_kernel_stream
 273  *
 274  *  Allocate and initialize a kernel stream. The stream is set to ACTIVE_FD by
 275  *  default.
 276  *
 277  *  Return pointer to structure or NULL.
 278  */
 279 struct ltt_kernel_stream *trace_create_kernel_stream(void)
 280 {
 281         struct ltt_kernel_stream *lks;
 282
 283         lks = malloc(sizeof(struct ltt_kernel_stream));
 284         if (lks == NULL) {
 285                 perror("kernel stream malloc");
 286                 goto error;
 287         }
 288
 289         /* Init stream */
 290         lks->fd = 0;
 291         lks->pathname = NULL;
 292         lks->state = 0;
 293
 294         return lks;
 295
 296 error:
 297         return NULL;
 298 }
 299
 300 void trace_destroy_kernel_stream(struct ltt_kernel_stream *stream)
 301 {
 302         DBG("[trace] Closing stream fd %d", stream->fd);
 303         /* Close kernel fd */
 304         close(stream->fd);
 305         free(stream->pathname);
 306
 307         /* Remove from stream list */
 308         cds_list_del(&stream->list);
 309         free(stream);
 310 }
 311
 312 void trace_destroy_kernel_event(struct ltt_kernel_event *event)
 313 {
 314         DBG("[trace] Closing event fd %d", event->fd);
 315         /* Close kernel fd */
 316         close(event->fd);
 317         /* Free attributes */
 318         free(event->event);
 319
 320         /* Remove from event list */
 321         cds_list_del(&event->list);
 322         free(event);
 323 }
 324
 325 void trace_destroy_kernel_channel(struct ltt_kernel_channel *channel)
 326 {
 327         struct ltt_kernel_stream *stream, *stmp;
 328         struct ltt_kernel_event *event, *etmp;
 329
 330         DBG("[trace] Closing channel fd %d", channel->fd);
 331         /* Close kernel fd */
 332         close(channel->fd);
 333         free(channel->pathname);
 334         /* Free attributes structure */
 335         free(channel->channel);
 336
 337         /* For each stream in the channel list */
 338         cds_list_for_each_entry_safe(stream, stmp, &channel->stream_list.head, list) {
 339                 trace_destroy_kernel_stream(stream);
 340         }
 341
 342         /* For each event in the channel list */
 343         cds_list_for_each_entry_safe(event, etmp, &channel->events_list.head, list) {
 344                 trace_destroy_kernel_event(event);
 345         }
 346
 347         /* Remove from channel list */
 348         cds_list_del(&channel->list);
 349         free(channel);
 350 }
 351
 352 void trace_destroy_kernel_metadata(struct ltt_kernel_metadata *metadata)
 353 {
 354         DBG("[trace] Closing metadata fd %d", metadata->fd);
 355         /* Close kernel fd */
 356         close(metadata->fd);
 357         /* Free attributes */
 358         free(metadata->conf);
 359
 360         free(metadata);
 361 }
 362
 363 void trace_destroy_kernel_session(struct ltt_kernel_session *session)
 364 {
 365         struct ltt_kernel_channel *channel, *ctmp;
 366
 367         DBG("[trace] Closing session fd %d", session->fd);
 368         /* Close kernel fds */
 369         close(session->fd);
 370         if (session->metadata_stream_fd != 0) {
 371                 DBG("[trace] Closing metadata stream fd %d", session->metadata_stream_fd);
 372                 close(session->metadata_stream_fd);
 373         }
 374
 375         if (session->metadata != NULL) {
 376                 trace_destroy_kernel_metadata(session->metadata);
 377         }
 378
 379         cds_list_for_each_entry_safe(channel, ctmp, &session->channel_list.head, list) {
 380                 trace_destroy_kernel_channel(channel);
 381         }
 382
 383         free(session);
 384 }