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                 break;
 187         case LTTNG_EVENT_FUNCTION:
 188                 attr->instrumentation = LTTNG_KERNEL_FUNCTION;
 189                 strncpy(attr->u.ftrace.symbol_name,
 190                                 ev->attr.ftrace.symbol_name, LTTNG_SYM_NAME_LEN);
 191                 break;
 192         case LTTNG_EVENT_TRACEPOINT:
 193                 attr->instrumentation = LTTNG_KERNEL_TRACEPOINT;
 194                 break;
 195         default:
 196                 ERR("Unknown kernel instrumentation type (%d)", ev->type);
 197                 goto error;
 198         }
 199
 200         /* Copy event name */
 201         strncpy(attr->name, ev->name, LTTNG_SYM_NAME_LEN);
 202
 203         /* Setting up a kernel event */
 204         lke->fd = 0;
 205         lke->event = attr;
 206         lke->enabled = 1;
 207         lke->ctx = NULL;
 208
 209         return lke;
 210
 211 error:
 212         return NULL;
 213 }
 214
 215 /*
 216  *  trace_create_kernel_metadata
 217  *
 218  *  Allocate and initialize a kernel metadata.
 219  *
 220  *  Return pointer to structure or NULL.
 221  */
 222 struct ltt_kernel_metadata *trace_create_kernel_metadata(char *path)
 223 {
 224         int ret;
 225         struct ltt_kernel_metadata *lkm;
 226         struct lttng_channel *chan;
 227
 228         lkm = malloc(sizeof(struct ltt_kernel_metadata));
 229         chan = malloc(sizeof(struct lttng_channel));
 230         if (lkm == NULL || chan == NULL) {
 231                 perror("kernel metadata malloc");
 232                 goto error;
 233         }
 234
 235         /* Set default attributes */
 236         chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 237         chan->attr.subbuf_size = DEFAULT_CHANNEL_SUBBUF_SIZE;
 238         chan->attr.num_subbuf = DEFAULT_CHANNEL_SUBBUF_NUM;
 239         chan->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 240         chan->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 241         chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
 242
 243         /* Init metadata */
 244         lkm->fd = 0;
 245         lkm->conf = chan;
 246         /* Set default metadata path */
 247         ret = asprintf(&lkm->pathname, "%s/metadata", path);
 248         if (ret < 0) {
 249                 perror("asprintf kernel metadata");
 250                 goto error;
 251         }
 252
 253         return lkm;
 254
 255 error:
 256         return NULL;
 257 }
 258
 259 /*
 260  *  trace_create_kernel_stream
 261  *
 262  *  Allocate and initialize a kernel stream. The stream is set to ACTIVE_FD by
 263  *  default.
 264  *
 265  *  Return pointer to structure or NULL.
 266  */
 267 struct ltt_kernel_stream *trace_create_kernel_stream(void)
 268 {
 269         struct ltt_kernel_stream *lks;
 270
 271         lks = malloc(sizeof(struct ltt_kernel_stream));
 272         if (lks == NULL) {
 273                 perror("kernel stream malloc");
 274                 goto error;
 275         }
 276
 277         /* Init stream */
 278         lks->fd = 0;
 279         lks->pathname = NULL;
 280         lks->state = 0;
 281
 282         return lks;
 283
 284 error:
 285         return NULL;
 286 }
 287
 288 void trace_destroy_kernel_stream(struct ltt_kernel_stream *stream)
 289 {
 290         DBG("[trace] Closing stream fd %d", stream->fd);
 291         /* Close kernel fd */
 292         close(stream->fd);
 293         free(stream->pathname);
 294
 295         /* Remove from stream list */
 296         cds_list_del(&stream->list);
 297         free(stream);
 298 }
 299
 300 void trace_destroy_kernel_event(struct ltt_kernel_event *event)
 301 {
 302         DBG("[trace] Closing event fd %d", event->fd);
 303         /* Close kernel fd */
 304         close(event->fd);
 305         /* Free attributes */
 306         free(event->event);
 307
 308         /* Remove from event list */
 309         cds_list_del(&event->list);
 310         free(event);
 311 }
 312
 313 void trace_destroy_kernel_channel(struct ltt_kernel_channel *channel)
 314 {
 315         struct ltt_kernel_stream *stream, *stmp;
 316         struct ltt_kernel_event *event, *etmp;
 317
 318         DBG("[trace] Closing channel fd %d", channel->fd);
 319         /* Close kernel fd */
 320         close(channel->fd);
 321         free(channel->pathname);
 322         /* Free attributes structure */
 323         free(channel->channel);
 324
 325         /* For each stream in the channel list */
 326         cds_list_for_each_entry_safe(stream, stmp, &channel->stream_list.head, list) {
 327                 trace_destroy_kernel_stream(stream);
 328         }
 329
 330         /* For each event in the channel list */
 331         cds_list_for_each_entry_safe(event, etmp, &channel->events_list.head, list) {
 332                 trace_destroy_kernel_event(event);
 333         }
 334
 335         /* Remove from channel list */
 336         cds_list_del(&channel->list);
 337         free(channel);
 338 }
 339
 340 void trace_destroy_kernel_metadata(struct ltt_kernel_metadata *metadata)
 341 {
 342         DBG("[trace] Closing metadata fd %d", metadata->fd);
 343         /* Close kernel fd */
 344         close(metadata->fd);
 345         /* Free attributes */
 346         free(metadata->conf);
 347
 348         free(metadata);
 349 }
 350
 351 void trace_destroy_kernel_session(struct ltt_kernel_session *session)
 352 {
 353         struct ltt_kernel_channel *channel, *ctmp;
 354
 355         DBG("[trace] Closing session fd %d", session->fd);
 356         /* Close kernel fds */
 357         close(session->fd);
 358         if (session->metadata_stream_fd != 0) {
 359                 DBG("[trace] Closing metadata stream fd %d", session->metadata_stream_fd);
 360                 close(session->metadata_stream_fd);
 361         }
 362
 363         if (session->metadata != NULL) {
 364                 trace_destroy_kernel_metadata(session->metadata);
 365         }
 366
 367         cds_list_for_each_entry_safe(channel, ctmp, &session->channel_list.head, list) {
 368                 trace_destroy_kernel_channel(channel);
 369         }
 370
 371         free(session);
 372 }