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         lks->consumer_fd = 0;
 107         CDS_INIT_LIST_HEAD(&lks->channel_list.head);
 108
 109         return lks;
 110
 111 error:
 112         return NULL;
 113 }
 114
 115 /*
 116  *  trace_create_kernel_channel
 117  *
 118  *  Allocate and initialize a kernel channel data structure.
 119  *
 120  *  Return pointer to structure or NULL.
 121  */
 122 struct ltt_kernel_channel *trace_create_kernel_channel(struct lttng_channel *chan, char *path)
 123 {
 124         int ret;
 125         struct ltt_kernel_channel *lkc;
 126
 127         lkc = malloc(sizeof(struct ltt_kernel_channel));
 128         if (lkc == NULL) {
 129                 perror("ltt_kernel_channel malloc");
 130                 goto error;
 131         }
 132
 133         lkc->channel = malloc(sizeof(struct lttng_channel));
 134         if (lkc->channel == NULL) {
 135                 perror("lttng_channel malloc");
 136                 goto error;
 137         }
 138         memcpy(lkc->channel, chan, sizeof(struct lttng_channel));
 139
 140         lkc->fd = 0;
 141         lkc->stream_count = 0;
 142         lkc->event_count = 0;
 143         lkc->enabled = 1;
 144         lkc->ctx = NULL;
 145         /* Init linked list */
 146         CDS_INIT_LIST_HEAD(&lkc->events_list.head);
 147         CDS_INIT_LIST_HEAD(&lkc->stream_list.head);
 148         /* Set default trace output path */
 149         ret = asprintf(&lkc->pathname, "%s", path);
 150         if (ret < 0) {
 151                 perror("asprintf kernel create channel");
 152                 goto error;
 153         }
 154
 155         return lkc;
 156
 157 error:
 158         return NULL;
 159 }
 160
 161 /*
 162  *  trace_create_kernel_event
 163  *
 164  *  Allocate and initialize a kernel event. Set name and event type.
 165  *
 166  *  Return pointer to structure or NULL.
 167  */
 168 struct ltt_kernel_event *trace_create_kernel_event(struct lttng_event *ev)
 169 {
 170         struct ltt_kernel_event *lke;
 171         struct lttng_kernel_event *attr;
 172
 173         lke = malloc(sizeof(struct ltt_kernel_event));
 174         attr = malloc(sizeof(struct lttng_kernel_event));
 175         if (lke == NULL || attr == NULL) {
 176                 perror("kernel event malloc");
 177                 goto error;
 178         }
 179
 180         switch (ev->type) {
 181         case LTTNG_EVENT_PROBE:
 182                 attr->instrumentation = LTTNG_KERNEL_KPROBE;
 183                 attr->u.kprobe.addr = ev->attr.probe.addr;
 184                 attr->u.kprobe.offset = ev->attr.probe.offset;
 185                 strncpy(attr->u.kprobe.symbol_name,
 186                                 ev->attr.probe.symbol_name, LTTNG_SYM_NAME_LEN);
 187                 attr->u.kprobe.symbol_name[LTTNG_SYM_NAME_LEN - 1] = '\0';
 188                 break;
 189         case LTTNG_EVENT_FUNCTION:
 190                 attr->instrumentation = LTTNG_KERNEL_KRETPROBE;
 191                 attr->u.kretprobe.addr = ev->attr.probe.addr;
 192                 attr->u.kretprobe.offset = ev->attr.probe.offset;
 193                 attr->u.kretprobe.offset = ev->attr.probe.offset;
 194                 strncpy(attr->u.kretprobe.symbol_name,
 195                                 ev->attr.probe.symbol_name, LTTNG_SYM_NAME_LEN);
 196                 attr->u.kretprobe.symbol_name[LTTNG_SYM_NAME_LEN - 1] = '\0';
 197                 break;
 198         case LTTNG_EVENT_FUNCTION_ENTRY:
 199                 attr->instrumentation = LTTNG_KERNEL_FUNCTION;
 200                 strncpy(attr->u.ftrace.symbol_name,
 201                                 ev->attr.ftrace.symbol_name, LTTNG_SYM_NAME_LEN);
 202                 attr->u.ftrace.symbol_name[LTTNG_SYM_NAME_LEN - 1] = '\0';
 203                 break;
 204         case LTTNG_EVENT_TRACEPOINT:
 205                 attr->instrumentation = LTTNG_KERNEL_TRACEPOINT;
 206                 break;
 207         default:
 208                 ERR("Unknown kernel instrumentation type (%d)", ev->type);
 209                 goto error;
 210         }
 211
 212         /* Copy event name */
 213         strncpy(attr->name, ev->name, LTTNG_SYM_NAME_LEN);
 214         attr->name[LTTNG_SYM_NAME_LEN - 1] = '\0';
 215
 216         /* Setting up a kernel event */
 217         lke->fd = 0;
 218         lke->event = attr;
 219         lke->enabled = 1;
 220         lke->ctx = NULL;
 221
 222         return lke;
 223
 224 error:
 225         return NULL;
 226 }
 227
 228 /*
 229  *  trace_create_kernel_metadata
 230  *
 231  *  Allocate and initialize a kernel metadata.
 232  *
 233  *  Return pointer to structure or NULL.
 234  */
 235 struct ltt_kernel_metadata *trace_create_kernel_metadata(char *path)
 236 {
 237         int ret;
 238         struct ltt_kernel_metadata *lkm;
 239         struct lttng_channel *chan;
 240
 241         lkm = malloc(sizeof(struct ltt_kernel_metadata));
 242         chan = malloc(sizeof(struct lttng_channel));
 243         if (lkm == NULL || chan == NULL) {
 244                 perror("kernel metadata malloc");
 245                 goto error;
 246         }
 247
 248         /* Set default attributes */
 249         chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 250         chan->attr.subbuf_size = DEFAULT_CHANNEL_SUBBUF_SIZE;
 251         chan->attr.num_subbuf = DEFAULT_CHANNEL_SUBBUF_NUM;
 252         chan->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 253         chan->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 254         chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
 255
 256         /* Init metadata */
 257         lkm->fd = 0;
 258         lkm->conf = chan;
 259         /* Set default metadata path */
 260         ret = asprintf(&lkm->pathname, "%s/metadata", path);
 261         if (ret < 0) {
 262                 perror("asprintf kernel metadata");
 263                 goto error;
 264         }
 265
 266         return lkm;
 267
 268 error:
 269         return NULL;
 270 }
 271
 272 /*
 273  *  trace_create_kernel_stream
 274  *
 275  *  Allocate and initialize a kernel stream. The stream is set to ACTIVE_FD by
 276  *  default.
 277  *
 278  *  Return pointer to structure or NULL.
 279  */
 280 struct ltt_kernel_stream *trace_create_kernel_stream(void)
 281 {
 282         struct ltt_kernel_stream *lks;
 283
 284         lks = malloc(sizeof(struct ltt_kernel_stream));
 285         if (lks == NULL) {
 286                 perror("kernel stream malloc");
 287                 goto error;
 288         }
 289
 290         /* Init stream */
 291         lks->fd = 0;
 292         lks->pathname = NULL;
 293         lks->state = 0;
 294
 295         return lks;
 296
 297 error:
 298         return NULL;
 299 }
 300
 301 void trace_destroy_kernel_stream(struct ltt_kernel_stream *stream)
 302 {
 303         DBG("[trace] Closing stream fd %d", stream->fd);
 304         /* Close kernel fd */
 305         close(stream->fd);
 306         free(stream->pathname);
 307
 308         /* Remove from stream list */
 309         cds_list_del(&stream->list);
 310         free(stream);
 311 }
 312
 313 void trace_destroy_kernel_event(struct ltt_kernel_event *event)
 314 {
 315         DBG("[trace] Closing event fd %d", event->fd);
 316         /* Close kernel fd */
 317         close(event->fd);
 318         /* Free attributes */
 319         free(event->event);
 320
 321         /* Remove from event list */
 322         cds_list_del(&event->list);
 323         free(event);
 324 }
 325
 326 void trace_destroy_kernel_channel(struct ltt_kernel_channel *channel)
 327 {
 328         struct ltt_kernel_stream *stream, *stmp;
 329         struct ltt_kernel_event *event, *etmp;
 330
 331         DBG("[trace] Closing channel fd %d", channel->fd);
 332         /* Close kernel fd */
 333         close(channel->fd);
 334         free(channel->pathname);
 335         /* Free attributes structure */
 336         free(channel->channel);
 337
 338         /* For each stream in the channel list */
 339         cds_list_for_each_entry_safe(stream, stmp, &channel->stream_list.head, list) {
 340                 trace_destroy_kernel_stream(stream);
 341         }
 342
 343         /* For each event in the channel list */
 344         cds_list_for_each_entry_safe(event, etmp, &channel->events_list.head, list) {
 345                 trace_destroy_kernel_event(event);
 346         }
 347
 348         /* Remove from channel list */
 349         cds_list_del(&channel->list);
 350         free(channel);
 351 }
 352
 353 void trace_destroy_kernel_metadata(struct ltt_kernel_metadata *metadata)
 354 {
 355         DBG("[trace] Closing metadata fd %d", metadata->fd);
 356         /* Close kernel fd */
 357         close(metadata->fd);
 358         /* Free attributes */
 359         free(metadata->conf);
 360
 361         free(metadata);
 362 }
 363
 364 void trace_destroy_kernel_session(struct ltt_kernel_session *session)
 365 {
 366         struct ltt_kernel_channel *channel, *ctmp;
 367
 368         DBG("[trace] Closing session fd %d", session->fd);
 369         /* Close kernel fds */
 370         close(session->fd);
 371         if (session->metadata_stream_fd != 0) {
 372                 DBG("[trace] Closing metadata stream fd %d", session->metadata_stream_fd);
 373                 close(session->metadata_stream_fd);
 374         }
 375
 376         if (session->metadata != NULL) {
 377                 trace_destroy_kernel_metadata(session->metadata);
 378         }
 379
 380         cds_list_for_each_entry_safe(channel, ctmp, &session->channel_list.head, list) {
 381                 trace_destroy_kernel_channel(channel);
 382         }
 383
 384         free(session);
 385 }