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_KRETPROBE;
 189                 attr->u.kretprobe.addr = ev->attr.probe.addr;
 190                 attr->u.kretprobe.offset = ev->attr.probe.offset;
 191                 attr->u.kretprobe.offset = ev->attr.probe.offset;
 192                 strncpy(attr->u.kretprobe.symbol_name,
 193                                 ev->attr.probe.symbol_name, LTTNG_SYM_NAME_LEN);
 194                 break;
 195         case LTTNG_EVENT_FUNCTION_ENTRY:
 196                 attr->instrumentation = LTTNG_KERNEL_FUNCTION;
 197                 strncpy(attr->u.ftrace.symbol_name,
 198                                 ev->attr.ftrace.symbol_name, LTTNG_SYM_NAME_LEN);
 199                 break;
 200         case LTTNG_EVENT_TRACEPOINT:
 201                 attr->instrumentation = LTTNG_KERNEL_TRACEPOINT;
 202                 break;
 203         default:
 204                 ERR("Unknown kernel instrumentation type (%d)", ev->type);
 205                 goto error;
 206         }
 207
 208         /* Copy event name */
 209         strncpy(attr->name, ev->name, LTTNG_SYM_NAME_LEN);
 210
 211         /* Setting up a kernel event */
 212         lke->fd = 0;
 213         lke->event = attr;
 214         lke->enabled = 1;
 215         lke->ctx = NULL;
 216
 217         return lke;
 218
 219 error:
 220         return NULL;
 221 }
 222
 223 /*
 224  *  trace_create_kernel_metadata
 225  *
 226  *  Allocate and initialize a kernel metadata.
 227  *
 228  *  Return pointer to structure or NULL.
 229  */
 230 struct ltt_kernel_metadata *trace_create_kernel_metadata(char *path)
 231 {
 232         int ret;
 233         struct ltt_kernel_metadata *lkm;
 234         struct lttng_channel *chan;
 235
 236         lkm = malloc(sizeof(struct ltt_kernel_metadata));
 237         chan = malloc(sizeof(struct lttng_channel));
 238         if (lkm == NULL || chan == NULL) {
 239                 perror("kernel metadata malloc");
 240                 goto error;
 241         }
 242
 243         /* Set default attributes */
 244         chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 245         chan->attr.subbuf_size = DEFAULT_CHANNEL_SUBBUF_SIZE;
 246         chan->attr.num_subbuf = DEFAULT_CHANNEL_SUBBUF_NUM;
 247         chan->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 248         chan->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 249         chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
 250
 251         /* Init metadata */
 252         lkm->fd = 0;
 253         lkm->conf = chan;
 254         /* Set default metadata path */
 255         ret = asprintf(&lkm->pathname, "%s/metadata", path);
 256         if (ret < 0) {
 257                 perror("asprintf kernel metadata");
 258                 goto error;
 259         }
 260
 261         return lkm;
 262
 263 error:
 264         return NULL;
 265 }
 266
 267 /*
 268  *  trace_create_kernel_stream
 269  *
 270  *  Allocate and initialize a kernel stream. The stream is set to ACTIVE_FD by
 271  *  default.
 272  *
 273  *  Return pointer to structure or NULL.
 274  */
 275 struct ltt_kernel_stream *trace_create_kernel_stream(void)
 276 {
 277         struct ltt_kernel_stream *lks;
 278
 279         lks = malloc(sizeof(struct ltt_kernel_stream));
 280         if (lks == NULL) {
 281                 perror("kernel stream malloc");
 282                 goto error;
 283         }
 284
 285         /* Init stream */
 286         lks->fd = 0;
 287         lks->pathname = NULL;
 288         lks->state = 0;
 289
 290         return lks;
 291
 292 error:
 293         return NULL;
 294 }
 295
 296 void trace_destroy_kernel_stream(struct ltt_kernel_stream *stream)
 297 {
 298         DBG("[trace] Closing stream fd %d", stream->fd);
 299         /* Close kernel fd */
 300         close(stream->fd);
 301         free(stream->pathname);
 302
 303         /* Remove from stream list */
 304         cds_list_del(&stream->list);
 305         free(stream);
 306 }
 307
 308 void trace_destroy_kernel_event(struct ltt_kernel_event *event)
 309 {
 310         DBG("[trace] Closing event fd %d", event->fd);
 311         /* Close kernel fd */
 312         close(event->fd);
 313         /* Free attributes */
 314         free(event->event);
 315
 316         /* Remove from event list */
 317         cds_list_del(&event->list);
 318         free(event);
 319 }
 320
 321 void trace_destroy_kernel_channel(struct ltt_kernel_channel *channel)
 322 {
 323         struct ltt_kernel_stream *stream, *stmp;
 324         struct ltt_kernel_event *event, *etmp;
 325
 326         DBG("[trace] Closing channel fd %d", channel->fd);
 327         /* Close kernel fd */
 328         close(channel->fd);
 329         free(channel->pathname);
 330         /* Free attributes structure */
 331         free(channel->channel);
 332
 333         /* For each stream in the channel list */
 334         cds_list_for_each_entry_safe(stream, stmp, &channel->stream_list.head, list) {
 335                 trace_destroy_kernel_stream(stream);
 336         }
 337
 338         /* For each event in the channel list */
 339         cds_list_for_each_entry_safe(event, etmp, &channel->events_list.head, list) {
 340                 trace_destroy_kernel_event(event);
 341         }
 342
 343         /* Remove from channel list */
 344         cds_list_del(&channel->list);
 345         free(channel);
 346 }
 347
 348 void trace_destroy_kernel_metadata(struct ltt_kernel_metadata *metadata)
 349 {
 350         DBG("[trace] Closing metadata fd %d", metadata->fd);
 351         /* Close kernel fd */
 352         close(metadata->fd);
 353         /* Free attributes */
 354         free(metadata->conf);
 355
 356         free(metadata);
 357 }
 358
 359 void trace_destroy_kernel_session(struct ltt_kernel_session *session)
 360 {
 361         struct ltt_kernel_channel *channel, *ctmp;
 362
 363         DBG("[trace] Closing session fd %d", session->fd);
 364         /* Close kernel fds */
 365         close(session->fd);
 366         if (session->metadata_stream_fd != 0) {
 367                 DBG("[trace] Closing metadata stream fd %d", session->metadata_stream_fd);
 368                 close(session->metadata_stream_fd);
 369         }
 370
 371         if (session->metadata != NULL) {
 372                 trace_destroy_kernel_metadata(session->metadata);
 373         }
 374
 375         cds_list_for_each_entry_safe(channel, ctmp, &session->channel_list.head, list) {
 376                 trace_destroy_kernel_channel(channel);
 377         }
 378
 379         free(session);
 380 }