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; either version 2
   7  * of the License, or (at your option) any later version.
   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 "ltt-sessiond.h"
  28 #include "trace.h"
  29
  30 /*
  31  *  get_kernel_channel_by_name
  32  *
  33  *  Find the channel name for the given kernel session.
  34  */
  35 struct ltt_kernel_channel *get_kernel_channel_by_name(
  36                 char *name, struct ltt_kernel_session *session)
  37 {
  38         struct ltt_kernel_channel *chan;
  39
  40         if (session == NULL) {
  41                 ERR("Undefine session");
  42                 goto error;
  43         }
  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  *  get_kernel_event_by_name
  58  *
  59  *  Find the event name for the given channel.
  60  */
  61 struct ltt_kernel_event *get_kernel_event_by_name(
  62                 char *name, struct ltt_kernel_channel *channel)
  63 {
  64         struct ltt_kernel_event *ev;
  65
  66         if (channel == NULL) {
  67                 ERR("Undefine channel");
  68                 goto error;
  69         }
  70
  71         cds_list_for_each_entry(ev, &channel->events_list.head, list) {
  72                 if (strcmp(name, ev->event->name) == 0) {
  73                         DBG("Found event by name %s for channel %s", name,
  74                                         channel->channel->name);
  75                         return ev;
  76                 }
  77         }
  78
  79 error:
  80         return NULL;
  81 }
  82
  83 /*
  84  *  trace_create_kernel_session
  85  *
  86  *  Allocate and initialize a kernel session data structure.
  87  *
  88  *  Return pointer to structure or NULL.
  89  */
  90 struct ltt_kernel_session *trace_create_kernel_session(void)
  91 {
  92         struct ltt_kernel_session *lks;
  93
  94         /* Allocate a new ltt kernel session */
  95         lks = malloc(sizeof(struct ltt_kernel_session));
  96         if (lks == NULL) {
  97                 perror("create kernel session malloc");
  98                 goto error;
  99         }
 100
 101         /* Init data structure */
 102         lks->fd = 0;
 103         lks->metadata_stream_fd = 0;
 104         lks->channel_count = 0;
 105         lks->stream_count_global = 0;
 106         lks->metadata = NULL;
 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)
 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         /* Init linked list */
 143         CDS_INIT_LIST_HEAD(&lkc->events_list.head);
 144         CDS_INIT_LIST_HEAD(&lkc->stream_list.head);
 145         /* Set default trace output path */
 146         ret = asprintf(&lkc->pathname, "%s", DEFAULT_TRACE_OUTPUT);
 147         if (ret < 0) {
 148                 perror("asprintf kernel create channel");
 149                 goto error;
 150         }
 151
 152         return lkc;
 153
 154 error:
 155         return NULL;
 156 }
 157
 158 /*
 159  *  trace_create_kernel_event
 160  *
 161  *  Allocate and initialize a kernel event. Set name and event type.
 162  *
 163  *  Return pointer to structure or NULL.
 164  */
 165 struct ltt_kernel_event *trace_create_kernel_event(struct lttng_event *ev)
 166 {
 167         struct ltt_kernel_event *lke;
 168         struct lttng_kernel_event *attr;
 169
 170         lke = malloc(sizeof(struct ltt_kernel_event));
 171         attr = malloc(sizeof(struct lttng_kernel_event));
 172         if (lke == NULL || attr == NULL) {
 173                 perror("kernel event malloc");
 174                 goto error;
 175         }
 176
 177         switch (ev->type) {
 178         case LTTNG_EVENT_KPROBES:
 179                 attr->instrumentation = LTTNG_KERNEL_KPROBES;
 180                 attr->u.kprobe.addr = ev->attr.kprobe.addr;
 181                 attr->u.kprobe.offset = ev->attr.kprobe.offset;
 182                 strncpy(attr->u.kprobe.symbol_name,
 183                                 ev->attr.kprobe.symbol_name, LTTNG_SYM_NAME_LEN);
 184                 break;
 185         case LTTNG_EVENT_FUNCTION:
 186                 attr->instrumentation = LTTNG_KERNEL_FUNCTION;
 187                 strncpy(attr->u.ftrace.symbol_name,
 188                                 ev->attr.ftrace.symbol_name, LTTNG_SYM_NAME_LEN);
 189                 break;
 190         case LTTNG_EVENT_TRACEPOINTS:
 191                 attr->instrumentation = LTTNG_KERNEL_TRACEPOINTS;
 192                 break;
 193         default:
 194                 ERR("Unknown kernel instrumentation type (%d)", ev->type);
 195                 goto error;
 196         }
 197
 198         /* Copy event name */
 199         strncpy(attr->name, ev->name, LTTNG_SYM_NAME_LEN);
 200
 201         /* Setting up a kernel event */
 202         lke->fd = 0;
 203         lke->event = attr;
 204
 205         return lke;
 206
 207 error:
 208         return NULL;
 209 }
 210
 211 /*
 212  *  trace_create_kernel_metadata
 213  *
 214  *  Allocate and initialize a kernel metadata.
 215  *
 216  *  Return pointer to structure or NULL.
 217  */
 218 struct ltt_kernel_metadata *trace_create_kernel_metadata(void)
 219 {
 220         int ret;
 221         struct ltt_kernel_metadata *lkm;
 222         struct lttng_channel *chan;
 223
 224         lkm = malloc(sizeof(struct ltt_kernel_metadata));
 225         chan = malloc(sizeof(struct lttng_channel));
 226         if (lkm == NULL || chan == NULL) {
 227                 perror("kernel metadata malloc");
 228                 goto error;
 229         }
 230
 231         /* Set default attributes */
 232         chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 233         chan->attr.subbuf_size = DEFAULT_CHANNEL_SUBBUF_SIZE;
 234         chan->attr.num_subbuf = DEFAULT_CHANNEL_SUBBUF_NUM;
 235         chan->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 236         chan->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 237
 238         /* Init metadata */
 239         lkm->fd = 0;
 240         lkm->conf = chan;
 241         /* Set default metadata path */
 242         ret = asprintf(&lkm->pathname, "%s/metadata", DEFAULT_TRACE_OUTPUT);
 243         if (ret < 0) {
 244                 perror("asprintf kernel metadata");
 245                 goto error;
 246         }
 247
 248         return lkm;
 249
 250 error:
 251         return NULL;
 252 }
 253
 254 /*
 255  *  trace_create_kernel_stream
 256  *
 257  *  Allocate and initialize a kernel stream. The stream is set to ACTIVE_FD by
 258  *  default.
 259  *
 260  *  Return pointer to structure or NULL.
 261  */
 262 struct ltt_kernel_stream *trace_create_kernel_stream(void)
 263 {
 264         struct ltt_kernel_stream *lks;
 265
 266         lks = malloc(sizeof(struct ltt_kernel_stream));
 267         if (lks == NULL) {
 268                 perror("kernel stream malloc");
 269                 goto error;
 270         }
 271
 272         /* Init stream */
 273         lks->fd = 0;
 274         lks->pathname = NULL;
 275         lks->state = 0;
 276
 277         return lks;
 278
 279 error:
 280         return NULL;
 281 }
 282
 283 void trace_destroy_kernel_stream(struct ltt_kernel_stream *stream)
 284 {
 285         DBG("[trace] Closing stream fd %d", stream->fd);
 286         /* Close kernel fd */
 287         close(stream->fd);
 288         free(stream->pathname);
 289
 290         /* Remove from stream list */
 291         cds_list_del(&stream->list);
 292         free(stream);
 293 }
 294
 295 void trace_destroy_kernel_event(struct ltt_kernel_event *event)
 296 {
 297         DBG("[trace] Closing event fd %d", event->fd);
 298         /* Close kernel fd */
 299         close(event->fd);
 300         /* Free attributes */
 301         free(event->event);
 302
 303         /* Remove from event list */
 304         cds_list_del(&event->list);
 305         free(event);
 306 }
 307
 308 void trace_destroy_kernel_channel(struct ltt_kernel_channel *channel)
 309 {
 310         struct ltt_kernel_stream *stream;
 311         struct ltt_kernel_event *event;
 312
 313         DBG("[trace] Closing channel fd %d", channel->fd);
 314         /* Close kernel fd */
 315         close(channel->fd);
 316         free(channel->pathname);
 317         /* Free attributes structure */
 318         free(channel->channel);
 319
 320         /* For each stream in the channel list */
 321         cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
 322                 trace_destroy_kernel_stream(stream);
 323         }
 324
 325         /* For each event in the channel list */
 326         cds_list_for_each_entry(event, &channel->events_list.head, list) {
 327                 trace_destroy_kernel_event(event);
 328         }
 329
 330         /* Remove from channel list */
 331         cds_list_del(&channel->list);
 332         free(channel);
 333 }
 334
 335 void trace_destroy_kernel_metadata(struct ltt_kernel_metadata *metadata)
 336 {
 337         DBG("[trace] Closing metadata fd %d", metadata->fd);
 338         /* Close kernel fd */
 339         close(metadata->fd);
 340         /* Free attributes */
 341         free(metadata->conf);
 342
 343         free(metadata);
 344 }
 345
 346 void trace_destroy_kernel_session(struct ltt_kernel_session *session)
 347 {
 348         struct ltt_kernel_channel *channel;
 349
 350         DBG("[trace] Closing session fd %d", session->fd);
 351         /* Close kernel fds */
 352         close(session->fd);
 353         if (session->metadata_stream_fd != 0) {
 354                 DBG("[trace] Closing metadata stream fd %d", session->metadata_stream_fd);
 355                 close(session->metadata_stream_fd);
 356         }
 357
 358         trace_destroy_kernel_metadata(session->metadata);
 359
 360         cds_list_for_each_entry(channel, &session->channel_list.head, list) {
 361                 trace_destroy_kernel_channel(channel);
 362         }
 363
 364         free(session);
 365 }