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