ltt-sessiond/trace-ust.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 modify it
   5  * under the terms of the GNU General Public License as published by the Free
   6  * Software Foundation; only version 2 of the License.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA  02111-1307, USA.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23
  24 #include <lttngerr.h>
  25 #include <lttng-share.h>
  26
  27 #include "trace-ust.h"
  28
  29 /*
  30  * Using a ust session list, it will return the session corresponding to the
  31  * pid. Must be a session of domain LTTNG_DOMAIN_UST_PID.
  32  */
  33 struct ltt_ust_session *trace_ust_get_session_by_pid(
  34                 struct ltt_ust_session_list *session_list, pid_t pid)
  35 {
  36         struct ltt_ust_session *sess;
  37
  38         if (session_list == NULL) {
  39                 ERR("Session list is NULL");
  40                 goto error;
  41         }
  42
  43         cds_list_for_each_entry(sess, &session_list->head, list) {
  44                 if (sess->domain.type == LTTNG_DOMAIN_UST_PID &&
  45                                 sess->domain.attr.pid == pid) {
  46                         DBG2("Trace UST session found by pid %d", pid);
  47                         return sess;
  48                 }
  49         }
  50
  51 error:
  52         return NULL;
  53 }
  54
  55 /*
  56  * Find the channel name for the given ust session.
  57  */
  58 struct ltt_ust_channel *trace_ust_get_channel_by_name(
  59                 char *name, struct ltt_ust_session *session)
  60 {
  61         struct ltt_ust_channel *chan;
  62
  63         if (session == NULL) {
  64                 ERR("Undefine session");
  65                 goto error;
  66         }
  67
  68         cds_list_for_each_entry(chan, &session->channels.head, list) {
  69                 if (strcmp(name, chan->name) == 0) {
  70                         DBG2("Found UST channel by name %s", name);
  71                         return chan;
  72                 }
  73         }
  74
  75 error:
  76         return NULL;
  77 }
  78
  79 /*
  80  * Find the event name for the given channel.
  81  */
  82 struct ltt_ust_event *trace_ust_get_event_by_name(
  83                 char *name, struct ltt_ust_channel *channel)
  84 {
  85         struct ltt_ust_event *ev;
  86
  87         if (channel == NULL) {
  88                 ERR("Undefine channel");
  89                 goto error;
  90         }
  91
  92         cds_list_for_each_entry(ev, &channel->events.head, list) {
  93                 if (strcmp(name, ev->attr.name) == 0) {
  94                         DBG("Found UST event by name %s for channel %s", name,
  95                                         channel->name);
  96                         return ev;
  97                 }
  98         }
  99
 100 error:
 101         return NULL;
 102 }
 103
 104 /*
 105  * Allocate and initialize a ust session data structure.
 106  *
 107  * Return pointer to structure or NULL.
 108  */
 109 struct ltt_ust_session *trace_ust_create_session(char *path, pid_t pid,
 110                 struct lttng_domain *domain)
 111 {
 112         int ret;
 113         struct ltt_ust_session *lus;
 114
 115         /* Allocate a new ltt ust session */
 116         lus = malloc(sizeof(struct ltt_ust_session));
 117         if (lus == NULL) {
 118                 perror("create ust session malloc");
 119                 goto error;
 120         }
 121
 122         /* Init data structure */
 123         lus->handle = -1;
 124         lus->enabled = 1;
 125         lus->consumer_fds_sent = 0;
 126         lus->metadata = NULL;
 127         lus->channels.count = 0;
 128         CDS_INIT_LIST_HEAD(&lus->channels.head);
 129
 130         /* Copy lttng_domain */
 131         memcpy(&lus->domain, domain, sizeof(struct lttng_domain));
 132
 133         /* Set session path */
 134         ret = snprintf(lus->path, PATH_MAX, "%s/ust_%d", path, pid);
 135         if (ret < 0) {
 136                 PERROR("snprintf kernel traces path");
 137                 goto error;
 138         }
 139
 140         DBG2("UST trace session create successful");
 141
 142         return lus;
 143
 144 error:
 145         return NULL;
 146 }
 147
 148 /*
 149  * Allocate and initialize a ust channel data structure.
 150  *
 151  * Return pointer to structure or NULL.
 152  */
 153 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
 154                 char *path)
 155 {
 156         int ret;
 157         struct ltt_ust_channel *luc;
 158
 159         luc = malloc(sizeof(struct ltt_ust_channel));
 160         if (luc == NULL) {
 161                 perror("ltt_ust_channel malloc");
 162                 goto error;
 163         }
 164
 165         /* Copy UST channel attributes */
 166         memcpy(&luc->attr, &chan->attr, sizeof(struct lttng_ust_channel));
 167
 168         /* Translate to UST output enum */
 169         switch (luc->attr.output) {
 170         default:
 171                 luc->attr.output = LTTNG_UST_MMAP;
 172                 break;
 173         }
 174
 175         luc->handle = -1;
 176         luc->enabled = 1;
 177         luc->events.count = 0;
 178         CDS_INIT_LIST_HEAD(&luc->events.head);
 179
 180         memset(&luc->ctx, 0, sizeof(struct lttng_ust_context));
 181
 182         /* Copy channel name */
 183         strncpy(luc->name, chan->name, sizeof(&luc->name));
 184         luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 185
 186         /* Set trace output path */
 187         ret = snprintf(luc->trace_path, PATH_MAX, "%s", path);
 188         if (ret < 0) {
 189                 perror("asprintf ust create channel");
 190                 goto error;
 191         }
 192         CDS_INIT_LIST_HEAD(&luc->stream_list.head);
 193
 194         return luc;
 195
 196 error:
 197         return NULL;
 198 }
 199
 200 /*
 201  * Allocate and initialize a ust event. Set name and event type.
 202  *
 203  * Return pointer to structure or NULL.
 204  */
 205 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev)
 206 {
 207         struct ltt_ust_event *lue;
 208
 209         lue = malloc(sizeof(struct ltt_ust_event));
 210         if (lue == NULL) {
 211                 PERROR("ust event malloc");
 212                 goto error;
 213         }
 214
 215         switch (ev->type) {
 216         case LTTNG_EVENT_PROBE:
 217                 lue->attr.instrumentation = LTTNG_UST_PROBE;
 218                 break;
 219         case LTTNG_EVENT_FUNCTION:
 220                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 221                 break;
 222         case LTTNG_EVENT_FUNCTION_ENTRY:
 223                 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
 224                 break;
 225         case LTTNG_EVENT_TRACEPOINT:
 226                 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
 227                 break;
 228         default:
 229                 ERR("Unknown ust instrumentation type (%d)", ev->type);
 230                 goto error;
 231         }
 232
 233         /* Copy event name */
 234         strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
 235         lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 236
 237         /* Setting up a ust event */
 238         lue->handle = -1;
 239         lue->enabled = 1;
 240         memset(&lue->ctx, 0, sizeof(struct lttng_ust_context));
 241
 242         return lue;
 243
 244 error:
 245         return NULL;
 246 }
 247
 248 /*
 249  * Allocate and initialize a ust metadata.
 250  *
 251  * Return pointer to structure or NULL.
 252  */
 253 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
 254 {
 255         int ret;
 256         struct ltt_ust_metadata *lum;
 257
 258         lum = malloc(sizeof(struct ltt_ust_metadata));
 259         if (lum == NULL) {
 260                 perror("ust metadata malloc");
 261                 goto error;
 262         }
 263
 264         /* Set default attributes */
 265         lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 266         lum->attr.subbuf_size = DEFAULT_METADATA_SUBBUF_SIZE;
 267         lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 268         lum->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 269         lum->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 270         lum->attr.output = DEFAULT_UST_CHANNEL_OUTPUT;
 271
 272         lum->handle = -1;
 273         /* Set metadata trace path */
 274         ret = asprintf(&lum->pathname, "%s/metadata", path);
 275         if (ret < 0) {
 276                 perror("asprintf ust metadata");
 277                 goto error;
 278         }
 279
 280         return lum;
 281
 282 error:
 283         return NULL;
 284 }
 285
 286 /*
 287  * Cleanup ust event structure.
 288  */
 289 void trace_ust_destroy_event(struct ltt_ust_event *event)
 290 {
 291         DBG("[trace] Destroy ust event %s", event->attr.name);
 292
 293         /* Remove from event list */
 294         cds_list_del(&event->list);
 295         free(event);
 296 }
 297
 298 /*
 299  * Cleanup ust channel structure.
 300  */
 301 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 302 {
 303         struct ltt_ust_event *event, *etmp;
 304
 305         DBG("[trace] Destroy ust channel %d", channel->handle);
 306
 307         /* For each event in the channel list */
 308         cds_list_for_each_entry_safe(event, etmp, &channel->events.head, list) {
 309                 trace_ust_destroy_event(event);
 310         }
 311
 312         /* Remove from channel list */
 313         cds_list_del(&channel->list);
 314         free(channel);
 315 }
 316
 317 /*
 318  * Cleanup ust metadata structure.
 319  */
 320 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 321 {
 322         DBG("[trace] Destroy ust metadata %d", metadata->handle);
 323
 324         /* Free attributes */
 325         free(metadata->pathname);
 326         free(metadata);
 327 }
 328
 329 /*
 330  * Cleanup ust session structure
 331  */
 332 void trace_ust_destroy_session(struct ltt_ust_session *session)
 333 {
 334         struct ltt_ust_channel *channel, *ctmp;
 335
 336         DBG("[trace] Destroy ust session %d", session->handle);
 337
 338         /* Extra safety */
 339         if (session == NULL) {
 340                 return;
 341         }
 342
 343         if (session->metadata != NULL) {
 344                 trace_ust_destroy_metadata(session->metadata);
 345         }
 346
 347         cds_list_for_each_entry_safe(channel, ctmp, &session->channels.head, list) {
 348                 trace_ust_destroy_channel(channel);
 349         }
 350
 351         if (session->path) {
 352                 free(session->path);
 353         }
 354
 355         free(session);
 356 }