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 #include <lttng-ust.h>
  27
  28 #include "trace-ust.h"
  29
  30 /*
  31  * Using a ust session list, it will return the session corresponding to the
  32  * pid. Must be a session of domain LTTNG_DOMAIN_UST_PID.
  33  */
  34 struct ltt_ust_session *trace_ust_get_session_by_pid(
  35                 struct ltt_ust_session_list *session_list, pid_t pid)
  36 {
  37         struct ltt_ust_session *sess;
  38
  39         if (session_list == NULL) {
  40                 ERR("Session list is NULL");
  41                 goto error;
  42         }
  43
  44         cds_list_for_each_entry(sess, &session_list->head, list) {
  45                 if (sess->domain.type == LTTNG_DOMAIN_UST_PID &&
  46                                 sess->domain.attr.pid == pid) {
  47                         DBG2("Trace UST session found by pid %d", pid);
  48                         return sess;
  49                 }
  50         }
  51
  52 error:
  53         return NULL;
  54 }
  55
  56 /*
  57  * Find the channel name for the given ust session.
  58  */
  59 struct ltt_ust_channel *trace_ust_get_channel_by_name(
  60                 char *name, struct ltt_ust_session *session)
  61 {
  62         struct ltt_ust_channel *chan;
  63
  64         if (session == NULL) {
  65                 ERR("Undefine session");
  66                 goto error;
  67         }
  68
  69         cds_list_for_each_entry(chan, &session->channels.head, list) {
  70                 if (strcmp(name, chan->name) == 0) {
  71                         DBG2("Found UST channel by name %s", name);
  72                         return chan;
  73                 }
  74         }
  75
  76 error:
  77         return NULL;
  78 }
  79
  80 /*
  81  * Find the event name for the given channel.
  82  */
  83 struct ltt_ust_event *trace_ust_get_event_by_name(
  84                 char *name, struct ltt_ust_channel *channel)
  85 {
  86         struct ltt_ust_event *ev;
  87
  88         if (channel == NULL) {
  89                 ERR("Undefine channel");
  90                 goto error;
  91         }
  92
  93         cds_list_for_each_entry(ev, &channel->events.head, list) {
  94                 if (strcmp(name, ev->attr.name) == 0) {
  95                         DBG("Found UST event by name %s for channel %s", name,
  96                                         channel->name);
  97                         return ev;
  98                 }
  99         }
 100
 101 error:
 102         return NULL;
 103 }
 104
 105 /*
 106  * Allocate and initialize a ust session data structure.
 107  *
 108  * Return pointer to structure or NULL.
 109  */
 110 struct ltt_ust_session *trace_ust_create_session(char *path, pid_t pid,
 111                 struct lttng_domain *domain)
 112 {
 113         int ret;
 114         struct ltt_ust_session *lus;
 115
 116         /* Allocate a new ltt ust session */
 117         lus = malloc(sizeof(struct ltt_ust_session));
 118         if (lus == NULL) {
 119                 perror("create ust session malloc");
 120                 goto error;
 121         }
 122
 123         /* Init data structure */
 124         lus->handle = -1;
 125         lus->enabled = 1;
 126         lus->uconsumer_fds_sent = 0;
 127         lus->metadata = NULL;
 128         lus->channels.count = 0;
 129         CDS_INIT_LIST_HEAD(&lus->channels.head);
 130
 131         /* Copy lttng_domain */
 132         memcpy(&lus->domain, domain, sizeof(struct lttng_domain));
 133
 134         /* Set session path */
 135         ret = snprintf(lus->path, PATH_MAX, "%s/ust_%d", path, pid);
 136         if (ret < 0) {
 137                 PERROR("snprintf kernel traces path");
 138                 goto error;
 139         }
 140
 141         DBG2("UST trace session create successful");
 142
 143         return lus;
 144
 145 error:
 146         return NULL;
 147 }
 148
 149 /*
 150  * Allocate and initialize a ust channel data structure.
 151  *
 152  * Return pointer to structure or NULL.
 153  */
 154 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
 155                 char *path)
 156 {
 157         int ret;
 158         struct ltt_ust_channel *luc;
 159
 160         luc = malloc(sizeof(struct ltt_ust_channel));
 161         if (luc == NULL) {
 162                 perror("ltt_ust_channel malloc");
 163                 goto error;
 164         }
 165
 166         /* Copy UST channel attributes */
 167         memcpy(&luc->attr, &chan->attr, sizeof(struct lttng_ust_channel));
 168
 169         /* Translate to UST output enum */
 170         switch (luc->attr.output) {
 171         default:
 172                 luc->attr.output = LTTNG_UST_MMAP;
 173                 break;
 174         }
 175
 176         luc->handle = -1;
 177         luc->enabled = 1;
 178         luc->events.count = 0;
 179         CDS_INIT_LIST_HEAD(&luc->events.head);
 180
 181         memset(&luc->ctx, 0, sizeof(struct lttng_ust_context));
 182
 183         /* Copy channel name */
 184         strncpy(luc->name, chan->name, sizeof(&luc->name));
 185         luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 186
 187         /* Set trace output path */
 188         ret = snprintf(luc->trace_path, PATH_MAX, "%s", path);
 189         if (ret < 0) {
 190                 perror("asprintf ust create channel");
 191                 goto error;
 192         }
 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->trace_path, "%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->trace_path);
 326
 327         free(metadata);
 328 }
 329
 330 /*
 331  * Cleanup ust session structure
 332  */
 333 void trace_ust_destroy_session(struct ltt_ust_session *session)
 334 {
 335         struct ltt_ust_channel *channel, *ctmp;
 336
 337         DBG("[trace] Destroy ust session %d", session->handle);
 338
 339         /* Extra safety */
 340         if (session == NULL) {
 341                 return;
 342         }
 343
 344         if (session->metadata != NULL) {
 345                 trace_ust_destroy_metadata(session->metadata);
 346         }
 347
 348         cds_list_for_each_entry_safe(channel, ctmp, &session->channels.head, list) {
 349                 trace_ust_destroy_channel(channel);
 350         }
 351
 352         if (session->path) {
 353                 free(session->path);
 354         }
 355
 356         free(session);
 357 }