ltt-sessiond/trace-kernel.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
  25 #include <lttngerr.h>
  26
  27 #include "trace-kernel.h"
  28
  29 /*
  30  * Find the channel name for the given kernel session.
  31  */
  32 struct ltt_kernel_channel *trace_kernel_get_channel_by_name(
  33                 char *name, struct ltt_kernel_session *session)
  34 {
  35         struct ltt_kernel_channel *chan;
  36
  37         if (session == NULL) {
  38                 ERR("Undefine session");
  39                 goto error;
  40         }
  41
  42         cds_list_for_each_entry(chan, &session->channel_list.head, list) {
  43                 if (strcmp(name, chan->channel->name) == 0) {
  44                         DBG("Found channel by name %s", name);
  45                         return chan;
  46                 }
  47         }
  48
  49 error:
  50         return NULL;
  51 }
  52
  53 /*
  54  * Find the event name for the given channel.
  55  */
  56 struct ltt_kernel_event *trace_kernel_get_event_by_name(
  57                 char *name, struct ltt_kernel_channel *channel)
  58 {
  59         struct ltt_kernel_event *ev;
  60
  61         if (channel == NULL) {
  62                 ERR("Undefine channel");
  63                 goto error;
  64         }
  65
  66         cds_list_for_each_entry(ev, &channel->events_list.head, list) {
  67                 if (strcmp(name, ev->event->name) == 0) {
  68                         DBG("Found event by name %s for channel %s", name,
  69                                         channel->channel->name);
  70                         return ev;
  71                 }
  72         }
  73
  74 error:
  75         return NULL;
  76 }
  77
  78 /*
  79  * Allocate and initialize a kernel session data structure.
  80  *
  81  * Return pointer to structure or NULL.
  82  */
  83 struct ltt_kernel_session *trace_kernel_create_session(void)
  84 {
  85         struct ltt_kernel_session *lks;
  86
  87         /* Allocate a new ltt kernel session */
  88         lks = malloc(sizeof(struct ltt_kernel_session));
  89         if (lks == NULL) {
  90                 perror("create kernel session malloc");
  91                 goto error;
  92         }
  93
  94         /* Init data structure */
  95         lks->fd = 0;
  96         lks->metadata_stream_fd = 0;
  97         lks->channel_count = 0;
  98         lks->stream_count_global = 0;
  99         lks->metadata = NULL;
 100         lks->consumer_fd = 0;
 101         CDS_INIT_LIST_HEAD(&lks->channel_list.head);
 102
 103         return lks;
 104
 105 error:
 106         return NULL;
 107 }
 108
 109 /*
 110  * Allocate and initialize a kernel channel data structure.
 111  *
 112  * Return pointer to structure or NULL.
 113  */
 114 struct ltt_kernel_channel *trace_kernel_create_channel(struct lttng_channel *chan, char *path)
 115 {
 116         int ret;
 117         struct ltt_kernel_channel *lkc;
 118
 119         lkc = malloc(sizeof(struct ltt_kernel_channel));
 120         if (lkc == NULL) {
 121                 perror("ltt_kernel_channel malloc");
 122                 goto error;
 123         }
 124
 125         lkc->channel = malloc(sizeof(struct lttng_channel));
 126         if (lkc->channel == NULL) {
 127                 perror("lttng_channel malloc");
 128                 goto error;
 129         }
 130         memcpy(lkc->channel, chan, sizeof(struct lttng_channel));
 131
 132         lkc->fd = 0;
 133         lkc->stream_count = 0;
 134         lkc->event_count = 0;
 135         lkc->enabled = 1;
 136         lkc->ctx = NULL;
 137         /* Init linked list */
 138         CDS_INIT_LIST_HEAD(&lkc->events_list.head);
 139         CDS_INIT_LIST_HEAD(&lkc->stream_list.head);
 140         /* Set default trace output path */
 141         ret = asprintf(&lkc->pathname, "%s", path);
 142         if (ret < 0) {
 143                 perror("asprintf kernel create channel");
 144                 goto error;
 145         }
 146
 147         return lkc;
 148
 149 error:
 150         return NULL;
 151 }
 152
 153 /*
 154  * Allocate and initialize a kernel event. Set name and event type.
 155  *
 156  * Return pointer to structure or NULL.
 157  */
 158 struct ltt_kernel_event *trace_kernel_create_event(struct lttng_event *ev)
 159 {
 160         struct ltt_kernel_event *lke;
 161         struct lttng_kernel_event *attr;
 162
 163         lke = malloc(sizeof(struct ltt_kernel_event));
 164         attr = malloc(sizeof(struct lttng_kernel_event));
 165         if (lke == NULL || attr == NULL) {
 166                 perror("kernel event malloc");
 167                 goto error;
 168         }
 169
 170         switch (ev->type) {
 171         case LTTNG_EVENT_PROBE:
 172                 attr->instrumentation = LTTNG_KERNEL_KPROBE;
 173                 attr->u.kprobe.addr = ev->attr.probe.addr;
 174                 attr->u.kprobe.offset = ev->attr.probe.offset;
 175                 strncpy(attr->u.kprobe.symbol_name,
 176                                 ev->attr.probe.symbol_name, LTTNG_SYM_NAME_LEN);
 177                 attr->u.kprobe.symbol_name[LTTNG_SYM_NAME_LEN - 1] = '\0';
 178                 break;
 179         case LTTNG_EVENT_FUNCTION:
 180                 attr->instrumentation = LTTNG_KERNEL_KRETPROBE;
 181                 attr->u.kretprobe.addr = ev->attr.probe.addr;
 182                 attr->u.kretprobe.offset = ev->attr.probe.offset;
 183                 attr->u.kretprobe.offset = ev->attr.probe.offset;
 184                 strncpy(attr->u.kretprobe.symbol_name,
 185                                 ev->attr.probe.symbol_name, LTTNG_SYM_NAME_LEN);
 186                 attr->u.kretprobe.symbol_name[LTTNG_SYM_NAME_LEN - 1] = '\0';
 187                 break;
 188         case LTTNG_EVENT_FUNCTION_ENTRY:
 189                 attr->instrumentation = LTTNG_KERNEL_FUNCTION;
 190                 strncpy(attr->u.ftrace.symbol_name,
 191                                 ev->attr.ftrace.symbol_name, LTTNG_SYM_NAME_LEN);
 192                 attr->u.ftrace.symbol_name[LTTNG_SYM_NAME_LEN - 1] = '\0';
 193                 break;
 194         case LTTNG_EVENT_TRACEPOINT:
 195                 attr->instrumentation = LTTNG_KERNEL_TRACEPOINT;
 196                 break;
 197         default:
 198                 ERR("Unknown kernel instrumentation type (%d)", ev->type);
 199                 goto error;
 200         }
 201
 202         /* Copy event name */
 203         strncpy(attr->name, ev->name, LTTNG_SYM_NAME_LEN);
 204         attr->name[LTTNG_SYM_NAME_LEN - 1] = '\0';
 205
 206         /* Setting up a kernel event */
 207         lke->fd = 0;
 208         lke->event = attr;
 209         lke->enabled = 1;
 210         lke->ctx = NULL;
 211
 212         return lke;
 213
 214 error:
 215         return NULL;
 216 }
 217
 218 /*
 219  * Allocate and initialize a kernel metadata.
 220  *
 221  * Return pointer to structure or NULL.
 222  */
 223 struct ltt_kernel_metadata *trace_kernel_create_metadata(char *path)
 224 {
 225         int ret;
 226         struct ltt_kernel_metadata *lkm;
 227         struct lttng_channel *chan;
 228
 229         lkm = malloc(sizeof(struct ltt_kernel_metadata));
 230         chan = malloc(sizeof(struct lttng_channel));
 231         if (lkm == NULL || chan == NULL) {
 232                 perror("kernel metadata malloc");
 233                 goto error;
 234         }
 235
 236         /* Set default attributes */
 237         chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
 238         chan->attr.subbuf_size = DEFAULT_METADATA_SUBBUF_SIZE;
 239         chan->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
 240         chan->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
 241         chan->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
 242         chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
 243
 244         /* Init metadata */
 245         lkm->fd = 0;
 246         lkm->conf = chan;
 247         /* Set default metadata path */
 248         ret = asprintf(&lkm->pathname, "%s/metadata", path);
 249         if (ret < 0) {
 250                 perror("asprintf kernel metadata");
 251                 goto error;
 252         }
 253
 254         return lkm;
 255
 256 error:
 257         return NULL;
 258 }
 259
 260 /*
 261  * Allocate and initialize a kernel stream. The stream is set to ACTIVE_FD by
 262  * default.
 263  *
 264  * Return pointer to structure or NULL.
 265  */
 266 struct ltt_kernel_stream *trace_kernel_create_stream(void)
 267 {
 268         struct ltt_kernel_stream *lks;
 269
 270         lks = malloc(sizeof(struct ltt_kernel_stream));
 271         if (lks == NULL) {
 272                 perror("kernel stream malloc");
 273                 goto error;
 274         }
 275
 276         /* Init stream */
 277         lks->fd = 0;
 278         lks->pathname = NULL;
 279         lks->state = 0;
 280
 281         return lks;
 282
 283 error:
 284         return NULL;
 285 }
 286
 287 /*
 288  * Cleanup kernel stream structure.
 289  */
 290 void trace_kernel_destroy_stream(struct ltt_kernel_stream *stream)
 291 {
 292         DBG("[trace] Closing stream fd %d", stream->fd);
 293         /* Close kernel fd */
 294         close(stream->fd);
 295         free(stream->pathname);
 296
 297         /* Remove from stream list */
 298         cds_list_del(&stream->list);
 299         free(stream);
 300 }
 301
 302 /*
 303  * Cleanup kernel event structure.
 304  */
 305 void trace_kernel_destroy_event(struct ltt_kernel_event *event)
 306 {
 307         DBG("[trace] Closing event fd %d", event->fd);
 308         /* Close kernel fd */
 309         close(event->fd);
 310         /* Free attributes */
 311         free(event->event);
 312
 313         /* Remove from event list */
 314         cds_list_del(&event->list);
 315         free(event);
 316 }
 317
 318 /*
 319  * Cleanup kernel channel structure.
 320  */
 321 void trace_kernel_destroy_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_kernel_destroy_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_kernel_destroy_event(event);
 341         }
 342
 343         /* Remove from channel list */
 344         cds_list_del(&channel->list);
 345         free(channel);
 346 }
 347
 348 /*
 349  * Cleanup kernel metadata structure.
 350  */
 351 void trace_kernel_destroy_metadata(struct ltt_kernel_metadata *metadata)
 352 {
 353         DBG("[trace] Closing metadata fd %d", metadata->fd);
 354         /* Close kernel fd */
 355         close(metadata->fd);
 356         /* Free attributes */
 357         free(metadata->conf);
 358
 359         free(metadata);
 360 }
 361
 362 /*
 363  * Cleanup kernel session structure
 364  */
 365 void trace_kernel_destroy_session(struct ltt_kernel_session *session)
 366 {
 367         struct ltt_kernel_channel *channel, *ctmp;
 368
 369         DBG("[trace] Closing session fd %d", session->fd);
 370         /* Close kernel fds */
 371         close(session->fd);
 372         if (session->metadata_stream_fd != 0) {
 373                 DBG("[trace] Closing metadata stream fd %d", session->metadata_stream_fd);
 374                 close(session->metadata_stream_fd);
 375         }
 376
 377         if (session->metadata != NULL) {
 378                 trace_kernel_destroy_metadata(session->metadata);
 379         }
 380
 381         cds_list_for_each_entry_safe(channel, ctmp, &session->channel_list.head, list) {
 382                 trace_kernel_destroy_channel(channel);
 383         }
 384
 385         free(session);
 386 }