liblttng-ust-ctl/ustctl.c

   1 /*
   2  * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
   3  *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; only version 2
   8  * of the License.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  18  */
  19
  20 #include <string.h>
  21 #include <lttng/ust-ctl.h>
  22 #include <lttng/ust-abi.h>
  23 #include <lttng/ust-events.h>
  24 #include <sys/mman.h>
  25
  26 #include <usterr-signal-safe.h>
  27 #include <ust-comm.h>
  28
  29 #include "../libringbuffer/backend.h"
  30 #include "../libringbuffer/frontend.h"
  31
  32 volatile enum ust_loglevel ust_loglevel;
  33
  34 static
  35 void init_object(struct lttng_ust_object_data *data)
  36 {
  37         data->handle = -1;
  38         data->shm_fd = -1;
  39         data->wait_fd = -1;
  40         data->memory_map_size = 0;
  41 }
  42
  43 int ustctl_release_handle(int sock, int handle)
  44 {
  45         struct ustcomm_ust_msg lum;
  46         struct ustcomm_ust_reply lur;
  47         int ret;
  48
  49         if (sock >= 0) {
  50                 memset(&lum, 0, sizeof(lum));
  51                 lum.handle = handle;
  52                 lum.cmd = LTTNG_UST_RELEASE;
  53                 ret = ustcomm_send_app_cmd(sock, &lum, &lur);
  54                 if (ret < 0) {
  55                         return ret;
  56                 }
  57         }
  58         return 0;
  59 }
  60 /*
  61  * If sock is negative, it means we don't have to notify the other side
  62  * (e.g. application has already vanished).
  63  */
  64 int ustctl_release_object(int sock, struct lttng_ust_object_data *data)
  65 {
  66         int ret;
  67
  68         if (data->shm_fd >= 0) {
  69                 ret = close(data->shm_fd);
  70                 if (ret < 0) {
  71                         return ret;
  72                 }
  73         }
  74         if (data->wait_fd >= 0) {
  75                 ret = close(data->wait_fd);
  76                 if (ret < 0) {
  77                         return ret;
  78                 }
  79         }
  80         return ustctl_release_handle(sock, data->handle);
  81 }
  82
  83 /*
  84  * Send registration done packet to the application.
  85  */
  86 int ustctl_register_done(int sock)
  87 {
  88         struct ustcomm_ust_msg lum;
  89         struct ustcomm_ust_reply lur;
  90         int ret;
  91
  92         DBG("Sending register done command to %d", sock);
  93         memset(&lum, 0, sizeof(lum));
  94         lum.handle = LTTNG_UST_ROOT_HANDLE;
  95         lum.cmd = LTTNG_UST_REGISTER_DONE;
  96         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
  97         if (ret)
  98                 return ret;
  99         if (lur.ret_code != USTCOMM_OK) {
 100                 DBG("Return code: %s", ustcomm_get_readable_code(lur.ret_code));
 101                 goto error;
 102         }
 103         return 0;
 104
 105 error:
 106         return -1;
 107 }
 108
 109 /*
 110  * returns session handle.
 111  */
 112 int ustctl_create_session(int sock)
 113 {
 114         struct ustcomm_ust_msg lum;
 115         struct ustcomm_ust_reply lur;
 116         int ret, session_handle;
 117
 118         /* Create session */
 119         memset(&lum, 0, sizeof(lum));
 120         lum.handle = LTTNG_UST_ROOT_HANDLE;
 121         lum.cmd = LTTNG_UST_SESSION;
 122         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 123         if (ret)
 124                 return ret;
 125         session_handle = lur.ret_val;
 126         DBG("received session handle %u", session_handle);
 127         return session_handle;
 128 }
 129
 130 /* open the metadata global channel */
 131 int ustctl_open_metadata(int sock, int session_handle,
 132                 struct lttng_ust_channel_attr *chops,
 133                 struct lttng_ust_object_data **_metadata_data)
 134 {
 135         struct ustcomm_ust_msg lum;
 136         struct ustcomm_ust_reply lur;
 137         struct lttng_ust_object_data *metadata_data;
 138         int ret;
 139
 140         metadata_data = malloc(sizeof(*metadata_data));
 141         if (!metadata_data)
 142                 return -ENOMEM;
 143         init_object(metadata_data);
 144         /* Create metadata channel */
 145         memset(&lum, 0, sizeof(lum));
 146         lum.handle = session_handle;
 147         lum.cmd = LTTNG_UST_METADATA;
 148         lum.u.channel.overwrite = chops->overwrite;
 149         lum.u.channel.subbuf_size = chops->subbuf_size;
 150         lum.u.channel.num_subbuf = chops->num_subbuf;
 151         lum.u.channel.switch_timer_interval = chops->switch_timer_interval;
 152         lum.u.channel.read_timer_interval = chops->read_timer_interval;
 153         lum.u.channel.output = chops->output;
 154         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 155         if (ret) {
 156                 free(metadata_data);
 157                 return ret;
 158         }
 159         if (lur.ret_code != USTCOMM_OK) {
 160                 free(metadata_data);
 161                 return lur.ret_code;
 162         }
 163         metadata_data->handle = lur.ret_val;
 164         DBG("received metadata handle %u", metadata_data->handle);
 165         metadata_data->memory_map_size = lur.u.channel.memory_map_size;
 166         /* get shm fd */
 167         ret = ustcomm_recv_fd(sock);
 168         if (ret < 0)
 169                 goto error;
 170         metadata_data->shm_fd = ret;
 171         /* get wait fd */
 172         ret = ustcomm_recv_fd(sock);
 173         if (ret < 0)
 174                 goto error;
 175         metadata_data->wait_fd = ret;
 176         *_metadata_data = metadata_data;
 177         return 0;
 178
 179 error:
 180         (void) ustctl_release_object(sock, metadata_data);
 181         free(metadata_data);
 182         return -EINVAL;
 183 }
 184
 185 int ustctl_create_channel(int sock, int session_handle,
 186                 struct lttng_ust_channel_attr *chops,
 187                 struct lttng_ust_object_data **_channel_data)
 188 {
 189         struct ustcomm_ust_msg lum;
 190         struct ustcomm_ust_reply lur;
 191         struct lttng_ust_object_data *channel_data;
 192         int ret;
 193
 194         channel_data = malloc(sizeof(*channel_data));
 195         if (!channel_data)
 196                 return -ENOMEM;
 197         init_object(channel_data);
 198         /* Create metadata channel */
 199         memset(&lum, 0, sizeof(lum));
 200         lum.handle = session_handle;
 201         lum.cmd = LTTNG_UST_CHANNEL;
 202         lum.u.channel.overwrite = chops->overwrite;
 203         lum.u.channel.subbuf_size = chops->subbuf_size;
 204         lum.u.channel.num_subbuf = chops->num_subbuf;
 205         lum.u.channel.switch_timer_interval = chops->switch_timer_interval;
 206         lum.u.channel.read_timer_interval = chops->read_timer_interval;
 207         lum.u.channel.output = chops->output;
 208         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 209         if (ret) {
 210                 free(channel_data);
 211                 return ret;
 212         }
 213         if (lur.ret_code != USTCOMM_OK) {
 214                 free(channel_data);
 215                 return lur.ret_code;
 216         }
 217         channel_data->handle = lur.ret_val;
 218         DBG("received channel handle %u", channel_data->handle);
 219         channel_data->memory_map_size = lur.u.channel.memory_map_size;
 220         /* get shm fd */
 221         ret = ustcomm_recv_fd(sock);
 222         if (ret < 0)
 223                 goto error;
 224         channel_data->shm_fd = ret;
 225         /* get wait fd */
 226         ret = ustcomm_recv_fd(sock);
 227         if (ret < 0)
 228                 goto error;
 229         channel_data->wait_fd = ret;
 230         *_channel_data = channel_data;
 231         return 0;
 232
 233 error:
 234         (void) ustctl_release_object(sock, channel_data);
 235         free(channel_data);
 236         return -EINVAL;
 237 }
 238
 239 /*
 240  * Return -ENOENT if no more stream is available for creation.
 241  * Return 0 on success.
 242  * Return negative error value on error.
 243  */
 244 int ustctl_create_stream(int sock, struct lttng_ust_object_data *channel_data,
 245                 struct lttng_ust_object_data **_stream_data)
 246 {
 247         struct ustcomm_ust_msg lum;
 248         struct ustcomm_ust_reply lur;
 249         struct lttng_ust_object_data *stream_data;
 250         int ret, fd;
 251
 252         stream_data = malloc(sizeof(*stream_data));
 253         if (!stream_data)
 254                 return -ENOMEM;
 255         init_object(stream_data);
 256         memset(&lum, 0, sizeof(lum));
 257         lum.handle = channel_data->handle;
 258         lum.cmd = LTTNG_UST_STREAM;
 259         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 260         if (ret) {
 261                 free(stream_data);
 262                 return ret;
 263         }
 264         if (lur.ret_code != USTCOMM_OK) {
 265                 free(stream_data);
 266                 return lur.ret_code;
 267         }
 268
 269         stream_data->handle = lur.ret_val;
 270         DBG("received stream handle %u", stream_data->handle);
 271         stream_data->memory_map_size = lur.u.stream.memory_map_size;
 272         /* get shm fd */
 273         fd = ustcomm_recv_fd(sock);
 274         if (fd < 0)
 275                 goto error;
 276         stream_data->shm_fd = fd;
 277         /* get wait fd */
 278         fd = ustcomm_recv_fd(sock);
 279         if (fd < 0)
 280                 goto error;
 281         stream_data->wait_fd = fd;
 282         *_stream_data = stream_data;
 283         return ret;
 284
 285 error:
 286         (void) ustctl_release_object(sock, stream_data);
 287         free(stream_data);
 288         return -EINVAL;
 289 }
 290
 291 int ustctl_create_event(int sock, struct lttng_ust_event *ev,
 292                 struct lttng_ust_object_data *channel_data,
 293                 struct lttng_ust_object_data **_event_data)
 294 {
 295         struct ustcomm_ust_msg lum;
 296         struct ustcomm_ust_reply lur;
 297         struct lttng_ust_object_data *event_data;
 298         int ret;
 299
 300         event_data = malloc(sizeof(*event_data));
 301         if (!event_data)
 302                 return -ENOMEM;
 303         init_object(event_data);
 304         memset(&lum, 0, sizeof(lum));
 305         lum.handle = channel_data->handle;
 306         lum.cmd = LTTNG_UST_EVENT;
 307         strncpy(lum.u.event.name, ev->name,
 308                 LTTNG_UST_SYM_NAME_LEN);
 309         lum.u.event.instrumentation = ev->instrumentation;
 310         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 311         if (ret) {
 312                 free(event_data);
 313                 return ret;
 314         }
 315         event_data->handle = lur.ret_val;
 316         DBG("received event handle %u", event_data->handle);
 317         *_event_data = event_data;
 318         return 0;
 319 }
 320
 321 int ustctl_add_context(int sock, struct lttng_ust_context *ctx,
 322                 struct lttng_ust_object_data *obj_data,
 323                 struct lttng_ust_object_data **_context_data)
 324 {
 325         struct ustcomm_ust_msg lum;
 326         struct ustcomm_ust_reply lur;
 327         struct lttng_ust_object_data *context_data;
 328         int ret;
 329
 330         context_data = malloc(sizeof(*context_data));
 331         if (!context_data)
 332                 return -ENOMEM;
 333         init_object(context_data);
 334         memset(&lum, 0, sizeof(lum));
 335         lum.handle = obj_data->handle;
 336         lum.cmd = LTTNG_UST_CONTEXT;
 337         lum.u.context.ctx = ctx->ctx;
 338         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 339         if (ret) {
 340                 free(context_data);
 341                 return ret;
 342         }
 343         context_data->handle = lur.ret_val;
 344         DBG("received context handle %u", context_data->handle);
 345         *_context_data = context_data;
 346         return ret;
 347 }
 348
 349 /* Enable event, channel and session ioctl */
 350 int ustctl_enable(int sock, struct lttng_ust_object_data *object)
 351 {
 352         struct ustcomm_ust_msg lum;
 353         struct ustcomm_ust_reply lur;
 354         int ret;
 355
 356         memset(&lum, 0, sizeof(lum));
 357         lum.handle = object->handle;
 358         lum.cmd = LTTNG_UST_ENABLE;
 359         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 360         if (ret)
 361                 return ret;
 362         DBG("enabled handle %u", object->handle);
 363         return 0;
 364 }
 365
 366 /* Disable event, channel and session ioctl */
 367 int ustctl_disable(int sock, struct lttng_ust_object_data *object)
 368 {
 369         struct ustcomm_ust_msg lum;
 370         struct ustcomm_ust_reply lur;
 371         int ret;
 372
 373         memset(&lum, 0, sizeof(lum));
 374         lum.handle = object->handle;
 375         lum.cmd = LTTNG_UST_DISABLE;
 376         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 377         if (ret)
 378                 return ret;
 379         DBG("disable handle %u", object->handle);
 380         return 0;
 381 }
 382
 383 int ustctl_start_session(int sock, int handle)
 384 {
 385         struct lttng_ust_object_data obj;
 386
 387         obj.handle = handle;
 388         return ustctl_enable(sock, &obj);
 389 }
 390
 391 int ustctl_stop_session(int sock, int handle)
 392 {
 393         struct lttng_ust_object_data obj;
 394
 395         obj.handle = handle;
 396         return ustctl_disable(sock, &obj);
 397 }
 398
 399 int ustctl_tracepoint_list(int sock)
 400 {
 401         struct ustcomm_ust_msg lum;
 402         struct ustcomm_ust_reply lur;
 403         int ret, tp_list_handle;
 404
 405         memset(&lum, 0, sizeof(lum));
 406         lum.handle = LTTNG_UST_ROOT_HANDLE;
 407         lum.cmd = LTTNG_UST_TRACEPOINT_LIST;
 408         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 409         if (ret)
 410                 return ret;
 411         tp_list_handle = lur.ret_val;
 412         DBG("received tracepoint list handle %u", tp_list_handle);
 413         return tp_list_handle;
 414 }
 415
 416 int ustctl_tracepoint_list_get(int sock, int tp_list_handle,
 417                 struct lttng_ust_tracepoint_iter *iter)
 418 {
 419         struct ustcomm_ust_msg lum;
 420         struct ustcomm_ust_reply lur;
 421         int ret;
 422
 423         memset(&lum, 0, sizeof(lum));
 424         lum.handle = tp_list_handle;
 425         lum.cmd = LTTNG_UST_TRACEPOINT_LIST_GET;
 426         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 427         if (ret)
 428                 return ret;
 429         DBG("received tracepoint list entry name %s loglevel %s loglevel_value %lld",
 430                 lur.u.tracepoint.name,
 431                 lur.u.tracepoint.loglevel,
 432                 (unsigned long long) lur.u.tracepoint.loglevel_value);
 433         memcpy(iter, &lur.u.tracepoint, sizeof(*iter));
 434         return 0;
 435 }
 436
 437 int ustctl_tracer_version(int sock, struct lttng_ust_tracer_version *v)
 438 {
 439         struct ustcomm_ust_msg lum;
 440         struct ustcomm_ust_reply lur;
 441         int ret;
 442
 443         memset(&lum, 0, sizeof(lum));
 444         lum.handle = LTTNG_UST_ROOT_HANDLE;
 445         lum.cmd = LTTNG_UST_TRACER_VERSION;
 446         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 447         if (ret)
 448                 return ret;
 449         memcpy(v, &lur.u.version, sizeof(*v));
 450         DBG("received tracer version");
 451         return 0;
 452 }
 453
 454 int ustctl_wait_quiescent(int sock)
 455 {
 456         struct ustcomm_ust_msg lum;
 457         struct ustcomm_ust_reply lur;
 458         int ret;
 459
 460         memset(&lum, 0, sizeof(lum));
 461         lum.handle = LTTNG_UST_ROOT_HANDLE;
 462         lum.cmd = LTTNG_UST_WAIT_QUIESCENT;
 463         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 464         if (ret)
 465                 return ret;
 466         DBG("waited for quiescent state");
 467         return 0;
 468 }
 469
 470 int ustctl_calibrate(int sock, struct lttng_ust_calibrate *calibrate)
 471 {
 472         return -ENOSYS;
 473 }
 474
 475 int ustctl_sock_flush_buffer(int sock, struct lttng_ust_object_data *object)
 476 {
 477         struct ustcomm_ust_msg lum;
 478         struct ustcomm_ust_reply lur;
 479         int ret;
 480
 481         memset(&lum, 0, sizeof(lum));
 482         lum.handle = object->handle;
 483         lum.cmd = LTTNG_UST_FLUSH_BUFFER;
 484         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 485         if (ret)
 486                 return ret;
 487         DBG("flushed buffer handle %u", object->handle);
 488         return 0;
 489 }
 490
 491 /* Buffer operations */
 492
 493 /* Map channel shm into process memory */
 494 struct lttng_ust_shm_handle *ustctl_map_channel(struct lttng_ust_object_data *chan_data)
 495 {
 496         struct lttng_ust_shm_handle *handle;
 497         struct channel *chan;
 498         size_t chan_size;
 499         struct lttng_ust_lib_ring_buffer_config *config;
 500         int ret;
 501
 502         handle = channel_handle_create(chan_data->shm_fd,
 503                 chan_data->wait_fd,
 504                 chan_data->memory_map_size);
 505         if (!handle) {
 506                 ERR("create handle error");
 507                 return NULL;
 508         }
 509         /*
 510          * Set to -1, and then close the shm fd, and set the handle shm
 511          * fd to -1 too. We don't need the shm fds after they have been
 512          * mapped.
 513          * The wait_fd is set to -1 in chan_data because it is now owned
 514          * by the handle.
 515          */
 516         chan_data->shm_fd = -1;
 517         chan_data->wait_fd = -1;
 518
 519         /* chan is object 0. This is hardcoded. */
 520         if (handle->table->objects[0].shm_fd >= 0) {
 521                 ret = close(handle->table->objects[0].shm_fd);
 522                 if (ret) {
 523                         perror("Error closing shm_fd");
 524                 }
 525                 handle->table->objects[0].shm_fd = -1;
 526         }
 527
 528         /*
 529          * TODO: add consistency checks to be resilient if the
 530          * application try to feed us with incoherent channel structure
 531          * values.
 532          */
 533         chan = shmp(handle, handle->chan);
 534         /* chan is object 0. This is hardcoded. */
 535         chan_size = handle->table->objects[0].allocated_len;
 536         handle->shadow_chan = malloc(chan_size);
 537         if (!handle->shadow_chan) {
 538                 channel_destroy(chan, handle, 1);
 539                 return NULL;
 540         }
 541         memcpy(handle->shadow_chan, chan, chan_size);
 542         /*
 543          * The callback pointers in the producer are invalid in the
 544          * consumer. We need to look them up here.
 545          */
 546         config = &handle->shadow_chan->backend.config;
 547         switch (config->client_type) {
 548         case LTTNG_CLIENT_METADATA:
 549                 memcpy(&config->cb, lttng_client_callbacks_metadata,
 550                         sizeof(config->cb));
 551                 break;
 552         case LTTNG_CLIENT_DISCARD:
 553                 memcpy(&config->cb, lttng_client_callbacks_discard,
 554                         sizeof(config->cb));
 555                 break;
 556         case LTTNG_CLIENT_OVERWRITE:
 557                 memcpy(&config->cb, lttng_client_callbacks_overwrite,
 558                         sizeof(config->cb));
 559                 break;
 560         default:
 561                 ERR("Unknown client type %d", config->client_type);
 562                 channel_destroy(chan, handle, 1);
 563                 return NULL;
 564         }
 565         /* Replace the object table pointer. */
 566         ret = munmap(handle->table->objects[0].memory_map,
 567                 handle->table->objects[0].memory_map_size);
 568         if (ret) {
 569                 perror("munmap");
 570                 assert(0);
 571         }
 572         handle->table->objects[0].memory_map = (char *) handle->shadow_chan;
 573         handle->table->objects[0].is_shadow = 1;
 574         return handle;
 575 }
 576
 577 /* Add stream to channel shm and map its shm into process memory */
 578 int ustctl_add_stream(struct lttng_ust_shm_handle *handle,
 579                 struct lttng_ust_object_data *stream_data)
 580 {
 581         int ret;
 582
 583         if (!stream_data->handle)
 584                 return -ENOENT;
 585         /* map stream */
 586         ret = channel_handle_add_stream(handle,
 587                 stream_data->shm_fd,
 588                 stream_data->wait_fd,
 589                 stream_data->memory_map_size);
 590         if (ret) {
 591                 ERR("add stream error\n");
 592                 return ret;
 593         }
 594         /*
 595          * Set to -1 because the lttng_ust_shm_handle destruction will take care
 596          * of closing shm_fd and wait_fd.
 597          */
 598         stream_data->shm_fd = -1;
 599         stream_data->wait_fd = -1;
 600         return 0;
 601 }
 602
 603 void ustctl_unmap_channel(struct lttng_ust_shm_handle *handle)
 604 {
 605         struct channel *chan;
 606
 607         chan = shmp(handle, handle->chan);
 608         channel_destroy(chan, handle, 1);
 609 }
 610
 611 /*
 612  * ustctl closes the shm_fd fds after mapping it.
 613  */
 614 struct lttng_ust_lib_ring_buffer *ustctl_open_stream_read(struct lttng_ust_shm_handle *handle,
 615         int cpu)
 616 {
 617         struct channel *chan = handle->shadow_chan;
 618         int *shm_fd, *wait_fd;
 619         uint64_t *memory_map_size;
 620         struct lttng_ust_lib_ring_buffer *buf;
 621         int ret;
 622
 623         buf = channel_get_ring_buffer(&chan->backend.config,
 624                 chan, cpu, handle, &shm_fd, &wait_fd, &memory_map_size);
 625         if (!buf)
 626                 return NULL;
 627         ret = lib_ring_buffer_open_read(buf, handle, 1);
 628         if (ret)
 629                 return NULL;
 630         /*
 631          * We can close shm_fd early, right after is has been mapped.
 632          */
 633         if (*shm_fd >= 0) {
 634                 ret = close(*shm_fd);
 635                 if (ret) {
 636                         perror("Error closing shm_fd");
 637                 }
 638                 *shm_fd = -1;
 639         }
 640         return buf;
 641 }
 642
 643 void ustctl_close_stream_read(struct lttng_ust_shm_handle *handle,
 644                 struct lttng_ust_lib_ring_buffer *buf)
 645 {
 646         lib_ring_buffer_release_read(buf, handle, 1);
 647 }
 648
 649 /* For mmap mode, readable without "get" operation */
 650
 651 void *ustctl_get_mmap_base(struct lttng_ust_shm_handle *handle,
 652                 struct lttng_ust_lib_ring_buffer *buf)
 653 {
 654         return shmp(handle, buf->backend.memory_map);
 655 }
 656
 657 /* returns the length to mmap. */
 658 int ustctl_get_mmap_len(struct lttng_ust_shm_handle *handle,
 659                 struct lttng_ust_lib_ring_buffer *buf,
 660                 unsigned long *len)
 661 {
 662         unsigned long mmap_buf_len;
 663         struct channel *chan = handle->shadow_chan;
 664
 665         if (chan->backend.config.output != RING_BUFFER_MMAP)
 666                 return -EINVAL;
 667         mmap_buf_len = chan->backend.buf_size;
 668         if (chan->backend.extra_reader_sb)
 669                 mmap_buf_len += chan->backend.subbuf_size;
 670         if (mmap_buf_len > INT_MAX)
 671                 return -EFBIG;
 672         *len = mmap_buf_len;
 673         return 0;
 674 }
 675
 676 /* returns the maximum size for sub-buffers. */
 677 int ustctl_get_max_subbuf_size(struct lttng_ust_shm_handle *handle,
 678                 struct lttng_ust_lib_ring_buffer *buf,
 679                 unsigned long *len)
 680 {
 681         struct channel *chan = handle->shadow_chan;
 682
 683         *len = chan->backend.subbuf_size;
 684         return 0;
 685 }
 686
 687 /*
 688  * For mmap mode, operate on the current packet (between get/put or
 689  * get_next/put_next).
 690  */
 691
 692 /* returns the offset of the subbuffer belonging to the mmap reader. */
 693 int ustctl_get_mmap_read_offset(struct lttng_ust_shm_handle *handle,
 694                 struct lttng_ust_lib_ring_buffer *buf, unsigned long *off)
 695 {
 696         struct channel *chan = handle->shadow_chan;
 697         unsigned long sb_bindex;
 698
 699         if (chan->backend.config.output != RING_BUFFER_MMAP)
 700                 return -EINVAL;
 701         sb_bindex = subbuffer_id_get_index(&chan->backend.config,
 702                                            buf->backend.buf_rsb.id);
 703         *off = shmp(handle, shmp_index(handle, buf->backend.array, sb_bindex)->shmp)->mmap_offset;
 704         return 0;
 705 }
 706
 707 /* returns the size of the current sub-buffer, without padding (for mmap). */
 708 int ustctl_get_subbuf_size(struct lttng_ust_shm_handle *handle,
 709                 struct lttng_ust_lib_ring_buffer *buf, unsigned long *len)
 710 {
 711         struct channel *chan = handle->shadow_chan;
 712
 713         *len = lib_ring_buffer_get_read_data_size(&chan->backend.config, buf,
 714                 handle);
 715         return 0;
 716 }
 717
 718 /* returns the size of the current sub-buffer, without padding (for mmap). */
 719 int ustctl_get_padded_subbuf_size(struct lttng_ust_shm_handle *handle,
 720                 struct lttng_ust_lib_ring_buffer *buf, unsigned long *len)
 721 {
 722         struct channel *chan = handle->shadow_chan;
 723
 724         *len = lib_ring_buffer_get_read_data_size(&chan->backend.config, buf,
 725                 handle);
 726         *len = PAGE_ALIGN(*len);
 727         return 0;
 728 }
 729
 730 /* Get exclusive read access to the next sub-buffer that can be read. */
 731 int ustctl_get_next_subbuf(struct lttng_ust_shm_handle *handle,
 732                 struct lttng_ust_lib_ring_buffer *buf)
 733 {
 734         return lib_ring_buffer_get_next_subbuf(buf, handle);
 735 }
 736
 737
 738 /* Release exclusive sub-buffer access, move consumer forward. */
 739 int ustctl_put_next_subbuf(struct lttng_ust_shm_handle *handle,
 740                 struct lttng_ust_lib_ring_buffer *buf)
 741 {
 742         lib_ring_buffer_put_next_subbuf(buf, handle);
 743         return 0;
 744 }
 745
 746 /* snapshot */
 747
 748 /* Get a snapshot of the current ring buffer producer and consumer positions */
 749 int ustctl_snapshot(struct lttng_ust_shm_handle *handle,
 750                 struct lttng_ust_lib_ring_buffer *buf)
 751 {
 752         return lib_ring_buffer_snapshot(buf, &buf->cons_snapshot,
 753                         &buf->prod_snapshot, handle);
 754 }
 755
 756 /* Get the consumer position (iteration start) */
 757 int ustctl_snapshot_get_consumed(struct lttng_ust_shm_handle *handle,
 758                 struct lttng_ust_lib_ring_buffer *buf, unsigned long *pos)
 759 {
 760         *pos = buf->cons_snapshot;
 761         return 0;
 762 }
 763
 764 /* Get the producer position (iteration end) */
 765 int ustctl_snapshot_get_produced(struct lttng_ust_shm_handle *handle,
 766                 struct lttng_ust_lib_ring_buffer *buf, unsigned long *pos)
 767 {
 768         *pos = buf->prod_snapshot;
 769         return 0;
 770 }
 771
 772 /* Get exclusive read access to the specified sub-buffer position */
 773 int ustctl_get_subbuf(struct lttng_ust_shm_handle *handle,
 774                 struct lttng_ust_lib_ring_buffer *buf, unsigned long *pos)
 775 {
 776         return lib_ring_buffer_get_subbuf(buf, *pos, handle);
 777 }
 778
 779 /* Release exclusive sub-buffer access */
 780 int ustctl_put_subbuf(struct lttng_ust_shm_handle *handle,
 781                 struct lttng_ust_lib_ring_buffer *buf)
 782 {
 783         lib_ring_buffer_put_subbuf(buf, handle);
 784         return 0;
 785 }
 786
 787 void ustctl_flush_buffer(struct lttng_ust_shm_handle *handle,
 788                 struct lttng_ust_lib_ring_buffer *buf,
 789                 int producer_active)
 790 {
 791         lib_ring_buffer_switch_slow(buf,
 792                 producer_active ? SWITCH_ACTIVE : SWITCH_FLUSH,
 793                 handle);
 794 }