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, err = 0;
 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                 err = 1;
 170         else
 171                 metadata_data->shm_fd = ret;
 172         /*
 173          * We need to get the second FD even if the first fails, because
 174          * libust expects us to read the two FDs.
 175          */
 176         /* get wait fd */
 177         ret = ustcomm_recv_fd(sock);
 178         if (ret < 0)
 179                 err = 1;
 180         else
 181                 metadata_data->wait_fd = ret;
 182         if (err)
 183                 goto error;
 184         *_metadata_data = metadata_data;
 185         return 0;
 186
 187 error:
 188         (void) ustctl_release_object(sock, metadata_data);
 189         free(metadata_data);
 190         return -EINVAL;
 191 }
 192
 193 int ustctl_create_channel(int sock, int session_handle,
 194                 struct lttng_ust_channel_attr *chops,
 195                 struct lttng_ust_object_data **_channel_data)
 196 {
 197         struct ustcomm_ust_msg lum;
 198         struct ustcomm_ust_reply lur;
 199         struct lttng_ust_object_data *channel_data;
 200         int ret, err = 0;
 201
 202         channel_data = malloc(sizeof(*channel_data));
 203         if (!channel_data)
 204                 return -ENOMEM;
 205         init_object(channel_data);
 206         /* Create metadata channel */
 207         memset(&lum, 0, sizeof(lum));
 208         lum.handle = session_handle;
 209         lum.cmd = LTTNG_UST_CHANNEL;
 210         lum.u.channel.overwrite = chops->overwrite;
 211         lum.u.channel.subbuf_size = chops->subbuf_size;
 212         lum.u.channel.num_subbuf = chops->num_subbuf;
 213         lum.u.channel.switch_timer_interval = chops->switch_timer_interval;
 214         lum.u.channel.read_timer_interval = chops->read_timer_interval;
 215         lum.u.channel.output = chops->output;
 216         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 217         if (ret) {
 218                 free(channel_data);
 219                 return ret;
 220         }
 221         if (lur.ret_code != USTCOMM_OK) {
 222                 free(channel_data);
 223                 return lur.ret_code;
 224         }
 225         channel_data->handle = lur.ret_val;
 226         DBG("received channel handle %u", channel_data->handle);
 227         channel_data->memory_map_size = lur.u.channel.memory_map_size;
 228         /* get shm fd */
 229         ret = ustcomm_recv_fd(sock);
 230         if (ret < 0)
 231                 err = 1;
 232         else
 233                 channel_data->shm_fd = ret;
 234         /*
 235          * We need to get the second FD even if the first fails, because
 236          * libust expects us to read the two FDs.
 237          */
 238         /* get wait fd */
 239         ret = ustcomm_recv_fd(sock);
 240         if (ret < 0)
 241                 err = 1;
 242         else
 243                 channel_data->wait_fd = ret;
 244         if (err)
 245                 goto error;
 246         *_channel_data = channel_data;
 247         return 0;
 248
 249 error:
 250         (void) ustctl_release_object(sock, channel_data);
 251         free(channel_data);
 252         return -EINVAL;
 253 }
 254
 255 /*
 256  * Return -ENOENT if no more stream is available for creation.
 257  * Return 0 on success.
 258  * Return negative error value on error.
 259  */
 260 int ustctl_create_stream(int sock, struct lttng_ust_object_data *channel_data,
 261                 struct lttng_ust_object_data **_stream_data)
 262 {
 263         struct ustcomm_ust_msg lum;
 264         struct ustcomm_ust_reply lur;
 265         struct lttng_ust_object_data *stream_data;
 266         int ret, fd, err = 0;
 267
 268         stream_data = malloc(sizeof(*stream_data));
 269         if (!stream_data)
 270                 return -ENOMEM;
 271         init_object(stream_data);
 272         memset(&lum, 0, sizeof(lum));
 273         lum.handle = channel_data->handle;
 274         lum.cmd = LTTNG_UST_STREAM;
 275         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 276         if (ret) {
 277                 free(stream_data);
 278                 return ret;
 279         }
 280         if (lur.ret_code != USTCOMM_OK) {
 281                 free(stream_data);
 282                 return lur.ret_code;
 283         }
 284
 285         stream_data->handle = lur.ret_val;
 286         DBG("received stream handle %u", stream_data->handle);
 287         stream_data->memory_map_size = lur.u.stream.memory_map_size;
 288         /* get shm fd */
 289         fd = ustcomm_recv_fd(sock);
 290         if (fd < 0)
 291                 err = 1;
 292         else
 293                 stream_data->shm_fd = fd;
 294         /*
 295          * We need to get the second FD even if the first fails, because
 296          * libust expects us to read the two FDs.
 297          */
 298         /* get wait fd */
 299         fd = ustcomm_recv_fd(sock);
 300         if (fd < 0)
 301                 err = 1;
 302         else
 303                 stream_data->wait_fd = fd;
 304         if (err)
 305                 goto error;
 306         *_stream_data = stream_data;
 307         return ret;
 308
 309 error:
 310         (void) ustctl_release_object(sock, stream_data);
 311         free(stream_data);
 312         return -EINVAL;
 313 }
 314
 315 int ustctl_create_event(int sock, struct lttng_ust_event *ev,
 316                 struct lttng_ust_object_data *channel_data,
 317                 struct lttng_ust_object_data **_event_data)
 318 {
 319         struct ustcomm_ust_msg lum;
 320         struct ustcomm_ust_reply lur;
 321         struct lttng_ust_object_data *event_data;
 322         int ret;
 323
 324         event_data = malloc(sizeof(*event_data));
 325         if (!event_data)
 326                 return -ENOMEM;
 327         init_object(event_data);
 328         memset(&lum, 0, sizeof(lum));
 329         lum.handle = channel_data->handle;
 330         lum.cmd = LTTNG_UST_EVENT;
 331         strncpy(lum.u.event.name, ev->name,
 332                 LTTNG_UST_SYM_NAME_LEN);
 333         lum.u.event.instrumentation = ev->instrumentation;
 334         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 335         if (ret) {
 336                 free(event_data);
 337                 return ret;
 338         }
 339         event_data->handle = lur.ret_val;
 340         DBG("received event handle %u", event_data->handle);
 341         *_event_data = event_data;
 342         return 0;
 343 }
 344
 345 int ustctl_add_context(int sock, struct lttng_ust_context *ctx,
 346                 struct lttng_ust_object_data *obj_data,
 347                 struct lttng_ust_object_data **_context_data)
 348 {
 349         struct ustcomm_ust_msg lum;
 350         struct ustcomm_ust_reply lur;
 351         struct lttng_ust_object_data *context_data;
 352         int ret;
 353
 354         context_data = malloc(sizeof(*context_data));
 355         if (!context_data)
 356                 return -ENOMEM;
 357         init_object(context_data);
 358         memset(&lum, 0, sizeof(lum));
 359         lum.handle = obj_data->handle;
 360         lum.cmd = LTTNG_UST_CONTEXT;
 361         lum.u.context.ctx = ctx->ctx;
 362         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 363         if (ret) {
 364                 free(context_data);
 365                 return ret;
 366         }
 367         context_data->handle = lur.ret_val;
 368         DBG("received context handle %u", context_data->handle);
 369         *_context_data = context_data;
 370         return ret;
 371 }
 372
 373 /* Enable event, channel and session ioctl */
 374 int ustctl_enable(int sock, struct lttng_ust_object_data *object)
 375 {
 376         struct ustcomm_ust_msg lum;
 377         struct ustcomm_ust_reply lur;
 378         int ret;
 379
 380         memset(&lum, 0, sizeof(lum));
 381         lum.handle = object->handle;
 382         lum.cmd = LTTNG_UST_ENABLE;
 383         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 384         if (ret)
 385                 return ret;
 386         DBG("enabled handle %u", object->handle);
 387         return 0;
 388 }
 389
 390 /* Disable event, channel and session ioctl */
 391 int ustctl_disable(int sock, struct lttng_ust_object_data *object)
 392 {
 393         struct ustcomm_ust_msg lum;
 394         struct ustcomm_ust_reply lur;
 395         int ret;
 396
 397         memset(&lum, 0, sizeof(lum));
 398         lum.handle = object->handle;
 399         lum.cmd = LTTNG_UST_DISABLE;
 400         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 401         if (ret)
 402                 return ret;
 403         DBG("disable handle %u", object->handle);
 404         return 0;
 405 }
 406
 407 int ustctl_start_session(int sock, int handle)
 408 {
 409         struct lttng_ust_object_data obj;
 410
 411         obj.handle = handle;
 412         return ustctl_enable(sock, &obj);
 413 }
 414
 415 int ustctl_stop_session(int sock, int handle)
 416 {
 417         struct lttng_ust_object_data obj;
 418
 419         obj.handle = handle;
 420         return ustctl_disable(sock, &obj);
 421 }
 422
 423 int ustctl_tracepoint_list(int sock)
 424 {
 425         struct ustcomm_ust_msg lum;
 426         struct ustcomm_ust_reply lur;
 427         int ret, tp_list_handle;
 428
 429         memset(&lum, 0, sizeof(lum));
 430         lum.handle = LTTNG_UST_ROOT_HANDLE;
 431         lum.cmd = LTTNG_UST_TRACEPOINT_LIST;
 432         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 433         if (ret)
 434                 return ret;
 435         tp_list_handle = lur.ret_val;
 436         DBG("received tracepoint list handle %u", tp_list_handle);
 437         return tp_list_handle;
 438 }
 439
 440 int ustctl_tracepoint_list_get(int sock, int tp_list_handle,
 441                 struct lttng_ust_tracepoint_iter *iter)
 442 {
 443         struct ustcomm_ust_msg lum;
 444         struct ustcomm_ust_reply lur;
 445         int ret;
 446
 447         memset(&lum, 0, sizeof(lum));
 448         lum.handle = tp_list_handle;
 449         lum.cmd = LTTNG_UST_TRACEPOINT_LIST_GET;
 450         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 451         if (ret)
 452                 return ret;
 453         DBG("received tracepoint list entry name %s loglevel %d",
 454                 lur.u.tracepoint.name,
 455                 lur.u.tracepoint.loglevel);
 456         memcpy(iter, &lur.u.tracepoint, sizeof(*iter));
 457         return 0;
 458 }
 459
 460 int ustctl_tracer_version(int sock, struct lttng_ust_tracer_version *v)
 461 {
 462         struct ustcomm_ust_msg lum;
 463         struct ustcomm_ust_reply lur;
 464         int ret;
 465
 466         memset(&lum, 0, sizeof(lum));
 467         lum.handle = LTTNG_UST_ROOT_HANDLE;
 468         lum.cmd = LTTNG_UST_TRACER_VERSION;
 469         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 470         if (ret)
 471                 return ret;
 472         memcpy(v, &lur.u.version, sizeof(*v));
 473         DBG("received tracer version");
 474         return 0;
 475 }
 476
 477 int ustctl_wait_quiescent(int sock)
 478 {
 479         struct ustcomm_ust_msg lum;
 480         struct ustcomm_ust_reply lur;
 481         int ret;
 482
 483         memset(&lum, 0, sizeof(lum));
 484         lum.handle = LTTNG_UST_ROOT_HANDLE;
 485         lum.cmd = LTTNG_UST_WAIT_QUIESCENT;
 486         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 487         if (ret)
 488                 return ret;
 489         DBG("waited for quiescent state");
 490         return 0;
 491 }
 492
 493 int ustctl_calibrate(int sock, struct lttng_ust_calibrate *calibrate)
 494 {
 495         return -ENOSYS;
 496 }
 497
 498 int ustctl_sock_flush_buffer(int sock, struct lttng_ust_object_data *object)
 499 {
 500         struct ustcomm_ust_msg lum;
 501         struct ustcomm_ust_reply lur;
 502         int ret;
 503
 504         memset(&lum, 0, sizeof(lum));
 505         lum.handle = object->handle;
 506         lum.cmd = LTTNG_UST_FLUSH_BUFFER;
 507         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 508         if (ret)
 509                 return ret;
 510         DBG("flushed buffer handle %u", object->handle);
 511         return 0;
 512 }
 513
 514 /* Buffer operations */
 515
 516 /* Map channel shm into process memory */
 517 struct lttng_ust_shm_handle *ustctl_map_channel(struct lttng_ust_object_data *chan_data)
 518 {
 519         struct lttng_ust_shm_handle *handle;
 520         struct channel *chan;
 521         size_t chan_size;
 522         struct lttng_ust_lib_ring_buffer_config *config;
 523         int ret;
 524
 525         handle = channel_handle_create(chan_data->shm_fd,
 526                 chan_data->wait_fd,
 527                 chan_data->memory_map_size);
 528         if (!handle) {
 529                 ERR("create handle error");
 530                 return NULL;
 531         }
 532         /*
 533          * Set to -1, and then close the shm fd, and set the handle shm
 534          * fd to -1 too. We don't need the shm fds after they have been
 535          * mapped.
 536          * The wait_fd is set to -1 in chan_data because it is now owned
 537          * by the handle.
 538          */
 539         chan_data->shm_fd = -1;
 540         chan_data->wait_fd = -1;
 541
 542         /* chan is object 0. This is hardcoded. */
 543         if (handle->table->objects[0].shm_fd >= 0) {
 544                 ret = close(handle->table->objects[0].shm_fd);
 545                 if (ret) {
 546                         perror("Error closing shm_fd");
 547                 }
 548                 handle->table->objects[0].shm_fd = -1;
 549         }
 550
 551         /*
 552          * TODO: add consistency checks to be resilient if the
 553          * application try to feed us with incoherent channel structure
 554          * values.
 555          */
 556         chan = shmp(handle, handle->chan);
 557         /* chan is object 0. This is hardcoded. */
 558         chan_size = handle->table->objects[0].allocated_len;
 559         handle->shadow_chan = malloc(chan_size);
 560         if (!handle->shadow_chan) {
 561                 channel_destroy(chan, handle, 1);
 562                 return NULL;
 563         }
 564         memcpy(handle->shadow_chan, chan, chan_size);
 565         /*
 566          * The callback pointers in the producer are invalid in the
 567          * consumer. We need to look them up here.
 568          */
 569         config = &handle->shadow_chan->backend.config;
 570         switch (config->client_type) {
 571         case LTTNG_CLIENT_METADATA:
 572                 memcpy(&config->cb, lttng_client_callbacks_metadata,
 573                         sizeof(config->cb));
 574                 break;
 575         case LTTNG_CLIENT_DISCARD:
 576                 memcpy(&config->cb, lttng_client_callbacks_discard,
 577                         sizeof(config->cb));
 578                 break;
 579         case LTTNG_CLIENT_OVERWRITE:
 580                 memcpy(&config->cb, lttng_client_callbacks_overwrite,
 581                         sizeof(config->cb));
 582                 break;
 583         default:
 584                 ERR("Unknown client type %d", config->client_type);
 585                 channel_destroy(chan, handle, 1);
 586                 return NULL;
 587         }
 588         /* Replace the object table pointer. */
 589         ret = munmap(handle->table->objects[0].memory_map,
 590                 handle->table->objects[0].memory_map_size);
 591         if (ret) {
 592                 perror("munmap");
 593                 assert(0);
 594         }
 595         handle->table->objects[0].memory_map = (char *) handle->shadow_chan;
 596         handle->table->objects[0].is_shadow = 1;
 597         return handle;
 598 }
 599
 600 /* Add stream to channel shm and map its shm into process memory */
 601 int ustctl_add_stream(struct lttng_ust_shm_handle *handle,
 602                 struct lttng_ust_object_data *stream_data)
 603 {
 604         int ret;
 605
 606         if (!stream_data->handle)
 607                 return -ENOENT;
 608         /* map stream */
 609         ret = channel_handle_add_stream(handle,
 610                 stream_data->shm_fd,
 611                 stream_data->wait_fd,
 612                 stream_data->memory_map_size);
 613         if (ret) {
 614                 ERR("add stream error\n");
 615                 return ret;
 616         }
 617         /*
 618          * Set to -1 because the lttng_ust_shm_handle destruction will take care
 619          * of closing shm_fd and wait_fd.
 620          */
 621         stream_data->shm_fd = -1;
 622         stream_data->wait_fd = -1;
 623         return 0;
 624 }
 625
 626 void ustctl_unmap_channel(struct lttng_ust_shm_handle *handle)
 627 {
 628         struct channel *chan;
 629
 630         chan = shmp(handle, handle->chan);
 631         channel_destroy(chan, handle, 1);
 632 }
 633
 634 /*
 635  * ustctl closes the shm_fd fds after mapping it.
 636  */
 637 struct lttng_ust_lib_ring_buffer *ustctl_open_stream_read(struct lttng_ust_shm_handle *handle,
 638         int cpu)
 639 {
 640         struct channel *chan = handle->shadow_chan;
 641         int *shm_fd, *wait_fd;
 642         uint64_t *memory_map_size;
 643         struct lttng_ust_lib_ring_buffer *buf;
 644         int ret;
 645
 646         buf = channel_get_ring_buffer(&chan->backend.config,
 647                 chan, cpu, handle, &shm_fd, &wait_fd, &memory_map_size);
 648         if (!buf)
 649                 return NULL;
 650         ret = lib_ring_buffer_open_read(buf, handle, 1);
 651         if (ret)
 652                 return NULL;
 653         /*
 654          * We can close shm_fd early, right after is has been mapped.
 655          */
 656         if (*shm_fd >= 0) {
 657                 ret = close(*shm_fd);
 658                 if (ret) {
 659                         perror("Error closing shm_fd");
 660                 }
 661                 *shm_fd = -1;
 662         }
 663         return buf;
 664 }
 665
 666 void ustctl_close_stream_read(struct lttng_ust_shm_handle *handle,
 667                 struct lttng_ust_lib_ring_buffer *buf)
 668 {
 669         lib_ring_buffer_release_read(buf, handle, 1);
 670 }
 671
 672 /* For mmap mode, readable without "get" operation */
 673
 674 void *ustctl_get_mmap_base(struct lttng_ust_shm_handle *handle,
 675                 struct lttng_ust_lib_ring_buffer *buf)
 676 {
 677         return shmp(handle, buf->backend.memory_map);
 678 }
 679
 680 /* returns the length to mmap. */
 681 int ustctl_get_mmap_len(struct lttng_ust_shm_handle *handle,
 682                 struct lttng_ust_lib_ring_buffer *buf,
 683                 unsigned long *len)
 684 {
 685         unsigned long mmap_buf_len;
 686         struct channel *chan = handle->shadow_chan;
 687
 688         if (chan->backend.config.output != RING_BUFFER_MMAP)
 689                 return -EINVAL;
 690         mmap_buf_len = chan->backend.buf_size;
 691         if (chan->backend.extra_reader_sb)
 692                 mmap_buf_len += chan->backend.subbuf_size;
 693         if (mmap_buf_len > INT_MAX)
 694                 return -EFBIG;
 695         *len = mmap_buf_len;
 696         return 0;
 697 }
 698
 699 /* returns the maximum size for sub-buffers. */
 700 int ustctl_get_max_subbuf_size(struct lttng_ust_shm_handle *handle,
 701                 struct lttng_ust_lib_ring_buffer *buf,
 702                 unsigned long *len)
 703 {
 704         struct channel *chan = handle->shadow_chan;
 705
 706         *len = chan->backend.subbuf_size;
 707         return 0;
 708 }
 709
 710 /*
 711  * For mmap mode, operate on the current packet (between get/put or
 712  * get_next/put_next).
 713  */
 714
 715 /* returns the offset of the subbuffer belonging to the mmap reader. */
 716 int ustctl_get_mmap_read_offset(struct lttng_ust_shm_handle *handle,
 717                 struct lttng_ust_lib_ring_buffer *buf, unsigned long *off)
 718 {
 719         struct channel *chan = handle->shadow_chan;
 720         unsigned long sb_bindex;
 721
 722         if (chan->backend.config.output != RING_BUFFER_MMAP)
 723                 return -EINVAL;
 724         sb_bindex = subbuffer_id_get_index(&chan->backend.config,
 725                                            buf->backend.buf_rsb.id);
 726         *off = shmp(handle, shmp_index(handle, buf->backend.array, sb_bindex)->shmp)->mmap_offset;
 727         return 0;
 728 }
 729
 730 /* returns the size of the current sub-buffer, without padding (for mmap). */
 731 int ustctl_get_subbuf_size(struct lttng_ust_shm_handle *handle,
 732                 struct lttng_ust_lib_ring_buffer *buf, unsigned long *len)
 733 {
 734         struct channel *chan = handle->shadow_chan;
 735
 736         *len = lib_ring_buffer_get_read_data_size(&chan->backend.config, buf,
 737                 handle);
 738         return 0;
 739 }
 740
 741 /* returns the size of the current sub-buffer, without padding (for mmap). */
 742 int ustctl_get_padded_subbuf_size(struct lttng_ust_shm_handle *handle,
 743                 struct lttng_ust_lib_ring_buffer *buf, unsigned long *len)
 744 {
 745         struct channel *chan = handle->shadow_chan;
 746
 747         *len = lib_ring_buffer_get_read_data_size(&chan->backend.config, buf,
 748                 handle);
 749         *len = PAGE_ALIGN(*len);
 750         return 0;
 751 }
 752
 753 /* Get exclusive read access to the next sub-buffer that can be read. */
 754 int ustctl_get_next_subbuf(struct lttng_ust_shm_handle *handle,
 755                 struct lttng_ust_lib_ring_buffer *buf)
 756 {
 757         return lib_ring_buffer_get_next_subbuf(buf, handle);
 758 }
 759
 760
 761 /* Release exclusive sub-buffer access, move consumer forward. */
 762 int ustctl_put_next_subbuf(struct lttng_ust_shm_handle *handle,
 763                 struct lttng_ust_lib_ring_buffer *buf)
 764 {
 765         lib_ring_buffer_put_next_subbuf(buf, handle);
 766         return 0;
 767 }
 768
 769 /* snapshot */
 770
 771 /* Get a snapshot of the current ring buffer producer and consumer positions */
 772 int ustctl_snapshot(struct lttng_ust_shm_handle *handle,
 773                 struct lttng_ust_lib_ring_buffer *buf)
 774 {
 775         return lib_ring_buffer_snapshot(buf, &buf->cons_snapshot,
 776                         &buf->prod_snapshot, handle);
 777 }
 778
 779 /* Get the consumer position (iteration start) */
 780 int ustctl_snapshot_get_consumed(struct lttng_ust_shm_handle *handle,
 781                 struct lttng_ust_lib_ring_buffer *buf, unsigned long *pos)
 782 {
 783         *pos = buf->cons_snapshot;
 784         return 0;
 785 }
 786
 787 /* Get the producer position (iteration end) */
 788 int ustctl_snapshot_get_produced(struct lttng_ust_shm_handle *handle,
 789                 struct lttng_ust_lib_ring_buffer *buf, unsigned long *pos)
 790 {
 791         *pos = buf->prod_snapshot;
 792         return 0;
 793 }
 794
 795 /* Get exclusive read access to the specified sub-buffer position */
 796 int ustctl_get_subbuf(struct lttng_ust_shm_handle *handle,
 797                 struct lttng_ust_lib_ring_buffer *buf, unsigned long *pos)
 798 {
 799         return lib_ring_buffer_get_subbuf(buf, *pos, handle);
 800 }
 801
 802 /* Release exclusive sub-buffer access */
 803 int ustctl_put_subbuf(struct lttng_ust_shm_handle *handle,
 804                 struct lttng_ust_lib_ring_buffer *buf)
 805 {
 806         lib_ring_buffer_put_subbuf(buf, handle);
 807         return 0;
 808 }
 809
 810 void ustctl_flush_buffer(struct lttng_ust_shm_handle *handle,
 811                 struct lttng_ust_lib_ring_buffer *buf,
 812                 int producer_active)
 813 {
 814         lib_ring_buffer_switch_slow(buf,
 815                 producer_active ? SWITCH_ACTIVE : SWITCH_FLUSH,
 816                 handle);
 817 }