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