libust/tracectl.c

   1 /* Copyright (C) 2009  Pierre-Marc Fournier
   2  *
   3  * This library is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU Lesser General Public
   5  * License as published by the Free Software Foundation; either
   6  * version 2.1 of the License, or (at your option) any later version.
   7  *
   8  * This library is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * Lesser General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public
  14  * License along with this library; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <stdio.h>
  20 #include <stdint.h>
  21 #include <signal.h>
  22 #include <sys/types.h>
  23 #include <sys/socket.h>
  24 #include <sys/un.h>
  25 #include <sched.h>
  26 #include <fcntl.h>
  27 #include <poll.h>
  28 #include <regex.h>
  29
  30 #include <urcu-bp.h>
  31
  32 #include <ust/marker.h>
  33 #include <ust/tracectl.h>
  34 #include "tracer.h"
  35 #include "usterr.h"
  36 #include "ustcomm.h"
  37 #include "buffers.h" /* FIXME: remove */
  38 #include "marker-control.h"
  39
  40 //#define USE_CLONE
  41
  42 #define USTSIGNAL SIGIO
  43
  44 #define MAX_MSG_SIZE (100)
  45 #define MSG_NOTIF 1
  46 #define MSG_REGISTER_NOTIF 2
  47
  48 char consumer_stack[10000];
  49
  50 /* This should only be accessed by the constructor, before the creation
  51  * of the listener, and then only by the listener.
  52  */
  53 s64 pidunique = -1LL;
  54
  55 struct list_head blocked_consumers = LIST_HEAD_INIT(blocked_consumers);
  56
  57 static struct ustcomm_app ustcomm_app;
  58
  59 struct tracecmd { /* no padding */
  60         uint32_t size;
  61         uint16_t command;
  62 };
  63
  64 /* volatile because shared between the listener and the main thread */
  65 volatile sig_atomic_t buffers_to_export = 0;
  66
  67 struct trctl_msg {
  68         /* size: the size of all the fields except size itself */
  69         uint32_t size;
  70         uint16_t type;
  71         /* Only the necessary part of the payload is transferred. It
  72          * may even be none of it.
  73          */
  74         char payload[94];
  75 };
  76
  77 struct consumer_channel {
  78         int fd;
  79         struct ltt_channel_struct *chan;
  80 };
  81
  82 struct blocked_consumer {
  83         int fd_consumer;
  84         int fd_producer;
  85         int tmp_poll_idx;
  86
  87         /* args to ustcomm_send_reply */
  88         struct ustcomm_server server;
  89         struct ustcomm_source src;
  90
  91         /* args to ust_buffers_do_get_subbuf */
  92         struct ust_buffer *buf;
  93
  94         struct list_head list;
  95 };
  96
  97 static long long make_pidunique(void)
  98 {
  99         s64 retval;
 100         struct timeval tv;
 101
 102         gettimeofday(&tv, NULL);
 103
 104         retval = tv.tv_sec;
 105         retval <<= 32;
 106         retval |= tv.tv_usec;
 107
 108         return retval;
 109 }
 110
 111 static void print_markers(FILE *fp)
 112 {
 113         struct marker_iter iter;
 114
 115         lock_markers();
 116         marker_iter_reset(&iter);
 117         marker_iter_start(&iter);
 118
 119         while(iter.marker) {
 120                 fprintf(fp, "marker: %s/%s %d \"%s\" %p\n", iter.marker->channel, iter.marker->name, (int)imv_read(iter.marker->state), iter.marker->format, iter.marker->location);
 121                 marker_iter_next(&iter);
 122         }
 123         unlock_markers();
 124 }
 125
 126 static int init_socket(void);
 127
 128 /* This needs to be called whenever a new thread is created. It notifies
 129  * liburcu of the new thread.
 130  */
 131
 132 void ust_register_thread(void)
 133 {
 134         rcu_register_thread();
 135 }
 136
 137 int fd_notif = -1;
 138 void notif_cb(void)
 139 {
 140         int result;
 141         struct trctl_msg msg;
 142
 143         /* FIXME: fd_notif should probably be protected by a spinlock */
 144
 145         if(fd_notif == -1)
 146                 return;
 147
 148         msg.type = MSG_NOTIF;
 149         msg.size = sizeof(msg.type);
 150
 151         /* FIXME: don't block here */
 152         result = write(fd_notif, &msg, msg.size+sizeof(msg.size));
 153         if(result == -1) {
 154                 PERROR("write");
 155                 return;
 156         }
 157 }
 158
 159 /* Ask the daemon to collect a trace called trace_name and being
 160  * produced by this pid.
 161  *
 162  * The trace must be at least allocated. (It can also be started.)
 163  * This is because _ltt_trace_find is used.
 164  */
 165
 166 static void inform_consumer_daemon(const char *trace_name)
 167 {
 168         int i;
 169         struct ltt_trace_struct *trace;
 170         pid_t pid = getpid();
 171         int result;
 172
 173         ltt_lock_traces();
 174
 175         trace = _ltt_trace_find(trace_name);
 176         if(trace == NULL) {
 177                 WARN("inform_consumer_daemon: could not find trace \"%s\"; it is probably already destroyed", trace_name);
 178                 goto finish;
 179         }
 180
 181         for(i=0; i < trace->nr_channels; i++) {
 182                 result = ustcomm_request_consumer(pid, trace->channels[i].channel_name);
 183                 if(result == -1) {
 184                         WARN("Failed to request collection for channel %s. Is the daemon available?", trace->channels[i].channel_name);
 185                         /* continue even if fail */
 186                 }
 187                 buffers_to_export++;
 188         }
 189
 190         finish:
 191         ltt_unlock_traces();
 192 }
 193
 194 void process_blocked_consumers(void)
 195 {
 196         int n_fds = 0;
 197         struct pollfd *fds;
 198         struct blocked_consumer *bc;
 199         int idx = 0;
 200         char inbuf;
 201         int result;
 202
 203         list_for_each_entry(bc, &blocked_consumers, list) {
 204                 n_fds++;
 205         }
 206
 207         fds = (struct pollfd *) malloc(n_fds * sizeof(struct pollfd));
 208         if(fds == NULL) {
 209                 ERR("malloc returned NULL");
 210                 return;
 211         }
 212
 213         list_for_each_entry(bc, &blocked_consumers, list) {
 214                 fds[idx].fd = bc->fd_producer;
 215                 fds[idx].events = POLLIN;
 216                 bc->tmp_poll_idx = idx;
 217                 idx++;
 218         }
 219
 220         while((result = poll(fds, n_fds, 0)) == -1 && errno == EINTR)
 221                 /* nothing */;
 222         if(result == -1) {
 223                 PERROR("poll");
 224                 return;
 225         }
 226
 227         list_for_each_entry(bc, &blocked_consumers, list) {
 228                 if(fds[bc->tmp_poll_idx].revents) {
 229                         long consumed_old = 0;
 230                         char *reply;
 231
 232                         result = read(bc->fd_producer, &inbuf, 1);
 233                         if(result == -1) {
 234                                 PERROR("read");
 235                                 continue;
 236                         }
 237                         if(result == 0) {
 238                                 DBG("PRODUCER END");
 239
 240                                 close(bc->fd_producer);
 241
 242                                 list_del(&bc->list);
 243
 244                                 result = ustcomm_send_reply(&bc->server, "END", &bc->src);
 245                                 if(result < 0) {
 246                                         ERR("ustcomm_send_reply failed");
 247                                         continue;
 248                                 }
 249
 250                                 continue;
 251                         }
 252
 253                         result = ust_buffers_do_get_subbuf(bc->buf, &consumed_old);
 254                         if(result == -EAGAIN) {
 255                                 WARN("missed buffer?");
 256                                 continue;
 257                         }
 258                         else if(result < 0) {
 259                                 DBG("ust_buffers_do_get_subbuf: error: %s", strerror(-result));
 260                         }
 261                         asprintf(&reply, "%s %ld", "OK", consumed_old);
 262                         result = ustcomm_send_reply(&bc->server, reply, &bc->src);
 263                         if(result < 0) {
 264                                 ERR("ustcomm_send_reply failed");
 265                                 free(reply);
 266                                 continue;
 267                         }
 268                         free(reply);
 269
 270                         list_del(&bc->list);
 271                 }
 272         }
 273
 274 }
 275
 276 void *listener_main(void *p)
 277 {
 278         int result;
 279
 280         ust_register_thread();
 281
 282         DBG("LISTENER");
 283
 284         for(;;) {
 285                 char trace_name[] = "auto";
 286                 char trace_type[] = "ustrelay";
 287                 char *recvbuf;
 288                 int len;
 289                 struct ustcomm_source src;
 290
 291                 process_blocked_consumers();
 292
 293                 result = ustcomm_app_recv_message(&ustcomm_app, &recvbuf, &src, 5);
 294                 if(result < 0) {
 295                         WARN("error in ustcomm_app_recv_message");
 296                         continue;
 297                 }
 298                 else if(result == 0) {
 299                         /* no message */
 300                         continue;
 301                 }
 302
 303                 DBG("received a message! it's: %s", recvbuf);
 304                 len = strlen(recvbuf);
 305
 306                 if(!strcmp(recvbuf, "print_markers")) {
 307                         print_markers(stderr);
 308                 }
 309                 else if(!strcmp(recvbuf, "list_markers")) {
 310                         char *ptr;
 311                         size_t size;
 312                         FILE *fp;
 313
 314                         fp = open_memstream(&ptr, &size);
 315                         print_markers(fp);
 316                         fclose(fp);
 317
 318                         result = ustcomm_send_reply(&ustcomm_app.server, ptr, &src);
 319
 320                         free(ptr);
 321                 }
 322                 else if(!strcmp(recvbuf, "start")) {
 323                         /* start is an operation that setups the trace, allocates it and starts it */
 324                         result = ltt_trace_setup(trace_name);
 325                         if(result < 0) {
 326                                 ERR("ltt_trace_setup failed");
 327                                 return (void *)1;
 328                         }
 329
 330                         result = ltt_trace_set_type(trace_name, trace_type);
 331                         if(result < 0) {
 332                                 ERR("ltt_trace_set_type failed");
 333                                 return (void *)1;
 334                         }
 335
 336                         result = ltt_trace_alloc(trace_name);
 337                         if(result < 0) {
 338                                 ERR("ltt_trace_alloc failed");
 339                                 return (void *)1;
 340                         }
 341
 342                         inform_consumer_daemon(trace_name);
 343
 344                         result = ltt_trace_start(trace_name);
 345                         if(result < 0) {
 346                                 ERR("ltt_trace_start failed");
 347                                 continue;
 348                         }
 349                 }
 350                 else if(!strcmp(recvbuf, "trace_setup")) {
 351                         DBG("trace setup");
 352
 353                         result = ltt_trace_setup(trace_name);
 354                         if(result < 0) {
 355                                 ERR("ltt_trace_setup failed");
 356                                 return (void *)1;
 357                         }
 358
 359                         result = ltt_trace_set_type(trace_name, trace_type);
 360                         if(result < 0) {
 361                                 ERR("ltt_trace_set_type failed");
 362                                 return (void *)1;
 363                         }
 364                 }
 365                 else if(!strcmp(recvbuf, "trace_alloc")) {
 366                         DBG("trace alloc");
 367
 368                         result = ltt_trace_alloc(trace_name);
 369                         if(result < 0) {
 370                                 ERR("ltt_trace_alloc failed");
 371                                 return (void *)1;
 372                         }
 373                 }
 374                 else if(!strcmp(recvbuf, "trace_create")) {
 375                         DBG("trace create");
 376
 377                         result = ltt_trace_setup(trace_name);
 378                         if(result < 0) {
 379                                 ERR("ltt_trace_setup failed");
 380                                 return (void *)1;
 381                         }
 382
 383                         result = ltt_trace_set_type(trace_name, trace_type);
 384                         if(result < 0) {
 385                                 ERR("ltt_trace_set_type failed");
 386                                 return (void *)1;
 387                         }
 388
 389                         result = ltt_trace_alloc(trace_name);
 390                         if(result < 0) {
 391                                 ERR("ltt_trace_alloc failed");
 392                                 return (void *)1;
 393                         }
 394
 395                         inform_consumer_daemon(trace_name);
 396                 }
 397                 else if(!strcmp(recvbuf, "trace_start")) {
 398                         DBG("trace start");
 399
 400                         result = ltt_trace_start(trace_name);
 401                         if(result < 0) {
 402                                 ERR("ltt_trace_start failed");
 403                                 continue;
 404                         }
 405                 }
 406                 else if(!strcmp(recvbuf, "trace_stop")) {
 407                         DBG("trace stop");
 408
 409                         result = ltt_trace_stop(trace_name);
 410                         if(result < 0) {
 411                                 ERR("ltt_trace_stop failed");
 412                                 return (void *)1;
 413                         }
 414                 }
 415                 else if(!strcmp(recvbuf, "trace_destroy")) {
 416
 417                         DBG("trace destroy");
 418
 419                         result = ltt_trace_destroy(trace_name);
 420                         if(result < 0) {
 421                                 ERR("ltt_trace_destroy failed");
 422                                 return (void *)1;
 423                         }
 424                 }
 425                 else if(nth_token_is(recvbuf, "get_shmid", 0) == 1) {
 426                         struct ltt_trace_struct *trace;
 427                         char trace_name[] = "auto";
 428                         int i;
 429                         char *channel_name;
 430
 431                         DBG("get_shmid");
 432
 433                         channel_name = nth_token(recvbuf, 1);
 434                         if(channel_name == NULL) {
 435                                 ERR("get_shmid: cannot parse channel");
 436                                 goto next_cmd;
 437                         }
 438
 439                         ltt_lock_traces();
 440                         trace = _ltt_trace_find(trace_name);
 441                         ltt_unlock_traces();
 442
 443                         if(trace == NULL) {
 444                                 ERR("cannot find trace!");
 445                                 return (void *)1;
 446                         }
 447
 448                         for(i=0; i<trace->nr_channels; i++) {
 449                                 struct ust_channel *channel = &trace->channels[i];
 450                                 struct ust_buffer *buf = channel->buf;
 451
 452                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 453                                         char *reply;
 454
 455                                         DBG("the shmid for the requested channel is %d", buf->shmid);
 456                                         DBG("the shmid for its buffer structure is %d", channel->buf_shmid);
 457                                         asprintf(&reply, "%d %d", buf->shmid, channel->buf_shmid);
 458
 459                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 460                                         if(result) {
 461                                                 ERR("listener: get_shmid: ustcomm_send_reply failed");
 462                                                 goto next_cmd;
 463                                         }
 464
 465                                         free(reply);
 466
 467                                         break;
 468                                 }
 469                         }
 470
 471                         buffers_to_export--;
 472                 }
 473                 else if(nth_token_is(recvbuf, "get_n_subbufs", 0) == 1) {
 474                         struct ltt_trace_struct *trace;
 475                         char trace_name[] = "auto";
 476                         int i;
 477                         char *channel_name;
 478
 479                         DBG("get_n_subbufs");
 480
 481                         channel_name = nth_token(recvbuf, 1);
 482                         if(channel_name == NULL) {
 483                                 ERR("get_n_subbufs: cannot parse channel");
 484                                 goto next_cmd;
 485                         }
 486
 487                         ltt_lock_traces();
 488                         trace = _ltt_trace_find(trace_name);
 489                         ltt_unlock_traces();
 490
 491                         if(trace == NULL) {
 492                                 ERR("cannot find trace!");
 493                                 return (void *)1;
 494                         }
 495
 496                         for(i=0; i<trace->nr_channels; i++) {
 497                                 struct ust_channel *channel = &trace->channels[i];
 498
 499                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 500                                         char *reply;
 501
 502                                         DBG("the n_subbufs for the requested channel is %d", channel->subbuf_cnt);
 503                                         asprintf(&reply, "%d", channel->subbuf_cnt);
 504
 505                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 506                                         if(result) {
 507                                                 ERR("listener: get_n_subbufs: ustcomm_send_reply failed");
 508                                                 goto next_cmd;
 509                                         }
 510
 511                                         free(reply);
 512
 513                                         break;
 514                                 }
 515                         }
 516                 }
 517                 else if(nth_token_is(recvbuf, "get_subbuf_size", 0) == 1) {
 518                         struct ltt_trace_struct *trace;
 519                         char trace_name[] = "auto";
 520                         int i;
 521                         char *channel_name;
 522
 523                         DBG("get_subbuf_size");
 524
 525                         channel_name = nth_token(recvbuf, 1);
 526                         if(channel_name == NULL) {
 527                                 ERR("get_subbuf_size: cannot parse channel");
 528                                 goto next_cmd;
 529                         }
 530
 531                         ltt_lock_traces();
 532                         trace = _ltt_trace_find(trace_name);
 533                         ltt_unlock_traces();
 534
 535                         if(trace == NULL) {
 536                                 ERR("cannot find trace!");
 537                                 return (void *)1;
 538                         }
 539
 540                         for(i=0; i<trace->nr_channels; i++) {
 541                                 struct ust_channel *channel = &trace->channels[i];
 542
 543                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 544                                         char *reply;
 545
 546                                         DBG("the subbuf_size for the requested channel is %zd", channel->subbuf_size);
 547                                         asprintf(&reply, "%zd", channel->subbuf_size);
 548
 549                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 550                                         if(result) {
 551                                                 ERR("listener: get_subbuf_size: ustcomm_send_reply failed");
 552                                                 goto next_cmd;
 553                                         }
 554
 555                                         free(reply);
 556
 557                                         break;
 558                                 }
 559                         }
 560                 }
 561                 else if(nth_token_is(recvbuf, "load_probe_lib", 0) == 1) {
 562                         char *libfile;
 563
 564                         libfile = nth_token(recvbuf, 1);
 565
 566                         DBG("load_probe_lib loading %s", libfile);
 567                 }
 568                 else if(nth_token_is(recvbuf, "get_subbuffer", 0) == 1) {
 569                         struct ltt_trace_struct *trace;
 570                         char trace_name[] = "auto";
 571                         int i;
 572                         char *channel_name;
 573
 574                         DBG("get_subbuf");
 575
 576                         channel_name = nth_token(recvbuf, 1);
 577                         if(channel_name == NULL) {
 578                                 ERR("get_subbuf: cannot parse channel");
 579                                 goto next_cmd;
 580                         }
 581
 582                         ltt_lock_traces();
 583                         trace = _ltt_trace_find(trace_name);
 584                         ltt_unlock_traces();
 585
 586                         if(trace == NULL) {
 587                                 ERR("cannot find trace!");
 588                                 return (void *)1;
 589                         }
 590
 591                         for(i=0; i<trace->nr_channels; i++) {
 592                                 struct ust_channel *channel = &trace->channels[i];
 593
 594                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 595                                         struct ust_buffer *buf = channel->buf;
 596                                         struct blocked_consumer *bc;
 597
 598                                         bc = (struct blocked_consumer *) malloc(sizeof(struct blocked_consumer));
 599                                         if(bc == NULL) {
 600                                                 ERR("malloc returned NULL");
 601                                                 goto next_cmd;
 602                                         }
 603                                         bc->fd_consumer = src.fd;
 604                                         bc->fd_producer = buf->data_ready_fd_read;
 605                                         bc->buf = buf;
 606                                         bc->src = src;
 607                                         bc->server = ustcomm_app.server;
 608
 609                                         list_add(&bc->list, &blocked_consumers);
 610
 611                                         break;
 612                                 }
 613                         }
 614                 }
 615                 else if(nth_token_is(recvbuf, "put_subbuffer", 0) == 1) {
 616                         struct ltt_trace_struct *trace;
 617                         char trace_name[] = "auto";
 618                         int i;
 619                         char *channel_name;
 620                         long consumed_old;
 621                         char *consumed_old_str;
 622                         char *endptr;
 623
 624                         DBG("put_subbuf");
 625
 626                         channel_name = strdup_malloc(nth_token(recvbuf, 1));
 627                         if(channel_name == NULL) {
 628                                 ERR("put_subbuf_size: cannot parse channel");
 629                                 goto next_cmd;
 630                         }
 631
 632                         consumed_old_str = strdup_malloc(nth_token(recvbuf, 2));
 633                         if(consumed_old_str == NULL) {
 634                                 ERR("put_subbuf: cannot parse consumed_old");
 635                                 goto next_cmd;
 636                         }
 637                         consumed_old = strtol(consumed_old_str, &endptr, 10);
 638                         if(*endptr != '\0') {
 639                                 ERR("put_subbuf: invalid value for consumed_old");
 640                                 goto next_cmd;
 641                         }
 642
 643                         ltt_lock_traces();
 644                         trace = _ltt_trace_find(trace_name);
 645                         ltt_unlock_traces();
 646
 647                         if(trace == NULL) {
 648                                 ERR("cannot find trace!");
 649                                 return (void *)1;
 650                         }
 651
 652                         for(i=0; i<trace->nr_channels; i++) {
 653                                 struct ust_channel *channel = &trace->channels[i];
 654
 655                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 656                                         struct ust_buffer *buf = channel->buf;
 657                                         char *reply;
 658                                         long consumed_old=0;
 659
 660                                         result = ust_buffers_do_put_subbuf(buf, consumed_old);
 661                                         if(result < 0) {
 662                                                 WARN("ust_buffers_do_put_subbuf: error (subbuf=%s)", channel_name);
 663                                                 asprintf(&reply, "%s", "ERROR");
 664                                         }
 665                                         else {
 666                                                 DBG("ust_buffers_do_put_subbuf: success (subbuf=%s)", channel_name);
 667                                                 asprintf(&reply, "%s", "OK");
 668                                         }
 669
 670                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 671                                         if(result) {
 672                                                 ERR("listener: put_subbuf: ustcomm_send_reply failed");
 673                                                 goto next_cmd;
 674                                         }
 675
 676                                         free(reply);
 677
 678                                         break;
 679                                 }
 680                         }
 681
 682                         free(channel_name);
 683                         free(consumed_old_str);
 684                 }
 685                 else if(nth_token_is(recvbuf, "enable_marker", 0) == 1) {
 686                         char *channel_slash_name = nth_token(recvbuf, 1);
 687                         char channel_name[256]="";
 688                         char marker_name[256]="";
 689
 690                         result = sscanf(channel_slash_name, "%255[^/]/%255s", channel_name, marker_name);
 691
 692                         if(channel_name == NULL || marker_name == NULL) {
 693                                 WARN("invalid marker name");
 694                                 goto next_cmd;
 695                         }
 696
 697                         result = ltt_marker_connect(channel_name, marker_name, "default");
 698                         if(result < 0) {
 699                                 WARN("could not enable marker; channel=%s, name=%s", channel_name, marker_name);
 700                         }
 701                 }
 702                 else if(nth_token_is(recvbuf, "disable_marker", 0) == 1) {
 703                         char *channel_slash_name = nth_token(recvbuf, 1);
 704                         char *marker_name;
 705                         char *channel_name;
 706
 707                         result = sscanf(channel_slash_name, "%a[^/]/%as", &channel_name, &marker_name);
 708
 709                         if(marker_name == NULL) {
 710                         }
 711
 712                         result = ltt_marker_disconnect(channel_name, marker_name, "default");
 713                         if(result < 0) {
 714                                 WARN("could not disable marker; channel=%s, name=%s", channel_name, marker_name);
 715                         }
 716                 }
 717                 else if(nth_token_is(recvbuf, "get_pidunique", 0) == 1) {
 718                         char *reply;
 719
 720                         asprintf(&reply, "%lld", pidunique);
 721
 722                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 723                         if(result) {
 724                                 ERR("listener: get_pidunique: ustcomm_send_reply failed");
 725                                 goto next_cmd;
 726                         }
 727
 728                         free(reply);
 729                 }
 730 //              else if(nth_token_is(recvbuf, "get_notifications", 0) == 1) {
 731 //                      struct ltt_trace_struct *trace;
 732 //                      char trace_name[] = "auto";
 733 //                      int i;
 734 //                      char *channel_name;
 735 //
 736 //                      DBG("get_notifications");
 737 //
 738 //                      channel_name = strdup_malloc(nth_token(recvbuf, 1));
 739 //                      if(channel_name == NULL) {
 740 //                              ERR("put_subbuf_size: cannot parse channel");
 741 //                              goto next_cmd;
 742 //                      }
 743 //
 744 //                      ltt_lock_traces();
 745 //                      trace = _ltt_trace_find(trace_name);
 746 //                      ltt_unlock_traces();
 747 //
 748 //                      if(trace == NULL) {
 749 //                              ERR("cannot find trace!");
 750 //                              return (void *)1;
 751 //                      }
 752 //
 753 //                      for(i=0; i<trace->nr_channels; i++) {
 754 //                              struct rchan *rchan = trace->channels[i].trans_channel_data;
 755 //                              int fd;
 756 //
 757 //                              if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 758 //                                      struct rchan_buf *rbuf = rchan->buf;
 759 //                                      struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 760 //
 761 //                                      result = fd = ustcomm_app_detach_client(&ustcomm_app, &src);
 762 //                                      if(result == -1) {
 763 //                                              ERR("ustcomm_app_detach_client failed");
 764 //                                              goto next_cmd;
 765 //                                      }
 766 //
 767 //                                      lttbuf->wake_consumer_arg = (void *) fd;
 768 //
 769 //                                      smp_wmb();
 770 //
 771 //                                      lttbuf->call_wake_consumer = 1;
 772 //
 773 //                                      break;
 774 //                              }
 775 //                      }
 776 //
 777 //                      free(channel_name);
 778 //              }
 779                 else {
 780                         ERR("unable to parse message: %s", recvbuf);
 781                 }
 782
 783         next_cmd:
 784                 free(recvbuf);
 785         }
 786 }
 787
 788 volatile sig_atomic_t have_listener = 0;
 789
 790 void create_listener(void)
 791 {
 792 #ifdef USE_CLONE
 793         static char listener_stack[16384];
 794         int result;
 795 #else
 796         pthread_t thread;
 797 #endif
 798
 799         if(have_listener) {
 800                 WARN("not creating listener because we already had one");
 801                 return;
 802         }
 803
 804 #ifdef USE_CLONE
 805         result = clone((int (*)(void *)) listener_main, listener_stack+sizeof(listener_stack)-1, CLONE_FS | CLONE_FILES | CLONE_VM | CLONE_SIGHAND | CLONE_THREAD, NULL);
 806         if(result == -1) {
 807                 perror("clone");
 808                 return;
 809         }
 810 #else
 811
 812         pthread_create(&thread, NULL, listener_main, NULL);
 813 #endif
 814
 815         have_listener = 1;
 816 }
 817
 818 static int init_socket(void)
 819 {
 820         return ustcomm_init_app(getpid(), &ustcomm_app);
 821 }
 822
 823 #define AUTOPROBE_DISABLED      0
 824 #define AUTOPROBE_ENABLE_ALL    1
 825 #define AUTOPROBE_ENABLE_REGEX  2
 826 static int autoprobe_method = AUTOPROBE_DISABLED;
 827 static regex_t autoprobe_regex;
 828
 829 static void auto_probe_connect(struct marker *m)
 830 {
 831         int result;
 832
 833         char* concat_name = NULL;
 834         const char *probe_name = "default";
 835
 836         if(autoprobe_method == AUTOPROBE_DISABLED) {
 837                 return;
 838         }
 839         else if(autoprobe_method == AUTOPROBE_ENABLE_REGEX) {
 840                 result = asprintf(&concat_name, "%s/%s", m->channel, m->name);
 841                 if(result == -1) {
 842                         ERR("auto_probe_connect: asprintf failed (marker %s/%s)",
 843                                 m->channel, m->name);
 844                         return;
 845                 }
 846                 if (regexec(&autoprobe_regex, concat_name, 0, NULL, 0)) {
 847                         free(concat_name);
 848                         return;
 849                 }
 850                 free(concat_name);
 851         }
 852
 853         result = ltt_marker_connect(m->channel, m->name, probe_name);
 854         if(result && result != -EEXIST)
 855                 ERR("ltt_marker_connect (marker = %s/%s, errno = %d)", m->channel, m->name, -result);
 856
 857         DBG("auto connected marker %s (addr: %p) %s to probe default", m->channel, m, m->name);
 858
 859 }
 860
 861 static void __attribute__((constructor)) init()
 862 {
 863         int result;
 864         char* autoprobe_val = NULL;
 865
 866         /* Assign the pidunique, to be able to differentiate the processes with same
 867          * pid, (before and after an exec).
 868          */
 869         pidunique = make_pidunique();
 870
 871         /* Initialize RCU in case the constructor order is not good. */
 872         urcu_init();
 873
 874         /* It is important to do this before events start to be generated. */
 875         ust_register_thread();
 876
 877         DBG("Tracectl constructor");
 878
 879         /* Must create socket before signal handler to prevent races.
 880          */
 881         result = init_socket();
 882         if(result == -1) {
 883                 ERR("init_socket error");
 884                 return;
 885         }
 886
 887         create_listener();
 888
 889         autoprobe_val = getenv("UST_AUTOPROBE");
 890         if(autoprobe_val) {
 891                 struct marker_iter iter;
 892
 893                 DBG("Autoprobe enabled.");
 894
 895                 /* Ensure markers are initialized */
 896                 //init_markers();
 897
 898                 /* Ensure marker control is initialized, for the probe */
 899                 init_marker_control();
 900
 901                 /* first, set the callback that will connect the
 902                  * probe on new markers
 903                  */
 904                 if(autoprobe_val[0] == '/') {
 905                         result = regcomp(&autoprobe_regex, autoprobe_val+1, 0);
 906                         if (result) {
 907                                 char regexerr[150];
 908
 909                                 regerror(result, &autoprobe_regex, regexerr, sizeof(regexerr));
 910                                 ERR("cannot parse regex %s (%s), will ignore UST_AUTOPROBE", autoprobe_val, regexerr);
 911                                 /* don't crash the application just for this */
 912                         }
 913                         else {
 914                                 autoprobe_method = AUTOPROBE_ENABLE_REGEX;
 915                         }
 916                 }
 917                 else {
 918                         /* just enable all instrumentation */
 919                         autoprobe_method = AUTOPROBE_ENABLE_ALL;
 920                 }
 921
 922                 marker_set_new_marker_cb(auto_probe_connect);
 923
 924                 /* Now, connect the probes that were already registered. */
 925                 marker_iter_reset(&iter);
 926                 marker_iter_start(&iter);
 927
 928                 DBG("now iterating on markers already registered");
 929                 while(iter.marker) {
 930                         DBG("now iterating on marker %s", iter.marker->name);
 931                         auto_probe_connect(iter.marker);
 932                         marker_iter_next(&iter);
 933                 }
 934         }
 935
 936         if(getenv("UST_TRACE")) {
 937                 char trace_name[] = "auto";
 938                 char trace_type[] = "ustrelay";
 939
 940                 DBG("starting early tracing");
 941
 942                 /* Ensure marker control is initialized */
 943                 init_marker_control();
 944
 945                 /* Ensure relay is initialized */
 946                 init_ustrelay_transport();
 947
 948                 /* Ensure markers are initialized */
 949                 init_markers();
 950
 951                 /* FIXME: When starting early tracing (here), depending on the
 952                  * order of constructors, it is very well possible some marker
 953                  * sections are not yet registered. Because of this, some
 954                  * channels may not be registered. Yet, we are about to ask the
 955                  * daemon to collect the channels. Channels which are not yet
 956                  * registered will not be collected.
 957                  *
 958                  * Currently, in LTTng, there is no way to add a channel after
 959                  * trace start. The reason for this is that it induces complex
 960                  * concurrency issues on the trace structures, which can only
 961                  * be resolved using RCU. This has not been done yet. As a
 962                  * workaround, we are forcing the registration of the "ust"
 963                  * channel here. This is the only channel (apart from metadata)
 964                  * that can be reliably used in early tracing.
 965                  *
 966                  * Non-early tracing does not have this problem and can use
 967                  * arbitrary channel names.
 968                  */
 969                 ltt_channels_register("ust");
 970
 971                 result = ltt_trace_setup(trace_name);
 972                 if(result < 0) {
 973                         ERR("ltt_trace_setup failed");
 974                         return;
 975                 }
 976
 977                 result = ltt_trace_set_type(trace_name, trace_type);
 978                 if(result < 0) {
 979                         ERR("ltt_trace_set_type failed");
 980                         return;
 981                 }
 982
 983                 result = ltt_trace_alloc(trace_name);
 984                 if(result < 0) {
 985                         ERR("ltt_trace_alloc failed");
 986                         return;
 987                 }
 988
 989                 result = ltt_trace_start(trace_name);
 990                 if(result < 0) {
 991                         ERR("ltt_trace_start failed");
 992                         return;
 993                 }
 994
 995                 /* Do this after the trace is started in order to avoid creating confusion
 996                  * if the trace fails to start. */
 997                 inform_consumer_daemon(trace_name);
 998         }
 999
1000
1001         return;
1002
1003         /* should decrementally destroy stuff if error */
1004
1005 }
1006
1007 /* This is only called if we terminate normally, not with an unhandled signal,
1008  * so we cannot rely on it. However, for now, LTTV requires that the header of
1009  * the last sub-buffer contain a valid end time for the trace. This is done
1010  * automatically only when the trace is properly stopped.
1011  *
1012  * If the traced program crashed, it is always possible to manually add the
1013  * right value in the header, or to open the trace in text mode.
1014  *
1015  * FIXME: Fix LTTV so it doesn't need this.
1016  */
1017
1018 static void destroy_traces(void)
1019 {
1020         int result;
1021
1022         /* if trace running, finish it */
1023
1024         DBG("destructor stopping traces");
1025
1026         result = ltt_trace_stop("auto");
1027         if(result == -1) {
1028                 ERR("ltt_trace_stop error");
1029         }
1030
1031         result = ltt_trace_destroy("auto");
1032         if(result == -1) {
1033                 ERR("ltt_trace_destroy error");
1034         }
1035 }
1036
1037 static int trace_recording(void)
1038 {
1039         int retval = 0;
1040         struct ltt_trace_struct *trace;
1041
1042         ltt_lock_traces();
1043
1044         list_for_each_entry(trace, &ltt_traces.head, list) {
1045                 if(trace->active) {
1046                         retval = 1;
1047                         break;
1048                 }
1049         }
1050
1051         ltt_unlock_traces();
1052
1053         return retval;
1054 }
1055
1056 #if 0
1057 static int have_consumer(void)
1058 {
1059         return !list_empty(&blocked_consumers);
1060 }
1061 #endif
1062
1063 int restarting_usleep(useconds_t usecs)
1064 {
1065         struct timespec tv;
1066         int result;
1067
1068         tv.tv_sec = 0;
1069         tv.tv_nsec = usecs * 1000;
1070
1071         do {
1072                 result = nanosleep(&tv, &tv);
1073         } while(result == -1 && errno == EINTR);
1074
1075         return result;
1076 }
1077
1078 /* This destructor keeps the process alive for a few seconds in order
1079  * to leave time to ustd to connect to its buffers. This is necessary
1080  * for programs whose execution is very short. It is also useful in all
1081  * programs when tracing is started close to the end of the program
1082  * execution.
1083  *
1084  * FIXME: For now, this only works for the first trace created in a
1085  * process.
1086  */
1087
1088 static void __attribute__((destructor)) keepalive()
1089 {
1090         if(trace_recording() && buffers_to_export) {
1091                 int total = 0;
1092                 DBG("Keeping process alive for consumer daemon...");
1093                 while(buffers_to_export) {
1094                         const int interv = 200000;
1095                         restarting_usleep(interv);
1096                         total += interv;
1097
1098                         if(total >= 3000000) {
1099                                 WARN("non-consumed buffers remaining after wait limit; not waiting anymore");
1100                                 break;
1101                         }
1102                 }
1103                 DBG("Finally dying...");
1104         }
1105
1106         destroy_traces();
1107
1108         ustcomm_fini_app(&ustcomm_app);
1109 }
1110
1111 void ust_potential_exec(void)
1112 {
1113         trace_mark(ust, potential_exec, MARK_NOARGS);
1114
1115         DBG("test");
1116
1117         keepalive();
1118 }
1119
1120 /* Notify ust that there was a fork. This needs to be called inside
1121  * the new process, anytime a process whose memory is not shared with
1122  * the parent is created. If this function is not called, the events
1123  * of the new process will not be collected.
1124  *
1125  * Signals should be disabled before the fork and reenabled only after
1126  * this call in order to guarantee tracing is not started before ust_fork()
1127  * sanitizes the new process.
1128  */
1129
1130 static void ust_fork(void)
1131 {
1132         struct blocked_consumer *bc;
1133         struct blocked_consumer *deletable_bc = NULL;
1134         int result;
1135
1136         DBG("ust: forking");
1137         ltt_trace_stop("auto");
1138         ltt_trace_destroy("auto");
1139         /* Delete all active connections */
1140         ustcomm_close_all_connections(&ustcomm_app.server);
1141
1142         /* Delete all blocked consumers */
1143         list_for_each_entry(bc, &blocked_consumers, list) {
1144                 close(bc->fd_producer);
1145                 close(bc->fd_consumer);
1146                 free(deletable_bc);
1147                 deletable_bc = bc;
1148                 list_del(&bc->list);
1149         }
1150
1151         have_listener = 0;
1152         create_listener();
1153         init_socket();
1154         ltt_trace_setup("auto");
1155         result = ltt_trace_set_type("auto", "ustrelay");
1156         if(result < 0) {
1157                 ERR("ltt_trace_set_type failed");
1158                 return;
1159         }
1160
1161         ltt_trace_alloc("auto");
1162         ltt_trace_start("auto");
1163         inform_consumer_daemon("auto");
1164 }
1165
1166 void ust_before_fork(ust_fork_info_t *fork_info)
1167 {
1168         /* Disable signals. This is to avoid that the child
1169          * intervenes before it is properly setup for tracing. It is
1170          * safer to disable all signals, because then we know we are not
1171          * breaking anything by restoring the original mask.
1172          */
1173         sigset_t all_sigs;
1174         int result;
1175
1176         /* FIXME:
1177                 - only do this if tracing is active
1178         */
1179
1180         /* Disable signals */
1181         sigfillset(&all_sigs);
1182         result = sigprocmask(SIG_BLOCK, &all_sigs, &fork_info->orig_sigs);
1183         if(result == -1) {
1184                 PERROR("sigprocmask");
1185                 return;
1186         }
1187 }
1188
1189 /* Don't call this function directly in a traced program */
1190 static void ust_after_fork_common(ust_fork_info_t *fork_info)
1191 {
1192         int result;
1193         sigset_t orig_sigs;
1194
1195         /* Restore signals */
1196         result = sigprocmask(SIG_SETMASK, &fork_info->orig_sigs, NULL);
1197         if(result == -1) {
1198                 PERROR("sigprocmask");
1199                 return;
1200         }
1201 }
1202
1203 void ust_after_fork_parent(ust_fork_info_t *fork_info)
1204 {
1205         /* Reenable signals */
1206         ust_after_fork_common(fork_info);
1207 }
1208
1209 void ust_after_fork_child(ust_fork_info_t *fork_info)
1210 {
1211         /* First sanitize the child */
1212         ust_fork();
1213
1214         /* Then reenable interrupts */
1215         ust_after_fork_common(fork_info);
1216 }
1217