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,j;
 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                 /* iterate on all cpus */
 183                 for(j=0; j<trace->channels[i].n_cpus; j++) {
 184                         char *buf;
 185                         asprintf(&buf, "%s_%d", trace->channels[i].channel_name, j);
 186                         result = ustcomm_request_consumer(pid, buf);
 187                         if(result == -1) {
 188                                 WARN("Failed to request collection for channel %s. Is the daemon available?", trace->channels[i].channel_name);
 189                                 /* continue even if fail */
 190                         }
 191                         free(buf);
 192                         buffers_to_export++;
 193                 }
 194         }
 195
 196         finish:
 197         ltt_unlock_traces();
 198 }
 199
 200 void process_blocked_consumers(void)
 201 {
 202         int n_fds = 0;
 203         struct pollfd *fds;
 204         struct blocked_consumer *bc;
 205         int idx = 0;
 206         char inbuf;
 207         int result;
 208
 209         list_for_each_entry(bc, &blocked_consumers, list) {
 210                 n_fds++;
 211         }
 212
 213         fds = (struct pollfd *) malloc(n_fds * sizeof(struct pollfd));
 214         if(fds == NULL) {
 215                 ERR("malloc returned NULL");
 216                 return;
 217         }
 218
 219         list_for_each_entry(bc, &blocked_consumers, list) {
 220                 fds[idx].fd = bc->fd_producer;
 221                 fds[idx].events = POLLIN;
 222                 bc->tmp_poll_idx = idx;
 223                 idx++;
 224         }
 225
 226         while((result = poll(fds, n_fds, 0)) == -1 && errno == EINTR)
 227                 /* nothing */;
 228         if(result == -1) {
 229                 PERROR("poll");
 230                 return;
 231         }
 232
 233         list_for_each_entry(bc, &blocked_consumers, list) {
 234                 if(fds[bc->tmp_poll_idx].revents) {
 235                         long consumed_old = 0;
 236                         char *reply;
 237
 238                         result = read(bc->fd_producer, &inbuf, 1);
 239                         if(result == -1) {
 240                                 PERROR("read");
 241                                 continue;
 242                         }
 243                         if(result == 0) {
 244                                 DBG("PRODUCER END");
 245
 246                                 close(bc->fd_producer);
 247
 248                                 list_del(&bc->list);
 249
 250                                 result = ustcomm_send_reply(&bc->server, "END", &bc->src);
 251                                 if(result < 0) {
 252                                         ERR("ustcomm_send_reply failed");
 253                                         continue;
 254                                 }
 255
 256                                 continue;
 257                         }
 258
 259                         result = ust_buffers_do_get_subbuf(bc->buf, &consumed_old);
 260                         if(result == -EAGAIN) {
 261                                 WARN("missed buffer?");
 262                                 continue;
 263                         }
 264                         else if(result < 0) {
 265                                 DBG("ust_buffers_do_get_subbuf: error: %s", strerror(-result));
 266                         }
 267                         asprintf(&reply, "%s %ld", "OK", consumed_old);
 268                         result = ustcomm_send_reply(&bc->server, reply, &bc->src);
 269                         if(result < 0) {
 270                                 ERR("ustcomm_send_reply failed");
 271                                 free(reply);
 272                                 continue;
 273                         }
 274                         free(reply);
 275
 276                         list_del(&bc->list);
 277                 }
 278         }
 279
 280 }
 281
 282 void seperate_channel_cpu(const char *channel_and_cpu, char **channel, int *cpu)
 283 {
 284         const char *sep;
 285
 286         sep = rindex(channel_and_cpu, '_');
 287         if(sep == NULL) {
 288                 *cpu = -1;
 289                 sep = channel_and_cpu + strlen(channel_and_cpu);
 290         }
 291         else {
 292                 *cpu = atoi(sep+1);
 293         }
 294
 295         asprintf(channel, "%.*s", (int)(sep-channel_and_cpu), channel_and_cpu);
 296 }
 297
 298 static int do_cmd_get_shmid(const char *recvbuf, struct ustcomm_source *src)
 299 {
 300         int retval = 0;
 301         struct ltt_trace_struct *trace;
 302         char trace_name[] = "auto";
 303         int i;
 304         char *channel_and_cpu;
 305         int found = 0;
 306         int result;
 307         char *ch_name;
 308         int ch_cpu;
 309
 310         DBG("get_shmid");
 311
 312         channel_and_cpu = nth_token(recvbuf, 1);
 313         if(channel_and_cpu == NULL) {
 314                 ERR("get_shmid: cannot parse channel");
 315                 goto end;
 316         }
 317
 318         seperate_channel_cpu(channel_and_cpu, &ch_name, &ch_cpu);
 319         if(ch_cpu == -1) {
 320                 ERR("Problem parsing channel name");
 321                 goto free_short_chan_name;
 322         }
 323
 324         ltt_lock_traces();
 325         trace = _ltt_trace_find(trace_name);
 326         ltt_unlock_traces();
 327
 328         if(trace == NULL) {
 329                 ERR("cannot find trace!");
 330                 retval = -1;
 331                 goto free_short_chan_name;
 332         }
 333
 334         for(i=0; i<trace->nr_channels; i++) {
 335                 struct ust_channel *channel = &trace->channels[i];
 336                 struct ust_buffer *buf = channel->buf[ch_cpu];
 337
 338                 if(!strcmp(trace->channels[i].channel_name, ch_name)) {
 339                         char *reply;
 340
 341 //                      DBG("the shmid for the requested channel is %d", buf->shmid);
 342 //                      DBG("the shmid for its buffer structure is %d", channel->buf_struct_shmids);
 343                         asprintf(&reply, "%d %d", buf->shmid, channel->buf_struct_shmids[ch_cpu]);
 344
 345                         result = ustcomm_send_reply(&ustcomm_app.server, reply, src);
 346                         if(result) {
 347                                 ERR("listener: get_shmid: ustcomm_send_reply failed");
 348                                 free(reply);
 349                                 retval = -1;
 350                                 goto free_short_chan_name;
 351                         }
 352
 353                         free(reply);
 354
 355                         found = 1;
 356                         break;
 357                 }
 358         }
 359
 360         if(found) {
 361                 buffers_to_export--;
 362         }
 363         else {
 364                 ERR("get_shmid: channel not found (%s)", channel_and_cpu);
 365         }
 366
 367         free_short_chan_name:
 368         free(ch_name);
 369
 370         end:
 371         return retval;
 372 }
 373
 374 static int do_cmd_get_n_subbufs(const char *recvbuf, struct ustcomm_source *src)
 375 {
 376         int retval = 0;
 377         struct ltt_trace_struct *trace;
 378         char trace_name[] = "auto";
 379         int i;
 380         char *channel_and_cpu;
 381         int found = 0;
 382         int result;
 383         char *ch_name;
 384         int ch_cpu;
 385
 386         DBG("get_n_subbufs");
 387
 388         channel_and_cpu = nth_token(recvbuf, 1);
 389         if(channel_and_cpu == NULL) {
 390                 ERR("get_n_subbufs: cannot parse channel");
 391                 goto end;
 392         }
 393
 394         seperate_channel_cpu(channel_and_cpu, &ch_name, &ch_cpu);
 395         if(ch_cpu == -1) {
 396                 ERR("Problem parsing channel name");
 397                 goto free_short_chan_name;
 398         }
 399
 400         ltt_lock_traces();
 401         trace = _ltt_trace_find(trace_name);
 402         ltt_unlock_traces();
 403
 404         if(trace == NULL) {
 405                 ERR("cannot find trace!");
 406                 retval = -1;
 407                 goto free_short_chan_name;
 408         }
 409
 410         for(i=0; i<trace->nr_channels; i++) {
 411                 struct ust_channel *channel = &trace->channels[i];
 412
 413                 if(!strcmp(trace->channels[i].channel_name, ch_name)) {
 414                         char *reply;
 415
 416                         DBG("the n_subbufs for the requested channel is %d", channel->subbuf_cnt);
 417                         asprintf(&reply, "%d", channel->subbuf_cnt);
 418
 419                         result = ustcomm_send_reply(&ustcomm_app.server, reply, src);
 420                         if(result) {
 421                                 ERR("listener: get_n_subbufs: ustcomm_send_reply failed");
 422                                 free(reply);
 423                                 retval = -1;
 424                                 goto free_short_chan_name;
 425                         }
 426
 427                         free(reply);
 428                         found = 1;
 429                         break;
 430                 }
 431         }
 432         if(found == 0) {
 433                 ERR("get_n_subbufs: unable to find channel");
 434         }
 435
 436         free_short_chan_name:
 437         free(ch_name);
 438
 439         end:
 440         return retval;
 441 }
 442
 443 static int do_cmd_get_subbuf_size(const char *recvbuf, struct ustcomm_source *src)
 444 {
 445         int retval = 0;
 446         struct ltt_trace_struct *trace;
 447         char trace_name[] = "auto";
 448         int i;
 449         char *channel_and_cpu;
 450         int found = 0;
 451         int result;
 452         char *ch_name;
 453         int ch_cpu;
 454
 455         DBG("get_subbuf_size");
 456
 457         channel_and_cpu = nth_token(recvbuf, 1);
 458         if(channel_and_cpu == NULL) {
 459                 ERR("get_subbuf_size: cannot parse channel");
 460                 goto end;
 461         }
 462
 463         seperate_channel_cpu(channel_and_cpu, &ch_name, &ch_cpu);
 464         if(ch_cpu == -1) {
 465                 ERR("Problem parsing channel name");
 466                 goto free_short_chan_name;
 467         }
 468
 469         ltt_lock_traces();
 470         trace = _ltt_trace_find(trace_name);
 471         ltt_unlock_traces();
 472
 473         if(trace == NULL) {
 474                 ERR("cannot find trace!");
 475                 retval = -1;
 476                 goto free_short_chan_name;
 477         }
 478
 479         for(i=0; i<trace->nr_channels; i++) {
 480                 struct ust_channel *channel = &trace->channels[i];
 481
 482                 if(!strcmp(trace->channels[i].channel_name, ch_name)) {
 483                         char *reply;
 484
 485                         DBG("the subbuf_size for the requested channel is %zd", channel->subbuf_size);
 486                         asprintf(&reply, "%zd", channel->subbuf_size);
 487
 488                         result = ustcomm_send_reply(&ustcomm_app.server, reply, src);
 489                         if(result) {
 490                                 ERR("listener: get_subbuf_size: ustcomm_send_reply failed");
 491                                 free(reply);
 492                                 retval = -1;
 493                                 goto free_short_chan_name;
 494                         }
 495
 496                         free(reply);
 497                         found = 1;
 498                         break;
 499                 }
 500         }
 501         if(found == 0) {
 502                 ERR("get_subbuf_size: unable to find channel");
 503         }
 504
 505         free_short_chan_name:
 506         free(ch_name);
 507
 508         end:
 509         return retval;
 510 }
 511
 512 static int do_cmd_get_subbuffer(const char *recvbuf, struct ustcomm_source *src)
 513 {
 514         int retval = 0;
 515         struct ltt_trace_struct *trace;
 516         char trace_name[] = "auto";
 517         int i;
 518         char *channel_and_cpu;
 519         int found = 0;
 520         char *ch_name;
 521         int ch_cpu;
 522
 523         DBG("get_subbuf");
 524
 525         channel_and_cpu = nth_token(recvbuf, 1);
 526         if(channel_and_cpu == NULL) {
 527                 ERR("get_subbuf: cannot parse channel");
 528                 goto end;
 529         }
 530
 531         seperate_channel_cpu(channel_and_cpu, &ch_name, &ch_cpu);
 532         if(ch_cpu == -1) {
 533                 ERR("Problem parsing channel name");
 534                 goto free_short_chan_name;
 535         }
 536
 537         ltt_lock_traces();
 538         trace = _ltt_trace_find(trace_name);
 539         ltt_unlock_traces();
 540
 541         if(trace == NULL) {
 542                 ERR("cannot find trace!");
 543                 retval = -1;
 544                 goto free_short_chan_name;
 545         }
 546
 547         for(i=0; i<trace->nr_channels; i++) {
 548                 struct ust_channel *channel = &trace->channels[i];
 549
 550                 if(!strcmp(trace->channels[i].channel_name, ch_name)) {
 551                         struct ust_buffer *buf = channel->buf[ch_cpu];
 552                         struct blocked_consumer *bc;
 553
 554                         found = 1;
 555
 556                         bc = (struct blocked_consumer *) malloc(sizeof(struct blocked_consumer));
 557                         if(bc == NULL) {
 558                                 ERR("malloc returned NULL");
 559                                 goto free_short_chan_name;
 560                         }
 561                         bc->fd_consumer = src->fd;
 562                         bc->fd_producer = buf->data_ready_fd_read;
 563                         bc->buf = buf;
 564                         bc->src = *src;
 565                         bc->server = ustcomm_app.server;
 566
 567                         list_add(&bc->list, &blocked_consumers);
 568
 569                         break;
 570                 }
 571         }
 572         if(found == 0) {
 573                 ERR("get_subbuf: unable to find channel");
 574         }
 575
 576         free_short_chan_name:
 577         free(ch_name);
 578
 579         end:
 580         return retval;
 581 }
 582
 583 static int do_cmd_put_subbuffer(const char *recvbuf, struct ustcomm_source *src)
 584 {
 585         int retval = 0;
 586         struct ltt_trace_struct *trace;
 587         char trace_name[] = "auto";
 588         int i;
 589         char *channel_and_cpu;
 590         int found = 0;
 591         int result;
 592         char *ch_name;
 593         int ch_cpu;
 594         long consumed_old;
 595         char *consumed_old_str;
 596         char *endptr;
 597
 598         DBG("put_subbuf");
 599
 600         channel_and_cpu = strdup_malloc(nth_token(recvbuf, 1));
 601         if(channel_and_cpu == NULL) {
 602                 ERR("put_subbuf_size: cannot parse channel");
 603                 retval = -1;
 604                 goto end;
 605         }
 606
 607         consumed_old_str = strdup_malloc(nth_token(recvbuf, 2));
 608         if(consumed_old_str == NULL) {
 609                 ERR("put_subbuf: cannot parse consumed_old");
 610                 retval = -1;
 611                 goto free_channel_and_cpu;
 612         }
 613         consumed_old = strtol(consumed_old_str, &endptr, 10);
 614         if(*endptr != '\0') {
 615                 ERR("put_subbuf: invalid value for consumed_old");
 616                 retval = -1;
 617                 goto free_consumed_old_str;
 618         }
 619
 620         seperate_channel_cpu(channel_and_cpu, &ch_name, &ch_cpu);
 621         if(ch_cpu == -1) {
 622                 ERR("Problem parsing channel name");
 623                 retval = -1;
 624                 goto free_short_chan_name;
 625         }
 626
 627         ltt_lock_traces();
 628         trace = _ltt_trace_find(trace_name);
 629         ltt_unlock_traces();
 630
 631         if(trace == NULL) {
 632                 ERR("cannot find trace!");
 633                 retval = -1;
 634                 goto free_short_chan_name;
 635         }
 636
 637         for(i=0; i<trace->nr_channels; i++) {
 638                 struct ust_channel *channel = &trace->channels[i];
 639
 640                 if(!strcmp(trace->channels[i].channel_name, ch_name)) {
 641                         struct ust_buffer *buf = channel->buf[ch_cpu];
 642                         char *reply;
 643                         long consumed_old=0;
 644
 645                         found = 1;
 646
 647                         result = ust_buffers_do_put_subbuf(buf, consumed_old);
 648                         if(result < 0) {
 649                                 WARN("ust_buffers_do_put_subbuf: error (subbuf=%s)", channel_and_cpu);
 650                                 asprintf(&reply, "%s", "ERROR");
 651                         }
 652                         else {
 653                                 DBG("ust_buffers_do_put_subbuf: success (subbuf=%s)", channel_and_cpu);
 654                                 asprintf(&reply, "%s", "OK");
 655                         }
 656
 657                         result = ustcomm_send_reply(&ustcomm_app.server, reply, src);
 658                         if(result) {
 659                                 ERR("listener: put_subbuf: ustcomm_send_reply failed");
 660                                 free(reply);
 661                                 retval = -1;
 662                                 goto free_channel_and_cpu;
 663                         }
 664
 665                         free(reply);
 666                         break;
 667                 }
 668         }
 669         if(found == 0) {
 670                 ERR("get_subbuf_size: unable to find channel");
 671         }
 672
 673         free_channel_and_cpu:
 674         free(channel_and_cpu);
 675         free_consumed_old_str:
 676         free(consumed_old_str);
 677         free_short_chan_name:
 678         free(ch_name);
 679
 680         end:
 681         return retval;
 682 }
 683
 684 void *listener_main(void *p)
 685 {
 686         int result;
 687
 688         ust_register_thread();
 689
 690         DBG("LISTENER");
 691
 692         for(;;) {
 693                 char trace_name[] = "auto";
 694                 char trace_type[] = "ustrelay";
 695                 char *recvbuf;
 696                 int len;
 697                 struct ustcomm_source src;
 698
 699                 process_blocked_consumers();
 700
 701                 result = ustcomm_app_recv_message(&ustcomm_app, &recvbuf, &src, 5);
 702                 if(result < 0) {
 703                         WARN("error in ustcomm_app_recv_message");
 704                         continue;
 705                 }
 706                 else if(result == 0) {
 707                         /* no message */
 708                         continue;
 709                 }
 710
 711                 DBG("received a message! it's: %s", recvbuf);
 712                 len = strlen(recvbuf);
 713
 714                 if(!strcmp(recvbuf, "print_markers")) {
 715                         print_markers(stderr);
 716                 }
 717                 else if(!strcmp(recvbuf, "list_markers")) {
 718                         char *ptr;
 719                         size_t size;
 720                         FILE *fp;
 721
 722                         fp = open_memstream(&ptr, &size);
 723                         print_markers(fp);
 724                         fclose(fp);
 725
 726                         result = ustcomm_send_reply(&ustcomm_app.server, ptr, &src);
 727
 728                         free(ptr);
 729                 }
 730                 else if(!strcmp(recvbuf, "start")) {
 731                         /* start is an operation that setups the trace, allocates it and starts it */
 732                         result = ltt_trace_setup(trace_name);
 733                         if(result < 0) {
 734                                 ERR("ltt_trace_setup failed");
 735                                 return (void *)1;
 736                         }
 737
 738                         result = ltt_trace_set_type(trace_name, trace_type);
 739                         if(result < 0) {
 740                                 ERR("ltt_trace_set_type failed");
 741                                 return (void *)1;
 742                         }
 743
 744                         result = ltt_trace_alloc(trace_name);
 745                         if(result < 0) {
 746                                 ERR("ltt_trace_alloc failed");
 747                                 return (void *)1;
 748                         }
 749
 750                         inform_consumer_daemon(trace_name);
 751
 752                         result = ltt_trace_start(trace_name);
 753                         if(result < 0) {
 754                                 ERR("ltt_trace_start failed");
 755                                 continue;
 756                         }
 757                 }
 758                 else if(!strcmp(recvbuf, "trace_setup")) {
 759                         DBG("trace setup");
 760
 761                         result = ltt_trace_setup(trace_name);
 762                         if(result < 0) {
 763                                 ERR("ltt_trace_setup failed");
 764                                 return (void *)1;
 765                         }
 766
 767                         result = ltt_trace_set_type(trace_name, trace_type);
 768                         if(result < 0) {
 769                                 ERR("ltt_trace_set_type failed");
 770                                 return (void *)1;
 771                         }
 772                 }
 773                 else if(!strcmp(recvbuf, "trace_alloc")) {
 774                         DBG("trace alloc");
 775
 776                         result = ltt_trace_alloc(trace_name);
 777                         if(result < 0) {
 778                                 ERR("ltt_trace_alloc failed");
 779                                 return (void *)1;
 780                         }
 781                 }
 782                 else if(!strcmp(recvbuf, "trace_create")) {
 783                         DBG("trace create");
 784
 785                         result = ltt_trace_setup(trace_name);
 786                         if(result < 0) {
 787                                 ERR("ltt_trace_setup failed");
 788                                 return (void *)1;
 789                         }
 790
 791                         result = ltt_trace_set_type(trace_name, trace_type);
 792                         if(result < 0) {
 793                                 ERR("ltt_trace_set_type failed");
 794                                 return (void *)1;
 795                         }
 796
 797                         result = ltt_trace_alloc(trace_name);
 798                         if(result < 0) {
 799                                 ERR("ltt_trace_alloc failed");
 800                                 return (void *)1;
 801                         }
 802
 803                         inform_consumer_daemon(trace_name);
 804                 }
 805                 else if(!strcmp(recvbuf, "trace_start")) {
 806                         DBG("trace start");
 807
 808                         result = ltt_trace_start(trace_name);
 809                         if(result < 0) {
 810                                 ERR("ltt_trace_start failed");
 811                                 continue;
 812                         }
 813                 }
 814                 else if(!strcmp(recvbuf, "trace_stop")) {
 815                         DBG("trace stop");
 816
 817                         result = ltt_trace_stop(trace_name);
 818                         if(result < 0) {
 819                                 ERR("ltt_trace_stop failed");
 820                                 return (void *)1;
 821                         }
 822                 }
 823                 else if(!strcmp(recvbuf, "trace_destroy")) {
 824
 825                         DBG("trace destroy");
 826
 827                         result = ltt_trace_destroy(trace_name);
 828                         if(result < 0) {
 829                                 ERR("ltt_trace_destroy failed");
 830                                 return (void *)1;
 831                         }
 832                 }
 833                 else if(nth_token_is(recvbuf, "get_shmid", 0) == 1) {
 834                         do_cmd_get_shmid(recvbuf, &src);
 835                 }
 836                 else if(nth_token_is(recvbuf, "get_n_subbufs", 0) == 1) {
 837                         do_cmd_get_n_subbufs(recvbuf, &src);
 838                 }
 839                 else if(nth_token_is(recvbuf, "get_subbuf_size", 0) == 1) {
 840                         do_cmd_get_subbuf_size(recvbuf, &src);
 841                 }
 842                 else if(nth_token_is(recvbuf, "load_probe_lib", 0) == 1) {
 843                         char *libfile;
 844
 845                         libfile = nth_token(recvbuf, 1);
 846
 847                         DBG("load_probe_lib loading %s", libfile);
 848
 849                         free(libfile);
 850                 }
 851                 else if(nth_token_is(recvbuf, "get_subbuffer", 0) == 1) {
 852                         do_cmd_get_subbuffer(recvbuf, &src);
 853                 }
 854                 else if(nth_token_is(recvbuf, "put_subbuffer", 0) == 1) {
 855                         do_cmd_put_subbuffer(recvbuf, &src);
 856                 }
 857                 else if(nth_token_is(recvbuf, "enable_marker", 0) == 1) {
 858                         char *channel_slash_name = nth_token(recvbuf, 1);
 859                         char channel_name[256]="";
 860                         char marker_name[256]="";
 861
 862                         result = sscanf(channel_slash_name, "%255[^/]/%255s", channel_name, marker_name);
 863
 864                         if(channel_name == NULL || marker_name == NULL) {
 865                                 WARN("invalid marker name");
 866                                 goto next_cmd;
 867                         }
 868
 869                         result = ltt_marker_connect(channel_name, marker_name, "default");
 870                         if(result < 0) {
 871                                 WARN("could not enable marker; channel=%s, name=%s", channel_name, marker_name);
 872                         }
 873                 }
 874                 else if(nth_token_is(recvbuf, "disable_marker", 0) == 1) {
 875                         char *channel_slash_name = nth_token(recvbuf, 1);
 876                         char *marker_name;
 877                         char *channel_name;
 878
 879                         result = sscanf(channel_slash_name, "%a[^/]/%as", &channel_name, &marker_name);
 880
 881                         if(marker_name == NULL) {
 882                         }
 883
 884                         result = ltt_marker_disconnect(channel_name, marker_name, "default");
 885                         if(result < 0) {
 886                                 WARN("could not disable marker; channel=%s, name=%s", channel_name, marker_name);
 887                         }
 888                 }
 889                 else if(nth_token_is(recvbuf, "get_pidunique", 0) == 1) {
 890                         char *reply;
 891
 892                         asprintf(&reply, "%lld", pidunique);
 893
 894                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 895                         if(result) {
 896                                 ERR("listener: get_pidunique: ustcomm_send_reply failed");
 897                                 goto next_cmd;
 898                         }
 899
 900                         free(reply);
 901                 }
 902 //              else if(nth_token_is(recvbuf, "get_notifications", 0) == 1) {
 903 //                      struct ltt_trace_struct *trace;
 904 //                      char trace_name[] = "auto";
 905 //                      int i;
 906 //                      char *channel_name;
 907 //
 908 //                      DBG("get_notifications");
 909 //
 910 //                      channel_name = strdup_malloc(nth_token(recvbuf, 1));
 911 //                      if(channel_name == NULL) {
 912 //                              ERR("put_subbuf_size: cannot parse channel");
 913 //                              goto next_cmd;
 914 //                      }
 915 //
 916 //                      ltt_lock_traces();
 917 //                      trace = _ltt_trace_find(trace_name);
 918 //                      ltt_unlock_traces();
 919 //
 920 //                      if(trace == NULL) {
 921 //                              ERR("cannot find trace!");
 922 //                              return (void *)1;
 923 //                      }
 924 //
 925 //                      for(i=0; i<trace->nr_channels; i++) {
 926 //                              struct rchan *rchan = trace->channels[i].trans_channel_data;
 927 //                              int fd;
 928 //
 929 //                              if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 930 //                                      struct rchan_buf *rbuf = rchan->buf;
 931 //                                      struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 932 //
 933 //                                      result = fd = ustcomm_app_detach_client(&ustcomm_app, &src);
 934 //                                      if(result == -1) {
 935 //                                              ERR("ustcomm_app_detach_client failed");
 936 //                                              goto next_cmd;
 937 //                                      }
 938 //
 939 //                                      lttbuf->wake_consumer_arg = (void *) fd;
 940 //
 941 //                                      smp_wmb();
 942 //
 943 //                                      lttbuf->call_wake_consumer = 1;
 944 //
 945 //                                      break;
 946 //                              }
 947 //                      }
 948 //
 949 //                      free(channel_name);
 950 //              }
 951                 else {
 952                         ERR("unable to parse message: %s", recvbuf);
 953                 }
 954
 955         next_cmd:
 956                 free(recvbuf);
 957         }
 958 }
 959
 960 volatile sig_atomic_t have_listener = 0;
 961
 962 void create_listener(void)
 963 {
 964 #ifdef USE_CLONE
 965         static char listener_stack[16384];
 966         int result;
 967 #else
 968         pthread_t thread;
 969 #endif
 970
 971         if(have_listener) {
 972                 WARN("not creating listener because we already had one");
 973                 return;
 974         }
 975
 976 #ifdef USE_CLONE
 977         result = clone((int (*)(void *)) listener_main, listener_stack+sizeof(listener_stack)-1, CLONE_FS | CLONE_FILES | CLONE_VM | CLONE_SIGHAND | CLONE_THREAD, NULL);
 978         if(result == -1) {
 979                 perror("clone");
 980                 return;
 981         }
 982 #else
 983
 984         pthread_create(&thread, NULL, listener_main, NULL);
 985 #endif
 986
 987         have_listener = 1;
 988 }
 989
 990 static int init_socket(void)
 991 {
 992         return ustcomm_init_app(getpid(), &ustcomm_app);
 993 }
 994
 995 #define AUTOPROBE_DISABLED      0
 996 #define AUTOPROBE_ENABLE_ALL    1
 997 #define AUTOPROBE_ENABLE_REGEX  2
 998 static int autoprobe_method = AUTOPROBE_DISABLED;
 999 static regex_t autoprobe_regex;
1000
1001 static void auto_probe_connect(struct marker *m)
1002 {
1003         int result;
1004
1005         char* concat_name = NULL;
1006         const char *probe_name = "default";
1007
1008         if(autoprobe_method == AUTOPROBE_DISABLED) {
1009                 return;
1010         }
1011         else if(autoprobe_method == AUTOPROBE_ENABLE_REGEX) {
1012                 result = asprintf(&concat_name, "%s/%s", m->channel, m->name);
1013                 if(result == -1) {
1014                         ERR("auto_probe_connect: asprintf failed (marker %s/%s)",
1015                                 m->channel, m->name);
1016                         return;
1017                 }
1018                 if (regexec(&autoprobe_regex, concat_name, 0, NULL, 0)) {
1019                         free(concat_name);
1020                         return;
1021                 }
1022                 free(concat_name);
1023         }
1024
1025         result = ltt_marker_connect(m->channel, m->name, probe_name);
1026         if(result && result != -EEXIST)
1027                 ERR("ltt_marker_connect (marker = %s/%s, errno = %d)", m->channel, m->name, -result);
1028
1029         DBG("auto connected marker %s (addr: %p) %s to probe default", m->channel, m, m->name);
1030
1031 }
1032
1033 static void __attribute__((constructor)) init()
1034 {
1035         int result;
1036         char* autoprobe_val = NULL;
1037
1038         /* Assign the pidunique, to be able to differentiate the processes with same
1039          * pid, (before and after an exec).
1040          */
1041         pidunique = make_pidunique();
1042
1043         /* Initialize RCU in case the constructor order is not good. */
1044         rcu_init();
1045
1046         /* It is important to do this before events start to be generated. */
1047         ust_register_thread();
1048
1049         DBG("Tracectl constructor");
1050
1051         /* Must create socket before signal handler to prevent races.
1052          */
1053         result = init_socket();
1054         if(result == -1) {
1055                 ERR("init_socket error");
1056                 return;
1057         }
1058
1059         create_listener();
1060
1061         autoprobe_val = getenv("UST_AUTOPROBE");
1062         if(autoprobe_val) {
1063                 struct marker_iter iter;
1064
1065                 DBG("Autoprobe enabled.");
1066
1067                 /* Ensure markers are initialized */
1068                 //init_markers();
1069
1070                 /* Ensure marker control is initialized, for the probe */
1071                 init_marker_control();
1072
1073                 /* first, set the callback that will connect the
1074                  * probe on new markers
1075                  */
1076                 if(autoprobe_val[0] == '/') {
1077                         result = regcomp(&autoprobe_regex, autoprobe_val+1, 0);
1078                         if (result) {
1079                                 char regexerr[150];
1080
1081                                 regerror(result, &autoprobe_regex, regexerr, sizeof(regexerr));
1082                                 ERR("cannot parse regex %s (%s), will ignore UST_AUTOPROBE", autoprobe_val, regexerr);
1083                                 /* don't crash the application just for this */
1084                         }
1085                         else {
1086                                 autoprobe_method = AUTOPROBE_ENABLE_REGEX;
1087                         }
1088                 }
1089                 else {
1090                         /* just enable all instrumentation */
1091                         autoprobe_method = AUTOPROBE_ENABLE_ALL;
1092                 }
1093
1094                 marker_set_new_marker_cb(auto_probe_connect);
1095
1096                 /* Now, connect the probes that were already registered. */
1097                 marker_iter_reset(&iter);
1098                 marker_iter_start(&iter);
1099
1100                 DBG("now iterating on markers already registered");
1101                 while(iter.marker) {
1102                         DBG("now iterating on marker %s", iter.marker->name);
1103                         auto_probe_connect(iter.marker);
1104                         marker_iter_next(&iter);
1105                 }
1106         }
1107
1108         if(getenv("UST_TRACE")) {
1109                 char trace_name[] = "auto";
1110                 char trace_type[] = "ustrelay";
1111
1112                 DBG("starting early tracing");
1113
1114                 /* Ensure marker control is initialized */
1115                 init_marker_control();
1116
1117                 /* Ensure relay is initialized */
1118                 init_ustrelay_transport();
1119
1120                 /* Ensure markers are initialized */
1121                 init_markers();
1122
1123                 /* FIXME: When starting early tracing (here), depending on the
1124                  * order of constructors, it is very well possible some marker
1125                  * sections are not yet registered. Because of this, some
1126                  * channels may not be registered. Yet, we are about to ask the
1127                  * daemon to collect the channels. Channels which are not yet
1128                  * registered will not be collected.
1129                  *
1130                  * Currently, in LTTng, there is no way to add a channel after
1131                  * trace start. The reason for this is that it induces complex
1132                  * concurrency issues on the trace structures, which can only
1133                  * be resolved using RCU. This has not been done yet. As a
1134                  * workaround, we are forcing the registration of the "ust"
1135                  * channel here. This is the only channel (apart from metadata)
1136                  * that can be reliably used in early tracing.
1137                  *
1138                  * Non-early tracing does not have this problem and can use
1139                  * arbitrary channel names.
1140                  */
1141                 ltt_channels_register("ust");
1142
1143                 result = ltt_trace_setup(trace_name);
1144                 if(result < 0) {
1145                         ERR("ltt_trace_setup failed");
1146                         return;
1147                 }
1148
1149                 result = ltt_trace_set_type(trace_name, trace_type);
1150                 if(result < 0) {
1151                         ERR("ltt_trace_set_type failed");
1152                         return;
1153                 }
1154
1155                 result = ltt_trace_alloc(trace_name);
1156                 if(result < 0) {
1157                         ERR("ltt_trace_alloc failed");
1158                         return;
1159                 }
1160
1161                 result = ltt_trace_start(trace_name);
1162                 if(result < 0) {
1163                         ERR("ltt_trace_start failed");
1164                         return;
1165                 }
1166
1167                 /* Do this after the trace is started in order to avoid creating confusion
1168                  * if the trace fails to start. */
1169                 inform_consumer_daemon(trace_name);
1170         }
1171
1172
1173         return;
1174
1175         /* should decrementally destroy stuff if error */
1176
1177 }
1178
1179 /* This is only called if we terminate normally, not with an unhandled signal,
1180  * so we cannot rely on it. However, for now, LTTV requires that the header of
1181  * the last sub-buffer contain a valid end time for the trace. This is done
1182  * automatically only when the trace is properly stopped.
1183  *
1184  * If the traced program crashed, it is always possible to manually add the
1185  * right value in the header, or to open the trace in text mode.
1186  *
1187  * FIXME: Fix LTTV so it doesn't need this.
1188  */
1189
1190 static void destroy_traces(void)
1191 {
1192         int result;
1193
1194         /* if trace running, finish it */
1195
1196         DBG("destructor stopping traces");
1197
1198         result = ltt_trace_stop("auto");
1199         if(result == -1) {
1200                 ERR("ltt_trace_stop error");
1201         }
1202
1203         result = ltt_trace_destroy("auto");
1204         if(result == -1) {
1205                 ERR("ltt_trace_destroy error");
1206         }
1207 }
1208
1209 static int trace_recording(void)
1210 {
1211         int retval = 0;
1212         struct ltt_trace_struct *trace;
1213
1214         ltt_lock_traces();
1215
1216         list_for_each_entry(trace, &ltt_traces.head, list) {
1217                 if(trace->active) {
1218                         retval = 1;
1219                         break;
1220                 }
1221         }
1222
1223         ltt_unlock_traces();
1224
1225         return retval;
1226 }
1227
1228 #if 0
1229 static int have_consumer(void)
1230 {
1231         return !list_empty(&blocked_consumers);
1232 }
1233 #endif
1234
1235 int restarting_usleep(useconds_t usecs)
1236 {
1237         struct timespec tv;
1238         int result;
1239
1240         tv.tv_sec = 0;
1241         tv.tv_nsec = usecs * 1000;
1242
1243         do {
1244                 result = nanosleep(&tv, &tv);
1245         } while(result == -1 && errno == EINTR);
1246
1247         return result;
1248 }
1249
1250 /* This destructor keeps the process alive for a few seconds in order
1251  * to leave time to ustd to connect to its buffers. This is necessary
1252  * for programs whose execution is very short. It is also useful in all
1253  * programs when tracing is started close to the end of the program
1254  * execution.
1255  *
1256  * FIXME: For now, this only works for the first trace created in a
1257  * process.
1258  */
1259
1260 static void __attribute__((destructor)) keepalive()
1261 {
1262         if(trace_recording() && buffers_to_export) {
1263                 int total = 0;
1264                 DBG("Keeping process alive for consumer daemon...");
1265                 while(buffers_to_export) {
1266                         const int interv = 200000;
1267                         restarting_usleep(interv);
1268                         total += interv;
1269
1270                         if(total >= 3000000) {
1271                                 WARN("non-consumed buffers remaining after wait limit; not waiting anymore");
1272                                 break;
1273                         }
1274                 }
1275                 DBG("Finally dying...");
1276         }
1277
1278         destroy_traces();
1279
1280         ustcomm_fini_app(&ustcomm_app);
1281 }
1282
1283 void ust_potential_exec(void)
1284 {
1285         trace_mark(ust, potential_exec, MARK_NOARGS);
1286
1287         DBG("test");
1288
1289         keepalive();
1290 }
1291
1292 /* Notify ust that there was a fork. This needs to be called inside
1293  * the new process, anytime a process whose memory is not shared with
1294  * the parent is created. If this function is not called, the events
1295  * of the new process will not be collected.
1296  *
1297  * Signals should be disabled before the fork and reenabled only after
1298  * this call in order to guarantee tracing is not started before ust_fork()
1299  * sanitizes the new process.
1300  */
1301
1302 static void ust_fork(void)
1303 {
1304         struct blocked_consumer *bc;
1305         struct blocked_consumer *deletable_bc = NULL;
1306         int result;
1307
1308         DBG("ust: forking");
1309         ltt_trace_stop("auto");
1310         ltt_trace_destroy("auto");
1311         /* Delete all active connections */
1312         ustcomm_close_all_connections(&ustcomm_app.server);
1313
1314         /* Delete all blocked consumers */
1315         list_for_each_entry(bc, &blocked_consumers, list) {
1316                 close(bc->fd_producer);
1317                 close(bc->fd_consumer);
1318                 free(deletable_bc);
1319                 deletable_bc = bc;
1320                 list_del(&bc->list);
1321         }
1322
1323         have_listener = 0;
1324         create_listener();
1325         init_socket();
1326         ltt_trace_setup("auto");
1327         result = ltt_trace_set_type("auto", "ustrelay");
1328         if(result < 0) {
1329                 ERR("ltt_trace_set_type failed");
1330                 return;
1331         }
1332
1333         ltt_trace_alloc("auto");
1334         ltt_trace_start("auto");
1335         inform_consumer_daemon("auto");
1336 }
1337
1338 void ust_before_fork(ust_fork_info_t *fork_info)
1339 {
1340         /* Disable signals. This is to avoid that the child
1341          * intervenes before it is properly setup for tracing. It is
1342          * safer to disable all signals, because then we know we are not
1343          * breaking anything by restoring the original mask.
1344          */
1345         sigset_t all_sigs;
1346         int result;
1347
1348         /* FIXME:
1349                 - only do this if tracing is active
1350         */
1351
1352         /* Disable signals */
1353         sigfillset(&all_sigs);
1354         result = sigprocmask(SIG_BLOCK, &all_sigs, &fork_info->orig_sigs);
1355         if(result == -1) {
1356                 PERROR("sigprocmask");
1357                 return;
1358         }
1359 }
1360
1361 /* Don't call this function directly in a traced program */
1362 static void ust_after_fork_common(ust_fork_info_t *fork_info)
1363 {
1364         int result;
1365
1366         /* Restore signals */
1367         result = sigprocmask(SIG_SETMASK, &fork_info->orig_sigs, NULL);
1368         if(result == -1) {
1369                 PERROR("sigprocmask");
1370                 return;
1371         }
1372 }
1373
1374 void ust_after_fork_parent(ust_fork_info_t *fork_info)
1375 {
1376         /* Reenable signals */
1377         ust_after_fork_common(fork_info);
1378 }
1379
1380 void ust_after_fork_child(ust_fork_info_t *fork_info)
1381 {
1382         /* First sanitize the child */
1383         ust_fork();
1384
1385         /* Then reenable interrupts */
1386         ust_after_fork_common(fork_info);
1387 }
1388