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"
  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_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 ust_trace *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_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_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 ust_trace *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 ust_trace *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 ust_trace *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 ust_trace *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                 char *reply;
 543                 int result;
 544
 545                 WARN("Cannot find trace. It was likely destroyed by the user.");
 546                 asprintf(&reply, "%s", "NOTFOUND");
 547                 result = ustcomm_send_reply(&ustcomm_app.server, reply, src);
 548                 if(result) {
 549                         ERR("ustcomm_send_reply failed");
 550                         free(reply);
 551                         retval = -1;
 552                         goto free_short_chan_name;
 553                 }
 554
 555                 free(reply);
 556                 goto free_short_chan_name;
 557         }
 558
 559         for(i=0; i<trace->nr_channels; i++) {
 560                 struct ust_channel *channel = &trace->channels[i];
 561
 562                 if(!strcmp(trace->channels[i].channel_name, ch_name)) {
 563                         struct ust_buffer *buf = channel->buf[ch_cpu];
 564                         struct blocked_consumer *bc;
 565
 566                         found = 1;
 567
 568                         bc = (struct blocked_consumer *) malloc(sizeof(struct blocked_consumer));
 569                         if(bc == NULL) {
 570                                 ERR("malloc returned NULL");
 571                                 goto free_short_chan_name;
 572                         }
 573                         bc->fd_consumer = src->fd;
 574                         bc->fd_producer = buf->data_ready_fd_read;
 575                         bc->buf = buf;
 576                         bc->src = *src;
 577                         bc->server = ustcomm_app.server;
 578
 579                         list_add(&bc->list, &blocked_consumers);
 580
 581                         break;
 582                 }
 583         }
 584         if(found == 0) {
 585                 ERR("get_subbuf: unable to find channel");
 586         }
 587
 588         free_short_chan_name:
 589         free(ch_name);
 590
 591         end:
 592         return retval;
 593 }
 594
 595 static int do_cmd_put_subbuffer(const char *recvbuf, struct ustcomm_source *src)
 596 {
 597         int retval = 0;
 598         struct ust_trace *trace;
 599         char trace_name[] = "auto";
 600         int i;
 601         char *channel_and_cpu;
 602         int found = 0;
 603         int result;
 604         char *ch_name;
 605         int ch_cpu;
 606         long consumed_old;
 607         char *consumed_old_str;
 608         char *endptr;
 609         char *reply = NULL;
 610
 611         DBG("put_subbuf");
 612
 613         channel_and_cpu = strdup_malloc(nth_token(recvbuf, 1));
 614         if(channel_and_cpu == NULL) {
 615                 ERR("put_subbuf_size: cannot parse channel");
 616                 retval = -1;
 617                 goto end;
 618         }
 619
 620         consumed_old_str = strdup_malloc(nth_token(recvbuf, 2));
 621         if(consumed_old_str == NULL) {
 622                 ERR("put_subbuf: cannot parse consumed_old");
 623                 retval = -1;
 624                 goto free_channel_and_cpu;
 625         }
 626         consumed_old = strtol(consumed_old_str, &endptr, 10);
 627         if(*endptr != '\0') {
 628                 ERR("put_subbuf: invalid value for consumed_old");
 629                 retval = -1;
 630                 goto free_consumed_old_str;
 631         }
 632
 633         seperate_channel_cpu(channel_and_cpu, &ch_name, &ch_cpu);
 634         if(ch_cpu == -1) {
 635                 ERR("Problem parsing channel name");
 636                 retval = -1;
 637                 goto free_short_chan_name;
 638         }
 639
 640         ltt_lock_traces();
 641         trace = _ltt_trace_find(trace_name);
 642         ltt_unlock_traces();
 643
 644         if(trace == NULL) {
 645                 WARN("Cannot find trace. It was likely destroyed by the user.");
 646                 asprintf(&reply, "%s", "NOTFOUND");
 647                 result = ustcomm_send_reply(&ustcomm_app.server, reply, src);
 648                 if(result) {
 649                         ERR("ustcomm_send_reply failed");
 650                         free(reply);
 651                         retval = -1;
 652                         goto free_short_chan_name;
 653                 }
 654
 655                 free(reply);
 656                 goto free_short_chan_name;
 657         }
 658
 659         for(i=0; i<trace->nr_channels; i++) {
 660                 struct ust_channel *channel = &trace->channels[i];
 661
 662                 if(!strcmp(trace->channels[i].channel_name, ch_name)) {
 663                         struct ust_buffer *buf = channel->buf[ch_cpu];
 664
 665                         found = 1;
 666
 667                         result = ust_buffers_put_subbuf(buf, consumed_old);
 668                         if(result < 0) {
 669                                 WARN("ust_buffers_put_subbuf: error (subbuf=%s)", channel_and_cpu);
 670                                 asprintf(&reply, "%s", "ERROR");
 671                         }
 672                         else {
 673                                 DBG("ust_buffers_put_subbuf: success (subbuf=%s)", channel_and_cpu);
 674                                 asprintf(&reply, "%s", "OK");
 675                         }
 676
 677                         result = ustcomm_send_reply(&ustcomm_app.server, reply, src);
 678                         if(result) {
 679                                 ERR("listener: put_subbuf: ustcomm_send_reply failed");
 680                                 free(reply);
 681                                 retval = -1;
 682                                 goto free_channel_and_cpu;
 683                         }
 684
 685                         free(reply);
 686                         break;
 687                 }
 688         }
 689         if(found == 0) {
 690                 ERR("unable to find channel");
 691         }
 692
 693         free_short_chan_name:
 694         free(ch_name);
 695         free_consumed_old_str:
 696         free(consumed_old_str);
 697         free_channel_and_cpu:
 698         free(channel_and_cpu);
 699
 700         end:
 701         return retval;
 702 }
 703
 704 void *listener_main(void *p)
 705 {
 706         int result;
 707
 708         ust_register_thread();
 709
 710         DBG("LISTENER");
 711
 712         for(;;) {
 713                 char trace_name[] = "auto";
 714                 char trace_type[] = "ustrelay";
 715                 char *recvbuf;
 716                 int len;
 717                 struct ustcomm_source src;
 718
 719                 process_blocked_consumers();
 720
 721                 result = ustcomm_app_recv_message(&ustcomm_app, &recvbuf, &src, 5);
 722                 if(result < 0) {
 723                         WARN("error in ustcomm_app_recv_message");
 724                         continue;
 725                 }
 726                 else if(result == 0) {
 727                         /* no message */
 728                         continue;
 729                 }
 730
 731                 DBG("received a message! it's: %s", recvbuf);
 732                 len = strlen(recvbuf);
 733
 734                 if(!strcmp(recvbuf, "print_markers")) {
 735                         print_markers(stderr);
 736                 }
 737                 else if(!strcmp(recvbuf, "list_markers")) {
 738                         char *ptr;
 739                         size_t size;
 740                         FILE *fp;
 741
 742                         fp = open_memstream(&ptr, &size);
 743                         print_markers(fp);
 744                         fclose(fp);
 745
 746                         result = ustcomm_send_reply(&ustcomm_app.server, ptr, &src);
 747
 748                         free(ptr);
 749                 }
 750                 else if(!strcmp(recvbuf, "start")) {
 751                         /* start is an operation that setups the trace, allocates it and starts it */
 752                         result = ltt_trace_setup(trace_name);
 753                         if(result < 0) {
 754                                 ERR("ltt_trace_setup failed");
 755                                 return (void *)1;
 756                         }
 757
 758                         result = ltt_trace_set_type(trace_name, trace_type);
 759                         if(result < 0) {
 760                                 ERR("ltt_trace_set_type failed");
 761                                 return (void *)1;
 762                         }
 763
 764                         result = ltt_trace_alloc(trace_name);
 765                         if(result < 0) {
 766                                 ERR("ltt_trace_alloc failed");
 767                                 return (void *)1;
 768                         }
 769
 770                         inform_consumer_daemon(trace_name);
 771
 772                         result = ltt_trace_start(trace_name);
 773                         if(result < 0) {
 774                                 ERR("ltt_trace_start failed");
 775                                 continue;
 776                         }
 777                 }
 778                 else if(!strcmp(recvbuf, "trace_setup")) {
 779                         DBG("trace setup");
 780
 781                         result = ltt_trace_setup(trace_name);
 782                         if(result < 0) {
 783                                 ERR("ltt_trace_setup failed");
 784                                 return (void *)1;
 785                         }
 786
 787                         result = ltt_trace_set_type(trace_name, trace_type);
 788                         if(result < 0) {
 789                                 ERR("ltt_trace_set_type failed");
 790                                 return (void *)1;
 791                         }
 792                 }
 793                 else if(!strcmp(recvbuf, "trace_alloc")) {
 794                         DBG("trace alloc");
 795
 796                         result = ltt_trace_alloc(trace_name);
 797                         if(result < 0) {
 798                                 ERR("ltt_trace_alloc failed");
 799                                 return (void *)1;
 800                         }
 801                 }
 802                 else if(!strcmp(recvbuf, "trace_create")) {
 803                         DBG("trace create");
 804
 805                         result = ltt_trace_setup(trace_name);
 806                         if(result < 0) {
 807                                 ERR("ltt_trace_setup failed");
 808                                 return (void *)1;
 809                         }
 810
 811                         result = ltt_trace_set_type(trace_name, trace_type);
 812                         if(result < 0) {
 813                                 ERR("ltt_trace_set_type failed");
 814                                 return (void *)1;
 815                         }
 816
 817                         result = ltt_trace_alloc(trace_name);
 818                         if(result < 0) {
 819                                 ERR("ltt_trace_alloc failed");
 820                                 return (void *)1;
 821                         }
 822
 823                         inform_consumer_daemon(trace_name);
 824                 }
 825                 else if(!strcmp(recvbuf, "trace_start")) {
 826                         DBG("trace start");
 827
 828                         result = ltt_trace_start(trace_name);
 829                         if(result < 0) {
 830                                 ERR("ltt_trace_start failed");
 831                                 continue;
 832                         }
 833                 }
 834                 else if(!strcmp(recvbuf, "trace_stop")) {
 835                         DBG("trace stop");
 836
 837                         result = ltt_trace_stop(trace_name);
 838                         if(result < 0) {
 839                                 ERR("ltt_trace_stop failed");
 840                                 return (void *)1;
 841                         }
 842                 }
 843                 else if(!strcmp(recvbuf, "trace_destroy")) {
 844
 845                         DBG("trace destroy");
 846
 847                         result = ltt_trace_destroy(trace_name);
 848                         if(result < 0) {
 849                                 ERR("ltt_trace_destroy failed");
 850                                 return (void *)1;
 851                         }
 852                 }
 853                 else if(nth_token_is(recvbuf, "get_shmid", 0) == 1) {
 854                         do_cmd_get_shmid(recvbuf, &src);
 855                 }
 856                 else if(nth_token_is(recvbuf, "get_n_subbufs", 0) == 1) {
 857                         do_cmd_get_n_subbufs(recvbuf, &src);
 858                 }
 859                 else if(nth_token_is(recvbuf, "get_subbuf_size", 0) == 1) {
 860                         do_cmd_get_subbuf_size(recvbuf, &src);
 861                 }
 862                 else if(nth_token_is(recvbuf, "load_probe_lib", 0) == 1) {
 863                         char *libfile;
 864
 865                         libfile = nth_token(recvbuf, 1);
 866
 867                         DBG("load_probe_lib loading %s", libfile);
 868
 869                         free(libfile);
 870                 }
 871                 else if(nth_token_is(recvbuf, "get_subbuffer", 0) == 1) {
 872                         do_cmd_get_subbuffer(recvbuf, &src);
 873                 }
 874                 else if(nth_token_is(recvbuf, "put_subbuffer", 0) == 1) {
 875                         do_cmd_put_subbuffer(recvbuf, &src);
 876                 }
 877                 else if(nth_token_is(recvbuf, "enable_marker", 0) == 1) {
 878                         char *channel_slash_name = nth_token(recvbuf, 1);
 879                         char channel_name[256]="";
 880                         char marker_name[256]="";
 881
 882                         result = sscanf(channel_slash_name, "%255[^/]/%255s", channel_name, marker_name);
 883
 884                         if(channel_name == NULL || marker_name == NULL) {
 885                                 WARN("invalid marker name");
 886                                 goto next_cmd;
 887                         }
 888
 889                         result = ltt_marker_connect(channel_name, marker_name, "default");
 890                         if(result < 0) {
 891                                 WARN("could not enable marker; channel=%s, name=%s", channel_name, marker_name);
 892                         }
 893                 }
 894                 else if(nth_token_is(recvbuf, "disable_marker", 0) == 1) {
 895                         char *channel_slash_name = nth_token(recvbuf, 1);
 896                         char *marker_name;
 897                         char *channel_name;
 898
 899                         result = sscanf(channel_slash_name, "%a[^/]/%as", &channel_name, &marker_name);
 900
 901                         if(marker_name == NULL) {
 902                         }
 903
 904                         result = ltt_marker_disconnect(channel_name, marker_name, "default");
 905                         if(result < 0) {
 906                                 WARN("could not disable marker; channel=%s, name=%s", channel_name, marker_name);
 907                         }
 908                 }
 909                 else if(nth_token_is(recvbuf, "get_pidunique", 0) == 1) {
 910                         char *reply;
 911
 912                         asprintf(&reply, "%lld", pidunique);
 913
 914                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 915                         if(result) {
 916                                 ERR("listener: get_pidunique: ustcomm_send_reply failed");
 917                                 goto next_cmd;
 918                         }
 919
 920                         free(reply);
 921                 }
 922 //              else if(nth_token_is(recvbuf, "get_notifications", 0) == 1) {
 923 //                      struct ust_trace *trace;
 924 //                      char trace_name[] = "auto";
 925 //                      int i;
 926 //                      char *channel_name;
 927 //
 928 //                      DBG("get_notifications");
 929 //
 930 //                      channel_name = strdup_malloc(nth_token(recvbuf, 1));
 931 //                      if(channel_name == NULL) {
 932 //                              ERR("put_subbuf_size: cannot parse channel");
 933 //                              goto next_cmd;
 934 //                      }
 935 //
 936 //                      ltt_lock_traces();
 937 //                      trace = _ltt_trace_find(trace_name);
 938 //                      ltt_unlock_traces();
 939 //
 940 //                      if(trace == NULL) {
 941 //                              ERR("cannot find trace!");
 942 //                              return (void *)1;
 943 //                      }
 944 //
 945 //                      for(i=0; i<trace->nr_channels; i++) {
 946 //                              struct rchan *rchan = trace->channels[i].trans_channel_data;
 947 //                              int fd;
 948 //
 949 //                              if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 950 //                                      struct rchan_buf *rbuf = rchan->buf;
 951 //                                      struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 952 //
 953 //                                      result = fd = ustcomm_app_detach_client(&ustcomm_app, &src);
 954 //                                      if(result == -1) {
 955 //                                              ERR("ustcomm_app_detach_client failed");
 956 //                                              goto next_cmd;
 957 //                                      }
 958 //
 959 //                                      lttbuf->wake_consumer_arg = (void *) fd;
 960 //
 961 //                                      smp_wmb();
 962 //
 963 //                                      lttbuf->call_wake_consumer = 1;
 964 //
 965 //                                      break;
 966 //                              }
 967 //                      }
 968 //
 969 //                      free(channel_name);
 970 //              }
 971                 else {
 972                         ERR("unable to parse message: %s", recvbuf);
 973                 }
 974
 975         next_cmd:
 976                 free(recvbuf);
 977         }
 978 }
 979
 980 volatile sig_atomic_t have_listener = 0;
 981
 982 void create_listener(void)
 983 {
 984 #ifdef USE_CLONE
 985         static char listener_stack[16384];
 986         int result;
 987 #else
 988         pthread_t thread;
 989 #endif
 990
 991         if(have_listener) {
 992                 WARN("not creating listener because we already had one");
 993                 return;
 994         }
 995
 996 #ifdef USE_CLONE
 997         result = clone((int (*)(void *)) listener_main, listener_stack+sizeof(listener_stack)-1, CLONE_FS | CLONE_FILES | CLONE_VM | CLONE_SIGHAND | CLONE_THREAD, NULL);
 998         if(result == -1) {
 999                 perror("clone");
1000                 return;
1001         }
1002 #else
1003
1004         pthread_create(&thread, NULL, listener_main, NULL);
1005 #endif
1006
1007         have_listener = 1;
1008 }
1009
1010 static int init_socket(void)
1011 {
1012         return ustcomm_init_app(getpid(), &ustcomm_app);
1013 }
1014
1015 #define AUTOPROBE_DISABLED      0
1016 #define AUTOPROBE_ENABLE_ALL    1
1017 #define AUTOPROBE_ENABLE_REGEX  2
1018 static int autoprobe_method = AUTOPROBE_DISABLED;
1019 static regex_t autoprobe_regex;
1020
1021 static void auto_probe_connect(struct marker *m)
1022 {
1023         int result;
1024
1025         char* concat_name = NULL;
1026         const char *probe_name = "default";
1027
1028         if(autoprobe_method == AUTOPROBE_DISABLED) {
1029                 return;
1030         }
1031         else if(autoprobe_method == AUTOPROBE_ENABLE_REGEX) {
1032                 result = asprintf(&concat_name, "%s/%s", m->channel, m->name);
1033                 if(result == -1) {
1034                         ERR("auto_probe_connect: asprintf failed (marker %s/%s)",
1035                                 m->channel, m->name);
1036                         return;
1037                 }
1038                 if (regexec(&autoprobe_regex, concat_name, 0, NULL, 0)) {
1039                         free(concat_name);
1040                         return;
1041                 }
1042                 free(concat_name);
1043         }
1044
1045         result = ltt_marker_connect(m->channel, m->name, probe_name);
1046         if(result && result != -EEXIST)
1047                 ERR("ltt_marker_connect (marker = %s/%s, errno = %d)", m->channel, m->name, -result);
1048
1049         DBG("auto connected marker %s (addr: %p) %s to probe default", m->channel, m, m->name);
1050
1051 }
1052
1053 static void __attribute__((constructor)) init()
1054 {
1055         int result;
1056         char* autoprobe_val = NULL;
1057
1058         /* Assign the pidunique, to be able to differentiate the processes with same
1059          * pid, (before and after an exec).
1060          */
1061         pidunique = make_pidunique();
1062
1063         /* Initialize RCU in case the constructor order is not good. */
1064         rcu_init();
1065
1066         /* It is important to do this before events start to be generated. */
1067         ust_register_thread();
1068
1069         DBG("Tracectl constructor");
1070
1071         /* Must create socket before signal handler to prevent races.
1072          */
1073         result = init_socket();
1074         if(result == -1) {
1075                 ERR("init_socket error");
1076                 return;
1077         }
1078
1079         create_listener();
1080
1081         autoprobe_val = getenv("UST_AUTOPROBE");
1082         if(autoprobe_val) {
1083                 struct marker_iter iter;
1084
1085                 DBG("Autoprobe enabled.");
1086
1087                 /* Ensure markers are initialized */
1088                 //init_markers();
1089
1090                 /* Ensure marker control is initialized, for the probe */
1091                 init_marker_control();
1092
1093                 /* first, set the callback that will connect the
1094                  * probe on new markers
1095                  */
1096                 if(autoprobe_val[0] == '/') {
1097                         result = regcomp(&autoprobe_regex, autoprobe_val+1, 0);
1098                         if (result) {
1099                                 char regexerr[150];
1100
1101                                 regerror(result, &autoprobe_regex, regexerr, sizeof(regexerr));
1102                                 ERR("cannot parse regex %s (%s), will ignore UST_AUTOPROBE", autoprobe_val, regexerr);
1103                                 /* don't crash the application just for this */
1104                         }
1105                         else {
1106                                 autoprobe_method = AUTOPROBE_ENABLE_REGEX;
1107                         }
1108                 }
1109                 else {
1110                         /* just enable all instrumentation */
1111                         autoprobe_method = AUTOPROBE_ENABLE_ALL;
1112                 }
1113
1114                 marker_set_new_marker_cb(auto_probe_connect);
1115
1116                 /* Now, connect the probes that were already registered. */
1117                 marker_iter_reset(&iter);
1118                 marker_iter_start(&iter);
1119
1120                 DBG("now iterating on markers already registered");
1121                 while(iter.marker) {
1122                         DBG("now iterating on marker %s", iter.marker->name);
1123                         auto_probe_connect(iter.marker);
1124                         marker_iter_next(&iter);
1125                 }
1126         }
1127
1128         if(getenv("UST_TRACE")) {
1129                 char trace_name[] = "auto";
1130                 char trace_type[] = "ustrelay";
1131
1132                 DBG("starting early tracing");
1133
1134                 /* Ensure marker control is initialized */
1135                 init_marker_control();
1136
1137                 /* Ensure markers are initialized */
1138                 init_markers();
1139
1140                 /* Ensure buffers are initialized, for the transport to be available.
1141                  * We are about to set a trace type and it will fail without this.
1142                  */
1143                 init_ustrelay_transport();
1144
1145                 /* FIXME: When starting early tracing (here), depending on the
1146                  * order of constructors, it is very well possible some marker
1147                  * sections are not yet registered. Because of this, some
1148                  * channels may not be registered. Yet, we are about to ask the
1149                  * daemon to collect the channels. Channels which are not yet
1150                  * registered will not be collected.
1151                  *
1152                  * Currently, in LTTng, there is no way to add a channel after
1153                  * trace start. The reason for this is that it induces complex
1154                  * concurrency issues on the trace structures, which can only
1155                  * be resolved using RCU. This has not been done yet. As a
1156                  * workaround, we are forcing the registration of the "ust"
1157                  * channel here. This is the only channel (apart from metadata)
1158                  * that can be reliably used in early tracing.
1159                  *
1160                  * Non-early tracing does not have this problem and can use
1161                  * arbitrary channel names.
1162                  */
1163                 ltt_channels_register("ust");
1164
1165                 result = ltt_trace_setup(trace_name);
1166                 if(result < 0) {
1167                         ERR("ltt_trace_setup failed");
1168                         return;
1169                 }
1170
1171                 result = ltt_trace_set_type(trace_name, trace_type);
1172                 if(result < 0) {
1173                         ERR("ltt_trace_set_type failed");
1174                         return;
1175                 }
1176
1177                 result = ltt_trace_alloc(trace_name);
1178                 if(result < 0) {
1179                         ERR("ltt_trace_alloc failed");
1180                         return;
1181                 }
1182
1183                 result = ltt_trace_start(trace_name);
1184                 if(result < 0) {
1185                         ERR("ltt_trace_start failed");
1186                         return;
1187                 }
1188
1189                 /* Do this after the trace is started in order to avoid creating confusion
1190                  * if the trace fails to start. */
1191                 inform_consumer_daemon(trace_name);
1192         }
1193
1194
1195         return;
1196
1197         /* should decrementally destroy stuff if error */
1198
1199 }
1200
1201 /* This is only called if we terminate normally, not with an unhandled signal,
1202  * so we cannot rely on it. However, for now, LTTV requires that the header of
1203  * the last sub-buffer contain a valid end time for the trace. This is done
1204  * automatically only when the trace is properly stopped.
1205  *
1206  * If the traced program crashed, it is always possible to manually add the
1207  * right value in the header, or to open the trace in text mode.
1208  *
1209  * FIXME: Fix LTTV so it doesn't need this.
1210  */
1211
1212 static void destroy_traces(void)
1213 {
1214         int result;
1215
1216         /* if trace running, finish it */
1217
1218         DBG("destructor stopping traces");
1219
1220         result = ltt_trace_stop("auto");
1221         if(result == -1) {
1222                 ERR("ltt_trace_stop error");
1223         }
1224
1225         result = ltt_trace_destroy("auto");
1226         if(result == -1) {
1227                 ERR("ltt_trace_destroy error");
1228         }
1229 }
1230
1231 static int trace_recording(void)
1232 {
1233         int retval = 0;
1234         struct ust_trace *trace;
1235
1236         ltt_lock_traces();
1237
1238         list_for_each_entry(trace, &ltt_traces.head, list) {
1239                 if(trace->active) {
1240                         retval = 1;
1241                         break;
1242                 }
1243         }
1244
1245         ltt_unlock_traces();
1246
1247         return retval;
1248 }
1249
1250 #if 0
1251 static int have_consumer(void)
1252 {
1253         return !list_empty(&blocked_consumers);
1254 }
1255 #endif
1256
1257 int restarting_usleep(useconds_t usecs)
1258 {
1259         struct timespec tv;
1260         int result;
1261
1262         tv.tv_sec = 0;
1263         tv.tv_nsec = usecs * 1000;
1264
1265         do {
1266                 result = nanosleep(&tv, &tv);
1267         } while(result == -1 && errno == EINTR);
1268
1269         return result;
1270 }
1271
1272 /* This destructor keeps the process alive for a few seconds in order
1273  * to leave time to ustd to connect to its buffers. This is necessary
1274  * for programs whose execution is very short. It is also useful in all
1275  * programs when tracing is started close to the end of the program
1276  * execution.
1277  *
1278  * FIXME: For now, this only works for the first trace created in a
1279  * process.
1280  */
1281
1282 static void __attribute__((destructor)) keepalive()
1283 {
1284         if(trace_recording() && buffers_to_export) {
1285                 int total = 0;
1286                 DBG("Keeping process alive for consumer daemon...");
1287                 while(buffers_to_export) {
1288                         const int interv = 200000;
1289                         restarting_usleep(interv);
1290                         total += interv;
1291
1292                         if(total >= 3000000) {
1293                                 WARN("non-consumed buffers remaining after wait limit; not waiting anymore");
1294                                 break;
1295                         }
1296                 }
1297                 DBG("Finally dying...");
1298         }
1299
1300         destroy_traces();
1301
1302         ustcomm_fini_app(&ustcomm_app);
1303 }
1304
1305 void ust_potential_exec(void)
1306 {
1307         trace_mark(ust, potential_exec, MARK_NOARGS);
1308
1309         DBG("test");
1310
1311         keepalive();
1312 }
1313
1314 /* Notify ust that there was a fork. This needs to be called inside
1315  * the new process, anytime a process whose memory is not shared with
1316  * the parent is created. If this function is not called, the events
1317  * of the new process will not be collected.
1318  *
1319  * Signals should be disabled before the fork and reenabled only after
1320  * this call in order to guarantee tracing is not started before ust_fork()
1321  * sanitizes the new process.
1322  */
1323
1324 static void ust_fork(void)
1325 {
1326         struct blocked_consumer *bc;
1327         struct blocked_consumer *deletable_bc = NULL;
1328         int result;
1329
1330         DBG("ust: forking");
1331         ltt_trace_stop("auto");
1332         ltt_trace_destroy("auto");
1333         /* Delete all active connections */
1334         ustcomm_close_all_connections(&ustcomm_app.server);
1335
1336         /* Delete all blocked consumers */
1337         list_for_each_entry(bc, &blocked_consumers, list) {
1338                 close(bc->fd_producer);
1339                 close(bc->fd_consumer);
1340                 free(deletable_bc);
1341                 deletable_bc = bc;
1342                 list_del(&bc->list);
1343         }
1344
1345         have_listener = 0;
1346         create_listener();
1347         init_socket();
1348         ltt_trace_setup("auto");
1349         result = ltt_trace_set_type("auto", "ustrelay");
1350         if(result < 0) {
1351                 ERR("ltt_trace_set_type failed");
1352                 return;
1353         }
1354
1355         ltt_trace_alloc("auto");
1356         ltt_trace_start("auto");
1357         inform_consumer_daemon("auto");
1358 }
1359
1360 void ust_before_fork(ust_fork_info_t *fork_info)
1361 {
1362         /* Disable signals. This is to avoid that the child
1363          * intervenes before it is properly setup for tracing. It is
1364          * safer to disable all signals, because then we know we are not
1365          * breaking anything by restoring the original mask.
1366          */
1367         sigset_t all_sigs;
1368         int result;
1369
1370         /* FIXME:
1371                 - only do this if tracing is active
1372         */
1373
1374         /* Disable signals */
1375         sigfillset(&all_sigs);
1376         result = sigprocmask(SIG_BLOCK, &all_sigs, &fork_info->orig_sigs);
1377         if(result == -1) {
1378                 PERROR("sigprocmask");
1379                 return;
1380         }
1381 }
1382
1383 /* Don't call this function directly in a traced program */
1384 static void ust_after_fork_common(ust_fork_info_t *fork_info)
1385 {
1386         int result;
1387
1388         /* Restore signals */
1389         result = sigprocmask(SIG_SETMASK, &fork_info->orig_sigs, NULL);
1390         if(result == -1) {
1391                 PERROR("sigprocmask");
1392                 return;
1393         }
1394 }
1395
1396 void ust_after_fork_parent(ust_fork_info_t *fork_info)
1397 {
1398         /* Reenable signals */
1399         ust_after_fork_common(fork_info);
1400 }
1401
1402 void ust_after_fork_child(ust_fork_info_t *fork_info)
1403 {
1404         /* First sanitize the child */
1405         ust_fork();
1406
1407         /* Then reenable interrupts */
1408         ust_after_fork_common(fork_info);
1409 }
1410