src/bin/lttng/commands/enable_events.c

   1 /*
   2  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License, version 2 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program 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
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <popt.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <sys/stat.h>
  24 #include <sys/types.h>
  25 #include <unistd.h>
  26 #include <inttypes.h>
  27 #include <ctype.h>
  28
  29 #include "../command.h"
  30 #include <src/common/sessiond-comm/sessiond-comm.h>
  31
  32 static char *opt_event_list;
  33 static int opt_event_type;
  34 static const char *opt_loglevel;
  35 static int opt_loglevel_type;
  36 static int opt_kernel;
  37 static char *opt_session_name;
  38 static int opt_userspace;
  39 static int opt_enable_all;
  40 static char *opt_probe;
  41 static char *opt_function;
  42 static char *opt_function_entry_symbol;
  43 static char *opt_channel_name;
  44 #if 0
  45 /* Not implemented yet */
  46 static char *opt_cmd_name;
  47 static pid_t opt_pid;
  48 #endif
  49
  50 enum {
  51         OPT_HELP = 1,
  52         OPT_TRACEPOINT,
  53         OPT_PROBE,
  54         OPT_FUNCTION,
  55         OPT_FUNCTION_ENTRY,
  56         OPT_SYSCALL,
  57         OPT_USERSPACE,
  58         OPT_LOGLEVEL,
  59         OPT_LOGLEVEL_ONLY,
  60         OPT_LIST_OPTIONS,
  61 };
  62
  63 static struct lttng_handle *handle;
  64
  65 static struct poptOption long_options[] = {
  66         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  67         {"help",           'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  68         {"session",        's', POPT_ARG_STRING, &opt_session_name, 0, 0, 0},
  69         {"all",            'a', POPT_ARG_VAL, &opt_enable_all, 1, 0, 0},
  70         {"channel",        'c', POPT_ARG_STRING, &opt_channel_name, 0, 0, 0},
  71         {"kernel",         'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
  72 #if 0
  73         /* Not implemented yet */
  74         {"userspace",      'u', POPT_ARG_STRING | POPT_ARGFLAG_OPTIONAL, &opt_cmd_name, OPT_USERSPACE, 0, 0},
  75         {"pid",            'p', POPT_ARG_INT, &opt_pid, 0, 0, 0},
  76 #else
  77         {"userspace",      'u', POPT_ARG_NONE, 0, OPT_USERSPACE, 0, 0},
  78 #endif
  79         {"tracepoint",     0,   POPT_ARG_NONE, 0, OPT_TRACEPOINT, 0, 0},
  80         {"probe",          0,   POPT_ARG_STRING, &opt_probe, OPT_PROBE, 0, 0},
  81         {"function",       0,   POPT_ARG_STRING, &opt_function, OPT_FUNCTION, 0, 0},
  82 #if 0
  83         /*
  84          * Currently removed from lttng kernel tracer. Removed from
  85          * lttng UI to discourage its use.
  86          */
  87         {"function:entry", 0,   POPT_ARG_STRING, &opt_function_entry_symbol, OPT_FUNCTION_ENTRY, 0, 0},
  88 #endif
  89         {"syscall",        0,   POPT_ARG_NONE, 0, OPT_SYSCALL, 0, 0},
  90         {"loglevel",       0,     POPT_ARG_STRING, 0, OPT_LOGLEVEL, 0, 0},
  91         {"loglevel-only",  0,     POPT_ARG_STRING, 0, OPT_LOGLEVEL_ONLY, 0, 0},
  92         {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  93         {0, 0, 0, 0, 0, 0, 0}
  94 };
  95
  96 /*
  97  * usage
  98  */
  99 static void usage(FILE *ofp)
 100 {
 101         fprintf(ofp, "usage: lttng enable-event NAME[,NAME2,...] [options] [event_options]\n");
 102         fprintf(ofp, "\n");
 103         fprintf(ofp, "  -h, --help               Show this help\n");
 104         fprintf(ofp, "      --list-options       Simple listing of options\n");
 105         fprintf(ofp, "  -s, --session            Apply to session name\n");
 106         fprintf(ofp, "  -c, --channel            Apply to this channel\n");
 107         fprintf(ofp, "  -a, --all                Enable all tracepoints and syscalls\n");
 108         fprintf(ofp, "  -k, --kernel             Apply for the kernel tracer\n");
 109 #if 0
 110         fprintf(ofp, "  -u, --userspace [CMD]    Apply to the user-space tracer\n");
 111         fprintf(ofp, "                           If no CMD, the domain used is UST global\n");
 112         fprintf(ofp, "                           or else the domain is UST EXEC_NAME\n");
 113         fprintf(ofp, "  -p, --pid PID            If -u, apply to specific PID (domain: UST PID)\n");
 114 #else
 115         fprintf(ofp, "  -u, --userspace          Apply to the user-space tracer\n");
 116 #endif
 117         fprintf(ofp, "\n");
 118         fprintf(ofp, "Event options:\n");
 119         fprintf(ofp, "    --tracepoint           Tracepoint event (default)\n");
 120         fprintf(ofp, "                           - userspace tracer supports wildcards at end of string.\n");
 121         fprintf(ofp, "                             Don't forget to quote to deal with bash expansion.\n");
 122         fprintf(ofp, "                             e.g.:\n");
 123         fprintf(ofp, "                               \"*\"\n");
 124         fprintf(ofp, "                               \"app_component:na*\"\n");
 125         fprintf(ofp, "    --probe [addr | symbol | symbol+offset]\n");
 126         fprintf(ofp, "                           Dynamic probe.\n");
 127         fprintf(ofp, "                           Addr and offset can be octal (0NNN...),\n");
 128         fprintf(ofp, "                           decimal (NNN...) or hexadecimal (0xNNN...)\n");
 129         fprintf(ofp, "    --function [addr | symbol | symbol+offset]\n");
 130         fprintf(ofp, "                           Dynamic function entry/return probe.\n");
 131         fprintf(ofp, "                           Addr and offset can be octal (0NNN...),\n");
 132         fprintf(ofp, "                           decimal (NNN...) or hexadecimal (0xNNN...)\n");
 133 #if 0
 134         fprintf(ofp, "    --function:entry symbol\n");
 135         fprintf(ofp, "                           Function tracer event\n");
 136 #endif
 137         fprintf(ofp, "    --syscall              System call event\n");
 138         fprintf(ofp, "\n");
 139         fprintf(ofp, "    --loglevel name\n");
 140         fprintf(ofp, "                           Tracepoint loglevel range from 0 to loglevel\n");
 141         fprintf(ofp, "    --loglevel-only name\n");
 142         fprintf(ofp, "                           Tracepoint loglevel (only this loglevel)\n");
 143         fprintf(ofp, "\n");
 144         fprintf(ofp, "                           The loglevel or loglevel-only options should be\n");
 145         fprintf(ofp, "                           combined with a tracepoint name or tracepoint\n");
 146         fprintf(ofp, "                           wildcard.\n");
 147         fprintf(ofp, "                           Available loglevels:\n");
 148         fprintf(ofp, "                                              (higher value is more verbose)\n");
 149         fprintf(ofp, "                               TRACE_EMERG          = 0\n");
 150         fprintf(ofp, "                               TRACE_ALERT          = 1\n");
 151         fprintf(ofp, "                               TRACE_CRIT           = 2\n");
 152         fprintf(ofp, "                               TRACE_ERR            = 3\n");
 153         fprintf(ofp, "                               TRACE_WARNING        = 4\n");
 154         fprintf(ofp, "                               TRACE_NOTICE         = 5\n");
 155         fprintf(ofp, "                               TRACE_INFO           = 6\n");
 156         fprintf(ofp, "                               TRACE_DEBUG_SYSTEM   = 7\n");
 157         fprintf(ofp, "                               TRACE_DEBUG_PROGRAM  = 8\n");
 158         fprintf(ofp, "                               TRACE_DEBUG_PROCESS  = 9\n");
 159         fprintf(ofp, "                               TRACE_DEBUG_MODULE   = 10\n");
 160         fprintf(ofp, "                               TRACE_DEBUG_UNIT     = 11\n");
 161         fprintf(ofp, "                               TRACE_DEBUG_FUNCTION = 12\n");
 162         fprintf(ofp, "                               TRACE_DEBUG_LINE     = 13\n");
 163         fprintf(ofp, "                               TRACE_DEBUG          = 14\n");
 164         fprintf(ofp, "                               (shortcuts such as \"system\" are allowed)\n");
 165         fprintf(ofp, "\n");
 166 }
 167
 168 /*
 169  * Parse probe options.
 170  */
 171 static int parse_probe_opts(struct lttng_event *ev, char *opt)
 172 {
 173         int ret;
 174         char s_hex[19];
 175         char name[LTTNG_SYMBOL_NAME_LEN];
 176
 177         if (opt == NULL) {
 178                 ret = -1;
 179                 goto end;
 180         }
 181
 182         /* Check for symbol+offset */
 183         ret = sscanf(opt, "%[^'+']+%s", name, s_hex);
 184         if (ret == 2) {
 185                 strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN);
 186                 ev->attr.probe.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 187                 DBG("probe symbol %s", ev->attr.probe.symbol_name);
 188                 if (strlen(s_hex) == 0) {
 189                         ERR("Invalid probe offset %s", s_hex);
 190                         ret = -1;
 191                         goto end;
 192                 }
 193                 ev->attr.probe.offset = strtoul(s_hex, NULL, 0);
 194                 DBG("probe offset %" PRIu64, ev->attr.probe.offset);
 195                 ev->attr.probe.addr = 0;
 196                 goto end;
 197         }
 198
 199         /* Check for symbol */
 200         if (isalpha(name[0])) {
 201                 ret = sscanf(opt, "%s", name);
 202                 if (ret == 1) {
 203                         strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN);
 204                         ev->attr.probe.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 205                         DBG("probe symbol %s", ev->attr.probe.symbol_name);
 206                         ev->attr.probe.offset = 0;
 207                         DBG("probe offset %" PRIu64, ev->attr.probe.offset);
 208                         ev->attr.probe.addr = 0;
 209                         goto end;
 210                 }
 211         }
 212
 213         /* Check for address */
 214         ret = sscanf(opt, "%s", s_hex);
 215         if (ret > 0) {
 216                 if (strlen(s_hex) == 0) {
 217                         ERR("Invalid probe address %s", s_hex);
 218                         ret = -1;
 219                         goto end;
 220                 }
 221                 ev->attr.probe.addr = strtoul(s_hex, NULL, 0);
 222                 DBG("probe addr %" PRIu64, ev->attr.probe.addr);
 223                 ev->attr.probe.offset = 0;
 224                 memset(ev->attr.probe.symbol_name, 0, LTTNG_SYMBOL_NAME_LEN);
 225                 goto end;
 226         }
 227
 228         /* No match */
 229         ret = -1;
 230
 231 end:
 232         return ret;
 233 }
 234
 235 /*
 236  * Maps loglevel from string to value
 237  */
 238 static
 239 int loglevel_str_to_value(const char *inputstr)
 240 {
 241         int i = 0;
 242         char str[LTTNG_SYMBOL_NAME_LEN];
 243
 244         while (inputstr[i] != '\0' && i < LTTNG_SYMBOL_NAME_LEN) {
 245                 str[i] = toupper(inputstr[i]);
 246                 i++;
 247         }
 248         str[i] = '\0';
 249         if (!strcmp(str, "TRACE_EMERG") || !strcmp(str, "EMERG")) {
 250                 return LTTNG_LOGLEVEL_EMERG;
 251         } else if (!strcmp(str, "TRACE_ALERT") || !strcmp(str, "ALERT")) {
 252                 return LTTNG_LOGLEVEL_ALERT;
 253         } else if (!strcmp(str, "TRACE_CRIT") || !strcmp(str, "CRIT")) {
 254                 return LTTNG_LOGLEVEL_CRIT;
 255         } else if (!strcmp(str, "TRACE_ERR") || !strcmp(str, "ERR")) {
 256                 return LTTNG_LOGLEVEL_ERR;
 257         } else if (!strcmp(str, "TRACE_WARNING") || !strcmp(str, "WARNING")) {
 258                 return LTTNG_LOGLEVEL_WARNING;
 259         } else if (!strcmp(str, "TRACE_NOTICE") || !strcmp(str, "NOTICE")) {
 260                 return LTTNG_LOGLEVEL_NOTICE;
 261         } else if (!strcmp(str, "TRACE_INFO") || !strcmp(str, "INFO")) {
 262                 return LTTNG_LOGLEVEL_INFO;
 263         } else if (!strcmp(str, "TRACE_DEBUG_SYSTEM") || !strcmp(str, "DEBUG_SYSTEM") || !strcmp(str, "SYSTEM")) {
 264                 return LTTNG_LOGLEVEL_DEBUG_SYSTEM;
 265         } else if (!strcmp(str, "TRACE_DEBUG_PROGRAM") || !strcmp(str, "DEBUG_PROGRAM") || !strcmp(str, "PROGRAM")) {
 266                 return LTTNG_LOGLEVEL_DEBUG_PROGRAM;
 267         } else if (!strcmp(str, "TRACE_DEBUG_PROCESS") || !strcmp(str, "DEBUG_PROCESS") || !strcmp(str, "PROCESS")) {
 268                 return LTTNG_LOGLEVEL_DEBUG_PROCESS;
 269         } else if (!strcmp(str, "TRACE_DEBUG_MODULE") || !strcmp(str, "DEBUG_MODULE") || !strcmp(str, "MODULE")) {
 270                 return LTTNG_LOGLEVEL_DEBUG_MODULE;
 271         } else if (!strcmp(str, "TRACE_DEBUG_UNIT") || !strcmp(str, "DEBUG_UNIT") || !strcmp(str, "UNIT")) {
 272                 return LTTNG_LOGLEVEL_DEBUG_UNIT;
 273         } else if (!strcmp(str, "TRACE_DEBUG_FUNCTION") || !strcmp(str, "DEBUG_FUNCTION") || !strcmp(str, "FUNCTION")) {
 274                 return LTTNG_LOGLEVEL_DEBUG_FUNCTION;
 275         } else if (!strcmp(str, "TRACE_DEBUG_LINE") || !strcmp(str, "DEBUG_LINE") || !strcmp(str, "LINE")) {
 276                 return LTTNG_LOGLEVEL_DEBUG_LINE;
 277         } else if (!strcmp(str, "TRACE_DEBUG") || !strcmp(str, "DEBUG")) {
 278                 return LTTNG_LOGLEVEL_DEBUG;
 279         } else {
 280                 return -1;
 281         }
 282 }
 283
 284 /*
 285  * Enabling event using the lttng API.
 286  */
 287 static int enable_events(char *session_name)
 288 {
 289         int err, ret = CMD_SUCCESS, warn = 0;
 290         char *event_name, *channel_name = NULL;
 291         struct lttng_event ev;
 292         struct lttng_domain dom;
 293
 294         memset(&ev, 0, sizeof(ev));
 295         memset(&dom, 0, sizeof(dom));
 296
 297         /* Create lttng domain */
 298         if (opt_kernel) {
 299                 dom.type = LTTNG_DOMAIN_KERNEL;
 300         } else if (opt_userspace) {
 301                 dom.type = LTTNG_DOMAIN_UST;
 302         } else {
 303                 ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
 304                 ret = CMD_ERROR;
 305                 goto error;
 306         }
 307
 308         if (opt_channel_name == NULL) {
 309                 err = asprintf(&channel_name, DEFAULT_CHANNEL_NAME);
 310                 if (err < 0) {
 311                         ret = CMD_FATAL;
 312                         goto error;
 313                 }
 314         } else {
 315                 channel_name = opt_channel_name;
 316         }
 317
 318         handle = lttng_create_handle(session_name, &dom);
 319         if (handle == NULL) {
 320                 ret = -1;
 321                 goto error;
 322         }
 323
 324         if (opt_enable_all) {
 325                 /* Default setup for enable all */
 326                 if (opt_kernel) {
 327                         ev.type = opt_event_type;
 328                         ev.name[0] = '\0';
 329                         /* kernel loglevels not implemented */
 330                         ev.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
 331                 } else {
 332                         ev.type = LTTNG_EVENT_TRACEPOINT;
 333                         strcpy(ev.name, "*");
 334                         ev.loglevel_type = opt_loglevel_type;
 335                         if (opt_loglevel) {
 336                                 ev.loglevel = loglevel_str_to_value(opt_loglevel);
 337                                 if (ev.loglevel == -1) {
 338                                         ERR("Unknown loglevel %s", opt_loglevel);
 339                                         ret = -1;
 340                                         goto error;
 341                                 }
 342                         } else {
 343                                 ev.loglevel = -1;
 344                         }
 345                 }
 346
 347                 ret = lttng_enable_event(handle, &ev, channel_name);
 348                 if (ret < 0) {
 349                         switch (-ret) {
 350                         case LTTCOMM_KERN_EVENT_EXIST:
 351                                 WARN("Kernel events already enabled (channel %s, session %s)",
 352                                                 channel_name, session_name);
 353                                 break;
 354                         default:
 355                                 ERR("Events: %s (channel %s, session %s)",
 356                                                 lttng_strerror(ret), channel_name, session_name);
 357                                 break;
 358                         }
 359                         goto end;
 360                 }
 361
 362                 switch (opt_event_type) {
 363                 case LTTNG_EVENT_TRACEPOINT:
 364                         if (opt_loglevel) {
 365                                 MSG("All %s tracepoints are enabled in channel %s for loglevel %s",
 366                                         opt_kernel ? "kernel" : "UST", channel_name,
 367                                         opt_loglevel);
 368                         } else {
 369                                 MSG("All %s tracepoints are enabled in channel %s",
 370                                         opt_kernel ? "kernel" : "UST", channel_name);
 371
 372                         }
 373                         break;
 374                 case LTTNG_EVENT_SYSCALL:
 375                         if (opt_kernel) {
 376                                 MSG("All kernel system calls are enabled in channel %s",
 377                                                 channel_name);
 378                         }
 379                         break;
 380                 case LTTNG_EVENT_ALL:
 381                         if (opt_loglevel) {
 382                                 MSG("All %s events are enabled in channel %s for loglevel %s",
 383                                         opt_kernel ? "kernel" : "UST", channel_name,
 384                                         opt_loglevel);
 385                         } else {
 386                                 MSG("All %s events are enabled in channel %s",
 387                                         opt_kernel ? "kernel" : "UST", channel_name);
 388                         }
 389                         break;
 390                 default:
 391                         /*
 392                          * We should not be here since lttng_enable_event should have
 393                          * failed on the event type.
 394                          */
 395                         goto error;
 396                 }
 397                 goto end;
 398         }
 399
 400         /* Strip event list */
 401         event_name = strtok(opt_event_list, ",");
 402         while (event_name != NULL) {
 403                 /* Copy name and type of the event */
 404                 strncpy(ev.name, event_name, LTTNG_SYMBOL_NAME_LEN);
 405                 ev.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 406                 ev.type = opt_event_type;
 407
 408                 /* Kernel tracer action */
 409                 if (opt_kernel) {
 410                         DBG("Enabling kernel event %s for channel %s",
 411                                         event_name, channel_name);
 412
 413                         switch (opt_event_type) {
 414                         case LTTNG_EVENT_ALL:   /* Default behavior is tracepoint */
 415                                 ev.type = LTTNG_EVENT_TRACEPOINT;
 416                                 /* Fall-through */
 417                         case LTTNG_EVENT_TRACEPOINT:
 418                                 break;
 419                         case LTTNG_EVENT_PROBE:
 420                                 ret = parse_probe_opts(&ev, opt_probe);
 421                                 if (ret < 0) {
 422                                         ERR("Unable to parse probe options");
 423                                         ret = 0;
 424                                         goto error;
 425                                 }
 426                                 break;
 427                         case LTTNG_EVENT_FUNCTION:
 428                                 ret = parse_probe_opts(&ev, opt_function);
 429                                 if (ret < 0) {
 430                                         ERR("Unable to parse function probe options");
 431                                         ret = 0;
 432                                         goto error;
 433                                 }
 434                                 break;
 435                         case LTTNG_EVENT_FUNCTION_ENTRY:
 436                                 strncpy(ev.attr.ftrace.symbol_name, opt_function_entry_symbol,
 437                                                 LTTNG_SYMBOL_NAME_LEN);
 438                                 ev.attr.ftrace.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 439                                 break;
 440                         case LTTNG_EVENT_SYSCALL:
 441                                 MSG("per-syscall selection not supported yet. Use \"-a\" "
 442                                                 "for all syscalls.");
 443                         default:
 444                                 ret = CMD_UNDEFINED;
 445                                 goto error;
 446                         }
 447
 448                         if (opt_loglevel) {
 449                                 MSG("Kernel loglevels are not supported.");
 450                                 ret = CMD_UNDEFINED;
 451                                 goto error;
 452                         }
 453
 454                         /* kernel loglevels not implemented */
 455                         ev.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
 456                 } else if (opt_userspace) {             /* User-space tracer action */
 457 #if 0
 458                         if (opt_cmd_name != NULL || opt_pid) {
 459                                 MSG("Only supporting tracing all UST processes (-u) for now.");
 460                                 ret = CMD_UNDEFINED;
 461                                 goto error;
 462                         }
 463 #endif
 464
 465                         DBG("Enabling UST event %s for channel %s, loglevel %s", event_name,
 466                                         channel_name, opt_loglevel ? : "<all>");
 467
 468                         switch (opt_event_type) {
 469                         case LTTNG_EVENT_ALL:   /* Default behavior is tracepoint */
 470                                 /* Fall-through */
 471                         case LTTNG_EVENT_TRACEPOINT:
 472                                 /* Copy name and type of the event */
 473                                 ev.type = LTTNG_EVENT_TRACEPOINT;
 474                                 strncpy(ev.name, event_name, LTTNG_SYMBOL_NAME_LEN);
 475                                 ev.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 476                                 break;
 477                         case LTTNG_EVENT_PROBE:
 478                         case LTTNG_EVENT_FUNCTION:
 479                         case LTTNG_EVENT_FUNCTION_ENTRY:
 480                         case LTTNG_EVENT_SYSCALL:
 481                         default:
 482                                 ERR("Event type not available for user-space tracing");
 483                                 ret = CMD_UNDEFINED;
 484                                 goto error;
 485                         }
 486
 487                         ev.loglevel_type = opt_loglevel_type;
 488                         if (opt_loglevel) {
 489                                 ev.loglevel = loglevel_str_to_value(opt_loglevel);
 490                                 if (ev.loglevel == -1) {
 491                                         ERR("Unknown loglevel %s", opt_loglevel);
 492                                         ret = -1;
 493                                         goto error;
 494                                 }
 495                         } else {
 496                                 ev.loglevel = -1;
 497                         }
 498                 } else {
 499                         ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
 500                         ret = CMD_ERROR;
 501                         goto error;
 502                 }
 503
 504                 ret = lttng_enable_event(handle, &ev, channel_name);
 505                 if (ret < 0) {
 506                         /* Turn ret to positive value to handle the positive error code */
 507                         switch (-ret) {
 508                         case LTTCOMM_KERN_EVENT_EXIST:
 509                                 WARN("Kernel event %s already enabled (channel %s, session %s)",
 510                                                 event_name, channel_name, session_name);
 511                                 break;
 512                         default:
 513                                 ERR("Event %s: %s (channel %s, session %s)", event_name,
 514                                                 lttng_strerror(ret), channel_name, session_name);
 515                                 break;
 516                         }
 517                         warn = 1;
 518                 } else {
 519                         MSG("%s event %s created in channel %s",
 520                                         opt_kernel ? "kernel": "UST", event_name, channel_name);
 521                 }
 522
 523                 /* Next event */
 524                 event_name = strtok(NULL, ",");
 525         }
 526
 527 end:
 528 error:
 529         if (warn) {
 530                 ret = CMD_WARNING;
 531         }
 532         if (opt_channel_name == NULL) {
 533                 free(channel_name);
 534         }
 535         lttng_destroy_handle(handle);
 536
 537         return ret;
 538 }
 539
 540 /*
 541  * Add event to trace session
 542  */
 543 int cmd_enable_events(int argc, const char **argv)
 544 {
 545         int opt, ret = CMD_SUCCESS;
 546         static poptContext pc;
 547         char *session_name = NULL;
 548
 549         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 550         poptReadDefaultConfig(pc, 0);
 551
 552         /* Default event type */
 553         opt_event_type = LTTNG_EVENT_ALL;
 554
 555         while ((opt = poptGetNextOpt(pc)) != -1) {
 556                 switch (opt) {
 557                 case OPT_HELP:
 558                         usage(stdout);
 559                         goto end;
 560                 case OPT_TRACEPOINT:
 561                         opt_event_type = LTTNG_EVENT_TRACEPOINT;
 562                         break;
 563                 case OPT_PROBE:
 564                         opt_event_type = LTTNG_EVENT_PROBE;
 565                         break;
 566                 case OPT_FUNCTION:
 567                         opt_event_type = LTTNG_EVENT_FUNCTION;
 568                         break;
 569                 case OPT_FUNCTION_ENTRY:
 570                         opt_event_type = LTTNG_EVENT_FUNCTION_ENTRY;
 571                         break;
 572                 case OPT_SYSCALL:
 573                         opt_event_type = LTTNG_EVENT_SYSCALL;
 574                         break;
 575                 case OPT_USERSPACE:
 576                         opt_userspace = 1;
 577                         break;
 578                 case OPT_LOGLEVEL:
 579                         opt_loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
 580                         opt_loglevel = poptGetOptArg(pc);
 581                         break;
 582                 case OPT_LOGLEVEL_ONLY:
 583                         opt_loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
 584                         opt_loglevel = poptGetOptArg(pc);
 585                         break;
 586                 case OPT_LIST_OPTIONS:
 587                         list_cmd_options(stdout, long_options);
 588                         goto end;
 589                 default:
 590                         usage(stderr);
 591                         ret = CMD_UNDEFINED;
 592                         goto end;
 593                 }
 594         }
 595
 596         opt_event_list = (char*) poptGetArg(pc);
 597         if (opt_event_list == NULL && opt_enable_all == 0) {
 598                 ERR("Missing event name(s).\n");
 599                 usage(stderr);
 600                 ret = CMD_ERROR;
 601                 goto end;
 602         }
 603
 604         if (!opt_session_name) {
 605                 session_name = get_session_name();
 606                 if (session_name == NULL) {
 607                         ret = CMD_ERROR;
 608                         goto end;
 609                 }
 610         } else {
 611                 session_name = opt_session_name;
 612         }
 613
 614         ret = enable_events(session_name);
 615
 616 end:
 617         if (opt_session_name == NULL) {
 618                 free(session_name);
 619         }
 620
 621         poptFreeContext(pc);
 622         return ret;
 623 }