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 static char *opt_filter;
  45 #if 0
  46 /* Not implemented yet */
  47 static char *opt_cmd_name;
  48 static pid_t opt_pid;
  49 #endif
  50
  51 enum {
  52         OPT_HELP = 1,
  53         OPT_TRACEPOINT,
  54         OPT_PROBE,
  55         OPT_FUNCTION,
  56         OPT_FUNCTION_ENTRY,
  57         OPT_SYSCALL,
  58         OPT_USERSPACE,
  59         OPT_LOGLEVEL,
  60         OPT_LOGLEVEL_ONLY,
  61         OPT_LIST_OPTIONS,
  62         OPT_FILTER,
  63 };
  64
  65 static struct lttng_handle *handle;
  66
  67 static struct poptOption long_options[] = {
  68         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  69         {"help",           'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  70         {"session",        's', POPT_ARG_STRING, &opt_session_name, 0, 0, 0},
  71         {"all",            'a', POPT_ARG_VAL, &opt_enable_all, 1, 0, 0},
  72         {"channel",        'c', POPT_ARG_STRING, &opt_channel_name, 0, 0, 0},
  73         {"kernel",         'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
  74 #if 0
  75         /* Not implemented yet */
  76         {"userspace",      'u', POPT_ARG_STRING | POPT_ARGFLAG_OPTIONAL, &opt_cmd_name, OPT_USERSPACE, 0, 0},
  77         {"pid",            'p', POPT_ARG_INT, &opt_pid, 0, 0, 0},
  78 #else
  79         {"userspace",      'u', POPT_ARG_NONE, 0, OPT_USERSPACE, 0, 0},
  80 #endif
  81         {"tracepoint",     0,   POPT_ARG_NONE, 0, OPT_TRACEPOINT, 0, 0},
  82         {"probe",          0,   POPT_ARG_STRING, &opt_probe, OPT_PROBE, 0, 0},
  83         {"function",       0,   POPT_ARG_STRING, &opt_function, OPT_FUNCTION, 0, 0},
  84 #if 0
  85         /*
  86          * Currently removed from lttng kernel tracer. Removed from
  87          * lttng UI to discourage its use.
  88          */
  89         {"function:entry", 0,   POPT_ARG_STRING, &opt_function_entry_symbol, OPT_FUNCTION_ENTRY, 0, 0},
  90 #endif
  91         {"syscall",        0,   POPT_ARG_NONE, 0, OPT_SYSCALL, 0, 0},
  92         {"loglevel",       0,     POPT_ARG_STRING, 0, OPT_LOGLEVEL, 0, 0},
  93         {"loglevel-only",  0,     POPT_ARG_STRING, 0, OPT_LOGLEVEL_ONLY, 0, 0},
  94         {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  95         {"filter",         'f', POPT_ARG_STRING, &opt_filter, OPT_FILTER, 0, 0},
  96         {0, 0, 0, 0, 0, 0, 0}
  97 };
  98
  99 /*
 100  * usage
 101  */
 102 static void usage(FILE *ofp)
 103 {
 104         fprintf(ofp, "usage: lttng enable-event NAME[,NAME2,...] [options] [event_options]\n");
 105         fprintf(ofp, "\n");
 106         fprintf(ofp, "  -h, --help               Show this help\n");
 107         fprintf(ofp, "      --list-options       Simple listing of options\n");
 108         fprintf(ofp, "  -s, --session            Apply to session name\n");
 109         fprintf(ofp, "  -c, --channel            Apply to this channel\n");
 110         fprintf(ofp, "  -a, --all                Enable all tracepoints and syscalls\n");
 111         fprintf(ofp, "  -k, --kernel             Apply for the kernel tracer\n");
 112 #if 0
 113         fprintf(ofp, "  -u, --userspace [CMD]    Apply to the user-space tracer\n");
 114         fprintf(ofp, "                           If no CMD, the domain used is UST global\n");
 115         fprintf(ofp, "                           or else the domain is UST EXEC_NAME\n");
 116         fprintf(ofp, "  -p, --pid PID            If -u, apply to specific PID (domain: UST PID)\n");
 117 #else
 118         fprintf(ofp, "  -u, --userspace          Apply to the user-space tracer\n");
 119 #endif
 120         fprintf(ofp, "\n");
 121         fprintf(ofp, "Event options:\n");
 122         fprintf(ofp, "    --tracepoint           Tracepoint event (default)\n");
 123         fprintf(ofp, "                           - userspace tracer supports wildcards at end of string.\n");
 124         fprintf(ofp, "                             Don't forget to quote to deal with bash expansion.\n");
 125         fprintf(ofp, "                             e.g.:\n");
 126         fprintf(ofp, "                               \"*\"\n");
 127         fprintf(ofp, "                               \"app_component:na*\"\n");
 128         fprintf(ofp, "    --probe [addr | symbol | symbol+offset]\n");
 129         fprintf(ofp, "                           Dynamic probe.\n");
 130         fprintf(ofp, "                           Addr and offset can be octal (0NNN...),\n");
 131         fprintf(ofp, "                           decimal (NNN...) or hexadecimal (0xNNN...)\n");
 132         fprintf(ofp, "    --function [addr | symbol | symbol+offset]\n");
 133         fprintf(ofp, "                           Dynamic function entry/return probe.\n");
 134         fprintf(ofp, "                           Addr and offset can be octal (0NNN...),\n");
 135         fprintf(ofp, "                           decimal (NNN...) or hexadecimal (0xNNN...)\n");
 136 #if 0
 137         fprintf(ofp, "    --function:entry symbol\n");
 138         fprintf(ofp, "                           Function tracer event\n");
 139 #endif
 140         fprintf(ofp, "    --syscall              System call event\n");
 141         fprintf(ofp, "\n");
 142         fprintf(ofp, "    --loglevel name\n");
 143         fprintf(ofp, "                           Tracepoint loglevel range from 0 to loglevel\n");
 144         fprintf(ofp, "    --loglevel-only name\n");
 145         fprintf(ofp, "                           Tracepoint loglevel (only this loglevel)\n");
 146         fprintf(ofp, "\n");
 147         fprintf(ofp, "                           The loglevel or loglevel-only options should be\n");
 148         fprintf(ofp, "                           combined with a tracepoint name or tracepoint\n");
 149         fprintf(ofp, "                           wildcard.\n");
 150         fprintf(ofp, "                           Available loglevels:\n");
 151         fprintf(ofp, "                                              (higher value is more verbose)\n");
 152         fprintf(ofp, "                               TRACE_EMERG          = 0\n");
 153         fprintf(ofp, "                               TRACE_ALERT          = 1\n");
 154         fprintf(ofp, "                               TRACE_CRIT           = 2\n");
 155         fprintf(ofp, "                               TRACE_ERR            = 3\n");
 156         fprintf(ofp, "                               TRACE_WARNING        = 4\n");
 157         fprintf(ofp, "                               TRACE_NOTICE         = 5\n");
 158         fprintf(ofp, "                               TRACE_INFO           = 6\n");
 159         fprintf(ofp, "                               TRACE_DEBUG_SYSTEM   = 7\n");
 160         fprintf(ofp, "                               TRACE_DEBUG_PROGRAM  = 8\n");
 161         fprintf(ofp, "                               TRACE_DEBUG_PROCESS  = 9\n");
 162         fprintf(ofp, "                               TRACE_DEBUG_MODULE   = 10\n");
 163         fprintf(ofp, "                               TRACE_DEBUG_UNIT     = 11\n");
 164         fprintf(ofp, "                               TRACE_DEBUG_FUNCTION = 12\n");
 165         fprintf(ofp, "                               TRACE_DEBUG_LINE     = 13\n");
 166         fprintf(ofp, "                               TRACE_DEBUG          = 14\n");
 167         fprintf(ofp, "                               (shortcuts such as \"system\" are allowed)\n");
 168         fprintf(ofp, "    --filter \'expression\'\n");
 169         fprintf(ofp, "                           Filter expression on event fields,\n");
 170         fprintf(ofp, "                           event recording depends on evaluation.\n");
 171         fprintf(ofp, "                           Only specify on first activation of\n");
 172         fprintf(ofp, "                           a given event within a session.\n");
 173         fprintf(ofp, "                           Filter only allowed when enabling\n");
 174         fprintf(ofp, "                           events within a session before tracing\n");
 175         fprintf(ofp, "                           is started.\n");
 176         fprintf(ofp, "\n");
 177 }
 178
 179 /*
 180  * Parse probe options.
 181  */
 182 static int parse_probe_opts(struct lttng_event *ev, char *opt)
 183 {
 184         int ret;
 185         char s_hex[19];
 186         char name[LTTNG_SYMBOL_NAME_LEN];
 187
 188         if (opt == NULL) {
 189                 ret = -1;
 190                 goto end;
 191         }
 192
 193         /* Check for symbol+offset */
 194         ret = sscanf(opt, "%[^'+']+%s", name, s_hex);
 195         if (ret == 2) {
 196                 strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN);
 197                 ev->attr.probe.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 198                 DBG("probe symbol %s", ev->attr.probe.symbol_name);
 199                 if (strlen(s_hex) == 0) {
 200                         ERR("Invalid probe offset %s", s_hex);
 201                         ret = -1;
 202                         goto end;
 203                 }
 204                 ev->attr.probe.offset = strtoul(s_hex, NULL, 0);
 205                 DBG("probe offset %" PRIu64, ev->attr.probe.offset);
 206                 ev->attr.probe.addr = 0;
 207                 goto end;
 208         }
 209
 210         /* Check for symbol */
 211         if (isalpha(name[0])) {
 212                 ret = sscanf(opt, "%s", name);
 213                 if (ret == 1) {
 214                         strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN);
 215                         ev->attr.probe.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 216                         DBG("probe symbol %s", ev->attr.probe.symbol_name);
 217                         ev->attr.probe.offset = 0;
 218                         DBG("probe offset %" PRIu64, ev->attr.probe.offset);
 219                         ev->attr.probe.addr = 0;
 220                         goto end;
 221                 }
 222         }
 223
 224         /* Check for address */
 225         ret = sscanf(opt, "%s", s_hex);
 226         if (ret > 0) {
 227                 if (strlen(s_hex) == 0) {
 228                         ERR("Invalid probe address %s", s_hex);
 229                         ret = -1;
 230                         goto end;
 231                 }
 232                 ev->attr.probe.addr = strtoul(s_hex, NULL, 0);
 233                 DBG("probe addr %" PRIu64, ev->attr.probe.addr);
 234                 ev->attr.probe.offset = 0;
 235                 memset(ev->attr.probe.symbol_name, 0, LTTNG_SYMBOL_NAME_LEN);
 236                 goto end;
 237         }
 238
 239         /* No match */
 240         ret = -1;
 241
 242 end:
 243         return ret;
 244 }
 245
 246 /*
 247  * Maps loglevel from string to value
 248  */
 249 static
 250 int loglevel_str_to_value(const char *inputstr)
 251 {
 252         int i = 0;
 253         char str[LTTNG_SYMBOL_NAME_LEN];
 254
 255         while (inputstr[i] != '\0' && i < LTTNG_SYMBOL_NAME_LEN) {
 256                 str[i] = toupper(inputstr[i]);
 257                 i++;
 258         }
 259         str[i] = '\0';
 260         if (!strcmp(str, "TRACE_EMERG") || !strcmp(str, "EMERG")) {
 261                 return LTTNG_LOGLEVEL_EMERG;
 262         } else if (!strcmp(str, "TRACE_ALERT") || !strcmp(str, "ALERT")) {
 263                 return LTTNG_LOGLEVEL_ALERT;
 264         } else if (!strcmp(str, "TRACE_CRIT") || !strcmp(str, "CRIT")) {
 265                 return LTTNG_LOGLEVEL_CRIT;
 266         } else if (!strcmp(str, "TRACE_ERR") || !strcmp(str, "ERR")) {
 267                 return LTTNG_LOGLEVEL_ERR;
 268         } else if (!strcmp(str, "TRACE_WARNING") || !strcmp(str, "WARNING")) {
 269                 return LTTNG_LOGLEVEL_WARNING;
 270         } else if (!strcmp(str, "TRACE_NOTICE") || !strcmp(str, "NOTICE")) {
 271                 return LTTNG_LOGLEVEL_NOTICE;
 272         } else if (!strcmp(str, "TRACE_INFO") || !strcmp(str, "INFO")) {
 273                 return LTTNG_LOGLEVEL_INFO;
 274         } else if (!strcmp(str, "TRACE_DEBUG_SYSTEM") || !strcmp(str, "DEBUG_SYSTEM") || !strcmp(str, "SYSTEM")) {
 275                 return LTTNG_LOGLEVEL_DEBUG_SYSTEM;
 276         } else if (!strcmp(str, "TRACE_DEBUG_PROGRAM") || !strcmp(str, "DEBUG_PROGRAM") || !strcmp(str, "PROGRAM")) {
 277                 return LTTNG_LOGLEVEL_DEBUG_PROGRAM;
 278         } else if (!strcmp(str, "TRACE_DEBUG_PROCESS") || !strcmp(str, "DEBUG_PROCESS") || !strcmp(str, "PROCESS")) {
 279                 return LTTNG_LOGLEVEL_DEBUG_PROCESS;
 280         } else if (!strcmp(str, "TRACE_DEBUG_MODULE") || !strcmp(str, "DEBUG_MODULE") || !strcmp(str, "MODULE")) {
 281                 return LTTNG_LOGLEVEL_DEBUG_MODULE;
 282         } else if (!strcmp(str, "TRACE_DEBUG_UNIT") || !strcmp(str, "DEBUG_UNIT") || !strcmp(str, "UNIT")) {
 283                 return LTTNG_LOGLEVEL_DEBUG_UNIT;
 284         } else if (!strcmp(str, "TRACE_DEBUG_FUNCTION") || !strcmp(str, "DEBUG_FUNCTION") || !strcmp(str, "FUNCTION")) {
 285                 return LTTNG_LOGLEVEL_DEBUG_FUNCTION;
 286         } else if (!strcmp(str, "TRACE_DEBUG_LINE") || !strcmp(str, "DEBUG_LINE") || !strcmp(str, "LINE")) {
 287                 return LTTNG_LOGLEVEL_DEBUG_LINE;
 288         } else if (!strcmp(str, "TRACE_DEBUG") || !strcmp(str, "DEBUG")) {
 289                 return LTTNG_LOGLEVEL_DEBUG;
 290         } else {
 291                 return -1;
 292         }
 293 }
 294
 295 /*
 296  * Enabling event using the lttng API.
 297  */
 298 static int enable_events(char *session_name)
 299 {
 300         int err, ret = CMD_SUCCESS, warn = 0;
 301         char *event_name, *channel_name = NULL;
 302         struct lttng_event ev;
 303         struct lttng_domain dom;
 304
 305         memset(&ev, 0, sizeof(ev));
 306         memset(&dom, 0, sizeof(dom));
 307
 308         if (opt_kernel) {
 309                 if (opt_filter) {
 310                         ERR("Filter not implement for kernel tracing yet");
 311                         ret = CMD_ERROR;
 312                         goto error;
 313                 }
 314         }
 315
 316         /* Create lttng domain */
 317         if (opt_kernel) {
 318                 dom.type = LTTNG_DOMAIN_KERNEL;
 319         } else if (opt_userspace) {
 320                 dom.type = LTTNG_DOMAIN_UST;
 321         } else {
 322                 ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
 323                 ret = CMD_ERROR;
 324                 goto error;
 325         }
 326
 327         if (opt_channel_name == NULL) {
 328                 err = asprintf(&channel_name, DEFAULT_CHANNEL_NAME);
 329                 if (err < 0) {
 330                         ret = CMD_FATAL;
 331                         goto error;
 332                 }
 333         } else {
 334                 channel_name = opt_channel_name;
 335         }
 336
 337         handle = lttng_create_handle(session_name, &dom);
 338         if (handle == NULL) {
 339                 ret = -1;
 340                 goto error;
 341         }
 342
 343         if (opt_enable_all) {
 344                 /* Default setup for enable all */
 345                 if (opt_kernel) {
 346                         ev.type = opt_event_type;
 347                         ev.name[0] = '\0';
 348                         /* kernel loglevels not implemented */
 349                         ev.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
 350                 } else {
 351                         ev.type = LTTNG_EVENT_TRACEPOINT;
 352                         strcpy(ev.name, "*");
 353                         ev.loglevel_type = opt_loglevel_type;
 354                         if (opt_loglevel) {
 355                                 ev.loglevel = loglevel_str_to_value(opt_loglevel);
 356                                 if (ev.loglevel == -1) {
 357                                         ERR("Unknown loglevel %s", opt_loglevel);
 358                                         ret = -1;
 359                                         goto error;
 360                                 }
 361                         } else {
 362                                 ev.loglevel = -1;
 363                         }
 364                 }
 365
 366                 ret = lttng_enable_event(handle, &ev, channel_name);
 367                 if (ret < 0) {
 368                         switch (-ret) {
 369                         case LTTCOMM_KERN_EVENT_EXIST:
 370                                 WARN("Kernel events already enabled (channel %s, session %s)",
 371                                                 channel_name, session_name);
 372                                 break;
 373                         default:
 374                                 ERR("Events: %s (channel %s, session %s)",
 375                                                 lttng_strerror(ret), channel_name, session_name);
 376                                 break;
 377                         }
 378                         goto end;
 379                 }
 380                 if (opt_filter) {
 381                         ret = lttng_set_event_filter(handle, ev.name, channel_name,
 382                                                 opt_filter);
 383                         if (ret < 0) {
 384                                 ERR("Error setting filter");
 385                                 ret = -1;
 386                                 goto error;
 387                         }
 388                 }
 389
 390                 switch (opt_event_type) {
 391                 case LTTNG_EVENT_TRACEPOINT:
 392                         if (opt_loglevel) {
 393                                 MSG("All %s tracepoints are enabled in channel %s for loglevel %s",
 394                                         opt_kernel ? "kernel" : "UST", channel_name,
 395                                         opt_loglevel);
 396                         } else {
 397                                 MSG("All %s tracepoints are enabled in channel %s",
 398                                         opt_kernel ? "kernel" : "UST", channel_name);
 399
 400                         }
 401                         break;
 402                 case LTTNG_EVENT_SYSCALL:
 403                         if (opt_kernel) {
 404                                 MSG("All kernel system calls are enabled in channel %s",
 405                                                 channel_name);
 406                         }
 407                         break;
 408                 case LTTNG_EVENT_ALL:
 409                         if (opt_loglevel) {
 410                                 MSG("All %s events are enabled in channel %s for loglevel %s",
 411                                         opt_kernel ? "kernel" : "UST", channel_name,
 412                                         opt_loglevel);
 413                         } else {
 414                                 MSG("All %s events are enabled in channel %s",
 415                                         opt_kernel ? "kernel" : "UST", channel_name);
 416                         }
 417                         break;
 418                 default:
 419                         /*
 420                          * We should not be here since lttng_enable_event should have
 421                          * failed on the event type.
 422                          */
 423                         goto error;
 424                 }
 425                 goto end;
 426         }
 427
 428         /* Strip event list */
 429         event_name = strtok(opt_event_list, ",");
 430         while (event_name != NULL) {
 431                 /* Copy name and type of the event */
 432                 strncpy(ev.name, event_name, LTTNG_SYMBOL_NAME_LEN);
 433                 ev.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 434                 ev.type = opt_event_type;
 435
 436                 /* Kernel tracer action */
 437                 if (opt_kernel) {
 438                         DBG("Enabling kernel event %s for channel %s",
 439                                         event_name, channel_name);
 440
 441                         switch (opt_event_type) {
 442                         case LTTNG_EVENT_ALL:   /* Default behavior is tracepoint */
 443                                 ev.type = LTTNG_EVENT_TRACEPOINT;
 444                                 /* Fall-through */
 445                         case LTTNG_EVENT_TRACEPOINT:
 446                                 break;
 447                         case LTTNG_EVENT_PROBE:
 448                                 ret = parse_probe_opts(&ev, opt_probe);
 449                                 if (ret < 0) {
 450                                         ERR("Unable to parse probe options");
 451                                         ret = 0;
 452                                         goto error;
 453                                 }
 454                                 break;
 455                         case LTTNG_EVENT_FUNCTION:
 456                                 ret = parse_probe_opts(&ev, opt_function);
 457                                 if (ret < 0) {
 458                                         ERR("Unable to parse function probe options");
 459                                         ret = 0;
 460                                         goto error;
 461                                 }
 462                                 break;
 463                         case LTTNG_EVENT_FUNCTION_ENTRY:
 464                                 strncpy(ev.attr.ftrace.symbol_name, opt_function_entry_symbol,
 465                                                 LTTNG_SYMBOL_NAME_LEN);
 466                                 ev.attr.ftrace.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 467                                 break;
 468                         case LTTNG_EVENT_SYSCALL:
 469                                 MSG("per-syscall selection not supported yet. Use \"-a\" "
 470                                                 "for all syscalls.");
 471                         default:
 472                                 ret = CMD_UNDEFINED;
 473                                 goto error;
 474                         }
 475
 476                         if (opt_loglevel) {
 477                                 MSG("Kernel loglevels are not supported.");
 478                                 ret = CMD_UNDEFINED;
 479                                 goto error;
 480                         }
 481
 482                         /* kernel loglevels not implemented */
 483                         ev.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
 484                 } else if (opt_userspace) {             /* User-space tracer action */
 485 #if 0
 486                         if (opt_cmd_name != NULL || opt_pid) {
 487                                 MSG("Only supporting tracing all UST processes (-u) for now.");
 488                                 ret = CMD_UNDEFINED;
 489                                 goto error;
 490                         }
 491 #endif
 492
 493                         DBG("Enabling UST event %s for channel %s, loglevel %s", event_name,
 494                                         channel_name, opt_loglevel ? : "<all>");
 495
 496                         switch (opt_event_type) {
 497                         case LTTNG_EVENT_ALL:   /* Default behavior is tracepoint */
 498                                 /* Fall-through */
 499                         case LTTNG_EVENT_TRACEPOINT:
 500                                 /* Copy name and type of the event */
 501                                 ev.type = LTTNG_EVENT_TRACEPOINT;
 502                                 strncpy(ev.name, event_name, LTTNG_SYMBOL_NAME_LEN);
 503                                 ev.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 504                                 break;
 505                         case LTTNG_EVENT_PROBE:
 506                         case LTTNG_EVENT_FUNCTION:
 507                         case LTTNG_EVENT_FUNCTION_ENTRY:
 508                         case LTTNG_EVENT_SYSCALL:
 509                         default:
 510                                 ERR("Event type not available for user-space tracing");
 511                                 ret = CMD_UNDEFINED;
 512                                 goto error;
 513                         }
 514
 515                         ev.loglevel_type = opt_loglevel_type;
 516                         if (opt_loglevel) {
 517                                 ev.loglevel = loglevel_str_to_value(opt_loglevel);
 518                                 if (ev.loglevel == -1) {
 519                                         ERR("Unknown loglevel %s", opt_loglevel);
 520                                         ret = -1;
 521                                         goto error;
 522                                 }
 523                         } else {
 524                                 ev.loglevel = -1;
 525                         }
 526                 } else {
 527                         ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
 528                         ret = CMD_ERROR;
 529                         goto error;
 530                 }
 531
 532                 ret = lttng_enable_event(handle, &ev, channel_name);
 533                 if (ret < 0) {
 534                         /* Turn ret to positive value to handle the positive error code */
 535                         switch (-ret) {
 536                         case LTTCOMM_KERN_EVENT_EXIST:
 537                                 WARN("Kernel event %s already enabled (channel %s, session %s)",
 538                                                 event_name, channel_name, session_name);
 539                                 break;
 540                         default:
 541                                 ERR("Event %s: %s (channel %s, session %s)", event_name,
 542                                                 lttng_strerror(ret), channel_name, session_name);
 543                                 break;
 544                         }
 545                         warn = 1;
 546                 } else {
 547                         MSG("%s event %s created in channel %s",
 548                                         opt_kernel ? "kernel": "UST", event_name, channel_name);
 549                 }
 550                 if (opt_filter) {
 551                         ret = lttng_set_event_filter(handle, ev.name,
 552                                 channel_name, opt_filter);
 553                         if (ret < 0) {
 554                                 ERR("Error setting filter");
 555                                 ret = -1;
 556                                 goto error;
 557                         }
 558                 }
 559
 560                 /* Next event */
 561                 event_name = strtok(NULL, ",");
 562         }
 563
 564 end:
 565 error:
 566         if (warn) {
 567                 ret = CMD_WARNING;
 568         }
 569         if (opt_channel_name == NULL) {
 570                 free(channel_name);
 571         }
 572         lttng_destroy_handle(handle);
 573
 574         return ret;
 575 }
 576
 577 /*
 578  * Add event to trace session
 579  */
 580 int cmd_enable_events(int argc, const char **argv)
 581 {
 582         int opt, ret = CMD_SUCCESS;
 583         static poptContext pc;
 584         char *session_name = NULL;
 585
 586         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 587         poptReadDefaultConfig(pc, 0);
 588
 589         /* Default event type */
 590         opt_event_type = LTTNG_EVENT_ALL;
 591
 592         while ((opt = poptGetNextOpt(pc)) != -1) {
 593                 switch (opt) {
 594                 case OPT_HELP:
 595                         usage(stdout);
 596                         goto end;
 597                 case OPT_TRACEPOINT:
 598                         opt_event_type = LTTNG_EVENT_TRACEPOINT;
 599                         break;
 600                 case OPT_PROBE:
 601                         opt_event_type = LTTNG_EVENT_PROBE;
 602                         break;
 603                 case OPT_FUNCTION:
 604                         opt_event_type = LTTNG_EVENT_FUNCTION;
 605                         break;
 606                 case OPT_FUNCTION_ENTRY:
 607                         opt_event_type = LTTNG_EVENT_FUNCTION_ENTRY;
 608                         break;
 609                 case OPT_SYSCALL:
 610                         opt_event_type = LTTNG_EVENT_SYSCALL;
 611                         break;
 612                 case OPT_USERSPACE:
 613                         opt_userspace = 1;
 614                         break;
 615                 case OPT_LOGLEVEL:
 616                         opt_loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
 617                         opt_loglevel = poptGetOptArg(pc);
 618                         break;
 619                 case OPT_LOGLEVEL_ONLY:
 620                         opt_loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
 621                         opt_loglevel = poptGetOptArg(pc);
 622                         break;
 623                 case OPT_LIST_OPTIONS:
 624                         list_cmd_options(stdout, long_options);
 625                         goto end;
 626                 case OPT_FILTER:
 627                         break;
 628                 default:
 629                         usage(stderr);
 630                         ret = CMD_UNDEFINED;
 631                         goto end;
 632                 }
 633         }
 634
 635         opt_event_list = (char*) poptGetArg(pc);
 636         if (opt_event_list == NULL && opt_enable_all == 0) {
 637                 ERR("Missing event name(s).\n");
 638                 usage(stderr);
 639                 ret = CMD_ERROR;
 640                 goto end;
 641         }
 642
 643         if (!opt_session_name) {
 644                 session_name = get_session_name();
 645                 if (session_name == NULL) {
 646                         ret = CMD_ERROR;
 647                         goto end;
 648                 }
 649         } else {
 650                 session_name = opt_session_name;
 651         }
 652
 653         ret = enable_events(session_name);
 654
 655 end:
 656         if (opt_session_name == NULL) {
 657                 free(session_name);
 658         }
 659
 660         poptFreeContext(pc);
 661         return ret;
 662 }