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. If the filter fails to link\n");
 176         fprintf(ofp, "                           with the event within the traced domain,\n");
 177         fprintf(ofp, "                           the event will be discarded. Currently,\n");
 178         fprintf(ofp, "                           filter is only implemented for the user-space\n");
 179         fprintf(ofp, "                           tracer.\n");
 180         fprintf(ofp, "                           Expression examples:.\n");
 181         fprintf(ofp, "                           \n");
 182         fprintf(ofp, "                           'intfield > 500 && intfield < 503'\n");
 183         fprintf(ofp, "                           '(stringfield == \"test\" || intfield != 10) && intfield > 33'\n");
 184         fprintf(ofp, "                           'doublefield > 1.1 && intfield < 5.3'\n");
 185         fprintf(ofp, "                           \n");
 186         fprintf(ofp, "                           Wildcards are allowed at the end of strings:\n");
 187         fprintf(ofp, "                           'seqfield1 == \"te*\"'\n");
 188         fprintf(ofp, "                           In string literals, the escape character is '\\'.\n");
 189         fprintf(ofp, "                           Use '\\*' for the '*' character, and '\\\\' for\n");
 190         fprintf(ofp, "                           the '\\' character.\n");
 191         fprintf(ofp, "\n");
 192 }
 193
 194 /*
 195  * Parse probe options.
 196  */
 197 static int parse_probe_opts(struct lttng_event *ev, char *opt)
 198 {
 199         int ret;
 200         char s_hex[19];
 201         char name[LTTNG_SYMBOL_NAME_LEN];
 202
 203         if (opt == NULL) {
 204                 ret = -1;
 205                 goto end;
 206         }
 207
 208         /* Check for symbol+offset */
 209         ret = sscanf(opt, "%[^'+']+%s", name, s_hex);
 210         if (ret == 2) {
 211                 strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN);
 212                 ev->attr.probe.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 213                 DBG("probe symbol %s", ev->attr.probe.symbol_name);
 214                 if (strlen(s_hex) == 0) {
 215                         ERR("Invalid probe offset %s", s_hex);
 216                         ret = -1;
 217                         goto end;
 218                 }
 219                 ev->attr.probe.offset = strtoul(s_hex, NULL, 0);
 220                 DBG("probe offset %" PRIu64, ev->attr.probe.offset);
 221                 ev->attr.probe.addr = 0;
 222                 goto end;
 223         }
 224
 225         /* Check for symbol */
 226         if (isalpha(name[0])) {
 227                 ret = sscanf(opt, "%s", name);
 228                 if (ret == 1) {
 229                         strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN);
 230                         ev->attr.probe.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 231                         DBG("probe symbol %s", ev->attr.probe.symbol_name);
 232                         ev->attr.probe.offset = 0;
 233                         DBG("probe offset %" PRIu64, ev->attr.probe.offset);
 234                         ev->attr.probe.addr = 0;
 235                         goto end;
 236                 }
 237         }
 238
 239         /* Check for address */
 240         ret = sscanf(opt, "%s", s_hex);
 241         if (ret > 0) {
 242                 if (strlen(s_hex) == 0) {
 243                         ERR("Invalid probe address %s", s_hex);
 244                         ret = -1;
 245                         goto end;
 246                 }
 247                 ev->attr.probe.addr = strtoul(s_hex, NULL, 0);
 248                 DBG("probe addr %" PRIu64, ev->attr.probe.addr);
 249                 ev->attr.probe.offset = 0;
 250                 memset(ev->attr.probe.symbol_name, 0, LTTNG_SYMBOL_NAME_LEN);
 251                 goto end;
 252         }
 253
 254         /* No match */
 255         ret = -1;
 256
 257 end:
 258         return ret;
 259 }
 260
 261 /*
 262  * Maps loglevel from string to value
 263  */
 264 static
 265 int loglevel_str_to_value(const char *inputstr)
 266 {
 267         int i = 0;
 268         char str[LTTNG_SYMBOL_NAME_LEN];
 269
 270         while (inputstr[i] != '\0' && i < LTTNG_SYMBOL_NAME_LEN) {
 271                 str[i] = toupper(inputstr[i]);
 272                 i++;
 273         }
 274         str[i] = '\0';
 275         if (!strcmp(str, "TRACE_EMERG") || !strcmp(str, "EMERG")) {
 276                 return LTTNG_LOGLEVEL_EMERG;
 277         } else if (!strcmp(str, "TRACE_ALERT") || !strcmp(str, "ALERT")) {
 278                 return LTTNG_LOGLEVEL_ALERT;
 279         } else if (!strcmp(str, "TRACE_CRIT") || !strcmp(str, "CRIT")) {
 280                 return LTTNG_LOGLEVEL_CRIT;
 281         } else if (!strcmp(str, "TRACE_ERR") || !strcmp(str, "ERR")) {
 282                 return LTTNG_LOGLEVEL_ERR;
 283         } else if (!strcmp(str, "TRACE_WARNING") || !strcmp(str, "WARNING")) {
 284                 return LTTNG_LOGLEVEL_WARNING;
 285         } else if (!strcmp(str, "TRACE_NOTICE") || !strcmp(str, "NOTICE")) {
 286                 return LTTNG_LOGLEVEL_NOTICE;
 287         } else if (!strcmp(str, "TRACE_INFO") || !strcmp(str, "INFO")) {
 288                 return LTTNG_LOGLEVEL_INFO;
 289         } else if (!strcmp(str, "TRACE_DEBUG_SYSTEM") || !strcmp(str, "DEBUG_SYSTEM") || !strcmp(str, "SYSTEM")) {
 290                 return LTTNG_LOGLEVEL_DEBUG_SYSTEM;
 291         } else if (!strcmp(str, "TRACE_DEBUG_PROGRAM") || !strcmp(str, "DEBUG_PROGRAM") || !strcmp(str, "PROGRAM")) {
 292                 return LTTNG_LOGLEVEL_DEBUG_PROGRAM;
 293         } else if (!strcmp(str, "TRACE_DEBUG_PROCESS") || !strcmp(str, "DEBUG_PROCESS") || !strcmp(str, "PROCESS")) {
 294                 return LTTNG_LOGLEVEL_DEBUG_PROCESS;
 295         } else if (!strcmp(str, "TRACE_DEBUG_MODULE") || !strcmp(str, "DEBUG_MODULE") || !strcmp(str, "MODULE")) {
 296                 return LTTNG_LOGLEVEL_DEBUG_MODULE;
 297         } else if (!strcmp(str, "TRACE_DEBUG_UNIT") || !strcmp(str, "DEBUG_UNIT") || !strcmp(str, "UNIT")) {
 298                 return LTTNG_LOGLEVEL_DEBUG_UNIT;
 299         } else if (!strcmp(str, "TRACE_DEBUG_FUNCTION") || !strcmp(str, "DEBUG_FUNCTION") || !strcmp(str, "FUNCTION")) {
 300                 return LTTNG_LOGLEVEL_DEBUG_FUNCTION;
 301         } else if (!strcmp(str, "TRACE_DEBUG_LINE") || !strcmp(str, "DEBUG_LINE") || !strcmp(str, "LINE")) {
 302                 return LTTNG_LOGLEVEL_DEBUG_LINE;
 303         } else if (!strcmp(str, "TRACE_DEBUG") || !strcmp(str, "DEBUG")) {
 304                 return LTTNG_LOGLEVEL_DEBUG;
 305         } else {
 306                 return -1;
 307         }
 308 }
 309
 310 /*
 311  * Enabling event using the lttng API.
 312  */
 313 static int enable_events(char *session_name)
 314 {
 315         int err, ret = CMD_SUCCESS, warn = 0;
 316         char *event_name, *channel_name = NULL;
 317         struct lttng_event ev;
 318         struct lttng_domain dom;
 319
 320         memset(&ev, 0, sizeof(ev));
 321         memset(&dom, 0, sizeof(dom));
 322
 323         if (opt_kernel) {
 324                 if (opt_filter) {
 325                         ERR("Filter not implement for kernel tracing yet");
 326                         ret = CMD_ERROR;
 327                         goto error;
 328                 }
 329         }
 330
 331         /* Create lttng domain */
 332         if (opt_kernel) {
 333                 dom.type = LTTNG_DOMAIN_KERNEL;
 334         } else if (opt_userspace) {
 335                 dom.type = LTTNG_DOMAIN_UST;
 336         } else {
 337                 ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
 338                 ret = CMD_ERROR;
 339                 goto error;
 340         }
 341
 342         if (opt_channel_name == NULL) {
 343                 err = asprintf(&channel_name, DEFAULT_CHANNEL_NAME);
 344                 if (err < 0) {
 345                         ret = CMD_FATAL;
 346                         goto error;
 347                 }
 348         } else {
 349                 channel_name = opt_channel_name;
 350         }
 351
 352         handle = lttng_create_handle(session_name, &dom);
 353         if (handle == NULL) {
 354                 ret = -1;
 355                 goto error;
 356         }
 357
 358         if (opt_enable_all) {
 359                 /* Default setup for enable all */
 360                 if (opt_kernel) {
 361                         ev.type = opt_event_type;
 362                         ev.name[0] = '\0';
 363                         /* kernel loglevels not implemented */
 364                         ev.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
 365                 } else {
 366                         ev.type = LTTNG_EVENT_TRACEPOINT;
 367                         strcpy(ev.name, "*");
 368                         ev.loglevel_type = opt_loglevel_type;
 369                         if (opt_loglevel) {
 370                                 ev.loglevel = loglevel_str_to_value(opt_loglevel);
 371                                 if (ev.loglevel == -1) {
 372                                         ERR("Unknown loglevel %s", opt_loglevel);
 373                                         ret = -1;
 374                                         goto error;
 375                                 }
 376                         } else {
 377                                 ev.loglevel = -1;
 378                         }
 379                 }
 380
 381                 ret = lttng_enable_event(handle, &ev, channel_name);
 382                 if (ret < 0) {
 383                         switch (-ret) {
 384                         case LTTCOMM_KERN_EVENT_EXIST:
 385                                 WARN("Kernel events already enabled (channel %s, session %s)",
 386                                                 channel_name, session_name);
 387                                 break;
 388                         default:
 389                                 ERR("Events: %s (channel %s, session %s)",
 390                                                 lttng_strerror(ret), channel_name, session_name);
 391                                 break;
 392                         }
 393                         goto end;
 394                 }
 395                 if (opt_filter) {
 396                         ret = lttng_set_event_filter(handle, ev.name, channel_name,
 397                                                 opt_filter);
 398                         if (ret < 0) {
 399                                 ERR("Error setting filter");
 400                                 ret = -1;
 401                                 goto error;
 402                         }
 403                 }
 404
 405                 switch (opt_event_type) {
 406                 case LTTNG_EVENT_TRACEPOINT:
 407                         if (opt_loglevel) {
 408                                 MSG("All %s tracepoints are enabled in channel %s for loglevel %s",
 409                                         opt_kernel ? "kernel" : "UST", channel_name,
 410                                         opt_loglevel);
 411                         } else {
 412                                 MSG("All %s tracepoints are enabled in channel %s",
 413                                         opt_kernel ? "kernel" : "UST", channel_name);
 414
 415                         }
 416                         break;
 417                 case LTTNG_EVENT_SYSCALL:
 418                         if (opt_kernel) {
 419                                 MSG("All kernel system calls are enabled in channel %s",
 420                                                 channel_name);
 421                         }
 422                         break;
 423                 case LTTNG_EVENT_ALL:
 424                         if (opt_loglevel) {
 425                                 MSG("All %s events are enabled in channel %s for loglevel %s",
 426                                         opt_kernel ? "kernel" : "UST", channel_name,
 427                                         opt_loglevel);
 428                         } else {
 429                                 MSG("All %s events are enabled in channel %s",
 430                                         opt_kernel ? "kernel" : "UST", channel_name);
 431                         }
 432                         break;
 433                 default:
 434                         /*
 435                          * We should not be here since lttng_enable_event should have
 436                          * failed on the event type.
 437                          */
 438                         goto error;
 439                 }
 440                 goto end;
 441         }
 442
 443         /* Strip event list */
 444         event_name = strtok(opt_event_list, ",");
 445         while (event_name != NULL) {
 446                 /* Copy name and type of the event */
 447                 strncpy(ev.name, event_name, LTTNG_SYMBOL_NAME_LEN);
 448                 ev.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 449                 ev.type = opt_event_type;
 450
 451                 /* Kernel tracer action */
 452                 if (opt_kernel) {
 453                         DBG("Enabling kernel event %s for channel %s",
 454                                         event_name, channel_name);
 455
 456                         switch (opt_event_type) {
 457                         case LTTNG_EVENT_ALL:   /* Default behavior is tracepoint */
 458                                 ev.type = LTTNG_EVENT_TRACEPOINT;
 459                                 /* Fall-through */
 460                         case LTTNG_EVENT_TRACEPOINT:
 461                                 break;
 462                         case LTTNG_EVENT_PROBE:
 463                                 ret = parse_probe_opts(&ev, opt_probe);
 464                                 if (ret < 0) {
 465                                         ERR("Unable to parse probe options");
 466                                         ret = 0;
 467                                         goto error;
 468                                 }
 469                                 break;
 470                         case LTTNG_EVENT_FUNCTION:
 471                                 ret = parse_probe_opts(&ev, opt_function);
 472                                 if (ret < 0) {
 473                                         ERR("Unable to parse function probe options");
 474                                         ret = 0;
 475                                         goto error;
 476                                 }
 477                                 break;
 478                         case LTTNG_EVENT_FUNCTION_ENTRY:
 479                                 strncpy(ev.attr.ftrace.symbol_name, opt_function_entry_symbol,
 480                                                 LTTNG_SYMBOL_NAME_LEN);
 481                                 ev.attr.ftrace.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 482                                 break;
 483                         case LTTNG_EVENT_SYSCALL:
 484                                 MSG("per-syscall selection not supported yet. Use \"-a\" "
 485                                                 "for all syscalls.");
 486                         default:
 487                                 ret = CMD_UNDEFINED;
 488                                 goto error;
 489                         }
 490
 491                         if (opt_loglevel) {
 492                                 MSG("Kernel loglevels are not supported.");
 493                                 ret = CMD_UNDEFINED;
 494                                 goto error;
 495                         }
 496
 497                         /* kernel loglevels not implemented */
 498                         ev.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
 499                 } else if (opt_userspace) {             /* User-space tracer action */
 500 #if 0
 501                         if (opt_cmd_name != NULL || opt_pid) {
 502                                 MSG("Only supporting tracing all UST processes (-u) for now.");
 503                                 ret = CMD_UNDEFINED;
 504                                 goto error;
 505                         }
 506 #endif
 507
 508                         DBG("Enabling UST event %s for channel %s, loglevel %s", event_name,
 509                                         channel_name, opt_loglevel ? : "<all>");
 510
 511                         switch (opt_event_type) {
 512                         case LTTNG_EVENT_ALL:   /* Default behavior is tracepoint */
 513                                 /* Fall-through */
 514                         case LTTNG_EVENT_TRACEPOINT:
 515                                 /* Copy name and type of the event */
 516                                 ev.type = LTTNG_EVENT_TRACEPOINT;
 517                                 strncpy(ev.name, event_name, LTTNG_SYMBOL_NAME_LEN);
 518                                 ev.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 519                                 break;
 520                         case LTTNG_EVENT_PROBE:
 521                         case LTTNG_EVENT_FUNCTION:
 522                         case LTTNG_EVENT_FUNCTION_ENTRY:
 523                         case LTTNG_EVENT_SYSCALL:
 524                         default:
 525                                 ERR("Event type not available for user-space tracing");
 526                                 ret = CMD_UNDEFINED;
 527                                 goto error;
 528                         }
 529
 530                         ev.loglevel_type = opt_loglevel_type;
 531                         if (opt_loglevel) {
 532                                 ev.loglevel = loglevel_str_to_value(opt_loglevel);
 533                                 if (ev.loglevel == -1) {
 534                                         ERR("Unknown loglevel %s", opt_loglevel);
 535                                         ret = -1;
 536                                         goto error;
 537                                 }
 538                         } else {
 539                                 ev.loglevel = -1;
 540                         }
 541                 } else {
 542                         ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
 543                         ret = CMD_ERROR;
 544                         goto error;
 545                 }
 546
 547                 ret = lttng_enable_event(handle, &ev, channel_name);
 548                 if (ret < 0) {
 549                         /* Turn ret to positive value to handle the positive error code */
 550                         switch (-ret) {
 551                         case LTTCOMM_KERN_EVENT_EXIST:
 552                                 WARN("Kernel event %s already enabled (channel %s, session %s)",
 553                                                 event_name, channel_name, session_name);
 554                                 break;
 555                         default:
 556                                 ERR("Event %s: %s (channel %s, session %s)", event_name,
 557                                                 lttng_strerror(ret), channel_name, session_name);
 558                                 break;
 559                         }
 560                         warn = 1;
 561                 } else {
 562                         MSG("%s event %s created in channel %s",
 563                                         opt_kernel ? "kernel": "UST", event_name, channel_name);
 564                 }
 565                 if (opt_filter) {
 566                         ret = lttng_set_event_filter(handle, ev.name,
 567                                 channel_name, opt_filter);
 568                         if (ret < 0) {
 569                                 ERR("Error setting filter");
 570                                 ret = -1;
 571                                 goto error;
 572                         }
 573                 }
 574
 575                 /* Next event */
 576                 event_name = strtok(NULL, ",");
 577         }
 578
 579 end:
 580 error:
 581         if (warn) {
 582                 ret = CMD_WARNING;
 583         }
 584         if (opt_channel_name == NULL) {
 585                 free(channel_name);
 586         }
 587         lttng_destroy_handle(handle);
 588
 589         return ret;
 590 }
 591
 592 /*
 593  * Add event to trace session
 594  */
 595 int cmd_enable_events(int argc, const char **argv)
 596 {
 597         int opt, ret = CMD_SUCCESS;
 598         static poptContext pc;
 599         char *session_name = NULL;
 600
 601         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 602         poptReadDefaultConfig(pc, 0);
 603
 604         /* Default event type */
 605         opt_event_type = LTTNG_EVENT_ALL;
 606
 607         while ((opt = poptGetNextOpt(pc)) != -1) {
 608                 switch (opt) {
 609                 case OPT_HELP:
 610                         usage(stdout);
 611                         goto end;
 612                 case OPT_TRACEPOINT:
 613                         opt_event_type = LTTNG_EVENT_TRACEPOINT;
 614                         break;
 615                 case OPT_PROBE:
 616                         opt_event_type = LTTNG_EVENT_PROBE;
 617                         break;
 618                 case OPT_FUNCTION:
 619                         opt_event_type = LTTNG_EVENT_FUNCTION;
 620                         break;
 621                 case OPT_FUNCTION_ENTRY:
 622                         opt_event_type = LTTNG_EVENT_FUNCTION_ENTRY;
 623                         break;
 624                 case OPT_SYSCALL:
 625                         opt_event_type = LTTNG_EVENT_SYSCALL;
 626                         break;
 627                 case OPT_USERSPACE:
 628                         opt_userspace = 1;
 629                         break;
 630                 case OPT_LOGLEVEL:
 631                         opt_loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
 632                         opt_loglevel = poptGetOptArg(pc);
 633                         break;
 634                 case OPT_LOGLEVEL_ONLY:
 635                         opt_loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
 636                         opt_loglevel = poptGetOptArg(pc);
 637                         break;
 638                 case OPT_LIST_OPTIONS:
 639                         list_cmd_options(stdout, long_options);
 640                         goto end;
 641                 case OPT_FILTER:
 642                         break;
 643                 default:
 644                         usage(stderr);
 645                         ret = CMD_UNDEFINED;
 646                         goto end;
 647                 }
 648         }
 649
 650         opt_event_list = (char*) poptGetArg(pc);
 651         if (opt_event_list == NULL && opt_enable_all == 0) {
 652                 ERR("Missing event name(s).\n");
 653                 usage(stderr);
 654                 ret = CMD_ERROR;
 655                 goto end;
 656         }
 657
 658         if (!opt_session_name) {
 659                 session_name = get_session_name();
 660                 if (session_name == NULL) {
 661                         ret = CMD_ERROR;
 662                         goto end;
 663                 }
 664         } else {
 665                 session_name = opt_session_name;
 666         }
 667
 668         ret = enable_events(session_name);
 669
 670 end:
 671         if (opt_session_name == NULL) {
 672                 free(session_name);
 673         }
 674
 675         poptFreeContext(pc);
 676         return ret;
 677 }