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         {"userspace",      'u', POPT_ARG_NONE, 0, OPT_USERSPACE, 0, 0},
  75         {"tracepoint",     0,   POPT_ARG_NONE, 0, OPT_TRACEPOINT, 0, 0},
  76         {"probe",          0,   POPT_ARG_STRING, &opt_probe, OPT_PROBE, 0, 0},
  77         {"function",       0,   POPT_ARG_STRING, &opt_function, OPT_FUNCTION, 0, 0},
  78 #if 0
  79         /*
  80          * Currently removed from lttng kernel tracer. Removed from
  81          * lttng UI to discourage its use.
  82          */
  83         {"function:entry", 0,   POPT_ARG_STRING, &opt_function_entry_symbol, OPT_FUNCTION_ENTRY, 0, 0},
  84 #endif
  85         {"syscall",        0,   POPT_ARG_NONE, 0, OPT_SYSCALL, 0, 0},
  86         {"loglevel",       0,     POPT_ARG_STRING, 0, OPT_LOGLEVEL, 0, 0},
  87         {"loglevel-only",  0,     POPT_ARG_STRING, 0, OPT_LOGLEVEL_ONLY, 0, 0},
  88         {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  89         {"filter",         'f', POPT_ARG_STRING, &opt_filter, OPT_FILTER, 0, 0},
  90         {0, 0, 0, 0, 0, 0, 0}
  91 };
  92
  93 /*
  94  * usage
  95  */
  96 static void usage(FILE *ofp)
  97 {
  98         fprintf(ofp, "usage: lttng enable-event NAME[,NAME2,...] [-k|-u] [OPTIONS] \n");
  99         fprintf(ofp, "\n");
 100         fprintf(ofp, "Options:\n");
 101         fprintf(ofp, "  -h, --help               Show this help\n");
 102         fprintf(ofp, "      --list-options       Simple listing of options\n");
 103         fprintf(ofp, "  -s, --session NAME       Apply to session name\n");
 104         fprintf(ofp, "  -c, --channel NAME       Apply to this channel\n");
 105         fprintf(ofp, "  -a, --all                Enable all tracepoints and syscalls\n");
 106         fprintf(ofp, "  -k, --kernel             Apply for the kernel tracer\n");
 107         fprintf(ofp, "  -u, --userspace          Apply to the user-space tracer\n");
 108         fprintf(ofp, "\n");
 109         fprintf(ofp, "Event options:\n");
 110         fprintf(ofp, "    --tracepoint           Tracepoint event (default)\n");
 111         fprintf(ofp, "                           - userspace tracer supports wildcards at end of string.\n");
 112         fprintf(ofp, "                             Don't forget to quote to deal with bash expansion.\n");
 113         fprintf(ofp, "                             e.g.:\n");
 114         fprintf(ofp, "                               \"*\"\n");
 115         fprintf(ofp, "                               \"app_component:na*\"\n");
 116         fprintf(ofp, "    --probe [addr | symbol | symbol+offset]\n");
 117         fprintf(ofp, "                           Dynamic probe.\n");
 118         fprintf(ofp, "                           Addr and offset can be octal (0NNN...),\n");
 119         fprintf(ofp, "                           decimal (NNN...) or hexadecimal (0xNNN...)\n");
 120         fprintf(ofp, "    --function [addr | symbol | symbol+offset]\n");
 121         fprintf(ofp, "                           Dynamic function entry/return probe.\n");
 122         fprintf(ofp, "                           Addr and offset can be octal (0NNN...),\n");
 123         fprintf(ofp, "                           decimal (NNN...) or hexadecimal (0xNNN...)\n");
 124 #if 0
 125         fprintf(ofp, "    --function:entry symbol\n");
 126         fprintf(ofp, "                           Function tracer event\n");
 127 #endif
 128         fprintf(ofp, "    --syscall              System call event\n");
 129         fprintf(ofp, "\n");
 130         fprintf(ofp, "    --loglevel name\n");
 131         fprintf(ofp, "                           Tracepoint loglevel range from 0 to loglevel\n");
 132         fprintf(ofp, "    --loglevel-only name\n");
 133         fprintf(ofp, "                           Tracepoint loglevel (only this loglevel)\n");
 134         fprintf(ofp, "\n");
 135         fprintf(ofp, "                           The loglevel or loglevel-only options should be\n");
 136         fprintf(ofp, "                           combined with a tracepoint name or tracepoint\n");
 137         fprintf(ofp, "                           wildcard.\n");
 138         fprintf(ofp, "                           Available loglevels:\n");
 139         fprintf(ofp, "                                              (higher value is more verbose)\n");
 140         fprintf(ofp, "                               TRACE_EMERG          = 0\n");
 141         fprintf(ofp, "                               TRACE_ALERT          = 1\n");
 142         fprintf(ofp, "                               TRACE_CRIT           = 2\n");
 143         fprintf(ofp, "                               TRACE_ERR            = 3\n");
 144         fprintf(ofp, "                               TRACE_WARNING        = 4\n");
 145         fprintf(ofp, "                               TRACE_NOTICE         = 5\n");
 146         fprintf(ofp, "                               TRACE_INFO           = 6\n");
 147         fprintf(ofp, "                               TRACE_DEBUG_SYSTEM   = 7\n");
 148         fprintf(ofp, "                               TRACE_DEBUG_PROGRAM  = 8\n");
 149         fprintf(ofp, "                               TRACE_DEBUG_PROCESS  = 9\n");
 150         fprintf(ofp, "                               TRACE_DEBUG_MODULE   = 10\n");
 151         fprintf(ofp, "                               TRACE_DEBUG_UNIT     = 11\n");
 152         fprintf(ofp, "                               TRACE_DEBUG_FUNCTION = 12\n");
 153         fprintf(ofp, "                               TRACE_DEBUG_LINE     = 13\n");
 154         fprintf(ofp, "                               TRACE_DEBUG          = 14\n");
 155         fprintf(ofp, "                               (shortcuts such as \"system\" are allowed)\n");
 156         fprintf(ofp, "    --filter \'expression\'\n");
 157         fprintf(ofp, "                           Filter expression on event fields,\n");
 158         fprintf(ofp, "                           event recording depends on evaluation.\n");
 159         fprintf(ofp, "                           Only specify on first activation of\n");
 160         fprintf(ofp, "                           a given event within a session.\n");
 161         fprintf(ofp, "                           Filter only allowed when enabling\n");
 162         fprintf(ofp, "                           events within a session before tracing\n");
 163         fprintf(ofp, "                           is started. If the filter fails to link\n");
 164         fprintf(ofp, "                           with the event within the traced domain,\n");
 165         fprintf(ofp, "                           the event will be discarded. Currently,\n");
 166         fprintf(ofp, "                           filter is only implemented for the user-space\n");
 167         fprintf(ofp, "                           tracer.\n");
 168         fprintf(ofp, "                           Expression examples:.\n");
 169         fprintf(ofp, "                           \n");
 170         fprintf(ofp, "                           'intfield > 500 && intfield < 503'\n");
 171         fprintf(ofp, "                           '(stringfield == \"test\" || intfield != 10) && intfield > 33'\n");
 172         fprintf(ofp, "                           'doublefield > 1.1 && intfield < 5.3'\n");
 173         fprintf(ofp, "                           \n");
 174         fprintf(ofp, "                           Wildcards are allowed at the end of strings:\n");
 175         fprintf(ofp, "                           'seqfield1 == \"te*\"'\n");
 176         fprintf(ofp, "                           In string literals, the escape character is '\\'.\n");
 177         fprintf(ofp, "                           Use '\\*' for the '*' character, and '\\\\' for\n");
 178         fprintf(ofp, "                           the '\\' character.\n");
 179         fprintf(ofp, "\n");
 180 }
 181
 182 /*
 183  * Parse probe options.
 184  */
 185 static int parse_probe_opts(struct lttng_event *ev, char *opt)
 186 {
 187         int ret;
 188         char s_hex[19];
 189         char name[LTTNG_SYMBOL_NAME_LEN];
 190
 191         if (opt == NULL) {
 192                 ret = -1;
 193                 goto end;
 194         }
 195
 196         /* Check for symbol+offset */
 197         ret = sscanf(opt, "%[^'+']+%s", name, s_hex);
 198         if (ret == 2) {
 199                 strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN);
 200                 ev->attr.probe.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 201                 DBG("probe symbol %s", ev->attr.probe.symbol_name);
 202                 if (strlen(s_hex) == 0) {
 203                         ERR("Invalid probe offset %s", s_hex);
 204                         ret = -1;
 205                         goto end;
 206                 }
 207                 ev->attr.probe.offset = strtoul(s_hex, NULL, 0);
 208                 DBG("probe offset %" PRIu64, ev->attr.probe.offset);
 209                 ev->attr.probe.addr = 0;
 210                 goto end;
 211         }
 212
 213         /* Check for symbol */
 214         if (isalpha(name[0])) {
 215                 ret = sscanf(opt, "%s", name);
 216                 if (ret == 1) {
 217                         strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN);
 218                         ev->attr.probe.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 219                         DBG("probe symbol %s", ev->attr.probe.symbol_name);
 220                         ev->attr.probe.offset = 0;
 221                         DBG("probe offset %" PRIu64, ev->attr.probe.offset);
 222                         ev->attr.probe.addr = 0;
 223                         goto end;
 224                 }
 225         }
 226
 227         /* Check for address */
 228         ret = sscanf(opt, "%s", s_hex);
 229         if (ret > 0) {
 230                 if (strlen(s_hex) == 0) {
 231                         ERR("Invalid probe address %s", s_hex);
 232                         ret = -1;
 233                         goto end;
 234                 }
 235                 ev->attr.probe.addr = strtoul(s_hex, NULL, 0);
 236                 DBG("probe addr %" PRIu64, ev->attr.probe.addr);
 237                 ev->attr.probe.offset = 0;
 238                 memset(ev->attr.probe.symbol_name, 0, LTTNG_SYMBOL_NAME_LEN);
 239                 goto end;
 240         }
 241
 242         /* No match */
 243         ret = -1;
 244
 245 end:
 246         return ret;
 247 }
 248
 249 /*
 250  * Maps loglevel from string to value
 251  */
 252 static
 253 int loglevel_str_to_value(const char *inputstr)
 254 {
 255         int i = 0;
 256         char str[LTTNG_SYMBOL_NAME_LEN];
 257
 258         while (inputstr[i] != '\0' && i < LTTNG_SYMBOL_NAME_LEN) {
 259                 str[i] = toupper(inputstr[i]);
 260                 i++;
 261         }
 262         str[i] = '\0';
 263         if (!strcmp(str, "TRACE_EMERG") || !strcmp(str, "EMERG")) {
 264                 return LTTNG_LOGLEVEL_EMERG;
 265         } else if (!strcmp(str, "TRACE_ALERT") || !strcmp(str, "ALERT")) {
 266                 return LTTNG_LOGLEVEL_ALERT;
 267         } else if (!strcmp(str, "TRACE_CRIT") || !strcmp(str, "CRIT")) {
 268                 return LTTNG_LOGLEVEL_CRIT;
 269         } else if (!strcmp(str, "TRACE_ERR") || !strcmp(str, "ERR")) {
 270                 return LTTNG_LOGLEVEL_ERR;
 271         } else if (!strcmp(str, "TRACE_WARNING") || !strcmp(str, "WARNING")) {
 272                 return LTTNG_LOGLEVEL_WARNING;
 273         } else if (!strcmp(str, "TRACE_NOTICE") || !strcmp(str, "NOTICE")) {
 274                 return LTTNG_LOGLEVEL_NOTICE;
 275         } else if (!strcmp(str, "TRACE_INFO") || !strcmp(str, "INFO")) {
 276                 return LTTNG_LOGLEVEL_INFO;
 277         } else if (!strcmp(str, "TRACE_DEBUG_SYSTEM") || !strcmp(str, "DEBUG_SYSTEM") || !strcmp(str, "SYSTEM")) {
 278                 return LTTNG_LOGLEVEL_DEBUG_SYSTEM;
 279         } else if (!strcmp(str, "TRACE_DEBUG_PROGRAM") || !strcmp(str, "DEBUG_PROGRAM") || !strcmp(str, "PROGRAM")) {
 280                 return LTTNG_LOGLEVEL_DEBUG_PROGRAM;
 281         } else if (!strcmp(str, "TRACE_DEBUG_PROCESS") || !strcmp(str, "DEBUG_PROCESS") || !strcmp(str, "PROCESS")) {
 282                 return LTTNG_LOGLEVEL_DEBUG_PROCESS;
 283         } else if (!strcmp(str, "TRACE_DEBUG_MODULE") || !strcmp(str, "DEBUG_MODULE") || !strcmp(str, "MODULE")) {
 284                 return LTTNG_LOGLEVEL_DEBUG_MODULE;
 285         } else if (!strcmp(str, "TRACE_DEBUG_UNIT") || !strcmp(str, "DEBUG_UNIT") || !strcmp(str, "UNIT")) {
 286                 return LTTNG_LOGLEVEL_DEBUG_UNIT;
 287         } else if (!strcmp(str, "TRACE_DEBUG_FUNCTION") || !strcmp(str, "DEBUG_FUNCTION") || !strcmp(str, "FUNCTION")) {
 288                 return LTTNG_LOGLEVEL_DEBUG_FUNCTION;
 289         } else if (!strcmp(str, "TRACE_DEBUG_LINE") || !strcmp(str, "DEBUG_LINE") || !strcmp(str, "LINE")) {
 290                 return LTTNG_LOGLEVEL_DEBUG_LINE;
 291         } else if (!strcmp(str, "TRACE_DEBUG") || !strcmp(str, "DEBUG")) {
 292                 return LTTNG_LOGLEVEL_DEBUG;
 293         } else {
 294                 return -1;
 295         }
 296 }
 297
 298 /*
 299  * Enabling event using the lttng API.
 300  */
 301 static int enable_events(char *session_name)
 302 {
 303         int err, ret = CMD_SUCCESS, warn = 0;
 304         char *event_name, *channel_name = NULL;
 305         struct lttng_event ev;
 306         struct lttng_domain dom;
 307
 308         memset(&ev, 0, sizeof(ev));
 309         memset(&dom, 0, sizeof(dom));
 310
 311         if (opt_kernel) {
 312                 if (opt_filter) {
 313                         ERR("Filter not implement for kernel tracing yet");
 314                         ret = CMD_ERROR;
 315                         goto error;
 316                 }
 317         }
 318
 319         /* Create lttng domain */
 320         if (opt_kernel) {
 321                 dom.type = LTTNG_DOMAIN_KERNEL;
 322         } else if (opt_userspace) {
 323                 dom.type = LTTNG_DOMAIN_UST;
 324         } else {
 325                 ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
 326                 ret = CMD_ERROR;
 327                 goto error;
 328         }
 329
 330         if (opt_channel_name == NULL) {
 331                 err = asprintf(&channel_name, DEFAULT_CHANNEL_NAME);
 332                 if (err < 0) {
 333                         ret = CMD_FATAL;
 334                         goto error;
 335                 }
 336         } else {
 337                 channel_name = opt_channel_name;
 338         }
 339
 340         handle = lttng_create_handle(session_name, &dom);
 341         if (handle == NULL) {
 342                 ret = -1;
 343                 goto error;
 344         }
 345
 346         if (opt_enable_all) {
 347                 /* Default setup for enable all */
 348                 if (opt_kernel) {
 349                         ev.type = opt_event_type;
 350                         ev.name[0] = '\0';
 351                         /* kernel loglevels not implemented */
 352                         ev.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
 353                 } else {
 354                         ev.type = LTTNG_EVENT_TRACEPOINT;
 355                         strcpy(ev.name, "*");
 356                         ev.loglevel_type = opt_loglevel_type;
 357                         if (opt_loglevel) {
 358                                 ev.loglevel = loglevel_str_to_value(opt_loglevel);
 359                                 if (ev.loglevel == -1) {
 360                                         ERR("Unknown loglevel %s", opt_loglevel);
 361                                         ret = -1;
 362                                         goto error;
 363                                 }
 364                         } else {
 365                                 ev.loglevel = -1;
 366                         }
 367                 }
 368
 369                 ret = lttng_enable_event(handle, &ev, channel_name);
 370                 if (ret < 0) {
 371                         switch (-ret) {
 372                         case LTTNG_ERR_KERN_EVENT_EXIST:
 373                                 WARN("Kernel events already enabled (channel %s, session %s)",
 374                                                 channel_name, session_name);
 375                                 break;
 376                         default:
 377                                 ERR("Events: %s (channel %s, session %s)",
 378                                                 lttng_strerror(ret), channel_name, session_name);
 379                                 break;
 380                         }
 381                         goto end;
 382                 }
 383                 if (opt_filter) {
 384                         ret = lttng_set_event_filter(handle, ev.name, channel_name,
 385                                                 opt_filter);
 386                         if (ret < 0) {
 387                                 ERR("Error setting filter");
 388                                 ret = -1;
 389                                 goto error;
 390                         }
 391                 }
 392
 393                 switch (opt_event_type) {
 394                 case LTTNG_EVENT_TRACEPOINT:
 395                         if (opt_loglevel) {
 396                                 MSG("All %s tracepoints are enabled in channel %s for loglevel %s",
 397                                         opt_kernel ? "kernel" : "UST", channel_name,
 398                                         opt_loglevel);
 399                         } else {
 400                                 MSG("All %s tracepoints are enabled in channel %s",
 401                                         opt_kernel ? "kernel" : "UST", channel_name);
 402
 403                         }
 404                         break;
 405                 case LTTNG_EVENT_SYSCALL:
 406                         if (opt_kernel) {
 407                                 MSG("All kernel system calls are enabled in channel %s",
 408                                                 channel_name);
 409                         }
 410                         break;
 411                 case LTTNG_EVENT_ALL:
 412                         if (opt_loglevel) {
 413                                 MSG("All %s events are enabled in channel %s for loglevel %s",
 414                                         opt_kernel ? "kernel" : "UST", channel_name,
 415                                         opt_loglevel);
 416                         } else {
 417                                 MSG("All %s events are enabled in channel %s",
 418                                         opt_kernel ? "kernel" : "UST", channel_name);
 419                         }
 420                         break;
 421                 default:
 422                         /*
 423                          * We should not be here since lttng_enable_event should have
 424                          * failed on the event type.
 425                          */
 426                         goto error;
 427                 }
 428                 goto end;
 429         }
 430
 431         /* Strip event list */
 432         event_name = strtok(opt_event_list, ",");
 433         while (event_name != NULL) {
 434                 /* Copy name and type of the event */
 435                 strncpy(ev.name, event_name, LTTNG_SYMBOL_NAME_LEN);
 436                 ev.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 437                 ev.type = opt_event_type;
 438
 439                 /* Kernel tracer action */
 440                 if (opt_kernel) {
 441                         DBG("Enabling kernel event %s for channel %s",
 442                                         event_name, channel_name);
 443
 444                         switch (opt_event_type) {
 445                         case LTTNG_EVENT_ALL:   /* Default behavior is tracepoint */
 446                                 ev.type = LTTNG_EVENT_TRACEPOINT;
 447                                 /* Fall-through */
 448                         case LTTNG_EVENT_TRACEPOINT:
 449                                 break;
 450                         case LTTNG_EVENT_PROBE:
 451                                 ret = parse_probe_opts(&ev, opt_probe);
 452                                 if (ret < 0) {
 453                                         ERR("Unable to parse probe options");
 454                                         ret = 0;
 455                                         goto error;
 456                                 }
 457                                 break;
 458                         case LTTNG_EVENT_FUNCTION:
 459                                 ret = parse_probe_opts(&ev, opt_function);
 460                                 if (ret < 0) {
 461                                         ERR("Unable to parse function probe options");
 462                                         ret = 0;
 463                                         goto error;
 464                                 }
 465                                 break;
 466                         case LTTNG_EVENT_FUNCTION_ENTRY:
 467                                 strncpy(ev.attr.ftrace.symbol_name, opt_function_entry_symbol,
 468                                                 LTTNG_SYMBOL_NAME_LEN);
 469                                 ev.attr.ftrace.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 470                                 break;
 471                         case LTTNG_EVENT_SYSCALL:
 472                                 MSG("per-syscall selection not supported yet. Use \"-a\" "
 473                                                 "for all syscalls.");
 474                         default:
 475                                 ret = CMD_UNDEFINED;
 476                                 goto error;
 477                         }
 478
 479                         if (opt_loglevel) {
 480                                 MSG("Kernel loglevels are not supported.");
 481                                 ret = CMD_UNDEFINED;
 482                                 goto error;
 483                         }
 484
 485                         /* kernel loglevels not implemented */
 486                         ev.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
 487                 } else if (opt_userspace) {             /* User-space tracer action */
 488 #if 0
 489                         if (opt_cmd_name != NULL || opt_pid) {
 490                                 MSG("Only supporting tracing all UST processes (-u) for now.");
 491                                 ret = CMD_UNDEFINED;
 492                                 goto error;
 493                         }
 494 #endif
 495
 496                         DBG("Enabling UST event %s for channel %s, loglevel %s", event_name,
 497                                         channel_name, opt_loglevel ? : "<all>");
 498
 499                         switch (opt_event_type) {
 500                         case LTTNG_EVENT_ALL:   /* Default behavior is tracepoint */
 501                                 /* Fall-through */
 502                         case LTTNG_EVENT_TRACEPOINT:
 503                                 /* Copy name and type of the event */
 504                                 ev.type = LTTNG_EVENT_TRACEPOINT;
 505                                 strncpy(ev.name, event_name, LTTNG_SYMBOL_NAME_LEN);
 506                                 ev.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 507                                 break;
 508                         case LTTNG_EVENT_PROBE:
 509                         case LTTNG_EVENT_FUNCTION:
 510                         case LTTNG_EVENT_FUNCTION_ENTRY:
 511                         case LTTNG_EVENT_SYSCALL:
 512                         default:
 513                                 ERR("Event type not available for user-space tracing");
 514                                 ret = CMD_UNDEFINED;
 515                                 goto error;
 516                         }
 517
 518                         ev.loglevel_type = opt_loglevel_type;
 519                         if (opt_loglevel) {
 520                                 ev.loglevel = loglevel_str_to_value(opt_loglevel);
 521                                 if (ev.loglevel == -1) {
 522                                         ERR("Unknown loglevel %s", opt_loglevel);
 523                                         ret = -1;
 524                                         goto error;
 525                                 }
 526                         } else {
 527                                 ev.loglevel = -1;
 528                         }
 529                 } else {
 530                         ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
 531                         ret = CMD_ERROR;
 532                         goto error;
 533                 }
 534
 535                 ret = lttng_enable_event(handle, &ev, channel_name);
 536                 if (ret < 0) {
 537                         /* Turn ret to positive value to handle the positive error code */
 538                         switch (-ret) {
 539                         case LTTNG_ERR_KERN_EVENT_EXIST:
 540                                 WARN("Kernel event %s already enabled (channel %s, session %s)",
 541                                                 event_name, channel_name, session_name);
 542                                 break;
 543                         default:
 544                                 ERR("Event %s: %s (channel %s, session %s)", event_name,
 545                                                 lttng_strerror(ret), channel_name, session_name);
 546                                 break;
 547                         }
 548                         warn = 1;
 549                 } else {
 550                         MSG("%s event %s created in channel %s",
 551                                         opt_kernel ? "kernel": "UST", event_name, channel_name);
 552                 }
 553                 if (opt_filter) {
 554                         ret = lttng_set_event_filter(handle, ev.name,
 555                                 channel_name, opt_filter);
 556                         if (ret < 0) {
 557                                 ERR("Error setting filter");
 558                                 ret = -1;
 559                                 goto error;
 560                         }
 561                 }
 562
 563                 /* Next event */
 564                 event_name = strtok(NULL, ",");
 565         }
 566
 567 end:
 568 error:
 569         if (warn) {
 570                 ret = CMD_WARNING;
 571         }
 572         if (opt_channel_name == NULL) {
 573                 free(channel_name);
 574         }
 575         lttng_destroy_handle(handle);
 576
 577         return ret;
 578 }
 579
 580 /*
 581  * Add event to trace session
 582  */
 583 int cmd_enable_events(int argc, const char **argv)
 584 {
 585         int opt, ret = CMD_SUCCESS;
 586         static poptContext pc;
 587         char *session_name = NULL;
 588
 589         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 590         poptReadDefaultConfig(pc, 0);
 591
 592         /* Default event type */
 593         opt_event_type = LTTNG_EVENT_ALL;
 594
 595         while ((opt = poptGetNextOpt(pc)) != -1) {
 596                 switch (opt) {
 597                 case OPT_HELP:
 598                         usage(stdout);
 599                         goto end;
 600                 case OPT_TRACEPOINT:
 601                         opt_event_type = LTTNG_EVENT_TRACEPOINT;
 602                         break;
 603                 case OPT_PROBE:
 604                         opt_event_type = LTTNG_EVENT_PROBE;
 605                         break;
 606                 case OPT_FUNCTION:
 607                         opt_event_type = LTTNG_EVENT_FUNCTION;
 608                         break;
 609                 case OPT_FUNCTION_ENTRY:
 610                         opt_event_type = LTTNG_EVENT_FUNCTION_ENTRY;
 611                         break;
 612                 case OPT_SYSCALL:
 613                         opt_event_type = LTTNG_EVENT_SYSCALL;
 614                         break;
 615                 case OPT_USERSPACE:
 616                         opt_userspace = 1;
 617                         break;
 618                 case OPT_LOGLEVEL:
 619                         opt_loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
 620                         opt_loglevel = poptGetOptArg(pc);
 621                         break;
 622                 case OPT_LOGLEVEL_ONLY:
 623                         opt_loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
 624                         opt_loglevel = poptGetOptArg(pc);
 625                         break;
 626                 case OPT_LIST_OPTIONS:
 627                         list_cmd_options(stdout, long_options);
 628                         goto end;
 629                 case OPT_FILTER:
 630                         break;
 631                 default:
 632                         usage(stderr);
 633                         ret = CMD_UNDEFINED;
 634                         goto end;
 635                 }
 636         }
 637
 638         opt_event_list = (char*) poptGetArg(pc);
 639         if (opt_event_list == NULL && opt_enable_all == 0) {
 640                 ERR("Missing event name(s).\n");
 641                 usage(stderr);
 642                 ret = CMD_ERROR;
 643                 goto end;
 644         }
 645
 646         if (!opt_session_name) {
 647                 session_name = get_session_name();
 648                 if (session_name == NULL) {
 649                         ret = CMD_ERROR;
 650                         goto end;
 651                 }
 652         } else {
 653                 session_name = opt_session_name;
 654         }
 655
 656         ret = enable_events(session_name);
 657
 658 end:
 659         if (opt_session_name == NULL) {
 660                 free(session_name);
 661         }
 662
 663         poptFreeContext(pc);
 664         return ret;
 665 }