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 and context.\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. Wildcard match any sequence of,\n");
 179         fprintf(ofp, "                           characters including an empty sub-string (match 0 or\n");
 180         fprintf(ofp, "                           more characters).\n");
 181         fprintf(ofp, "\n");
 182         fprintf(ofp, "                           Context information can be used for filtering. The\n");
 183         fprintf(ofp, "                           examples below show usage of context filtering on\n");
 184         fprintf(ofp, "                           process name (with a wildcard), process ID range, and\n");
 185         fprintf(ofp, "                           unique thread ID for filtering. The process and\n");
 186         fprintf(ofp, "                           thread ID of running applications can be found under\n");
 187         fprintf(ofp, "                           columns \"PID\" and \"LWP\" of the \"ps -eLf\" command.\n");
 188         fprintf(ofp, "\n");
 189         fprintf(ofp, "                           '$ctx.procname == \"demo*\"'\n");
 190         fprintf(ofp, "                           '$ctx.vpid >= 4433 && $ctx.vpid < 4455'\n");
 191         fprintf(ofp, "                           '$ctx.vtid == 1234'\n");
 192         fprintf(ofp, "\n");
 193 }
 194
 195 /*
 196  * Parse probe options.
 197  */
 198 static int parse_probe_opts(struct lttng_event *ev, char *opt)
 199 {
 200         int ret;
 201         char s_hex[19];
 202         char name[LTTNG_SYMBOL_NAME_LEN];
 203
 204         if (opt == NULL) {
 205                 ret = -1;
 206                 goto end;
 207         }
 208
 209         /* Check for symbol+offset */
 210         ret = sscanf(opt, "%[^'+']+%s", name, s_hex);
 211         if (ret == 2) {
 212                 strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN);
 213                 ev->attr.probe.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 214                 DBG("probe symbol %s", ev->attr.probe.symbol_name);
 215                 if (*s_hex == '\0') {
 216                         ERR("Invalid probe offset %s", s_hex);
 217                         ret = -1;
 218                         goto end;
 219                 }
 220                 ev->attr.probe.offset = strtoul(s_hex, NULL, 0);
 221                 DBG("probe offset %" PRIu64, ev->attr.probe.offset);
 222                 ev->attr.probe.addr = 0;
 223                 goto end;
 224         }
 225
 226         /* Check for symbol */
 227         if (isalpha(name[0])) {
 228                 ret = sscanf(opt, "%s", name);
 229                 if (ret == 1) {
 230                         strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN);
 231                         ev->attr.probe.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 232                         DBG("probe symbol %s", ev->attr.probe.symbol_name);
 233                         ev->attr.probe.offset = 0;
 234                         DBG("probe offset %" PRIu64, ev->attr.probe.offset);
 235                         ev->attr.probe.addr = 0;
 236                         goto end;
 237                 }
 238         }
 239
 240         /* Check for address */
 241         ret = sscanf(opt, "%s", s_hex);
 242         if (ret > 0) {
 243                 if (*s_hex == '\0') {
 244                         ERR("Invalid probe address %s", s_hex);
 245                         ret = -1;
 246                         goto end;
 247                 }
 248                 ev->attr.probe.addr = strtoul(s_hex, NULL, 0);
 249                 DBG("probe addr %" PRIu64, ev->attr.probe.addr);
 250                 ev->attr.probe.offset = 0;
 251                 memset(ev->attr.probe.symbol_name, 0, LTTNG_SYMBOL_NAME_LEN);
 252                 goto end;
 253         }
 254
 255         /* No match */
 256         ret = -1;
 257
 258 end:
 259         return ret;
 260 }
 261
 262 /*
 263  * Maps loglevel from string to value
 264  */
 265 static
 266 int loglevel_str_to_value(const char *inputstr)
 267 {
 268         int i = 0;
 269         char str[LTTNG_SYMBOL_NAME_LEN];
 270
 271         while (i < LTTNG_SYMBOL_NAME_LEN && inputstr[i] != '\0') {
 272                 str[i] = toupper(inputstr[i]);
 273                 i++;
 274         }
 275         str[i] = '\0';
 276         if (!strcmp(str, "TRACE_EMERG") || !strcmp(str, "EMERG")) {
 277                 return LTTNG_LOGLEVEL_EMERG;
 278         } else if (!strcmp(str, "TRACE_ALERT") || !strcmp(str, "ALERT")) {
 279                 return LTTNG_LOGLEVEL_ALERT;
 280         } else if (!strcmp(str, "TRACE_CRIT") || !strcmp(str, "CRIT")) {
 281                 return LTTNG_LOGLEVEL_CRIT;
 282         } else if (!strcmp(str, "TRACE_ERR") || !strcmp(str, "ERR")) {
 283                 return LTTNG_LOGLEVEL_ERR;
 284         } else if (!strcmp(str, "TRACE_WARNING") || !strcmp(str, "WARNING")) {
 285                 return LTTNG_LOGLEVEL_WARNING;
 286         } else if (!strcmp(str, "TRACE_NOTICE") || !strcmp(str, "NOTICE")) {
 287                 return LTTNG_LOGLEVEL_NOTICE;
 288         } else if (!strcmp(str, "TRACE_INFO") || !strcmp(str, "INFO")) {
 289                 return LTTNG_LOGLEVEL_INFO;
 290         } else if (!strcmp(str, "TRACE_DEBUG_SYSTEM") || !strcmp(str, "DEBUG_SYSTEM") || !strcmp(str, "SYSTEM")) {
 291                 return LTTNG_LOGLEVEL_DEBUG_SYSTEM;
 292         } else if (!strcmp(str, "TRACE_DEBUG_PROGRAM") || !strcmp(str, "DEBUG_PROGRAM") || !strcmp(str, "PROGRAM")) {
 293                 return LTTNG_LOGLEVEL_DEBUG_PROGRAM;
 294         } else if (!strcmp(str, "TRACE_DEBUG_PROCESS") || !strcmp(str, "DEBUG_PROCESS") || !strcmp(str, "PROCESS")) {
 295                 return LTTNG_LOGLEVEL_DEBUG_PROCESS;
 296         } else if (!strcmp(str, "TRACE_DEBUG_MODULE") || !strcmp(str, "DEBUG_MODULE") || !strcmp(str, "MODULE")) {
 297                 return LTTNG_LOGLEVEL_DEBUG_MODULE;
 298         } else if (!strcmp(str, "TRACE_DEBUG_UNIT") || !strcmp(str, "DEBUG_UNIT") || !strcmp(str, "UNIT")) {
 299                 return LTTNG_LOGLEVEL_DEBUG_UNIT;
 300         } else if (!strcmp(str, "TRACE_DEBUG_FUNCTION") || !strcmp(str, "DEBUG_FUNCTION") || !strcmp(str, "FUNCTION")) {
 301                 return LTTNG_LOGLEVEL_DEBUG_FUNCTION;
 302         } else if (!strcmp(str, "TRACE_DEBUG_LINE") || !strcmp(str, "DEBUG_LINE") || !strcmp(str, "LINE")) {
 303                 return LTTNG_LOGLEVEL_DEBUG_LINE;
 304         } else if (!strcmp(str, "TRACE_DEBUG") || !strcmp(str, "DEBUG")) {
 305                 return LTTNG_LOGLEVEL_DEBUG;
 306         } else {
 307                 return -1;
 308         }
 309 }
 310
 311 /*
 312  * Enabling event using the lttng API.
 313  */
 314 static int enable_events(char *session_name)
 315 {
 316         int err, ret = CMD_SUCCESS, warn = 0;
 317         char *event_name, *channel_name = NULL;
 318         struct lttng_event ev;
 319         struct lttng_domain dom;
 320
 321         memset(&ev, 0, sizeof(ev));
 322         memset(&dom, 0, sizeof(dom));
 323
 324         if (opt_kernel) {
 325                 if (opt_filter) {
 326                         ERR("Filter not implement for kernel tracing yet");
 327                         ret = CMD_ERROR;
 328                         goto error;
 329                 }
 330         }
 331
 332         /* Create lttng domain */
 333         if (opt_kernel) {
 334                 dom.type = LTTNG_DOMAIN_KERNEL;
 335                 dom.buf_type = LTTNG_BUFFER_GLOBAL;
 336         } else if (opt_userspace) {
 337                 dom.type = LTTNG_DOMAIN_UST;
 338                 /* Default. */
 339                 dom.buf_type = LTTNG_BUFFER_PER_PID;
 340         } else {
 341                 ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
 342                 ret = CMD_ERROR;
 343                 goto error;
 344         }
 345
 346         if (opt_channel_name == NULL) {
 347                 err = asprintf(&channel_name, DEFAULT_CHANNEL_NAME);
 348                 if (err < 0) {
 349                         ret = CMD_FATAL;
 350                         goto error;
 351                 }
 352         } else {
 353                 channel_name = opt_channel_name;
 354         }
 355
 356         handle = lttng_create_handle(session_name, &dom);
 357         if (handle == NULL) {
 358                 ret = -1;
 359                 goto error;
 360         }
 361
 362         if (opt_enable_all) {
 363                 /* Default setup for enable all */
 364                 if (opt_kernel) {
 365                         ev.type = opt_event_type;
 366                         ev.name[0] = '\0';
 367                         /* kernel loglevels not implemented */
 368                         ev.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
 369                 } else {
 370                         ev.type = LTTNG_EVENT_TRACEPOINT;
 371                         strcpy(ev.name, "*");
 372                         ev.loglevel_type = opt_loglevel_type;
 373                         if (opt_loglevel) {
 374                                 ev.loglevel = loglevel_str_to_value(opt_loglevel);
 375                                 if (ev.loglevel == -1) {
 376                                         ERR("Unknown loglevel %s", opt_loglevel);
 377                                         ret = -LTTNG_ERR_INVALID;
 378                                         goto error;
 379                                 }
 380                         } else {
 381                                 ev.loglevel = -1;
 382                         }
 383                 }
 384
 385                 if (!opt_filter) {
 386                         ret = lttng_enable_event(handle, &ev, channel_name);
 387                         if (ret < 0) {
 388                                 switch (-ret) {
 389                                 case LTTNG_ERR_KERN_EVENT_EXIST:
 390                                         WARN("Kernel events already enabled (channel %s, session %s)",
 391                                                         channel_name, session_name);
 392                                         break;
 393                                 default:
 394                                         ERR("Events: %s (channel %s, session %s)",
 395                                                         lttng_strerror(ret), channel_name, session_name);
 396                                         break;
 397                                 }
 398                                 goto end;
 399                         }
 400
 401                         switch (opt_event_type) {
 402                         case LTTNG_EVENT_TRACEPOINT:
 403                                 if (opt_loglevel) {
 404                                         MSG("All %s tracepoints are enabled in channel %s for loglevel %s",
 405                                                         opt_kernel ? "kernel" : "UST", channel_name,
 406                                                         opt_loglevel);
 407                                 } else {
 408                                         MSG("All %s tracepoints are enabled in channel %s",
 409                                                         opt_kernel ? "kernel" : "UST", channel_name);
 410
 411                                 }
 412                                 break;
 413                         case LTTNG_EVENT_SYSCALL:
 414                                 if (opt_kernel) {
 415                                         MSG("All kernel system calls are enabled in channel %s",
 416                                                         channel_name);
 417                                 }
 418                                 break;
 419                         case LTTNG_EVENT_ALL:
 420                                 if (opt_loglevel) {
 421                                         MSG("All %s events are enabled in channel %s for loglevel %s",
 422                                                         opt_kernel ? "kernel" : "UST", channel_name,
 423                                                         opt_loglevel);
 424                                 } else {
 425                                         MSG("All %s events are enabled in channel %s",
 426                                                         opt_kernel ? "kernel" : "UST", channel_name);
 427                                 }
 428                                 break;
 429                         default:
 430                                 /*
 431                                  * We should not be here since lttng_enable_event should have
 432                                  * failed on the event type.
 433                                  */
 434                                 goto error;
 435                         }
 436                 }
 437                 if (opt_filter) {
 438                         ret = lttng_enable_event_with_filter(handle, &ev, channel_name,
 439                                                 opt_filter);
 440                         if (ret < 0) {
 441                                 switch (-ret) {
 442                                 case LTTNG_ERR_FILTER_EXIST:
 443                                         WARN("Filter on events is already enabled"
 444                                                         " (channel %s, session %s)",
 445                                                 channel_name, session_name);
 446                                         break;
 447                                 case LTTNG_ERR_FILTER_INVAL:
 448                                 case LTTNG_ERR_FILTER_NOMEM:
 449                                 default:
 450                                         ERR("%s", lttng_strerror(ret));
 451                                         break;
 452                                 }
 453                                 goto error;
 454                         } else {
 455                                 MSG("Filter '%s' successfully set", opt_filter);
 456                         }
 457                 }
 458                 goto end;
 459         }
 460
 461         /* Strip event list */
 462         event_name = strtok(opt_event_list, ",");
 463         while (event_name != NULL) {
 464                 /* Copy name and type of the event */
 465                 strncpy(ev.name, event_name, LTTNG_SYMBOL_NAME_LEN);
 466                 ev.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 467                 ev.type = opt_event_type;
 468
 469                 /* Kernel tracer action */
 470                 if (opt_kernel) {
 471                         DBG("Enabling kernel event %s for channel %s",
 472                                         event_name, channel_name);
 473
 474                         switch (opt_event_type) {
 475                         case LTTNG_EVENT_ALL:   /* Default behavior is tracepoint */
 476                                 ev.type = LTTNG_EVENT_TRACEPOINT;
 477                                 /* Fall-through */
 478                         case LTTNG_EVENT_TRACEPOINT:
 479                                 break;
 480                         case LTTNG_EVENT_PROBE:
 481                                 ret = parse_probe_opts(&ev, opt_probe);
 482                                 if (ret < 0) {
 483                                         ERR("Unable to parse probe options");
 484                                         ret = 0;
 485                                         goto error;
 486                                 }
 487                                 break;
 488                         case LTTNG_EVENT_FUNCTION:
 489                                 ret = parse_probe_opts(&ev, opt_function);
 490                                 if (ret < 0) {
 491                                         ERR("Unable to parse function probe options");
 492                                         ret = 0;
 493                                         goto error;
 494                                 }
 495                                 break;
 496                         case LTTNG_EVENT_FUNCTION_ENTRY:
 497                                 strncpy(ev.attr.ftrace.symbol_name, opt_function_entry_symbol,
 498                                                 LTTNG_SYMBOL_NAME_LEN);
 499                                 ev.attr.ftrace.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 500                                 break;
 501                         case LTTNG_EVENT_SYSCALL:
 502                                 MSG("per-syscall selection not supported yet. Use \"-a\" "
 503                                                 "for all syscalls.");
 504                         default:
 505                                 ret = CMD_UNDEFINED;
 506                                 goto error;
 507                         }
 508
 509                         if (opt_loglevel) {
 510                                 MSG("Kernel loglevels are not supported.");
 511                                 ret = CMD_UNSUPPORTED;
 512                                 goto error;
 513                         }
 514
 515                         /* kernel loglevels not implemented */
 516                         ev.loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
 517                 } else if (opt_userspace) {             /* User-space tracer action */
 518 #if 0
 519                         if (opt_cmd_name != NULL || opt_pid) {
 520                                 MSG("Only supporting tracing all UST processes (-u) for now.");
 521                                 ret = CMD_UNDEFINED;
 522                                 goto error;
 523                         }
 524 #endif
 525
 526                         DBG("Enabling UST event %s for channel %s, loglevel %s", event_name,
 527                                         channel_name, opt_loglevel ? : "<all>");
 528
 529                         switch (opt_event_type) {
 530                         case LTTNG_EVENT_ALL:   /* Default behavior is tracepoint */
 531                                 /* Fall-through */
 532                         case LTTNG_EVENT_TRACEPOINT:
 533                                 /* Copy name and type of the event */
 534                                 ev.type = LTTNG_EVENT_TRACEPOINT;
 535                                 strncpy(ev.name, event_name, LTTNG_SYMBOL_NAME_LEN);
 536                                 ev.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 537                                 break;
 538                         case LTTNG_EVENT_PROBE:
 539                         case LTTNG_EVENT_FUNCTION:
 540                         case LTTNG_EVENT_FUNCTION_ENTRY:
 541                         case LTTNG_EVENT_SYSCALL:
 542                         default:
 543                                 ERR("Event type not available for user-space tracing");
 544                                 ret = CMD_UNSUPPORTED;
 545                                 goto error;
 546                         }
 547
 548                         ev.loglevel_type = opt_loglevel_type;
 549                         if (opt_loglevel) {
 550                                 ev.loglevel = loglevel_str_to_value(opt_loglevel);
 551                                 if (ev.loglevel == -1) {
 552                                         ERR("Unknown loglevel %s", opt_loglevel);
 553                                         ret = -LTTNG_ERR_INVALID;
 554                                         goto error;
 555                                 }
 556                         } else {
 557                                 ev.loglevel = -1;
 558                         }
 559                 } else {
 560                         ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
 561                         ret = CMD_ERROR;
 562                         goto error;
 563                 }
 564
 565                 if (!opt_filter) {
 566                         ret = lttng_enable_event(handle, &ev, channel_name);
 567                         if (ret < 0) {
 568                                 /* Turn ret to positive value to handle the positive error code */
 569                                 switch (-ret) {
 570                                 case LTTNG_ERR_KERN_EVENT_EXIST:
 571                                         WARN("Kernel event %s already enabled (channel %s, session %s)",
 572                                                         event_name, channel_name, session_name);
 573                                         break;
 574                                 default:
 575                                         ERR("Event %s: %s (channel %s, session %s)", event_name,
 576                                                         lttng_strerror(ret), channel_name, session_name);
 577                                         break;
 578                                 }
 579                                 warn = 1;
 580                         } else {
 581                                 MSG("%s event %s created in channel %s",
 582                                                 opt_kernel ? "kernel": "UST", event_name, channel_name);
 583                         }
 584                 }
 585
 586                 if (opt_filter) {
 587                         ret = lttng_enable_event_with_filter(handle, &ev, channel_name,
 588                                         opt_filter);
 589                         if (ret < 0) {
 590                                 switch (-ret) {
 591                                 case LTTNG_ERR_FILTER_EXIST:
 592                                         WARN("Filter on event %s is already enabled"
 593                                                         " (channel %s, session %s)",
 594                                                 event_name, channel_name, session_name);
 595                                         break;
 596                                 case LTTNG_ERR_FILTER_INVAL:
 597                                 case LTTNG_ERR_FILTER_NOMEM:
 598                                         ERR("%s", lttng_strerror(ret));
 599                                 default:
 600                                         ERR("Setting filter for event %s: '%s'", ev.name,
 601                                                         opt_filter);
 602                                         break;
 603                                 }
 604                                 goto error;
 605                         } else {
 606                                 MSG("Filter '%s' successfully set", opt_filter);
 607                         }
 608                 }
 609
 610                 /* Next event */
 611                 event_name = strtok(NULL, ",");
 612         }
 613
 614 end:
 615 error:
 616         if (warn) {
 617                 ret = CMD_WARNING;
 618         }
 619         if (opt_channel_name == NULL) {
 620                 free(channel_name);
 621         }
 622         lttng_destroy_handle(handle);
 623
 624         return ret;
 625 }
 626
 627 /*
 628  * Add event to trace session
 629  */
 630 int cmd_enable_events(int argc, const char **argv)
 631 {
 632         int opt, ret = CMD_SUCCESS;
 633         static poptContext pc;
 634         char *session_name = NULL;
 635         int event_type = -1;
 636
 637         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 638         poptReadDefaultConfig(pc, 0);
 639
 640         /* Default event type */
 641         opt_event_type = LTTNG_EVENT_ALL;
 642
 643         while ((opt = poptGetNextOpt(pc)) != -1) {
 644                 switch (opt) {
 645                 case OPT_HELP:
 646                         usage(stdout);
 647                         goto end;
 648                 case OPT_TRACEPOINT:
 649                         opt_event_type = LTTNG_EVENT_TRACEPOINT;
 650                         break;
 651                 case OPT_PROBE:
 652                         opt_event_type = LTTNG_EVENT_PROBE;
 653                         break;
 654                 case OPT_FUNCTION:
 655                         opt_event_type = LTTNG_EVENT_FUNCTION;
 656                         break;
 657                 case OPT_FUNCTION_ENTRY:
 658                         opt_event_type = LTTNG_EVENT_FUNCTION_ENTRY;
 659                         break;
 660                 case OPT_SYSCALL:
 661                         opt_event_type = LTTNG_EVENT_SYSCALL;
 662                         break;
 663                 case OPT_USERSPACE:
 664                         opt_userspace = 1;
 665                         break;
 666                 case OPT_LOGLEVEL:
 667                         opt_loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
 668                         opt_loglevel = poptGetOptArg(pc);
 669                         break;
 670                 case OPT_LOGLEVEL_ONLY:
 671                         opt_loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
 672                         opt_loglevel = poptGetOptArg(pc);
 673                         break;
 674                 case OPT_LIST_OPTIONS:
 675                         list_cmd_options(stdout, long_options);
 676                         goto end;
 677                 case OPT_FILTER:
 678                         break;
 679                 default:
 680                         usage(stderr);
 681                         ret = CMD_UNDEFINED;
 682                         goto end;
 683                 }
 684
 685                 /* Validate event type. Multiple event type are not supported. */
 686                 if (event_type == -1) {
 687                         event_type = opt_event_type;
 688                 } else {
 689                         if (event_type != opt_event_type) {
 690                                 ERR("Multiple event type not supported.");
 691                                 ret = CMD_ERROR;
 692                                 goto end;
 693                         }
 694                 }
 695         }
 696
 697         opt_event_list = (char*) poptGetArg(pc);
 698         if (opt_event_list == NULL && opt_enable_all == 0) {
 699                 ERR("Missing event name(s).\n");
 700                 usage(stderr);
 701                 ret = CMD_ERROR;
 702                 goto end;
 703         }
 704
 705         if (!opt_session_name) {
 706                 session_name = get_session_name();
 707                 if (session_name == NULL) {
 708                         ret = CMD_ERROR;
 709                         goto end;
 710                 }
 711         } else {
 712                 session_name = opt_session_name;
 713         }
 714
 715         ret = enable_events(session_name);
 716
 717 end:
 718         if (opt_session_name == NULL) {
 719                 free(session_name);
 720         }
 721
 722         poptFreeContext(pc);
 723         return ret;
 724 }