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
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17  */
  18
  19 #define _GNU_SOURCE
  20 #include <popt.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <sys/stat.h>
  25 #include <sys/types.h>
  26 #include <unistd.h>
  27
  28 #include "cmd.h"
  29 #include "conf.h"
  30 #include "utils.h"
  31
  32 static char *opt_event_list;
  33 static int opt_event_type;
  34 static char *opt_kernel;
  35 static char *opt_cmd_name;
  36 static char *opt_session_name;
  37 static int opt_pid_all;
  38 static int opt_userspace;
  39 static int opt_enable_all;
  40 static pid_t opt_pid;
  41 static char *opt_kprobe;
  42 static char *opt_function_symbol;
  43 static char *opt_channel_name;
  44
  45 enum {
  46         OPT_HELP = 1,
  47         OPT_USERSPACE,
  48         OPT_TRACEPOINT,
  49         OPT_MARKER,
  50         OPT_KPROBE,
  51         OPT_FUNCTION,
  52 };
  53
  54 static struct poptOption long_options[] = {
  55         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  56         {"help",           'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  57         {"session",        's', POPT_ARG_STRING, &opt_session_name, 0, 0, 0},
  58         {"all-events",     'a', POPT_ARG_VAL, &opt_enable_all, 1, 0, 0},
  59         {"channel",        'c', POPT_ARG_STRING, &opt_channel_name, 0, 0, 0},
  60         {"kernel",         'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
  61         {"userspace",      'u', POPT_ARG_STRING | POPT_ARGFLAG_OPTIONAL, 0, OPT_USERSPACE, 0, 0},
  62         {"all",            0,   POPT_ARG_VAL, &opt_pid_all, 1, 0, 0},
  63         {"pid",            'p', POPT_ARG_INT, &opt_pid, 0, 0, 0},
  64         {"tracepoint",     0,   POPT_ARG_NONE, 0, OPT_TRACEPOINT, 0, 0},
  65         {"marker",         0,   POPT_ARG_NONE, 0, OPT_MARKER, 0, 0},
  66         {"kprobe",         0,   POPT_ARG_STRING, 0, OPT_KPROBE, 0, 0},
  67         {"function",       0,   POPT_ARG_STRING, 0, OPT_FUNCTION, 0, 0},
  68         {0, 0, 0, 0, 0, 0, 0}
  69 };
  70
  71 /*
  72  * usage
  73  */
  74 static void usage(FILE *ofp)
  75 {
  76         fprintf(ofp, "usage: lttng enable-event NAME[,NAME2,...] [options] [event_options]\n");
  77         fprintf(ofp, "\n");
  78         fprintf(ofp, "  -h, --help               Show this help\n");
  79         fprintf(ofp, "  -s, --session            Apply on session name\n");
  80         fprintf(ofp, "  -c, --channel            Apply on this channel\n");
  81         fprintf(ofp, "  -a, --all-events         Enable all tracepoints\n");
  82         fprintf(ofp, "  -k, --kernel             Apply for the kernel tracer\n");
  83         fprintf(ofp, "  -u, --userspace [CMD]    Apply for the user-space tracer\n");
  84         fprintf(ofp, "      --all                If -u, apply on all traceable apps\n");
  85         fprintf(ofp, "  -p, --pid PID            If -u, apply on a specific PID\n");
  86         fprintf(ofp, "\n");
  87         fprintf(ofp, "Event options:\n");
  88         fprintf(ofp, "    --tracepoint           Tracepoint event (default)\n");
  89         fprintf(ofp, "    --kprobe [addr | symbol+offset]\n");
  90         fprintf(ofp, "                           Kernel Kprobe. (addr or offset can be base 8,10 and 16)\n");
  91         fprintf(ofp, "    --function SYMBOL      Function tracer event\n");
  92         fprintf(ofp, "    --marker               User-space marker (deprecated)\n");
  93         fprintf(ofp, "\n");
  94 }
  95
  96 /*
  97  *  parse_kprobe_addr
  98  *
  99  *  Parse kprobe options.
 100  */
 101 static int parse_kprobe_opts(struct lttng_event *ev, char *opt)
 102 {
 103         int ret;
 104         uint64_t hex;
 105         char name[LTTNG_SYMBOL_NAME_LEN];
 106
 107         if (opt == NULL) {
 108                 ret = -1;
 109                 goto error;
 110         }
 111
 112         /* Check for symbol+offset */
 113         ret = sscanf(opt, "%[^'+']+%li", name, &hex);
 114         if (ret == 2) {
 115                 strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN);
 116                 DBG("kprobe symbol %s", ev->attr.probe.symbol_name);
 117                 if (hex == 0) {
 118                         ERR("Invalid kprobe offset %lu", hex);
 119                         ret = -1;
 120                         goto error;
 121                 }
 122                 ev->attr.probe.offset = hex;
 123                 DBG("kprobe offset %lu", ev->attr.probe.offset);
 124                 goto error;
 125         }
 126
 127         /* Check for address */
 128         ret = sscanf(opt, "%li", &hex);
 129         if (ret > 0) {
 130                 if (hex == 0) {
 131                         ERR("Invalid kprobe address %lu", hex);
 132                         ret = -1;
 133                         goto error;
 134                 }
 135                 ev->attr.probe.addr = hex;
 136                 DBG("kprobe addr %lu", ev->attr.probe.addr);
 137                 goto error;
 138         }
 139
 140         /* No match */
 141         ret = -1;
 142
 143 error:
 144         return ret;
 145 }
 146
 147 /*
 148  *  enable_events
 149  *
 150  *  Enabling event using the lttng API.
 151  */
 152 static int enable_events(void)
 153 {
 154         int err, ret = CMD_SUCCESS;
 155         char *event_name, *channel_name = NULL;
 156         struct lttng_event ev;
 157         struct lttng_domain dom;
 158
 159         if (set_session_name(opt_session_name) < 0) {
 160                 ret = CMD_ERROR;
 161                 goto error;
 162         }
 163
 164         if (opt_channel_name == NULL) {
 165                 err = asprintf(&channel_name, DEFAULT_CHANNEL_NAME);
 166                 if (err < 0) {
 167                         ret = CMD_FATAL;
 168                         goto error;
 169                 }
 170         } else {
 171                 channel_name = opt_channel_name;
 172         }
 173
 174         /* Create lttng domain */
 175         if (opt_kernel) {
 176                 dom.type = LTTNG_DOMAIN_KERNEL;
 177         }
 178
 179         if (opt_enable_all) {
 180                 if (opt_kernel) {
 181                         ret = lttng_enable_event(&dom, NULL, channel_name);
 182                         goto error;
 183                 }
 184
 185                 /* TODO: User-space tracer */
 186         }
 187
 188         /* Strip event list */
 189         event_name = strtok(opt_event_list, ",");
 190         while (event_name != NULL) {
 191                 /* Kernel tracer action */
 192                 if (opt_kernel) {
 193                         DBG("Enabling kernel event %s for channel %s",
 194                                         event_name, channel_name);
 195                         /* Copy name and type of the event */
 196                         strncpy(ev.name, event_name, LTTNG_SYMBOL_NAME_LEN);
 197                         ev.type = opt_event_type;
 198
 199                         switch (opt_event_type) {
 200                         case LTTNG_EVENT_TRACEPOINT:
 201                                 break;
 202                         case LTTNG_EVENT_PROBE:
 203                                 ret = parse_kprobe_opts(&ev, opt_kprobe);
 204                                 if (ret < 0) {
 205                                         ERR("Unable to parse kprobe options");
 206                                         ret = 0;
 207                                         goto error;
 208                                 }
 209                                 break;
 210                         case LTTNG_EVENT_FUNCTION:
 211                                 strncpy(ev.attr.ftrace.symbol_name, opt_function_symbol, LTTNG_SYMBOL_NAME_LEN);
 212                                 break;
 213                         default:
 214                                 ret = CMD_NOT_IMPLEMENTED;
 215                                 goto error;
 216                         }
 217
 218                         ret = lttng_enable_event(&dom, &ev, channel_name);
 219                         if (ret == 0) {
 220                                 MSG("Kernel event %s created in channel %s", event_name, channel_name);
 221                         } else if (ret < 0) {
 222                                 ERR("Unable to find event %s", ev.name);
 223                         }
 224                 } else if (opt_userspace) {             /* User-space tracer action */
 225                         /*
 226                          * TODO: Waiting on lttng UST 2.0
 227                          */
 228                         if (opt_pid_all) {
 229                         } else if (opt_pid != 0) {
 230                         }
 231                         ret = CMD_NOT_IMPLEMENTED;
 232                         goto error;
 233                 } else {
 234                         ERR("Please specify a tracer (kernel or user-space)");
 235                         goto error;
 236                 }
 237
 238                 /* Next event */
 239                 event_name = strtok(NULL, ",");
 240         }
 241
 242 error:
 243         if (opt_channel_name == NULL) {
 244                 free(channel_name);
 245         }
 246         return ret;
 247 }
 248
 249 /*
 250  *  cmd_enable_events
 251  *
 252  *  Add event to trace session
 253  */
 254 int cmd_enable_events(int argc, const char **argv)
 255 {
 256         int opt, ret;
 257         static poptContext pc;
 258
 259         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 260         poptReadDefaultConfig(pc, 0);
 261
 262         /* Default event type */
 263         opt_event_type = LTTNG_EVENT_TRACEPOINT;
 264
 265         while ((opt = poptGetNextOpt(pc)) != -1) {
 266                 switch (opt) {
 267                 case OPT_HELP:
 268                         usage(stderr);
 269                         ret = CMD_SUCCESS;
 270                         goto end;
 271                 case OPT_USERSPACE:
 272                         opt_userspace = 1;
 273                         opt_cmd_name = poptGetOptArg(pc);
 274                         break;
 275                 case OPT_TRACEPOINT:
 276                         opt_event_type = LTTNG_EVENT_TRACEPOINT;
 277                         break;
 278                 case OPT_MARKER:
 279                         ret = CMD_NOT_IMPLEMENTED;
 280                         goto end;
 281                 case OPT_KPROBE:
 282                         opt_event_type = LTTNG_EVENT_PROBE;
 283                         opt_kprobe = poptGetOptArg(pc);
 284                         break;
 285                 case OPT_FUNCTION:
 286                         opt_event_type = LTTNG_EVENT_FUNCTION;
 287                         opt_function_symbol = poptGetOptArg(pc);
 288                         break;
 289                 default:
 290                         usage(stderr);
 291                         ret = CMD_UNDEFINED;
 292                         goto end;
 293                 }
 294         }
 295
 296         opt_event_list = (char*) poptGetArg(pc);
 297         if (opt_event_list == NULL && opt_enable_all == 0) {
 298                 ERR("Missing event name(s).\n");
 299                 usage(stderr);
 300                 ret = CMD_SUCCESS;
 301                 goto end;
 302         }
 303
 304         ret = enable_events();
 305
 306 end:
 307         return ret;
 308 }