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; only version 2
   7  * of the License.
   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 #include <inttypes.h>
  28
  29 #include "../cmd.h"
  30 #include "../conf.h"
  31 #include "../utils.h"
  32
  33 static char *opt_event_list;
  34 static int opt_event_type;
  35 static char *opt_kernel;
  36 static char *opt_cmd_name;
  37 static char *opt_session_name;
  38 static int opt_pid_all;
  39 static int opt_userspace;
  40 static int opt_enable_all;
  41 static pid_t opt_pid;
  42 static char *opt_kprobe;
  43 static char *opt_function_symbol;
  44 static char *opt_channel_name;
  45
  46 enum {
  47         OPT_HELP = 1,
  48         OPT_USERSPACE,
  49         OPT_TRACEPOINT,
  50         OPT_MARKER,
  51         OPT_KPROBE,
  52         OPT_FUNCTION,
  53 };
  54
  55 static struct poptOption long_options[] = {
  56         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  57         {"help",           'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  58         {"session",        's', POPT_ARG_STRING, &opt_session_name, 0, 0, 0},
  59         {"all-events",     'a', POPT_ARG_VAL, &opt_enable_all, 1, 0, 0},
  60         {"channel",        'c', POPT_ARG_STRING, &opt_channel_name, 0, 0, 0},
  61         {"kernel",         'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
  62         {"userspace",      'u', POPT_ARG_STRING | POPT_ARGFLAG_OPTIONAL, 0, OPT_USERSPACE, 0, 0},
  63         {"all",            0,   POPT_ARG_VAL, &opt_pid_all, 1, 0, 0},
  64         {"pid",            'p', POPT_ARG_INT, &opt_pid, 0, 0, 0},
  65         {"tracepoint",     0,   POPT_ARG_NONE, 0, OPT_TRACEPOINT, 0, 0},
  66         {"marker",         0,   POPT_ARG_NONE, 0, OPT_MARKER, 0, 0},
  67         {"kprobe",         0,   POPT_ARG_STRING, 0, OPT_KPROBE, 0, 0},
  68         {"function",       0,   POPT_ARG_STRING, 0, OPT_FUNCTION, 0, 0},
  69         {0, 0, 0, 0, 0, 0, 0}
  70 };
  71
  72 /*
  73  * usage
  74  */
  75 static void usage(FILE *ofp)
  76 {
  77         fprintf(ofp, "usage: lttng enable-event NAME[,NAME2,...] [options] [event_options]\n");
  78         fprintf(ofp, "\n");
  79         fprintf(ofp, "  -h, --help               Show this help\n");
  80         fprintf(ofp, "  -s, --session            Apply on session name\n");
  81         fprintf(ofp, "  -c, --channel            Apply on this channel\n");
  82         fprintf(ofp, "  -a, --all-events         Enable all tracepoints\n");
  83         fprintf(ofp, "  -k, --kernel             Apply for the kernel tracer\n");
  84         fprintf(ofp, "  -u, --userspace [CMD]    Apply for the user-space tracer\n");
  85         fprintf(ofp, "      --all                If -u, apply on all traceable apps\n");
  86         fprintf(ofp, "  -p, --pid PID            If -u, apply on a specific PID\n");
  87         fprintf(ofp, "\n");
  88         fprintf(ofp, "Event options:\n");
  89         fprintf(ofp, "    --tracepoint           Tracepoint event (default)\n");
  90         fprintf(ofp, "    --kprobe [addr | symbol+offset]\n");
  91         fprintf(ofp, "                           Kernel Kprobe. (addr or offset can be base 8,10 and 16)\n");
  92         fprintf(ofp, "    --function SYMBOL      Function tracer event\n");
  93         fprintf(ofp, "    --marker               User-space marker (deprecated)\n");
  94         fprintf(ofp, "\n");
  95 }
  96
  97 /*
  98  *  parse_kprobe_addr
  99  *
 100  *  Parse kprobe options.
 101  */
 102 static int parse_kprobe_opts(struct lttng_event *ev, char *opt)
 103 {
 104         int ret;
 105         uint64_t hex;
 106         char name[LTTNG_SYMBOL_NAME_LEN];
 107
 108         if (opt == NULL) {
 109                 ret = -1;
 110                 goto error;
 111         }
 112
 113         /* Check for symbol+offset */
 114         ret = sscanf(opt, "%[^'+']+%" SCNu64, name, &hex);
 115         if (ret == 2) {
 116                 strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN);
 117                 DBG("kprobe symbol %s", ev->attr.probe.symbol_name);
 118                 if (hex == 0) {
 119                         ERR("Invalid kprobe offset %" PRIu64, hex);
 120                         ret = -1;
 121                         goto error;
 122                 }
 123                 ev->attr.probe.offset = hex;
 124                 DBG("kprobe offset %" PRIu64, ev->attr.probe.offset);
 125                 goto error;
 126         }
 127
 128         /* Check for address */
 129         ret = sscanf(opt, "%" SCNu64, &hex);
 130         if (ret > 0) {
 131                 if (hex == 0) {
 132                         ERR("Invalid kprobe address %" PRIu64, hex);
 133                         ret = -1;
 134                         goto error;
 135                 }
 136                 ev->attr.probe.addr = hex;
 137                 DBG("kprobe addr %" PRIu64, ev->attr.probe.addr);
 138                 goto error;
 139         }
 140
 141         /* No match */
 142         ret = -1;
 143
 144 error:
 145         return ret;
 146 }
 147
 148 /*
 149  *  enable_events
 150  *
 151  *  Enabling event using the lttng API.
 152  */
 153 static int enable_events(void)
 154 {
 155         int err, ret = CMD_SUCCESS;
 156         char *event_name, *channel_name = NULL;
 157         struct lttng_event ev;
 158         struct lttng_domain dom;
 159
 160         if (set_session_name(opt_session_name) < 0) {
 161                 ret = CMD_ERROR;
 162                 goto error;
 163         }
 164
 165         if (opt_channel_name == NULL) {
 166                 err = asprintf(&channel_name, DEFAULT_CHANNEL_NAME);
 167                 if (err < 0) {
 168                         ret = CMD_FATAL;
 169                         goto error;
 170                 }
 171         } else {
 172                 channel_name = opt_channel_name;
 173         }
 174
 175         /* Create lttng domain */
 176         if (opt_kernel) {
 177                 dom.type = LTTNG_DOMAIN_KERNEL;
 178         }
 179
 180         if (opt_enable_all) {
 181                 if (opt_kernel) {
 182                         ret = lttng_enable_event(&dom, NULL, channel_name);
 183                         if (ret == 0) {
 184                                 MSG("All kernel events are enabled in channel %s", channel_name);
 185                         }
 186                         goto error;
 187                 }
 188
 189                 /* TODO: User-space tracer */
 190         }
 191
 192         /* Strip event list */
 193         event_name = strtok(opt_event_list, ",");
 194         while (event_name != NULL) {
 195                 /* Kernel tracer action */
 196                 if (opt_kernel) {
 197                         DBG("Enabling kernel event %s for channel %s",
 198                                         event_name, channel_name);
 199                         /* Copy name and type of the event */
 200                         strncpy(ev.name, event_name, LTTNG_SYMBOL_NAME_LEN);
 201                         ev.type = opt_event_type;
 202
 203                         switch (opt_event_type) {
 204                         case LTTNG_EVENT_TRACEPOINT:
 205                                 break;
 206                         case LTTNG_EVENT_PROBE:
 207                                 ret = parse_kprobe_opts(&ev, opt_kprobe);
 208                                 if (ret < 0) {
 209                                         ERR("Unable to parse kprobe options");
 210                                         ret = 0;
 211                                         goto error;
 212                                 }
 213                                 break;
 214                         case LTTNG_EVENT_FUNCTION:
 215                                 strncpy(ev.attr.ftrace.symbol_name, opt_function_symbol, LTTNG_SYMBOL_NAME_LEN);
 216                                 break;
 217                         default:
 218                                 ret = CMD_NOT_IMPLEMENTED;
 219                                 goto error;
 220                         }
 221
 222                         ret = lttng_enable_event(&dom, &ev, channel_name);
 223                         if (ret == 0) {
 224                                 MSG("Kernel event %s created in channel %s", event_name, channel_name);
 225                         } else if (ret < 0) {
 226                                 ERR("Unable to find event %s", ev.name);
 227                         }
 228                 } else if (opt_userspace) {             /* User-space tracer action */
 229                         /*
 230                          * TODO: Waiting on lttng UST 2.0
 231                          */
 232                         if (opt_pid_all) {
 233                         } else if (opt_pid != 0) {
 234                         }
 235                         ret = CMD_NOT_IMPLEMENTED;
 236                         goto error;
 237                 } else {
 238                         ERR("Please specify a tracer (kernel or user-space)");
 239                         goto error;
 240                 }
 241
 242                 /* Next event */
 243                 event_name = strtok(NULL, ",");
 244         }
 245
 246 error:
 247         if (opt_channel_name == NULL) {
 248                 free(channel_name);
 249         }
 250         return ret;
 251 }
 252
 253 /*
 254  *  cmd_enable_events
 255  *
 256  *  Add event to trace session
 257  */
 258 int cmd_enable_events(int argc, const char **argv)
 259 {
 260         int opt, ret;
 261         static poptContext pc;
 262
 263         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 264         poptReadDefaultConfig(pc, 0);
 265
 266         /* Default event type */
 267         opt_event_type = LTTNG_EVENT_TRACEPOINT;
 268
 269         while ((opt = poptGetNextOpt(pc)) != -1) {
 270                 switch (opt) {
 271                 case OPT_HELP:
 272                         usage(stderr);
 273                         ret = CMD_SUCCESS;
 274                         goto end;
 275                 case OPT_USERSPACE:
 276                         opt_userspace = 1;
 277                         opt_cmd_name = poptGetOptArg(pc);
 278                         break;
 279                 case OPT_TRACEPOINT:
 280                         opt_event_type = LTTNG_EVENT_TRACEPOINT;
 281                         break;
 282                 case OPT_MARKER:
 283                         ret = CMD_NOT_IMPLEMENTED;
 284                         goto end;
 285                 case OPT_KPROBE:
 286                         opt_event_type = LTTNG_EVENT_PROBE;
 287                         opt_kprobe = poptGetOptArg(pc);
 288                         break;
 289                 case OPT_FUNCTION:
 290                         opt_event_type = LTTNG_EVENT_FUNCTION;
 291                         opt_function_symbol = poptGetOptArg(pc);
 292                         break;
 293                 default:
 294                         usage(stderr);
 295                         ret = CMD_UNDEFINED;
 296                         goto end;
 297                 }
 298         }
 299
 300         opt_event_list = (char*) poptGetArg(pc);
 301         if (opt_event_list == NULL && opt_enable_all == 0) {
 302                 ERR("Missing event name(s).\n");
 303                 usage(stderr);
 304                 ret = CMD_SUCCESS;
 305                 goto end;
 306         }
 307
 308         ret = enable_events();
 309
 310 end:
 311         return ret;
 312 }