lttng-sessiond/context.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 it
   5  * under the terms of the GNU General Public License as published by the Free
   6  * Software Foundation; only version 2 of the License.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA  02111-1307, USA.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23 #include <urcu/list.h>
  24
  25 #include <lttng-sessiond-comm.h>
  26 #include <lttngerr.h>
  27
  28 #include "context.h"
  29 #include "hashtable.h"
  30 #include "kernel.h"
  31 #include "ust-app.h"
  32 #include "trace-ust.h"
  33
  34 /*
  35  * Add kernel context to an event of a specific channel.
  36  */
  37 static int add_kctx_to_event(struct lttng_kernel_context *kctx,
  38                 struct ltt_kernel_channel *kchan, char *event_name)
  39 {
  40         int ret, found = 0;
  41         struct ltt_kernel_event *kevent;
  42
  43         DBG("Add kernel context to event %s", event_name);
  44
  45         kevent = trace_kernel_get_event_by_name(event_name, kchan);
  46         if (kevent != NULL) {
  47                 ret = kernel_add_event_context(kevent, kctx);
  48                 if (ret < 0) {
  49                         goto error;
  50                 }
  51                 found = 1;
  52         }
  53
  54         ret = found;
  55
  56 error:
  57         return ret;
  58 }
  59
  60 /*
  61  * Add kernel context to all channel.
  62  *
  63  * If event_name is specified, add context to event instead.
  64  */
  65 static int add_kctx_all_channels(struct ltt_kernel_session *ksession,
  66                 struct lttng_kernel_context *kctx, char *event_name)
  67 {
  68         int ret, no_event = 0, found = 0;
  69         struct ltt_kernel_channel *kchan;
  70
  71         if (strlen(event_name) == 0) {
  72                 no_event = 1;
  73         }
  74
  75         DBG("Adding kernel context to all channels (event: %s)", event_name);
  76
  77         /* Go over all channels */
  78         cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
  79                 if (no_event) {
  80                         ret = kernel_add_channel_context(kchan, kctx);
  81                         if (ret < 0) {
  82                                 ret = LTTCOMM_KERN_CONTEXT_FAIL;
  83                                 goto error;
  84                         }
  85                 } else {
  86                         ret = add_kctx_to_event(kctx, kchan, event_name);
  87                         if (ret < 0) {
  88                                 ret = LTTCOMM_KERN_CONTEXT_FAIL;
  89                                 goto error;
  90                         } else if (ret == 1) {
  91                                 /* Event found and context added */
  92                                 found = 1;
  93                                 break;
  94                         }
  95                 }
  96         }
  97
  98         if (!found && !no_event) {
  99                 ret = LTTCOMM_NO_EVENT;
 100                 goto error;
 101         }
 102
 103         ret = LTTCOMM_OK;
 104
 105 error:
 106         return ret;
 107 }
 108
 109 /*
 110  * Add kernel context to a specific channel.
 111  *
 112  * If event_name is specified, add context to that event.
 113  */
 114 static int add_kctx_to_channel(struct lttng_kernel_context *kctx,
 115                 struct ltt_kernel_channel *kchan, char *event_name)
 116 {
 117         int ret, no_event = 0, found = 0;
 118
 119         if (strlen(event_name) == 0) {
 120                 no_event = 1;
 121         }
 122
 123         DBG("Add kernel context to channel '%s', event '%s'",
 124                         kchan->channel->name, event_name);
 125
 126         if (no_event) {
 127                 ret = kernel_add_channel_context(kchan, kctx);
 128                 if (ret < 0) {
 129                         ret = LTTCOMM_KERN_CONTEXT_FAIL;
 130                         goto error;
 131                 }
 132         } else {
 133                 ret = add_kctx_to_event(kctx, kchan, event_name);
 134                 if (ret < 0) {
 135                         ret = LTTCOMM_KERN_CONTEXT_FAIL;
 136                         goto error;
 137                 } else if (ret == 1) {
 138                         /* Event found and context added */
 139                         found = 1;
 140                 }
 141         }
 142
 143         if (!found && !no_event) {
 144                 ret = LTTCOMM_NO_EVENT;
 145                 goto error;
 146         }
 147
 148         ret = LTTCOMM_OK;
 149
 150 error:
 151         return ret;
 152 }
 153
 154 /*
 155  * Add UST context to channel.
 156  */
 157 static int add_uctx_to_channel(struct ltt_ust_session *usess, int domain,
 158                 struct ltt_ust_channel *uchan, struct lttng_event_context *ctx)
 159 {
 160         int ret;
 161         struct ltt_ust_context *uctx;
 162
 163         /* Create ltt UST context */
 164         uctx = trace_ust_create_context(ctx);
 165         if (uctx == NULL) {
 166                 ret = LTTCOMM_FATAL;
 167                 goto error;
 168         }
 169
 170         switch (domain) {
 171         case LTTNG_DOMAIN_UST:
 172                 ret = ust_app_add_ctx_channel_glb(usess, uchan, uctx);
 173                 if (ret < 0) {
 174                         goto error;
 175                 }
 176                 break;
 177         default:
 178                 ret = LTTCOMM_NOT_IMPLEMENTED;
 179                 goto error;
 180         }
 181
 182         /* Add ltt UST context node to ltt UST channel */
 183         hashtable_add_unique(uchan->ctx, &uctx->node);
 184
 185         return LTTCOMM_OK;
 186
 187 error:
 188         free(uctx);
 189         return ret;
 190 }
 191
 192 /*
 193  * Add UST context to event.
 194  */
 195 static int add_uctx_to_event(struct ltt_ust_session *usess, int domain,
 196                 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent,
 197                 struct lttng_event_context *ctx)
 198 {
 199         int ret;
 200         struct ltt_ust_context *uctx;
 201
 202         /* Create ltt UST context */
 203         uctx = trace_ust_create_context(ctx);
 204         if (uctx == NULL) {
 205                 ret = LTTCOMM_FATAL;
 206                 goto error;
 207         }
 208
 209         switch (domain) {
 210         case LTTNG_DOMAIN_UST:
 211                 ret = ust_app_add_ctx_event_glb(usess, uchan, uevent, uctx);
 212                 if (ret < 0) {
 213                         goto error;
 214                 }
 215                 break;
 216         default:
 217                 ret = LTTCOMM_NOT_IMPLEMENTED;
 218                 goto error;
 219         }
 220
 221         /* Add ltt UST context node to ltt UST event */
 222         hashtable_add_unique(uevent->ctx, &uctx->node);
 223
 224         return LTTCOMM_OK;
 225
 226 error:
 227         free(uctx);
 228         return ret;
 229 }
 230
 231 /*
 232  * Add kernel context to tracer.
 233  */
 234 int context_kernel_add(struct ltt_kernel_session *ksession,
 235                 struct lttng_event_context *ctx, char *event_name,
 236                 char *channel_name)
 237 {
 238         int ret;
 239         struct ltt_kernel_channel *kchan;
 240         struct lttng_kernel_context kctx;
 241
 242         /* Setup kernel context structure */
 243         kctx.ctx = ctx->ctx;
 244         kctx.u.perf_counter.type = ctx->u.perf_counter.type;
 245         kctx.u.perf_counter.config = ctx->u.perf_counter.config;
 246         strncpy(kctx.u.perf_counter.name, ctx->u.perf_counter.name,
 247                         LTTNG_SYMBOL_NAME_LEN);
 248         kctx.u.perf_counter.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 249
 250         if (strlen(channel_name) == 0) {
 251                 ret = add_kctx_all_channels(ksession, &kctx, event_name);
 252                 if (ret != LTTCOMM_OK) {
 253                         goto error;
 254                 }
 255         } else {
 256                 /* Get kernel channel */
 257                 kchan = trace_kernel_get_channel_by_name(channel_name, ksession);
 258                 if (kchan == NULL) {
 259                         ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
 260                         goto error;
 261                 }
 262
 263                 ret = add_kctx_to_channel(&kctx, kchan, event_name);
 264                 if (ret != LTTCOMM_OK) {
 265                         goto error;
 266                 }
 267         }
 268
 269         ret = LTTCOMM_OK;
 270
 271 error:
 272         return ret;
 273 }
 274
 275 /*
 276  * Add UST context to tracer.
 277  */
 278 int context_ust_add(struct ltt_ust_session *usess, int domain,
 279                 struct lttng_event_context *ctx, char *event_name,
 280                 char *channel_name)
 281 {
 282         int ret = LTTCOMM_OK, have_event = 0;
 283         struct cds_lfht_iter iter, uiter;
 284         struct cds_lfht *chan_ht;
 285         struct ltt_ust_channel *uchan = NULL;
 286         struct ltt_ust_event *uevent = NULL;
 287
 288         /*
 289          * Define which channel's hashtable to use from the domain or quit if
 290          * unknown domain.
 291          */
 292         switch (domain) {
 293         case LTTNG_DOMAIN_UST:
 294                 chan_ht = usess->domain_global.channels;
 295                 break;
 296         case LTTNG_DOMAIN_UST_EXEC_NAME:
 297         case LTTNG_DOMAIN_UST_PID:
 298         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 299         default:
 300                 ret = LTTCOMM_NOT_IMPLEMENTED;
 301                 goto error;
 302         }
 303
 304         /* Do we have an event name */
 305         if (strlen(event_name) != 0) {
 306                 have_event = 1;
 307         }
 308
 309         /* Get UST channel if defined */
 310         if (strlen(channel_name) != 0) {
 311                 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
 312                 if (uchan == NULL) {
 313                         ret = LTTCOMM_UST_CHAN_NOT_FOUND;
 314                         goto error;
 315                 }
 316         }
 317
 318         /* If UST channel specified and event name, get UST event ref */
 319         if (uchan && have_event) {
 320                 uevent = trace_ust_find_event_by_name(uchan->events, event_name);
 321                 if (uevent == NULL) {
 322                         ret = LTTCOMM_UST_EVENT_NOT_FOUND;
 323                         goto error;
 324                 }
 325         }
 326
 327         /* At this point, we have 4 possibilities */
 328
 329         if (uchan && uevent) {                          /* Add ctx to event in channel */
 330                 ret = add_uctx_to_event(usess, domain, uchan, uevent, ctx);
 331         } else if (uchan && !have_event) {      /* Add ctx to channel */
 332                 ret = add_uctx_to_channel(usess, domain, uchan, ctx);
 333         } else if (!uchan && have_event) {      /* Add ctx to event */
 334                 /* Add context to event without having the channel name */
 335                 cds_lfht_for_each_entry(chan_ht, &iter, uchan, node) {
 336                         uevent = trace_ust_find_event_by_name(uchan->events, event_name);
 337                         if (uevent != NULL) {
 338                                 ret = add_uctx_to_event(usess, domain, uchan, uevent, ctx);
 339                                 /*
 340                                  * LTTng UST does not allowed the same event to be registered
 341                                  * multiple time in different or the same channel. So, if we
 342                                  * found our event, we stop.
 343                                  */
 344                                 goto end;
 345                         }
 346                 }
 347                 ret = LTTCOMM_UST_EVENT_NOT_FOUND;
 348                 goto error;
 349         } else if (!uchan && !have_event) {     /* Add ctx all events, all channels */
 350                 /* For all channels */
 351                 cds_lfht_for_each_entry(chan_ht, &iter, uchan, node) {
 352                         ret = add_uctx_to_channel(usess, domain, uchan, ctx);
 353                         if (ret < 0) {
 354                                 ERR("Context added to channel %s failed", uchan->name);
 355                                 continue;
 356                         }
 357
 358                         /* For all events in channel */
 359                         cds_lfht_for_each_entry(uchan->events, &uiter, uevent, node) {
 360                                 ret = add_uctx_to_event(usess, domain, uchan, uevent, ctx);
 361                                 if (ret < 0) {
 362                                         ERR("Context add to event %s in channel %s failed",
 363                                                         uevent->attr.name, uchan->name);
 364                                         continue;
 365                                 }
 366                         }
 367                 }
 368         }
 369
 370 end:
 371         switch (ret) {
 372         case -EEXIST:
 373                 ret = LTTCOMM_UST_CONTEXT_EXIST;
 374                 goto error;
 375         case -ENOMEM:
 376                 ret = LTTCOMM_FATAL;
 377                 goto error;
 378         }
 379
 380         return LTTCOMM_OK;
 381
 382 error:
 383         return ret;
 384 }