src/bin/lttng-sessiond/context.c

   1 /*
   2  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   3  * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License, version 2 only,
   7  * as published by the Free Software Foundation.
   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 along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 #define _LGPL_SOURCE
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24 #include <urcu/list.h>
  25
  26 #include <common/error.h>
  27 #include <common/sessiond-comm/sessiond-comm.h>
  28
  29 #include "context.h"
  30 #include "kernel.h"
  31 #include "ust-app.h"
  32 #include "trace-ust.h"
  33 #include "agent.h"
  34
  35 /*
  36  * Add kernel context to all channel.
  37  *
  38  * Assumes the ownership of kctx.
  39  */
  40 static int add_kctx_all_channels(struct ltt_kernel_session *ksession,
  41                 struct ltt_kernel_context *kctx)
  42 {
  43         int ret;
  44         struct ltt_kernel_channel *kchan;
  45
  46         assert(ksession);
  47         assert(kctx);
  48
  49         DBG("Adding kernel context to all channels");
  50
  51         /* Go over all channels */
  52         cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
  53                 struct ltt_kernel_context *kctx_copy;
  54
  55                 kctx_copy = trace_kernel_copy_context(kctx);
  56                 if (!kctx_copy) {
  57                         PERROR("zmalloc ltt_kernel_context");
  58                         ret = -ENOMEM;
  59                         goto error;
  60                 }
  61
  62                 /* Ownership of kctx_copy is transferred to the callee. */
  63                 ret = kernel_add_channel_context(kchan, kctx_copy);
  64                 kctx_copy = NULL;
  65                 if (ret != 0) {
  66                         goto error;
  67                 }
  68         }
  69
  70         ret = LTTNG_OK;
  71
  72 error:
  73         trace_kernel_destroy_context(kctx);
  74         return ret;
  75 }
  76
  77 /*
  78  * Add kernel context to a specific channel.
  79  *
  80  * Assumes the ownership of kctx.
  81  */
  82 static int add_kctx_to_channel(struct ltt_kernel_context *kctx,
  83                 struct ltt_kernel_channel *kchan)
  84 {
  85         int ret;
  86
  87         assert(kchan);
  88         assert(kctx);
  89
  90         DBG("Add kernel context to channel '%s'", kchan->channel->name);
  91
  92         /* Ownership of kctx is transferred to the callee. */
  93         ret = kernel_add_channel_context(kchan, kctx);
  94         kctx = NULL;
  95         if (ret != 0) {
  96                 goto error;
  97         }
  98
  99         ret = LTTNG_OK;
 100
 101 error:
 102         return ret;
 103 }
 104
 105 /*
 106  * Add UST context to channel.
 107  */
 108 static int add_uctx_to_channel(struct ltt_ust_session *usess,
 109                 enum lttng_domain_type domain,
 110                 struct ltt_ust_channel *uchan, struct lttng_event_context *ctx)
 111 {
 112         int ret;
 113         struct ltt_ust_context *uctx = NULL;
 114
 115         assert(usess);
 116         assert(uchan);
 117         assert(ctx);
 118
 119         /* Check if context is duplicate */
 120         cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
 121                 if (trace_ust_match_context(uctx, ctx)) {
 122                         ret = -EEXIST;
 123                         goto duplicate;
 124                 }
 125         }
 126         uctx = NULL;
 127
 128         switch (domain) {
 129         case LTTNG_DOMAIN_JUL:
 130         case LTTNG_DOMAIN_LOG4J:
 131         {
 132                 struct agent *agt;
 133
 134                 if (ctx->ctx != LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
 135                         /* Other contexts are not needed by the agent. */
 136                         break;
 137                 }
 138                 agt = trace_ust_find_agent(usess, domain);
 139
 140                 if (!agt) {
 141                         agt = agent_create(domain);
 142                         if (!agt) {
 143                                 ret = LTTNG_ERR_NOMEM;
 144                                 goto error;
 145                         }
 146                         agent_add(agt, usess->agents);
 147                 }
 148                 ret = agent_add_context(ctx, agt);
 149                 if (ret != LTTNG_OK) {
 150                         goto error;
 151                 }
 152
 153                 ret = agent_enable_context(ctx, domain);
 154                 if (ret != LTTNG_OK) {
 155                         goto error;
 156                 }
 157                 break;
 158         }
 159         case LTTNG_DOMAIN_UST:
 160                 break;
 161         default:
 162                 assert(0);
 163         }
 164
 165         /* Create ltt UST context */
 166         uctx = trace_ust_create_context(ctx);
 167         if (uctx == NULL) {
 168                 ret = -EINVAL;
 169                 goto error;
 170         }
 171
 172         ret = ust_app_add_ctx_channel_glb(usess, uchan, uctx);
 173         if (ret < 0) {
 174                 goto error;
 175         }
 176
 177         rcu_read_lock();
 178
 179         /* Add ltt UST context node to ltt UST channel */
 180         lttng_ht_add_ulong(uchan->ctx, &uctx->node);
 181         rcu_read_unlock();
 182         cds_list_add_tail(&uctx->list, &uchan->ctx_list);
 183
 184         DBG("Context UST %d added to channel %s", uctx->ctx.ctx, uchan->name);
 185
 186         return 0;
 187
 188 error:
 189         free(uctx);
 190 duplicate:
 191         return ret;
 192 }
 193
 194 /*
 195  * Add kernel context to tracer.
 196  */
 197 int context_kernel_add(struct ltt_kernel_session *ksession,
 198                 struct lttng_event_context *ctx, char *channel_name)
 199 {
 200         int ret;
 201         struct ltt_kernel_channel *kchan;
 202         struct ltt_kernel_context *kctx;
 203
 204         assert(ksession);
 205         assert(ctx);
 206         assert(channel_name);
 207
 208         kctx = trace_kernel_create_context(NULL);
 209         if (!kctx) {
 210                 ret = LTTNG_ERR_NOMEM;
 211                 goto error;
 212         }
 213
 214         /* Setup kernel context structure */
 215         switch (ctx->ctx) {
 216         case LTTNG_EVENT_CONTEXT_PID:
 217                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PID;
 218                 break;
 219         case LTTNG_EVENT_CONTEXT_PROCNAME:
 220                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PROCNAME;
 221                 break;
 222         case LTTNG_EVENT_CONTEXT_PRIO:
 223                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PRIO;
 224                 break;
 225         case LTTNG_EVENT_CONTEXT_NICE:
 226                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_NICE;
 227                 break;
 228         case LTTNG_EVENT_CONTEXT_VPID:
 229                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_VPID;
 230                 break;
 231         case LTTNG_EVENT_CONTEXT_TID:
 232                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_TID;
 233                 break;
 234         case LTTNG_EVENT_CONTEXT_VTID:
 235                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_VTID;
 236                 break;
 237         case LTTNG_EVENT_CONTEXT_PPID:
 238                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PPID;
 239                 break;
 240         case LTTNG_EVENT_CONTEXT_VPPID:
 241                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_VPPID;
 242                 break;
 243         case LTTNG_EVENT_CONTEXT_HOSTNAME:
 244                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_HOSTNAME;
 245                 break;
 246         case LTTNG_EVENT_CONTEXT_PERF_CPU_COUNTER:
 247         case LTTNG_EVENT_CONTEXT_PERF_COUNTER:
 248                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PERF_CPU_COUNTER;
 249                 break;
 250         case LTTNG_EVENT_CONTEXT_INTERRUPTIBLE:
 251                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_INTERRUPTIBLE;
 252                 break;
 253         case LTTNG_EVENT_CONTEXT_PREEMPTIBLE:
 254                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PREEMPTIBLE;
 255                 break;
 256         case LTTNG_EVENT_CONTEXT_NEED_RESCHEDULE:
 257                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_NEED_RESCHEDULE;
 258                 break;
 259         case LTTNG_EVENT_CONTEXT_MIGRATABLE:
 260                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_MIGRATABLE;
 261                 break;
 262         default:
 263                 ret = LTTNG_ERR_KERN_CONTEXT_FAIL;
 264                 goto error;
 265         }
 266
 267         kctx->ctx.u.perf_counter.type = ctx->u.perf_counter.type;
 268         kctx->ctx.u.perf_counter.config = ctx->u.perf_counter.config;
 269         strncpy(kctx->ctx.u.perf_counter.name, ctx->u.perf_counter.name,
 270                         LTTNG_SYMBOL_NAME_LEN);
 271         kctx->ctx.u.perf_counter.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 272
 273         if (*channel_name == '\0') {
 274                 ret = add_kctx_all_channels(ksession, kctx);
 275                 /* Ownership of kctx is transferred to the callee. */
 276                 kctx = NULL;
 277                 if (ret != LTTNG_OK) {
 278                         goto error;
 279                 }
 280         } else {
 281                 /* Get kernel channel */
 282                 kchan = trace_kernel_get_channel_by_name(channel_name, ksession);
 283                 if (kchan == NULL) {
 284                         ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
 285                         goto error;
 286                 }
 287
 288                 ret = add_kctx_to_channel(kctx, kchan);
 289                 /* Ownership of kctx is transferred to the callee. */
 290                 kctx = NULL;
 291                 if (ret != LTTNG_OK) {
 292                         goto error;
 293                 }
 294         }
 295
 296         ret = LTTNG_OK;
 297
 298 error:
 299         if (kctx) {
 300                 trace_kernel_destroy_context(kctx);
 301         }
 302         return ret;
 303 }
 304
 305 /*
 306  * Add UST context to tracer.
 307  */
 308 int context_ust_add(struct ltt_ust_session *usess,
 309                 enum lttng_domain_type domain, struct lttng_event_context *ctx,
 310                 char *channel_name)
 311 {
 312         int ret = LTTNG_OK;
 313         struct lttng_ht_iter iter;
 314         struct lttng_ht *chan_ht;
 315         struct ltt_ust_channel *uchan = NULL;
 316
 317         assert(usess);
 318         assert(ctx);
 319         assert(channel_name);
 320
 321         rcu_read_lock();
 322
 323         chan_ht = usess->domain_global.channels;
 324
 325         /* Get UST channel if defined */
 326         if (channel_name[0] != '\0') {
 327                 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
 328                 if (uchan == NULL) {
 329                         ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
 330                         goto error;
 331                 }
 332         }
 333
 334         if (uchan) {
 335                 /* Add ctx to channel */
 336                 ret = add_uctx_to_channel(usess, domain, uchan, ctx);
 337         } else {
 338                 rcu_read_lock();
 339                 /* Add ctx all events, all channels */
 340                 cds_lfht_for_each_entry(chan_ht->ht, &iter.iter, uchan, node.node) {
 341                         ret = add_uctx_to_channel(usess, domain, uchan, ctx);
 342                         if (ret < 0) {
 343                                 ERR("Failed to add context to channel %s",
 344                                                 uchan->name);
 345                                 continue;
 346                         }
 347                 }
 348                 rcu_read_unlock();
 349         }
 350
 351         switch (ret) {
 352         case -EEXIST:
 353                 ret = LTTNG_ERR_UST_CONTEXT_EXIST;
 354                 break;
 355         case -ENOMEM:
 356                 ret = LTTNG_ERR_FATAL;
 357                 break;
 358         case -EINVAL:
 359                 ret = LTTNG_ERR_UST_CONTEXT_INVAL;
 360                 break;
 361         case -ENOSYS:
 362                 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
 363                 break;
 364         default:
 365                 ret = LTTNG_OK;
 366                 break;
 367         }
 368
 369 error:
 370         rcu_read_unlock();
 371         return ret;
 372 }