src/bin/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
   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 #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
  34 /*
  35  * Add kernel context to all channel.
  36  */
  37 static int add_kctx_all_channels(struct ltt_kernel_session *ksession,
  38                 struct ltt_kernel_context *kctx)
  39 {
  40         int ret;
  41         struct ltt_kernel_channel *kchan;
  42
  43         assert(ksession);
  44         assert(kctx);
  45
  46         DBG("Adding kernel context to all channels");
  47
  48         /* Go over all channels */
  49         cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
  50                 ret = kernel_add_channel_context(kchan, kctx);
  51                 if (ret < 0) {
  52                         ret = LTTNG_ERR_KERN_CONTEXT_FAIL;
  53                         goto error;
  54                 }
  55         }
  56
  57         ret = LTTNG_OK;
  58
  59 error:
  60         return ret;
  61 }
  62
  63 /*
  64  * Add kernel context to a specific channel.
  65  */
  66 static int add_kctx_to_channel(struct ltt_kernel_context *kctx,
  67                 struct ltt_kernel_channel *kchan)
  68 {
  69         int ret;
  70
  71         assert(kchan);
  72         assert(kctx);
  73
  74         DBG("Add kernel context to channel '%s'", kchan->channel->name);
  75
  76         ret = kernel_add_channel_context(kchan, kctx);
  77         if (ret < 0) {
  78                 ret = LTTNG_ERR_KERN_CONTEXT_FAIL;
  79                 goto error;
  80         }
  81
  82         ret = LTTNG_OK;
  83
  84 error:
  85         return ret;
  86 }
  87
  88 /*
  89  * Add UST context to channel.
  90  */
  91 static int add_uctx_to_channel(struct ltt_ust_session *usess, int domain,
  92                 struct ltt_ust_channel *uchan, struct lttng_event_context *ctx)
  93 {
  94         int ret;
  95         struct ltt_ust_context *uctx;
  96
  97         assert(usess);
  98         assert(uchan);
  99         assert(ctx);
 100
 101         /* Check if context is duplicate */
 102         cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
 103                 if (trace_ust_match_context(uctx, ctx)) {
 104                         ret = -EEXIST;
 105                         goto duplicate;
 106                 }
 107         }
 108
 109         /* Create ltt UST context */
 110         uctx = trace_ust_create_context(ctx);
 111         if (uctx == NULL) {
 112                 ret = -EINVAL;
 113                 goto error;
 114         }
 115
 116         switch (domain) {
 117         case LTTNG_DOMAIN_UST:
 118                 ret = ust_app_add_ctx_channel_glb(usess, uchan, uctx);
 119                 if (ret < 0) {
 120                         goto error;
 121                 }
 122                 break;
 123         default:
 124                 ret = -ENOSYS;
 125                 goto error;
 126         }
 127
 128         rcu_read_lock();
 129
 130         /* Add ltt UST context node to ltt UST channel */
 131         lttng_ht_add_ulong(uchan->ctx, &uctx->node);
 132         rcu_read_unlock();
 133         cds_list_add_tail(&uctx->list, &uchan->ctx_list);
 134
 135         DBG("Context UST %d added to channel %s", uctx->ctx.ctx, uchan->name);
 136
 137         return 0;
 138
 139 error:
 140         free(uctx);
 141 duplicate:
 142         return ret;
 143 }
 144
 145 /*
 146  * Add kernel context to tracer.
 147  */
 148 int context_kernel_add(struct ltt_kernel_session *ksession,
 149                 struct lttng_event_context *ctx, char *channel_name)
 150 {
 151         int ret;
 152         struct ltt_kernel_channel *kchan;
 153         struct ltt_kernel_context *kctx;
 154
 155         assert(ksession);
 156         assert(ctx);
 157         assert(channel_name);
 158
 159         kctx = trace_kernel_create_context(NULL);
 160         if (!kctx) {
 161                 ret = LTTNG_ERR_NOMEM;
 162                 goto error;
 163         }
 164
 165         /* Setup kernel context structure */
 166         switch (ctx->ctx) {
 167         case LTTNG_EVENT_CONTEXT_PID:
 168                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PID;
 169                 break;
 170         case LTTNG_EVENT_CONTEXT_PROCNAME:
 171                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PROCNAME;
 172                 break;
 173         case LTTNG_EVENT_CONTEXT_PRIO:
 174                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PRIO;
 175                 break;
 176         case LTTNG_EVENT_CONTEXT_NICE:
 177                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_NICE;
 178                 break;
 179         case LTTNG_EVENT_CONTEXT_VPID:
 180                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_VPID;
 181                 break;
 182         case LTTNG_EVENT_CONTEXT_TID:
 183                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_TID;
 184                 break;
 185         case LTTNG_EVENT_CONTEXT_VTID:
 186                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_VTID;
 187                 break;
 188         case LTTNG_EVENT_CONTEXT_PPID:
 189                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PPID;
 190                 break;
 191         case LTTNG_EVENT_CONTEXT_VPPID:
 192                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_VPPID;
 193                 break;
 194         case LTTNG_EVENT_CONTEXT_HOSTNAME:
 195                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_HOSTNAME;
 196                 break;
 197         case LTTNG_EVENT_CONTEXT_PERF_CPU_COUNTER:
 198         case LTTNG_EVENT_CONTEXT_PERF_COUNTER:
 199                 kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PERF_CPU_COUNTER;
 200                 break;
 201         default:
 202                 ret = LTTNG_ERR_KERN_CONTEXT_FAIL;
 203                 goto error;
 204         }
 205
 206         kctx->ctx.u.perf_counter.type = ctx->u.perf_counter.type;
 207         kctx->ctx.u.perf_counter.config = ctx->u.perf_counter.config;
 208         strncpy(kctx->ctx.u.perf_counter.name, ctx->u.perf_counter.name,
 209                         LTTNG_SYMBOL_NAME_LEN);
 210         kctx->ctx.u.perf_counter.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 211
 212         if (*channel_name == '\0') {
 213                 ret = add_kctx_all_channels(ksession, kctx);
 214                 if (ret != LTTNG_OK) {
 215                         goto error;
 216                 }
 217         } else {
 218                 /* Get kernel channel */
 219                 kchan = trace_kernel_get_channel_by_name(channel_name, ksession);
 220                 if (kchan == NULL) {
 221                         ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
 222                         goto error;
 223                 }
 224
 225                 ret = add_kctx_to_channel(kctx, kchan);
 226                 if (ret != LTTNG_OK) {
 227                         goto error;
 228                 }
 229         }
 230
 231         return LTTNG_OK;
 232
 233 error:
 234         if (kctx) {
 235                 trace_kernel_destroy_context(kctx);
 236         }
 237         return ret;
 238 }
 239
 240 /*
 241  * Add UST context to tracer.
 242  */
 243 int context_ust_add(struct ltt_ust_session *usess, int domain,
 244                 struct lttng_event_context *ctx, char *channel_name)
 245 {
 246         int ret = LTTNG_OK;
 247         struct lttng_ht_iter iter;
 248         struct lttng_ht *chan_ht;
 249         struct ltt_ust_channel *uchan = NULL;
 250
 251         assert(usess);
 252         assert(ctx);
 253         assert(channel_name);
 254
 255         rcu_read_lock();
 256
 257         /*
 258          * Define which channel's hashtable to use from the domain or quit if
 259          * unknown domain.
 260          */
 261         switch (domain) {
 262         case LTTNG_DOMAIN_UST:
 263                 chan_ht = usess->domain_global.channels;
 264                 break;
 265         default:
 266                 ret = LTTNG_ERR_UND;
 267                 goto error;
 268         }
 269
 270         /* Get UST channel if defined */
 271         if (channel_name[0] != '\0') {
 272                 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
 273                 if (uchan == NULL) {
 274                         ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
 275                         goto error;
 276                 }
 277         }
 278
 279         if (uchan) {
 280                 /* Add ctx to channel */
 281                 ret = add_uctx_to_channel(usess, domain, uchan, ctx);
 282         } else {
 283                 rcu_read_lock();
 284                 /* Add ctx all events, all channels */
 285                 cds_lfht_for_each_entry(chan_ht->ht, &iter.iter, uchan, node.node) {
 286                         ret = add_uctx_to_channel(usess, domain, uchan, ctx);
 287                         if (ret < 0) {
 288                                 ERR("Context failed for channel %s", uchan->name);
 289                                 continue;
 290                         }
 291                 }
 292                 rcu_read_unlock();
 293         }
 294
 295         switch (ret) {
 296         case -EEXIST:
 297                 ret = LTTNG_ERR_UST_CONTEXT_EXIST;
 298                 break;
 299         case -ENOMEM:
 300                 ret = LTTNG_ERR_FATAL;
 301                 break;
 302         case -EINVAL:
 303                 ret = LTTNG_ERR_UST_CONTEXT_INVAL;
 304                 break;
 305         case -ENOSYS:
 306                 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
 307                 break;
 308         default:
 309                 ret = LTTNG_OK;
 310                 break;
 311         }
 312
 313 error:
 314         rcu_read_unlock();
 315         return ret;
 316 }