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 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23 #include <urcu/list.h>
  24
  25 #include <common/error.h>
  26 #include <common/sessiond-comm/sessiond-comm.h>
  27
  28 #include "context.h"
  29 #include "kernel.h"
  30 #include "ust-app.h"
  31 #include "trace-ust.h"
  32
  33 /*
  34  * Add kernel context to all channel.
  35  */
  36 static int add_kctx_all_channels(struct ltt_kernel_session *ksession,
  37                 struct lttng_kernel_context *kctx)
  38 {
  39         int ret;
  40         struct ltt_kernel_channel *kchan;
  41
  42         assert(ksession);
  43         assert(kctx);
  44
  45         DBG("Adding kernel context to all channels");
  46
  47         /* Go over all channels */
  48         cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
  49                 ret = kernel_add_channel_context(kchan, kctx);
  50                 if (ret < 0) {
  51                         ret = LTTNG_ERR_KERN_CONTEXT_FAIL;
  52                         goto error;
  53                 }
  54         }
  55
  56         ret = LTTNG_OK;
  57
  58 error:
  59         return ret;
  60 }
  61
  62 /*
  63  * Add kernel context to a specific channel.
  64  */
  65 static int add_kctx_to_channel(struct lttng_kernel_context *kctx,
  66                 struct ltt_kernel_channel *kchan)
  67 {
  68         int ret;
  69
  70         assert(kchan);
  71         assert(kctx);
  72
  73         DBG("Add kernel context to channel '%s'", kchan->channel->name);
  74
  75         ret = kernel_add_channel_context(kchan, kctx);
  76         if (ret < 0) {
  77                 ret = LTTNG_ERR_KERN_CONTEXT_FAIL;
  78                 goto error;
  79         }
  80
  81         ret = LTTNG_OK;
  82
  83 error:
  84         return ret;
  85 }
  86
  87 /*
  88  * Add UST context to channel.
  89  */
  90 static int add_uctx_to_channel(struct ltt_ust_session *usess, int domain,
  91                 struct ltt_ust_channel *uchan, struct lttng_event_context *ctx)
  92 {
  93         int ret;
  94         struct ltt_ust_context *uctx;
  95         struct lttng_ht_iter iter;
  96         struct lttng_ht_node_ulong *uctx_node;
  97
  98         assert(usess);
  99         assert(uchan);
 100         assert(ctx);
 101
 102         /* Create ltt UST context */
 103         uctx = trace_ust_create_context(ctx);
 104         if (uctx == NULL) {
 105                 ret = -EINVAL;
 106                 goto error;
 107         }
 108
 109         switch (domain) {
 110         case LTTNG_DOMAIN_UST:
 111                 ret = ust_app_add_ctx_channel_glb(usess, uchan, uctx);
 112                 if (ret < 0) {
 113                         goto error;
 114                 }
 115                 break;
 116         default:
 117                 ret = -ENOSYS;
 118                 goto error;
 119         }
 120
 121         rcu_read_lock();
 122
 123         /* Lookup context before adding it */
 124         lttng_ht_lookup(uchan->ctx, (void *)((unsigned long)uctx->ctx.ctx), &iter);
 125         uctx_node = lttng_ht_iter_get_node_ulong(&iter);
 126         if (uctx_node != NULL) {
 127                 ret = -EEXIST;
 128                 rcu_read_unlock();
 129                 goto error;
 130         }
 131
 132         /* Add ltt UST context node to ltt UST channel */
 133         lttng_ht_add_unique_ulong(uchan->ctx, &uctx->node);
 134         rcu_read_unlock();
 135         cds_list_add_tail(&uctx->list, &uchan->ctx_list);
 136
 137         DBG("Context UST %d added to channel %s", uctx->ctx.ctx, uchan->name);
 138
 139         return 0;
 140
 141 error:
 142         free(uctx);
 143         return ret;
 144 }
 145
 146 /*
 147  * Add kernel context to tracer.
 148  */
 149 int context_kernel_add(struct ltt_kernel_session *ksession,
 150                 struct lttng_event_context *ctx, char *channel_name)
 151 {
 152         int ret;
 153         struct ltt_kernel_channel *kchan;
 154         struct lttng_kernel_context kctx;
 155
 156         assert(ksession);
 157         assert(ctx);
 158         assert(channel_name);
 159
 160         /* Setup kernel context structure */
 161         switch (ctx->ctx) {
 162         case LTTNG_EVENT_CONTEXT_PID:
 163                 kctx.ctx = LTTNG_KERNEL_CONTEXT_PID;
 164                 break;
 165         case LTTNG_EVENT_CONTEXT_PERF_COUNTER:
 166                 kctx.ctx = LTTNG_KERNEL_CONTEXT_PERF_COUNTER;
 167                 break;
 168         case LTTNG_EVENT_CONTEXT_PROCNAME:
 169                 kctx.ctx = LTTNG_KERNEL_CONTEXT_PROCNAME;
 170                 break;
 171         case LTTNG_EVENT_CONTEXT_PRIO:
 172                 kctx.ctx = LTTNG_KERNEL_CONTEXT_PRIO;
 173                 break;
 174         case LTTNG_EVENT_CONTEXT_NICE:
 175                 kctx.ctx = LTTNG_KERNEL_CONTEXT_NICE;
 176                 break;
 177         case LTTNG_EVENT_CONTEXT_VPID:
 178                 kctx.ctx = LTTNG_KERNEL_CONTEXT_VPID;
 179                 break;
 180         case LTTNG_EVENT_CONTEXT_TID:
 181                 kctx.ctx = LTTNG_KERNEL_CONTEXT_TID;
 182                 break;
 183         case LTTNG_EVENT_CONTEXT_VTID:
 184                 kctx.ctx = LTTNG_KERNEL_CONTEXT_VTID;
 185                 break;
 186         case LTTNG_EVENT_CONTEXT_PPID:
 187                 kctx.ctx = LTTNG_KERNEL_CONTEXT_PPID;
 188                 break;
 189         case LTTNG_EVENT_CONTEXT_VPPID:
 190                 kctx.ctx = LTTNG_KERNEL_CONTEXT_VPPID;
 191                 break;
 192         case LTTNG_EVENT_CONTEXT_HOSTNAME:
 193                 kctx.ctx = LTTNG_KERNEL_CONTEXT_HOSTNAME;
 194                 break;
 195         default:
 196                 return LTTNG_ERR_KERN_CONTEXT_FAIL;
 197         }
 198
 199         kctx.u.perf_counter.type = ctx->u.perf_counter.type;
 200         kctx.u.perf_counter.config = ctx->u.perf_counter.config;
 201         strncpy(kctx.u.perf_counter.name, ctx->u.perf_counter.name,
 202                         LTTNG_SYMBOL_NAME_LEN);
 203         kctx.u.perf_counter.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 204
 205         if (*channel_name == '\0') {
 206                 ret = add_kctx_all_channels(ksession, &kctx);
 207                 if (ret != LTTNG_OK) {
 208                         goto error;
 209                 }
 210         } else {
 211                 /* Get kernel channel */
 212                 kchan = trace_kernel_get_channel_by_name(channel_name, ksession);
 213                 if (kchan == NULL) {
 214                         ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
 215                         goto error;
 216                 }
 217
 218                 ret = add_kctx_to_channel(&kctx, kchan);
 219                 if (ret != LTTNG_OK) {
 220                         goto error;
 221                 }
 222         }
 223
 224         ret = LTTNG_OK;
 225
 226 error:
 227         return ret;
 228 }
 229
 230 /*
 231  * Add UST context to tracer.
 232  */
 233 int context_ust_add(struct ltt_ust_session *usess, int domain,
 234                 struct lttng_event_context *ctx, char *channel_name)
 235 {
 236         int ret = LTTNG_OK;
 237         struct lttng_ht_iter iter;
 238         struct lttng_ht *chan_ht;
 239         struct ltt_ust_channel *uchan = NULL;
 240
 241         assert(usess);
 242         assert(ctx);
 243         assert(channel_name);
 244
 245         rcu_read_lock();
 246
 247         /*
 248          * Define which channel's hashtable to use from the domain or quit if
 249          * unknown domain.
 250          */
 251         switch (domain) {
 252         case LTTNG_DOMAIN_UST:
 253                 chan_ht = usess->domain_global.channels;
 254                 break;
 255 #if 0
 256         case LTTNG_DOMAIN_UST_EXEC_NAME:
 257         case LTTNG_DOMAIN_UST_PID:
 258         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 259 #endif
 260         default:
 261                 ret = LTTNG_ERR_UND;
 262                 goto error;
 263         }
 264
 265         /* Get UST channel if defined */
 266         if (channel_name[0] != '\0') {
 267                 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
 268                 if (uchan == NULL) {
 269                         ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
 270                         goto error;
 271                 }
 272         }
 273
 274         if (uchan) {
 275                 /* Add ctx to channel */
 276                 ret = add_uctx_to_channel(usess, domain, uchan, ctx);
 277         } else {
 278                 rcu_read_lock();
 279                 /* Add ctx all events, all channels */
 280                 cds_lfht_for_each_entry(chan_ht->ht, &iter.iter, uchan, node.node) {
 281                         ret = add_uctx_to_channel(usess, domain, uchan, ctx);
 282                         if (ret < 0) {
 283                                 ERR("Context failed for channel %s", uchan->name);
 284                                 continue;
 285                         }
 286                 }
 287                 rcu_read_unlock();
 288         }
 289
 290         switch (ret) {
 291         case -EEXIST:
 292                 ret = LTTNG_ERR_UST_CONTEXT_EXIST;
 293                 break;
 294         case -ENOMEM:
 295                 ret = LTTNG_ERR_FATAL;
 296                 break;
 297         case -EINVAL:
 298                 ret = LTTNG_ERR_UST_CONTEXT_INVAL;
 299                 break;
 300         case -ENOSYS:
 301                 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
 302                 break;
 303         default:
 304                 ret = LTTNG_OK;
 305                 break;
 306         }
 307
 308 error:
 309         rcu_read_unlock();
 310         return ret;
 311 }