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