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