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