lttng-sessiond/event.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 it
   5  * under the terms of the GNU General Public License as published by the Free
   6  * Software Foundation; only version 2 of the License.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA  02111-1307, USA.
  16  */
  17
  18 #include <errno.h>
  19 #include <urcu/list.h>
  20 #include <string.h>
  21
  22 #include <lttng/lttng.h>
  23 #include <lttng-sessiond-comm.h>
  24 #include <lttngerr.h>
  25
  26 #include "channel.h"
  27 #include "event.h"
  28 #include "hashtable.h"
  29 #include "kernel.h"
  30 #include "ust-ctl.h"
  31 #include "ust-app.h"
  32 #include "trace-kernel.h"
  33 #include "trace-ust.h"
  34
  35 /*
  36  * Setup a lttng_event used to enable *all* syscall tracing.
  37  */
  38 static void init_syscalls_kernel_event(struct lttng_event *event)
  39 {
  40         event->name[0] = '\0';
  41         /*
  42          * We use LTTNG_EVENT* here since the trace kernel creation will make the
  43          * right changes for the kernel.
  44          */
  45         event->type = LTTNG_EVENT_SYSCALL;
  46 }
  47
  48 /*
  49  * Disable kernel tracepoint event for a channel from the kernel session.
  50  */
  51 int event_kernel_disable_tracepoint(struct ltt_kernel_session *ksession,
  52                 struct ltt_kernel_channel *kchan, char *event_name)
  53 {
  54         int ret;
  55         struct ltt_kernel_event *kevent;
  56
  57         kevent = trace_kernel_get_event_by_name(event_name, kchan);
  58         if (kevent == NULL) {
  59                 ret = LTTCOMM_NO_EVENT;
  60                 goto error;
  61         }
  62
  63         ret = kernel_disable_event(kevent);
  64         if (ret < 0) {
  65                 ret = LTTCOMM_KERN_DISABLE_FAIL;
  66                 goto error;
  67         }
  68
  69         DBG("Kernel event %s disable for channel %s.",
  70                         kevent->event->name, kchan->channel->name);
  71
  72         ret = LTTCOMM_OK;
  73
  74 error:
  75         return ret;
  76 }
  77
  78 /*
  79  * Disable kernel tracepoint events for a channel from the kernel session.
  80  */
  81 int event_kernel_disable_all_tracepoints(struct ltt_kernel_session *ksession,
  82                 struct ltt_kernel_channel *kchan)
  83 {
  84         int ret;
  85         struct ltt_kernel_event *kevent;
  86
  87         /* For each event in the kernel session */
  88         cds_list_for_each_entry(kevent, &kchan->events_list.head, list) {
  89                 ret = kernel_disable_event(kevent);
  90                 if (ret < 0) {
  91                         /* We continue disabling the rest */
  92                         continue;
  93                 }
  94         }
  95         ret = LTTCOMM_OK;
  96         return ret;
  97 }
  98
  99 /*
 100  * Disable kernel syscall events for a channel from the kernel session.
 101  */
 102 int event_kernel_disable_all_syscalls(struct ltt_kernel_session *ksession,
 103                 struct ltt_kernel_channel *kchan)
 104 {
 105         ERR("Cannot disable syscall tracing for existing session. Please destroy session instead.");
 106         return LTTCOMM_OK;      /* Return OK so disable all succeeds */
 107 }
 108
 109 /*
 110  * Disable all kernel event for a channel from the kernel session.
 111  */
 112 int event_kernel_disable_all(struct ltt_kernel_session *ksession,
 113                 struct ltt_kernel_channel *kchan)
 114 {
 115         int ret;
 116
 117         ret = event_kernel_disable_all_tracepoints(ksession, kchan);
 118         if (ret != LTTCOMM_OK)
 119                 return ret;
 120         ret = event_kernel_disable_all_syscalls(ksession, kchan);
 121         return ret;
 122 }
 123
 124 /*
 125  * Enable kernel tracepoint event for a channel from the kernel session.
 126  */
 127 int event_kernel_enable_tracepoint(struct ltt_kernel_session *ksession,
 128                 struct ltt_kernel_channel *kchan, struct lttng_event *event)
 129 {
 130         int ret;
 131         struct ltt_kernel_event *kevent;
 132
 133         kevent = trace_kernel_get_event_by_name(event->name, kchan);
 134         if (kevent == NULL) {
 135                 ret = kernel_create_event(event, kchan);
 136                 if (ret < 0) {
 137                         if (ret == -EEXIST) {
 138                                 ret = LTTCOMM_KERN_EVENT_EXIST;
 139                         } else {
 140                                 ret = LTTCOMM_KERN_ENABLE_FAIL;
 141                         }
 142                         goto end;
 143                 }
 144         } else if (kevent->enabled == 0) {
 145                 ret = kernel_enable_event(kevent);
 146                 if (ret < 0) {
 147                         ret = LTTCOMM_KERN_ENABLE_FAIL;
 148                         goto end;
 149                 }
 150         }
 151         ret = LTTCOMM_OK;
 152 end:
 153         return ret;
 154 }
 155
 156 /*
 157  * Enable all kernel tracepoint events of a channel of the kernel session.
 158  */
 159 int event_kernel_enable_all_tracepoints(struct ltt_kernel_session *ksession,
 160                 struct ltt_kernel_channel *kchan, int kernel_tracer_fd)
 161 {
 162         int size, i, ret;
 163         struct ltt_kernel_event *kevent;
 164         struct lttng_event *event_list;
 165
 166         /* For each event in the kernel session */
 167         cds_list_for_each_entry(kevent, &kchan->events_list.head, list) {
 168                 ret = kernel_enable_event(kevent);
 169                 if (ret < 0) {
 170                         /* Enable failed but still continue */
 171                         continue;
 172                 }
 173         }
 174
 175         size = kernel_list_events(kernel_tracer_fd, &event_list);
 176         if (size < 0) {
 177                 ret = LTTCOMM_KERN_LIST_FAIL;
 178                 goto end;
 179         }
 180
 181         for (i = 0; i < size; i++) {
 182                 kevent = trace_kernel_get_event_by_name(event_list[i].name, kchan);
 183                 if (kevent == NULL) {
 184                         /* Default event type for enable all */
 185                         event_list[i].type = LTTNG_EVENT_TRACEPOINT;
 186                         /* Enable each single tracepoint event */
 187                         ret = kernel_create_event(&event_list[i], kchan);
 188                         if (ret < 0) {
 189                                 /* Ignore error here and continue */
 190                         }
 191                 }
 192         }
 193         free(event_list);
 194         ret = LTTCOMM_OK;
 195 end:
 196         return ret;
 197
 198 }
 199
 200 /*
 201  * Enable all kernel tracepoint events of a channel of the kernel session.
 202  */
 203 int event_kernel_enable_all_syscalls(struct ltt_kernel_session *ksession,
 204                 struct ltt_kernel_channel *kchan, int kernel_tracer_fd)
 205 {
 206         int ret;
 207         struct lttng_event event;
 208
 209         init_syscalls_kernel_event(&event);
 210
 211         DBG("Enabling all syscall tracing");
 212
 213         ret = kernel_create_event(&event, kchan);
 214         if (ret < 0) {
 215                 goto end;
 216         }
 217         ret = LTTCOMM_OK;
 218 end:
 219         return ret;
 220 }
 221
 222 /*
 223  * Enable all kernel events of a channel of the kernel session.
 224  */
 225 int event_kernel_enable_all(struct ltt_kernel_session *ksession,
 226                 struct ltt_kernel_channel *kchan, int kernel_tracer_fd)
 227 {
 228         int ret;
 229
 230         ret = event_kernel_enable_all_tracepoints(ksession, kchan, kernel_tracer_fd);
 231         if (ret != LTTCOMM_OK) {
 232                 goto end;
 233         }
 234         ret = event_kernel_enable_all_syscalls(ksession, kchan, kernel_tracer_fd);
 235 end:
 236         return ret;
 237 }
 238
 239 /*
 240  * Enable UST tracepoint event for a channel from a UST session.
 241  */
 242 int event_ust_enable_tracepoint(struct ltt_ust_session *usess, int domain,
 243                 struct ltt_ust_channel *uchan, struct lttng_event *event)
 244 {
 245         int ret, to_create = 0;
 246         struct ltt_ust_event *uevent;
 247
 248         uevent = trace_ust_find_event_by_name(uchan->events, event->name);
 249         if (uevent == NULL) {
 250                 uevent = trace_ust_create_event(event);
 251                 if (uevent == NULL) {
 252                         ret = LTTCOMM_FATAL;
 253                         goto error;
 254                 }
 255                 to_create = 1;
 256         }
 257
 258         switch (domain) {
 259         case LTTNG_DOMAIN_UST:
 260         {
 261                 if (to_create) {
 262                         /* Create event on all UST registered apps for session */
 263                         ret = ust_app_create_event_glb(usess, uchan, uevent);
 264                 } else {
 265                         /* Enable event on all UST registered apps for session */
 266                         ret = ust_app_enable_event_glb(usess, uchan, uevent);
 267                 }
 268
 269                 if (ret < 0) {
 270                         if (ret == -EEXIST) {
 271                                 ret = LTTCOMM_UST_EVENT_EXIST;
 272                         } else {
 273                                 ret = LTTCOMM_UST_ENABLE_FAIL;
 274                         }
 275                         goto error;
 276                 }
 277
 278                 DBG("Event UST %s added to channel %s", uevent->attr.name,
 279                                 uchan->name);
 280                 break;
 281         }
 282         case LTTNG_DOMAIN_UST_EXEC_NAME:
 283         case LTTNG_DOMAIN_UST_PID:
 284         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 285         default:
 286                 ret = LTTCOMM_NOT_IMPLEMENTED;
 287                 goto error;
 288         }
 289
 290         uevent->enabled = 1;
 291         /* Add ltt ust event to channel */
 292         rcu_read_lock();
 293         hashtable_add_unique(uchan->events, &uevent->node);
 294         rcu_read_unlock();
 295
 296         return LTTCOMM_OK;
 297
 298 error:
 299         trace_ust_destroy_event(uevent);
 300         return ret;
 301 }
 302
 303 #ifdef DISABLE
 304 int event_ust_disable_tracepoint(struct ltt_ust_session *ustsession,
 305                 struct ltt_ust_channel *ustchan, char *event_name)
 306 {
 307         int ret;
 308         struct ltt_ust_event *ustevent;
 309
 310         ustevent = trace_ust_find_event_by_name(ustchan->events, event_name);
 311         if (ustevent == NULL) {
 312                 ret = LTTCOMM_NO_EVENT;
 313                 goto end;
 314         }
 315         //ret = ustctl_disable(ustsession->sock, ustevent->obj);
 316         if (ret < 0) {
 317                 ret = LTTCOMM_UST_ENABLE_FAIL;
 318                 goto end;
 319         }
 320         ustevent->enabled = 0;
 321         ret = LTTCOMM_OK;
 322 end:
 323         return ret;
 324 }
 325 #endif