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 = NULL;
 165
 166         /* For each event in the kernel session */
 167         cds_list_for_each_entry(kevent, &kchan->events_list.head, list) {
 168                 if (kevent->enabled == 0) {
 169                         ret = kernel_enable_event(kevent);
 170                         if (ret < 0) {
 171                                 /* Enable failed but still continue */
 172                                 continue;
 173                         }
 174                 }
 175         }
 176
 177         size = kernel_list_events(kernel_tracer_fd, &event_list);
 178         if (size < 0) {
 179                 ret = LTTCOMM_KERN_LIST_FAIL;
 180                 goto end;
 181         }
 182
 183         for (i = 0; i < size; i++) {
 184                 kevent = trace_kernel_get_event_by_name(event_list[i].name, kchan);
 185                 if (kevent == NULL) {
 186                         /* Default event type for enable all */
 187                         event_list[i].type = LTTNG_EVENT_TRACEPOINT;
 188                         /* Enable each single tracepoint event */
 189                         ret = kernel_create_event(&event_list[i], kchan);
 190                         if (ret < 0) {
 191                                 /* Ignore error here and continue */
 192                         }
 193                 }
 194         }
 195         free(event_list);
 196
 197         ret = LTTCOMM_OK;
 198 end:
 199         return ret;
 200
 201 }
 202
 203 /*
 204  * Enable all kernel tracepoint events of a channel of the kernel session.
 205  */
 206 int event_kernel_enable_all_syscalls(struct ltt_kernel_session *ksession,
 207                 struct ltt_kernel_channel *kchan, int kernel_tracer_fd)
 208 {
 209         int ret;
 210         struct lttng_event event;
 211
 212         init_syscalls_kernel_event(&event);
 213
 214         DBG("Enabling all syscall tracing");
 215
 216         ret = kernel_create_event(&event, kchan);
 217         if (ret < 0) {
 218                 if (ret == -EEXIST) {
 219                         ret = LTTCOMM_KERN_EVENT_EXIST;
 220                 } else {
 221                         ret = LTTCOMM_KERN_ENABLE_FAIL;
 222                 }
 223                 goto end;
 224         }
 225
 226         ret = LTTCOMM_OK;
 227 end:
 228         return ret;
 229 }
 230
 231 /*
 232  * Enable all kernel events of a channel of the kernel session.
 233  */
 234 int event_kernel_enable_all(struct ltt_kernel_session *ksession,
 235                 struct ltt_kernel_channel *kchan, int kernel_tracer_fd)
 236 {
 237         int ret;
 238
 239         ret = event_kernel_enable_all_tracepoints(ksession, kchan, kernel_tracer_fd);
 240         if (ret != LTTCOMM_OK) {
 241                 goto end;
 242         }
 243         ret = event_kernel_enable_all_syscalls(ksession, kchan, kernel_tracer_fd);
 244 end:
 245         return ret;
 246 }
 247
 248 /*
 249  * Enable UST tracepoint event for a channel from a UST session.
 250  */
 251 int event_ust_enable_tracepoint(struct ltt_ust_session *usess, int domain,
 252                 struct ltt_ust_channel *uchan, struct lttng_event *event)
 253 {
 254         int ret, to_create = 0;
 255         struct ltt_ust_event *uevent;
 256
 257         uevent = trace_ust_find_event_by_name(uchan->events, event->name);
 258         if (uevent == NULL) {
 259                 uevent = trace_ust_create_event(event);
 260                 if (uevent == NULL) {
 261                         ret = LTTCOMM_FATAL;
 262                         goto error;
 263                 }
 264                 to_create = 1;
 265         }
 266
 267         switch (domain) {
 268         case LTTNG_DOMAIN_UST:
 269         {
 270                 if (to_create) {
 271                         /* Create event on all UST registered apps for session */
 272                         ret = ust_app_create_event_glb(usess, uchan, uevent);
 273                 } else {
 274                         /* Enable event on all UST registered apps for session */
 275                         ret = ust_app_enable_event_glb(usess, uchan, uevent);
 276                 }
 277
 278                 if (ret < 0) {
 279                         if (ret == -EEXIST) {
 280                                 ret = LTTCOMM_UST_EVENT_EXIST;
 281                         } else {
 282                                 ret = LTTCOMM_UST_ENABLE_FAIL;
 283                         }
 284                         goto error;
 285                 }
 286
 287                 DBG("Event UST %s added to channel %s", uevent->attr.name,
 288                                 uchan->name);
 289                 break;
 290         }
 291         case LTTNG_DOMAIN_UST_EXEC_NAME:
 292         case LTTNG_DOMAIN_UST_PID:
 293         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 294         default:
 295                 ret = LTTCOMM_NOT_IMPLEMENTED;
 296                 goto error;
 297         }
 298
 299         uevent->enabled = 1;
 300         /* Add ltt ust event to channel */
 301         rcu_read_lock();
 302         hashtable_add_unique(uchan->events, &uevent->node);
 303         rcu_read_unlock();
 304
 305         return LTTCOMM_OK;
 306
 307 error:
 308         trace_ust_destroy_event(uevent);
 309         return ret;
 310 }
 311
 312 #ifdef DISABLE
 313 int event_ust_disable_tracepoint(struct ltt_ust_session *ustsession,
 314                 struct ltt_ust_channel *ustchan, char *event_name)
 315 {
 316         int ret;
 317         struct ltt_ust_event *ustevent;
 318
 319         ustevent = trace_ust_find_event_by_name(ustchan->events, event_name);
 320         if (ustevent == NULL) {
 321                 ret = LTTCOMM_NO_EVENT;
 322                 goto end;
 323         }
 324         //ret = ustctl_disable(ustsession->sock, ustevent->obj);
 325         if (ret < 0) {
 326                 ret = LTTCOMM_UST_ENABLE_FAIL;
 327                 goto end;
 328         }
 329         ustevent->enabled = 0;
 330         ret = LTTCOMM_OK;
 331 end:
 332         return ret;
 333 }
 334 #endif