baddr: include missing header

[lttng-ust.git] / liblttng-ust / lttng-ust-comm.c

diff --git a/liblttng-ust/lttng-ust-comm.c b/liblttng-ust/lttng-ust-comm.c
index a6e4ba35c9a68f9dae607d196f6c640f751c2989..256cbdc625ef19f6da306124542a6e0a08ab593f 100644 (file)
--- a/liblttng-ust/lttng-ust-comm.c
+++ b/liblttng-ust/lttng-ust-comm.c
@@ -34,6 +34,7 @@
 #include <time.h>
 #include <assert.h>
 #include <signal.h>
+#include <dlfcn.h>
 #include <urcu/uatomic.h>
 #include <urcu/futex.h>
 #include <urcu/compiler.h>
@@ -51,6 +52,7 @@
 #include "lttng-tracer-core.h"
 #include "compat.h"
 #include "../libringbuffer/tlsfixup.h"
+#include "lttng-ust-baddr.h"
 
 /*
  * Has lttng ust comm constructor been called ?
@@ -106,6 +108,8 @@ struct sock_info {
 
        char wait_shm_path[PATH_MAX];
        char *wait_shm_mmap;
+       /* Keep track of lazy state dump not performed yet. */
+       int statedump_pending;
 };
 
 /* Socket from app (connect) to session daemon (listen) for communication */
@@ -122,6 +126,8 @@ struct sock_info global_apps = {
        .notify_socket = -1,
 
        .wait_shm_path = "/" LTTNG_UST_WAIT_FILENAME,
+
+       .statedump_pending = 0,
 };
 
 /* TODO: allow global_apps_sock_path override */
@@ -135,6 +141,8 @@ struct sock_info local_apps = {
 
        .socket = -1,
        .notify_socket = -1,
+
+       .statedump_pending = 0,
 };
 
 static int wait_poll_fallback;
@@ -172,6 +180,7 @@ static const char *cmd_name_mapping[] = {
 
        /* Event FD commands */
        [ LTTNG_UST_FILTER ] = "Create Filter",
+       [ LTTNG_UST_EXCLUSION ] = "Add exclusions to event",
 };
 
 static const char *str_timeout;
@@ -379,6 +388,28 @@ int handle_register_done(struct sock_info *sock_info)
        return 0;
 }
 
+/*
+ * Only execute pending statedump after the constructor semaphore has
+ * been posted by each listener thread. This means statedump will only
+ * be performed after the "registration done" command is received from
+ * each session daemon the application is connected to.
+ *
+ * This ensures we don't run into deadlock issues with the dynamic
+ * loader mutex, which is held while the constructor is called and
+ * waiting on the constructor semaphore. All operations requiring this
+ * dynamic loader lock need to be postponed using this mechanism.
+ */
+static
+void handle_pending_statedump(struct sock_info *sock_info)
+{
+       int ctor_passed = sock_info->constructor_sem_posted;
+
+       if (ctor_passed && sock_info->statedump_pending) {
+               sock_info->statedump_pending = 0;
+               lttng_handle_pending_statedump(sock_info);
+       }
+}
+
 static
 int handle_message(struct sock_info *sock_info,
                int sock, struct ustcomm_ust_msg *lum)
@@ -487,6 +518,68 @@ int handle_message(struct sock_info *sock_info,
                }
                break;
        }
+       case LTTNG_UST_EXCLUSION:
+       {
+               /* Receive exclusion names */
+               struct lttng_ust_excluder_node *node;
+               unsigned int count;
+
+               count = lum->u.exclusion.count;
+               if (count == 0) {
+                       /* There are no names to read */
+                       ret = 0;
+                       goto error;
+               }
+               node = zmalloc(sizeof(*node) +
+                               count * LTTNG_UST_SYM_NAME_LEN);
+               if (!node) {
+                       ret = -ENOMEM;
+                       goto error;
+               }
+               node->excluder.count = count;
+               len = ustcomm_recv_unix_sock(sock, node->excluder.names,
+                               count * LTTNG_UST_SYM_NAME_LEN);
+               switch (len) {
+               case 0: /* orderly shutdown */
+                       ret = 0;
+                       free(node);
+                       goto error;
+               default:
+                       if (len == count * LTTNG_UST_SYM_NAME_LEN) {
+                               DBG("Exclusion data received");
+                               break;
+                       } else if (len < 0) {
+                               DBG("Receive failed from lttng-sessiond with errno %d", (int) -len);
+                               if (len == -ECONNRESET) {
+                                       ERR("%s remote end closed connection", sock_info->name);
+                                       ret = len;
+                                       free(node);
+                                       goto error;
+                               }
+                               ret = len;
+                               free(node);
+                               goto end;
+                       } else {
+                               DBG("Incorrect exclusion data message size: %zd", len);
+                               ret = -EINVAL;
+                               free(node);
+                               goto end;
+                       }
+               }
+               if (ops->cmd) {
+                       ret = ops->cmd(lum->handle, lum->cmd,
+                                       (unsigned long) node,
+                                       &args, sock_info);
+                       if (ret) {
+                               free(node);
+                       }
+                       /* Don't free exclusion data if everything went fine. */
+               } else {
+                       ret = -ENOSYS;
+                       free(node);
+               }
+               break;
+       }
        case LTTNG_UST_CHANNEL:
        {
                void *chan_data;
@@ -635,6 +728,14 @@ end:
 
 error:
        ust_unlock();
+
+       /*
+        * Performed delayed statedump operations outside of the UST
+        * lock. We need to take the dynamic loader lock before we take
+        * the UST lock internally within handle_pending_statedump().
+         */
+       handle_pending_statedump(sock_info);
+
        return ret;
 }
 
@@ -1456,3 +1557,9 @@ void ust_after_fork_child(sigset_t *restore_sigset)
        ust_after_fork_common(restore_sigset);
        lttng_ust_init();
 }
+
+void lttng_ust_sockinfo_session_enabled(void *owner)
+{
+       struct sock_info *sock_info = owner;
+       sock_info->statedump_pending = 1;
+}