Fix double PID registration race

Introduce a second hash table indexed by application socket which have
the exact same content as the hash table indexed by PID.

On unregister, we now use a direct lookup per socket instead of using
the key map between sock and PID. This prevents the PID-sock lookup race
when the unregister happens just after the replace and before the
close(fd).

We also use an add_replace call on application registration for the PID
hash table and kept the add_unique for the socket hash table.

(closes #7)

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: David Goulet <dgoulet@efficios.com>

diff --git a/src/bin/lttng-sessiond/ust-app.c b/src/bin/lttng-sessiond/ust-app.c
index 8e6d20e86d8f19dec7d63d1a1a7b2e155ef86153..10ffe403bc44448a9d9511fb60e3983345988829 100644 (file)
--- a/src/bin/lttng-sessiond/ust-app.c
+++ b/src/bin/lttng-sessiond/ust-app.c
@@ -180,29 +180,37 @@ void delete_ust_app(struct ust_app *app)
        rcu_read_lock();
 
        /* Delete ust app sessions info */
-       sock = app->key.sock;
-       app->key.sock = -1;
+       sock = app->sock;
+       app->sock = -1;
 
        /* Wipe sessions */
        cds_lfht_for_each_entry(app->sessions->ht, &iter.iter, ua_sess,
                        node.node) {
                ret = lttng_ht_del(app->sessions, &iter);
                assert(!ret);
-               delete_ust_app_session(app->key.sock, ua_sess);
+               delete_ust_app_session(app->sock, ua_sess);
        }
        lttng_ht_destroy(app->sessions);
 
        /*
-        * Wait until we have removed the key from the sock hash table before
-        * closing this socket, otherwise an application could re-use the socket ID
-        * and race with the teardown, using the same hash table entry.
+        * Wait until we have deleted the application from the sock hash table
+        * before closing this socket, otherwise an application could re-use the
+        * socket ID and race with the teardown, using the same hash table entry.
+        *
+        * It's OK to leave the close in call_rcu. We want it to stay unique for
+        * all RCU readers that could run concurrently with unregister app,
+        * therefore we _need_ to only close that socket after a grace period. So
+        * it should stay in this RCU callback.
+        *
+        * This close() is a very important step of the synchronization model so
+        * every modification to this function must be carefully reviewed.
         */
        ret = close(sock);
        if (ret) {
                PERROR("close");
        }
 
-       DBG2("UST app pid %d deleted", app->key.pid);
+       DBG2("UST app pid %d deleted", app->pid);
        free(app);
 
        rcu_read_unlock();
@@ -217,9 +225,9 @@ void delete_ust_app_rcu(struct rcu_head *head)
        struct lttng_ht_node_ulong *node =
                caa_container_of(head, struct lttng_ht_node_ulong, head);
        struct ust_app *app =
-               caa_container_of(node, struct ust_app, node);
+               caa_container_of(node, struct ust_app, pid_n);
 
-       DBG3("Call RCU deleting app PID %d", app->key.pid);
+       DBG3("Call RCU deleting app PID %d", app->pid);
        delete_ust_app(app);
 }
 
@@ -354,25 +362,16 @@ static
 struct ust_app *find_app_by_sock(int sock)
 {
        struct lttng_ht_node_ulong *node;
-       struct ust_app_key *key;
        struct lttng_ht_iter iter;
 
-       lttng_ht_lookup(ust_app_sock_key_map, (void *)((unsigned long) sock),
-                       &iter);
-       node = lttng_ht_iter_get_node_ulong(&iter);
-       if (node == NULL) {
-               DBG2("UST app find by sock %d key not found", sock);
-               goto error;
-       }
-       key = caa_container_of(node, struct ust_app_key, node);
-
-       lttng_ht_lookup(ust_app_ht, (void *)((unsigned long) key->pid), &iter);
+       lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
        node = lttng_ht_iter_get_node_ulong(&iter);
        if (node == NULL) {
                DBG2("UST app find by sock %d not found", sock);
                goto error;
        }
-       return caa_container_of(node, struct ust_app, node);
+
+       return caa_container_of(node, struct ust_app, sock_n);
 
 error:
        return NULL;
@@ -387,7 +386,7 @@ int create_ust_channel_context(struct ust_app_channel *ua_chan,
 {
        int ret;
 
-       ret = ustctl_add_context(app->key.sock, &ua_ctx->ctx,
+       ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
                        ua_chan->obj, &ua_ctx->obj);
        if (ret < 0) {
                goto error;
@@ -410,7 +409,7 @@ int create_ust_event_context(struct ust_app_event *ua_event,
 {
        int ret;
 
-       ret = ustctl_add_context(app->key.sock, &ua_ctx->ctx,
+       ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
                        ua_event->obj, &ua_ctx->obj);
        if (ret < 0) {
                goto error;
@@ -432,16 +431,16 @@ static int disable_ust_event(struct ust_app *app,
 {
        int ret;
 
-       ret = ustctl_disable(app->key.sock, ua_event->obj);
+       ret = ustctl_disable(app->sock, ua_event->obj);
        if (ret < 0) {
                ERR("UST app event %s disable failed for app (pid: %d) "
                                "and session handle %d with ret %d",
-                               ua_event->attr.name, app->key.pid, ua_sess->handle, ret);
+                               ua_event->attr.name, app->pid, ua_sess->handle, ret);
                goto error;
        }
 
        DBG2("UST app event %s disabled successfully for app (pid: %d)",
-                       ua_event->attr.name, app->key.pid);
+                       ua_event->attr.name, app->pid);
 
 error:
        return ret;
@@ -455,16 +454,16 @@ static int disable_ust_channel(struct ust_app *app,
 {
        int ret;
 
-       ret = ustctl_disable(app->key.sock, ua_chan->obj);
+       ret = ustctl_disable(app->sock, ua_chan->obj);
        if (ret < 0) {
                ERR("UST app channel %s disable failed for app (pid: %d) "
                                "and session handle %d with ret %d",
-                               ua_chan->name, app->key.pid, ua_sess->handle, ret);
+                               ua_chan->name, app->pid, ua_sess->handle, ret);
                goto error;
        }
 
        DBG2("UST app channel %s disabled successfully for app (pid: %d)",
-                       ua_chan->name, app->key.pid);
+                       ua_chan->name, app->pid);
 
 error:
        return ret;
@@ -478,18 +477,18 @@ static int enable_ust_channel(struct ust_app *app,
 {
        int ret;
 
-       ret = ustctl_enable(app->key.sock, ua_chan->obj);
+       ret = ustctl_enable(app->sock, ua_chan->obj);
        if (ret < 0) {
                ERR("UST app channel %s enable failed for app (pid: %d) "
                                "and session handle %d with ret %d",
-                               ua_chan->name, app->key.pid, ua_sess->handle, ret);
+                               ua_chan->name, app->pid, ua_sess->handle, ret);
                goto error;
        }
 
        ua_chan->enabled = 1;
 
        DBG2("UST app channel %s enabled successfully for app (pid: %d)",
-                       ua_chan->name, app->key.pid);
+                       ua_chan->name, app->pid);
 
 error:
        return ret;
@@ -503,16 +502,16 @@ static int enable_ust_event(struct ust_app *app,
 {
        int ret;
 
-       ret = ustctl_enable(app->key.sock, ua_event->obj);
+       ret = ustctl_enable(app->sock, ua_event->obj);
        if (ret < 0) {
                ERR("UST app event %s enable failed for app (pid: %d) "
                                "and session handle %d with ret %d",
-                               ua_event->attr.name, app->key.pid, ua_sess->handle, ret);
+                               ua_event->attr.name, app->pid, ua_sess->handle, ret);
                goto error;
        }
 
        DBG2("UST app event %s enabled successfully for app (pid: %d)",
-                       ua_event->attr.name, app->key.pid);
+                       ua_event->attr.name, app->pid);
 
 error:
        return ret;
@@ -537,11 +536,11 @@ static int open_ust_metadata(struct ust_app *app,
        uattr.output = ua_sess->metadata->attr.output;
 
        /* UST tracer metadata creation */
-       ret = ustctl_open_metadata(app->key.sock, ua_sess->handle, &uattr,
+       ret = ustctl_open_metadata(app->sock, ua_sess->handle, &uattr,
                        &ua_sess->metadata->obj);
        if (ret < 0) {
                ERR("UST app open metadata failed for app pid:%d with ret %d",
-                               app->key.pid, ret);
+                               app->pid, ret);
                goto error;
        }
 
@@ -559,7 +558,7 @@ static int create_ust_stream(struct ust_app *app,
 {
        int ret;
 
-       ret = ustctl_create_stream(app->key.sock, ua_sess->metadata->obj,
+       ret = ustctl_create_stream(app->sock, ua_sess->metadata->obj,
                        &ua_sess->metadata->stream_obj);
        if (ret < 0) {
                ERR("UST create metadata stream failed");
@@ -579,12 +578,12 @@ static int create_ust_channel(struct ust_app *app,
        int ret;
 
        /* TODO: remove cast and use lttng-ust-abi.h */
-       ret = ustctl_create_channel(app->key.sock, ua_sess->handle,
+       ret = ustctl_create_channel(app->sock, ua_sess->handle,
                        (struct lttng_ust_channel_attr *)&ua_chan->attr, &ua_chan->obj);
        if (ret < 0) {
                ERR("Creating channel %s for app (pid: %d, sock: %d) "
                                "and session handle %d with ret %d",
-                               ua_chan->name, app->key.pid, app->key.sock,
+                               ua_chan->name, app->pid, app->sock,
                                ua_sess->handle, ret);
                goto error;
        }
@@ -592,7 +591,7 @@ static int create_ust_channel(struct ust_app *app,
        ua_chan->handle = ua_chan->obj->handle;
 
        DBG2("UST app channel %s created successfully for pid:%d and sock:%d",
-                       ua_chan->name, app->key.pid, app->key.sock);
+                       ua_chan->name, app->pid, app->sock);
 
        /* If channel is not enabled, disable it on the tracer */
        if (!ua_chan->enabled) {
@@ -616,7 +615,7 @@ int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
        int ret = 0;
 
        /* Create UST event on tracer */
-       ret = ustctl_create_event(app->key.sock, &ua_event->attr, ua_chan->obj,
+       ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
                        &ua_event->obj);
        if (ret < 0) {
                if (ret == -EEXIST) {
@@ -624,14 +623,14 @@ int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
                        goto error;
                }
                ERR("Error ustctl create event %s for app pid: %d with ret %d",
-                               ua_event->attr.name, app->key.pid, ret);
+                               ua_event->attr.name, app->pid, ret);
                goto error;
        }
 
        ua_event->handle = ua_event->obj->handle;
 
        DBG2("UST app event %s created successfully for pid:%d",
-                       ua_event->attr.name, app->key.pid);
+                       ua_event->attr.name, app->pid);
 
        /* If event not enabled, disable it on the tracer */
        if (ua_event->enabled == 0) {
@@ -772,7 +771,7 @@ static void shadow_copy_session(struct ust_app_session *ua_sess,
        ua_sess->gid = usess->gid;
 
        ret = snprintf(ua_sess->path, PATH_MAX, "%s/%s-%d-%s", usess->pathname,
-                       app->name, app->key.pid, datetime);
+                       app->name, app->pid, datetime);
        if (ret < 0) {
                PERROR("asprintf UST shadow copy session");
                /* TODO: We cannot return an error from here.. */
@@ -854,7 +853,7 @@ static struct ust_app_session *create_ust_app_session(
        ua_sess = lookup_session_by_app(usess, app);
        if (ua_sess == NULL) {
                DBG2("UST app pid: %d session id %d not found, creating it",
-                               app->key.pid, usess->id);
+                               app->pid, usess->id);
                ua_sess = alloc_ust_app_session();
                if (ua_sess == NULL) {
                        /* Only malloc can failed so something is really wrong */
@@ -864,9 +863,9 @@ static struct ust_app_session *create_ust_app_session(
        }
 
        if (ua_sess->handle == -1) {
-               ret = ustctl_create_session(app->key.sock);
+               ret = ustctl_create_session(app->sock);
                if (ret < 0) {
-                       ERR("Creating session for app pid %d", app->key.pid);
+                       ERR("Creating session for app pid %d", app->pid);
                        /* This means that the tracer is gone... */
                        ua_sess = (void*) -1UL;
                        goto error;
@@ -1097,7 +1096,7 @@ static struct ust_app_channel *create_ust_app_channel(
        lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
 
        DBG2("UST app create channel %s for PID %d completed", ua_chan->name,
-                       app->key.pid);
+                       app->pid);
 
 end:
        return ua_chan;
@@ -1148,7 +1147,7 @@ int create_ust_app_event(struct ust_app_session *ua_sess,
        lttng_ht_add_unique_str(ua_chan->events, &ua_event->node);
 
        DBG2("UST app create event %s for PID %d completed", ua_event->name,
-                       app->key.pid);
+                       app->pid);
 
 end:
        return ret;
@@ -1189,7 +1188,7 @@ static int create_ust_app_metadata(struct ust_app_session *ua_sess,
                        goto error;
                }
 
-               DBG2("UST metadata opened for app pid %d", app->key.pid);
+               DBG2("UST metadata opened for app pid %d", app->pid);
        }
 
        /* Open UST metadata stream */
@@ -1214,7 +1213,7 @@ static int create_ust_app_metadata(struct ust_app_session *ua_sess,
                }
 
                DBG2("UST metadata stream object created for app pid %d",
-                               app->key.pid);
+                               app->pid);
        } else {
                ERR("Attempting to create stream without metadata opened");
                goto error;
@@ -1253,7 +1252,7 @@ struct ust_app *ust_app_find_by_pid(pid_t pid)
 
        DBG2("Found UST app by pid %d", pid);
 
-       return caa_container_of(node, struct ust_app, node);
+       return caa_container_of(node, struct ust_app, pid_n);
 
 error:
        rcu_read_unlock();
@@ -1310,20 +1309,31 @@ int ust_app_register(struct ust_register_msg *msg, int sock)
        lta->name[16] = '\0';
        lta->sessions = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 
-       /* Set key map */
-       lta->key.pid = msg->pid;
-       lttng_ht_node_init_ulong(&lta->node, (unsigned long)lta->key.pid);
-       lta->key.sock = sock;
-       lttng_ht_node_init_ulong(&lta->key.node, (unsigned long)lta->key.sock);
+       lta->pid = msg->pid;
+       lttng_ht_node_init_ulong(&lta->pid_n, (unsigned long)lta->pid);
+       lta->sock = sock;
+       lttng_ht_node_init_ulong(&lta->sock_n, (unsigned long)lta->sock);
 
        rcu_read_lock();
-       lttng_ht_add_unique_ulong(ust_app_sock_key_map, &lta->key.node);
-       lttng_ht_add_unique_ulong(ust_app_ht, &lta->node);
+
+       /*
+        * On a re-registration, we want to kick out the previous registration of
+        * that pid
+        */
+       lttng_ht_add_replace_ulong(ust_app_ht, &lta->pid_n);
+
+       /*
+        * The socket _should_ be unique until _we_ call close. So, a add_unique
+        * for the ust_app_ht_by_sock is used which asserts fail if the entry was
+        * already in the table.
+        */
+       lttng_ht_add_unique_ulong(ust_app_ht_by_sock, &lta->sock_n);
+
        rcu_read_unlock();
 
        DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s"
-                       " (version %d.%d)", lta->key.pid, lta->ppid, lta->uid, lta->gid,
-                       lta->key.sock, lta->name, lta->v_major, lta->v_minor);
+                       " (version %d.%d)", lta->pid, lta->ppid, lta->uid, lta->gid,
+                       lta->sock, lta->name, lta->v_major, lta->v_minor);
 
        return 0;
 }
@@ -1342,31 +1352,32 @@ void ust_app_unregister(int sock)
        int ret;
 
        rcu_read_lock();
-       lta = find_app_by_sock(sock);
-       if (lta == NULL) {
-               ERR("Unregister app sock %d not found!", sock);
-               goto error;
-       }
-
-       DBG("PID %d unregistering with sock %d", lta->key.pid, sock);
-
-       /* Remove application from socket hash table */
-       lttng_ht_lookup(ust_app_sock_key_map, (void *)((unsigned long) sock), &iter);
-       ret = lttng_ht_del(ust_app_sock_key_map, &iter);
-       assert(!ret);
 
        /* Get the node reference for a call_rcu */
-       lttng_ht_lookup(ust_app_ht, (void *)((unsigned long) lta->key.pid), &iter);
+       lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
        node = lttng_ht_iter_get_node_ulong(&iter);
        if (node == NULL) {
-               ERR("Unable to find app sock %d by pid %d", sock, lta->key.pid);
+               ERR("Unable to find app by sock %d", sock);
                goto error;
        }
 
+       lta = caa_container_of(node, struct ust_app, sock_n);
+
+       DBG("PID %d unregistering with sock %d", lta->pid, sock);
+
        /* Remove application from PID hash table */
+       ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
+       assert(!ret);
+
+       /* Assign second node for deletion */
+       iter.iter.node = &lta->pid_n.node;
+
        ret = lttng_ht_del(ust_app_ht, &iter);
        assert(!ret);
-       call_rcu(&node->head, delete_ust_app_rcu);
+
+       /* Free memory */
+       call_rcu(&lta->pid_n.head, delete_ust_app_rcu);
+
 error:
        rcu_read_unlock();
        return;
@@ -1407,7 +1418,7 @@ int ust_app_list_events(struct lttng_event **events)
 
        rcu_read_lock();
 
-       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, node.node) {
+       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
                struct lttng_ust_tracepoint_iter uiter;
 
                if (!app->compatible) {
@@ -1417,14 +1428,14 @@ int ust_app_list_events(struct lttng_event **events)
                         */
                        continue;
                }
-               handle = ustctl_tracepoint_list(app->key.sock);
+               handle = ustctl_tracepoint_list(app->sock);
                if (handle < 0) {
                        ERR("UST app list events getting handle failed for app pid %d",
-                                       app->key.pid);
+                                       app->pid);
                        continue;
                }
 
-               while ((ret = ustctl_tracepoint_list_get(app->key.sock, handle,
+               while ((ret = ustctl_tracepoint_list_get(app->sock, handle,
                                                &uiter)) != -ENOENT) {
                        if (count >= nbmem) {
                                DBG2("Reallocating event list from %zu to %zu entries", nbmem,
@@ -1440,7 +1451,7 @@ int ust_app_list_events(struct lttng_event **events)
                        memcpy(tmp[count].name, uiter.name, LTTNG_UST_SYM_NAME_LEN);
                        tmp[count].loglevel = uiter.loglevel;
                        tmp[count].type = LTTNG_UST_TRACEPOINT;
-                       tmp[count].pid = app->key.pid;
+                       tmp[count].pid = app->pid;
                        tmp[count].enabled = -1;
                        count++;
                }
@@ -1475,15 +1486,16 @@ void ust_app_clean_list(void)
                assert(!ret);
                call_rcu(&node->head, delete_ust_app_rcu);
        }
-       /* Destroy is done only when the ht is empty */
-       lttng_ht_destroy(ust_app_ht);
 
-       cds_lfht_for_each_entry(ust_app_sock_key_map->ht, &iter.iter, node, node) {
-               ret = lttng_ht_del(ust_app_sock_key_map, &iter);
+       /* Cleanup socket hash table */
+       cds_lfht_for_each_entry(ust_app_ht_by_sock->ht, &iter.iter, node, node) {
+               ret = lttng_ht_del(ust_app_ht_by_sock, &iter);
                assert(!ret);
        }
+
        /* Destroy is done only when the ht is empty */
-       lttng_ht_destroy(ust_app_sock_key_map);
+       lttng_ht_destroy(ust_app_ht);
+       lttng_ht_destroy(ust_app_ht_by_sock);
 
        rcu_read_unlock();
 }
@@ -1494,7 +1506,7 @@ void ust_app_clean_list(void)
 void ust_app_ht_alloc(void)
 {
        ust_app_ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
-       ust_app_sock_key_map = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
+       ust_app_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
 }
 
 /*
@@ -1522,7 +1534,7 @@ int ust_app_disable_channel_glb(struct ltt_ust_session *usess,
        rcu_read_lock();
 
        /* For every registered applications */
-       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, node.node) {
+       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
                struct lttng_ht_iter uiter;
                if (!app->compatible) {
                        /*
@@ -1583,7 +1595,7 @@ int ust_app_enable_channel_glb(struct ltt_ust_session *usess,
        rcu_read_lock();
 
        /* For every registered applications */
-       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, node.node) {
+       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
                if (!app->compatible) {
                        /*
                         * TODO: In time, we should notice the caller of this error by
@@ -1630,7 +1642,7 @@ int ust_app_disable_event_glb(struct ltt_ust_session *usess,
        rcu_read_lock();
 
        /* For all registered applications */
-       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, node.node) {
+       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
                if (!app->compatible) {
                        /*
                         * TODO: In time, we should notice the caller of this error by
@@ -1649,7 +1661,7 @@ int ust_app_disable_event_glb(struct ltt_ust_session *usess,
                ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
                if (ua_chan_node == NULL) {
                        DBG2("Channel %s not found in session id %d for app pid %d."
-                                       "Skipping", uchan->name, usess->id, app->key.pid);
+                                       "Skipping", uchan->name, usess->id, app->pid);
                        continue;
                }
                ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
@@ -1658,7 +1670,7 @@ int ust_app_disable_event_glb(struct ltt_ust_session *usess,
                ua_event_node = lttng_ht_iter_get_node_str(&uiter);
                if (ua_event_node == NULL) {
                        DBG2("Event %s not found in channel %s for app pid %d."
-                                       "Skipping", uevent->attr.name, uchan->name, app->key.pid);
+                                       "Skipping", uevent->attr.name, uchan->name, app->pid);
                        continue;
                }
                ua_event = caa_container_of(ua_event_node, struct ust_app_event, node);
@@ -1696,7 +1708,7 @@ int ust_app_disable_all_event_glb(struct ltt_ust_session *usess,
        rcu_read_lock();
 
        /* For all registered applications */
-       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, node.node) {
+       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
                if (!app->compatible) {
                        /*
                         * TODO: In time, we should notice the caller of this error by
@@ -1753,7 +1765,7 @@ int ust_app_create_channel_glb(struct ltt_ust_session *usess,
        rcu_read_lock();
 
        /* For every registered applications */
-       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, node.node) {
+       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
                if (!app->compatible) {
                        /*
                         * TODO: In time, we should notice the caller of this error by
@@ -1817,7 +1829,7 @@ int ust_app_enable_event_glb(struct ltt_ust_session *usess,
        rcu_read_lock();
 
        /* For all registered applications */
-       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, node.node) {
+       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
                if (!app->compatible) {
                        /*
                         * TODO: In time, we should notice the caller of this error by
@@ -1841,7 +1853,7 @@ int ust_app_enable_event_glb(struct ltt_ust_session *usess,
                ua_event_node = lttng_ht_iter_get_node_str(&uiter);
                if (ua_event_node == NULL) {
                        DBG3("UST app enable event %s not found for app PID %d."
-                                       "Skipping app", uevent->attr.name, app->key.pid);
+                                       "Skipping app", uevent->attr.name, app->pid);
                        continue;
                }
                ua_event = caa_container_of(ua_event_node, struct ust_app_event, node);
@@ -1877,7 +1889,7 @@ int ust_app_create_event_glb(struct ltt_ust_session *usess,
        rcu_read_lock();
 
        /* For all registered applications */
-       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, node.node) {
+       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
                if (!app->compatible) {
                        /*
                         * TODO: In time, we should notice the caller of this error by
@@ -1904,7 +1916,7 @@ int ust_app_create_event_glb(struct ltt_ust_session *usess,
                                break;
                        }
                        DBG2("UST app event %s already exist on app PID %d",
-                                       uevent->attr.name, app->key.pid);
+                                       uevent->attr.name, app->pid);
                        continue;
                }
        }
@@ -1926,7 +1938,7 @@ int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
        struct ltt_ust_stream *ustream;
        int consumerd_fd;
 
-       DBG("Starting tracing for ust app pid %d", app->key.pid);
+       DBG("Starting tracing for ust app pid %d", app->pid);
 
        rcu_read_lock();
 
@@ -1964,7 +1976,7 @@ int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
                                goto error_rcu_unlock;
                        }
 
-                       ret = ustctl_create_stream(app->key.sock, ua_chan->obj,
+                       ret = ustctl_create_stream(app->sock, ua_chan->obj,
                                        &ustream->obj);
                        if (ret < 0) {
                                /* Got all streams */
@@ -2006,14 +2018,14 @@ int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
 
 skip_setup:
        /* This start the UST tracing */
-       ret = ustctl_start_session(app->key.sock, ua_sess->handle);
+       ret = ustctl_start_session(app->sock, ua_sess->handle);
        if (ret < 0) {
-               ERR("Error starting tracing for app pid: %d", app->key.pid);
+               ERR("Error starting tracing for app pid: %d", app->pid);
                goto error_rcu_unlock;
        }
 
        /* Quiescent wait after starting trace */
-       ustctl_wait_quiescent(app->key.sock);
+       ustctl_wait_quiescent(app->sock);
 
 end:
        rcu_read_unlock();
@@ -2034,7 +2046,7 @@ int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
        struct ust_app_session *ua_sess;
        struct ust_app_channel *ua_chan;
 
-       DBG("Stopping tracing for ust app pid %d", app->key.pid);
+       DBG("Stopping tracing for ust app pid %d", app->pid);
 
        rcu_read_lock();
 
@@ -2056,31 +2068,31 @@ int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
        assert(ua_sess->started == 1);
 
        /* This inhibits UST tracing */
-       ret = ustctl_stop_session(app->key.sock, ua_sess->handle);
+       ret = ustctl_stop_session(app->sock, ua_sess->handle);
        if (ret < 0) {
-               ERR("Error stopping tracing for app pid: %d", app->key.pid);
+               ERR("Error stopping tracing for app pid: %d", app->pid);
                goto error_rcu_unlock;
        }
 
        /* Quiescent wait after stopping trace */
-       ustctl_wait_quiescent(app->key.sock);
+       ustctl_wait_quiescent(app->sock);
 
        /* Flushing buffers */
        cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
                        node.node) {
-               ret = ustctl_sock_flush_buffer(app->key.sock, ua_chan->obj);
+               ret = ustctl_sock_flush_buffer(app->sock, ua_chan->obj);
                if (ret < 0) {
                        ERR("UST app PID %d channel %s flush failed with ret %d",
-                                       app->key.pid, ua_chan->name, ret);
+                                       app->pid, ua_chan->name, ret);
                        /* Continuing flushing all buffers */
                        continue;
                }
        }
 
        /* Flush all buffers before stopping */
-       ret = ustctl_sock_flush_buffer(app->key.sock, ua_sess->metadata->obj);
+       ret = ustctl_sock_flush_buffer(app->sock, ua_sess->metadata->obj);
        if (ret < 0) {
-               ERR("UST app PID %d metadata flush failed with ret %d", app->key.pid,
+               ERR("UST app PID %d metadata flush failed with ret %d", app->pid,
                                ret);
        }
 
@@ -2104,7 +2116,7 @@ int ust_app_destroy_trace(struct ltt_ust_session *usess, struct ust_app *app)
        struct lttng_ht_node_ulong *node;
        int ret;
 
-       DBG("Destroy tracing for ust app pid %d", app->key.pid);
+       DBG("Destroy tracing for ust app pid %d", app->pid);
 
        rcu_read_lock();
 
@@ -2125,12 +2137,12 @@ int ust_app_destroy_trace(struct ltt_ust_session *usess, struct ust_app *app)
        obj.shm_fd = -1;
        obj.wait_fd = -1;
        obj.memory_map_size = 0;
-       ustctl_release_object(app->key.sock, &obj);
+       ustctl_release_object(app->sock, &obj);
 
-       delete_ust_app_session(app->key.sock, ua_sess);
+       delete_ust_app_session(app->sock, ua_sess);
 
        /* Quiescent wait after stopping trace */
-       ustctl_wait_quiescent(app->key.sock);
+       ustctl_wait_quiescent(app->sock);
 
 end:
        rcu_read_unlock();
@@ -2154,7 +2166,7 @@ int ust_app_start_trace_all(struct ltt_ust_session *usess)
 
        rcu_read_lock();
 
-       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, node.node) {
+       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
                ret = ust_app_start_trace(usess, app);
                if (ret < 0) {
                        /* Continue to next apps even on error */
@@ -2180,7 +2192,7 @@ int ust_app_stop_trace_all(struct ltt_ust_session *usess)
 
        rcu_read_lock();
 
-       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, node.node) {
+       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
                ret = ust_app_stop_trace(usess, app);
                if (ret < 0) {
                        /* Continue to next apps even on error */
@@ -2206,7 +2218,7 @@ int ust_app_destroy_trace_all(struct ltt_ust_session *usess)
 
        rcu_read_lock();
 
-       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, node.node) {
+       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
                ret = ust_app_destroy_trace(usess, app);
                if (ret < 0) {
                        /* Continue to next apps even on error */
@@ -2307,7 +2319,7 @@ void ust_app_global_update(struct ltt_ust_session *usess, int sock)
                        goto error;
                }
 
-               DBG2("UST trace started for app pid %d", app->key.pid);
+               DBG2("UST trace started for app pid %d", app->pid);
        }
 
 error:
@@ -2330,7 +2342,7 @@ int ust_app_add_ctx_channel_glb(struct ltt_ust_session *usess,
 
        rcu_read_lock();
 
-       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, node.node) {
+       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
                if (!app->compatible) {
                        /*
                         * TODO: In time, we should notice the caller of this error by
@@ -2379,7 +2391,7 @@ int ust_app_add_ctx_event_glb(struct ltt_ust_session *usess,
 
        rcu_read_lock();
 
-       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, node.node) {
+       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
                if (!app->compatible) {
                        /*
                         * TODO: In time, we should notice the caller of this error by
@@ -2567,7 +2579,7 @@ int ust_app_validate_version(int sock)
        }
 
        DBG2("UST app PID %d is compatible with major version %d "
-                       "(supporting <= %d)", app->key.pid, app->version.major,
+                       "(supporting <= %d)", app->pid, app->version.major,
                        UST_APP_MAJOR_VERSION);
        app->compatible = 1;
        rcu_read_unlock();
@@ -2575,7 +2587,7 @@ int ust_app_validate_version(int sock)
 
 error:
        DBG2("UST app PID %d is not compatible with major version %d "
-                       "(supporting <= %d)", app->key.pid, app->version.major,
+                       "(supporting <= %d)", app->pid, app->version.major,
                        UST_APP_MAJOR_VERSION);
        app->compatible = 0;
        rcu_read_unlock();
@@ -2593,7 +2605,7 @@ int ust_app_calibrate_glb(struct lttng_ust_calibrate *calibrate)
 
        rcu_read_lock();
 
-       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, node.node) {
+       cds_lfht_for_each_entry(ust_app_ht->ht, &iter.iter, app, pid_n.node) {
                if (!app->compatible) {
                        /*
                         * TODO: In time, we should notice the caller of this error by
@@ -2602,7 +2614,7 @@ int ust_app_calibrate_glb(struct lttng_ust_calibrate *calibrate)
                        continue;
                }
 
-               ret = ustctl_calibrate(app->key.sock, calibrate);
+               ret = ustctl_calibrate(app->sock, calibrate);
                if (ret < 0) {
                        switch (ret) {
                        case -ENOSYS:
@@ -2612,7 +2624,7 @@ int ust_app_calibrate_glb(struct lttng_ust_calibrate *calibrate)
                        default:
                                /* TODO: Report error to user */
                                DBG2("Calibrate app PID %d returned with error %d",
-                                               app->key.pid, ret);
+                                               app->pid, ret);
                                break;
                        }
                }

diff --git a/src/bin/lttng-sessiond/ust-app.h b/src/bin/lttng-sessiond/ust-app.h
index 906a6a209b1e63eca442e438fbb76497d1937775..8e98082207a59f9f398a551aa5a7ad7041d45eba 100644 (file)
--- a/src/bin/lttng-sessiond/ust-app.h
+++ b/src/bin/lttng-sessiond/ust-app.h
@@ -45,17 +45,16 @@ struct ust_register_msg {
 };
 
 /*
- * Global applications HT used by the session daemon.
+ * Global applications HT used by the session daemon. This table is indexed by
+ * PID using the pid_n node and pid value of an ust_app.
  */
 struct lttng_ht *ust_app_ht;
 
-struct lttng_ht *ust_app_sock_key_map;
-
-struct ust_app_key {
-       pid_t pid;
-       int sock;
-       struct lttng_ht_node_ulong node;
-};
+/*
+ * Global applications HT used by the session daemon. This table is indexed by
+ * socket using the sock_n node and sock value of an ust_app.
+ */
+struct lttng_ht *ust_app_ht_by_sock;
 
 struct ust_app_ctx {
        int handle;
@@ -106,6 +105,8 @@ struct ust_app_session {
  * and a linked list is kept of all running traceable app.
  */
 struct ust_app {
+       int sock;
+       pid_t pid;
        pid_t ppid;
        uid_t uid;           /* User ID that owns the apps */
        gid_t gid;           /* Group ID that owns the apps */
@@ -118,8 +119,8 @@ struct ust_app {
        uint32_t v_minor;    /* Verion minor number */
        char name[17];       /* Process name (short) */
        struct lttng_ht *sessions;
-       struct lttng_ht_node_ulong node;
-       struct ust_app_key key;
+       struct lttng_ht_node_ulong pid_n;
+       struct lttng_ht_node_ulong sock_n;
 };
 
 #ifdef HAVE_LIBLTTNG_UST_CTL

diff --git a/src/common/hashtable/hashtable.h b/src/common/hashtable/hashtable.h
index d2d6979bae1682c22515acbf8f413e939d1dca8f..f242e75e895c78ab22769468efca4aa3c074be95 100644 (file)
--- a/src/common/hashtable/hashtable.h
+++ b/src/common/hashtable/hashtable.h
@@ -72,8 +72,8 @@ extern void lttng_ht_add_unique_str(struct lttng_ht *ht,
                struct lttng_ht_node_str *node);
 extern void lttng_ht_add_unique_ulong(struct lttng_ht *ht,
                struct lttng_ht_node_ulong *node);
-struct lttng_ht_node_ulong *lttng_ht_add_replace_ulong(struct lttng_ht *ht,
-               struct lttng_ht_node_ulong *node);
+extern struct lttng_ht_node_ulong *lttng_ht_add_replace_ulong(
+               struct lttng_ht *ht, struct lttng_ht_node_ulong *node);
 
 extern int lttng_ht_del(struct lttng_ht *ht, struct lttng_ht_iter *iter);