--- /dev/null
+/*
+ * ltt-events.c
+ *
+ * Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * Holds LTTng per-session event registry.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <endian.h>
+#include <urcu/list.h>
+#include <urcu/hlist.h>
+#include <pthread.h>
+#include <urcu-bp.h>
+#include <urcu/compiler.h>
+#include <urcu/uatomic.h>
+#include <uuid/uuid.h>
+#include <lttng/tracepoint.h>
+#include <errno.h>
+#include <sys/shm.h>
+#include <sys/ipc.h>
+#include <lttng/ust-events.h>
+#include <lttng/usterr-signal-safe.h>
+#include "lttng/core.h"
+#include "ltt-tracer.h"
+#include "ltt-tracer-core.h"
+#include "lttng/wait.h"
+#include "../libringbuffer/shm.h"
+
+typedef u32 uint32_t;
+#include <lttng/kcompat/jhash.h>
+
+/*
+ * The sessions mutex is the centralized mutex across UST tracing
+ * control and probe registration. All operations within this file are
+ * called by the communication thread, under ust_lock protection.
+ */
+static DEFINE_MUTEX(sessions_mutex);
+
+void ust_lock(void)
+{
+ pthread_mutex_lock(&sessions_mutex);
+}
+
+void ust_unlock(void)
+{
+ pthread_mutex_unlock(&sessions_mutex);
+}
+
+static CDS_LIST_HEAD(sessions);
+static CDS_LIST_HEAD(ltt_transport_list);
+
+/*
+ * Pending probes hash table, containing the registered ltt events for
+ * which tracepoint probes are still missing. Protected by the sessions
+ * mutex.
+ */
+#define PENDING_PROBE_HASH_BITS 6
+#define PENDING_PROBE_HASH_SIZE (1 << PENDING_PROBE_HASH_BITS)
+static struct cds_hlist_head pending_probe_table[PENDING_PROBE_HASH_SIZE];
+
+struct ust_pending_probe {
+ struct ltt_event *event;
+ struct cds_hlist_node node;
+ char name[];
+};
+
+static void _ltt_event_destroy(struct ltt_event *event);
+static void _ltt_channel_destroy(struct ltt_channel *chan);
+static int _ltt_event_unregister(struct ltt_event *event);
+static
+int _ltt_event_metadata_statedump(struct ltt_session *session,
+ struct ltt_channel *chan,
+ struct ltt_event *event);
+static
+int _ltt_session_metadata_statedump(struct ltt_session *session);
+
+/*
+ * called at event creation if probe is missing.
+ * called with session mutex held.
+ */
+static
+int add_pending_probe(struct ltt_event *event, const char *name)
+{
+ struct cds_hlist_head *head;
+ struct ust_pending_probe *e;
+ size_t name_len = strlen(name) + 1;
+ u32 hash = jhash(name, name_len - 1, 0);
+
+ head = &pending_probe_table[hash & (PENDING_PROBE_HASH_SIZE - 1)];
+ e = zmalloc(sizeof(struct ust_pending_probe) + name_len);
+ if (!e)
+ return -ENOMEM;
+ memcpy(&e->name[0], name, name_len);
+ cds_hlist_add_head(&e->node, head);
+ e->event = event;
+ event->pending_probe = e;
+ return 0;
+}
+
+/*
+ * remove a pending probe. called when at event teardown and when an
+ * event is fixed (probe is loaded).
+ * called with session mutex held.
+ */
+static
+void remove_pending_probe(struct ust_pending_probe *e)
+{
+ if (!e)
+ return;
+ cds_hlist_del(&e->node);
+ free(e);
+}
+
+/*
+ * Called at library load: connect the probe on the events pending on
+ * probe load.
+ * called with session mutex held.
+ */
+int pending_probe_fix_events(const struct lttng_event_desc *desc)
+{
+ struct cds_hlist_head *head;
+ struct cds_hlist_node *node, *p;
+ struct ust_pending_probe *e;
+ const char *name = desc->name;
+ size_t name_len = strlen(name) + 1;
+ u32 hash = jhash(name, name_len - 1, 0);
+ int ret = 0;
+
+ head = &pending_probe_table[hash & (PENDING_PROBE_HASH_SIZE - 1)];
+ cds_hlist_for_each_entry_safe(e, node, p, head, node) {
+ struct ltt_event *event;
+ struct ltt_channel *chan;
+
+ if (strcmp(name, e->name))
+ continue;
+ event = e->event;
+ chan = event->chan;
+ assert(!event->desc);
+ event->desc = desc;
+ event->pending_probe = NULL;
+ remove_pending_probe(e);
+ ret |= __tracepoint_probe_register(name,
+ event->desc->probe_callback,
+ event);
+ if (ret)
+ continue;
+ event->id = chan->free_event_id++;
+ ret |= _ltt_event_metadata_statedump(chan->session, chan,
+ event);
+ }
+ return ret;
+}
+
+void synchronize_trace(void)
+{
+ synchronize_rcu();
+}
+
+struct ltt_session *ltt_session_create(void)
+{
+ struct ltt_session *session;
+
+ session = zmalloc(sizeof(struct ltt_session));
+ if (!session)
+ return NULL;
+ CDS_INIT_LIST_HEAD(&session->chan);
+ CDS_INIT_LIST_HEAD(&session->events);
+ uuid_generate(session->uuid);
+ cds_list_add(&session->list, &sessions);
+ return session;
+}
+
+void ltt_session_destroy(struct ltt_session *session)
+{
+ struct ltt_channel *chan, *tmpchan;
+ struct ltt_event *event, *tmpevent;
+ int ret;
+
+ CMM_ACCESS_ONCE(session->active) = 0;
+ cds_list_for_each_entry(event, &session->events, list) {
+ ret = _ltt_event_unregister(event);
+ WARN_ON(ret);
+ }
+ synchronize_trace(); /* Wait for in-flight events to complete */
+ cds_list_for_each_entry_safe(event, tmpevent, &session->events, list)
+ _ltt_event_destroy(event);
+ cds_list_for_each_entry_safe(chan, tmpchan, &session->chan, list)
+ _ltt_channel_destroy(chan);
+ cds_list_del(&session->list);
+ free(session);
+}
+
+int ltt_session_enable(struct ltt_session *session)
+{
+ int ret = 0;
+ struct ltt_channel *chan;
+
+ if (session->active) {
+ ret = -EBUSY;
+ goto end;
+ }
+
+ /*
+ * Snapshot the number of events per channel to know the type of header
+ * we need to use.
+ */
+ cds_list_for_each_entry(chan, &session->chan, list) {
+ if (chan->header_type)
+ continue; /* don't change it if session stop/restart */
+ if (chan->free_event_id < 31)
+ chan->header_type = 1; /* compact */
+ else
+ chan->header_type = 2; /* large */
+ }
+
+ CMM_ACCESS_ONCE(session->active) = 1;
+ CMM_ACCESS_ONCE(session->been_active) = 1;
+ ret = _ltt_session_metadata_statedump(session);
+ if (ret)
+ CMM_ACCESS_ONCE(session->active) = 0;
+end:
+ return ret;
+}
+
+int ltt_session_disable(struct ltt_session *session)
+{
+ int ret = 0;
+
+ if (!session->active) {
+ ret = -EBUSY;
+ goto end;
+ }
+ CMM_ACCESS_ONCE(session->active) = 0;
+end:
+ return ret;
+}
+
+int ltt_channel_enable(struct ltt_channel *channel)
+{
+ int old;
+
+ if (channel == channel->session->metadata)
+ return -EPERM;
+ old = uatomic_xchg(&channel->enabled, 1);
+ if (old)
+ return -EEXIST;
+ return 0;
+}
+
+int ltt_channel_disable(struct ltt_channel *channel)
+{
+ int old;
+
+ if (channel == channel->session->metadata)
+ return -EPERM;
+ old = uatomic_xchg(&channel->enabled, 0);
+ if (!old)
+ return -EEXIST;
+ return 0;
+}
+
+int ltt_event_enable(struct ltt_event *event)
+{
+ int old;
+
+ if (event->chan == event->chan->session->metadata)
+ return -EPERM;
+ old = uatomic_xchg(&event->enabled, 1);
+ if (old)
+ return -EEXIST;
+ return 0;
+}
+
+int ltt_event_disable(struct ltt_event *event)
+{
+ int old;
+
+ if (event->chan == event->chan->session->metadata)
+ return -EPERM;
+ old = uatomic_xchg(&event->enabled, 0);
+ if (!old)
+ return -EEXIST;
+ return 0;
+}
+
+static struct ltt_transport *ltt_transport_find(const char *name)
+{
+ struct ltt_transport *transport;
+
+ cds_list_for_each_entry(transport, <t_transport_list, node) {
+ if (!strcmp(transport->name, name))
+ return transport;
+ }
+ return NULL;
+}
+
+struct ltt_channel *ltt_channel_create(struct ltt_session *session,
+ const char *transport_name,
+ void *buf_addr,
+ size_t subbuf_size, size_t num_subbuf,
+ unsigned int switch_timer_interval,
+ unsigned int read_timer_interval,
+ int *shm_fd, int *wait_fd,
+ uint64_t *memory_map_size)
+{
+ struct ltt_channel *chan;
+ struct ltt_transport *transport;
+
+ if (session->been_active)
+ goto active; /* Refuse to add channel to active session */
+ transport = ltt_transport_find(transport_name);
+ if (!transport) {
+ DBG("LTTng transport %s not found\n",
+ transport_name);
+ goto notransport;
+ }
+ chan = zmalloc(sizeof(struct ltt_channel));
+ if (!chan)
+ goto nomem;
+ chan->session = session;
+ chan->id = session->free_chan_id++;
+ /*
+ * Note: the channel creation op already writes into the packet
+ * headers. Therefore the "chan" information used as input
+ * should be already accessible.
+ */
+ transport->ops.channel_create("[lttng]", chan, buf_addr,
+ subbuf_size, num_subbuf, switch_timer_interval,
+ read_timer_interval, shm_fd, wait_fd,
+ memory_map_size);
+ if (!chan->chan)
+ goto create_error;
+ chan->enabled = 1;
+ chan->ops = &transport->ops;
+ cds_list_add(&chan->list, &session->chan);
+ return chan;
+
+create_error:
+ free(chan);
+nomem:
+notransport:
+active:
+ return NULL;
+}
+
+/*
+ * Only used internally at session destruction.
+ */
+static
+void _ltt_channel_destroy(struct ltt_channel *chan)
+{
+ chan->ops->channel_destroy(chan);
+ cds_list_del(&chan->list);
+ lttng_destroy_context(chan->ctx);
+ free(chan);
+}
+
+/*
+ * Supports event creation while tracing session is active.
+ */
+struct ltt_event *ltt_event_create(struct ltt_channel *chan,
+ struct lttng_ust_event *event_param,
+ void *filter)
+{
+ struct ltt_event *event;
+ int ret;
+
+ if (chan->used_event_id == -1UL)
+ goto full;
+ /*
+ * This is O(n^2) (for each event, the loop is called at event
+ * creation). Might require a hash if we have lots of events.
+ */
+ cds_list_for_each_entry(event, &chan->session->events, list)
+ if (event->desc && !strcmp(event->desc->name, event_param->name))
+ goto exist;
+ event = zmalloc(sizeof(struct ltt_event));
+ if (!event)
+ goto cache_error;
+ event->chan = chan;
+ event->filter = filter;
+ /*
+ * used_event_id counts the maximum number of event IDs that can
+ * register if all probes register.
+ */
+ chan->used_event_id++;
+ event->enabled = 1;
+ event->instrumentation = event_param->instrumentation;
+ /* Populate ltt_event structure before tracepoint registration. */
+ cmm_smp_wmb();
+ switch (event_param->instrumentation) {
+ case LTTNG_UST_TRACEPOINT:
+ event->desc = ltt_event_get(event_param->name);
+ if (event->desc) {
+ ret = __tracepoint_probe_register(event_param->name,
+ event->desc->probe_callback,
+ event);
+ if (ret)
+ goto register_error;
+ event->id = chan->free_event_id++;
+ } else {
+ /*
+ * If the probe is not present, event->desc stays NULL,
+ * waiting for the probe to register, and the event->id
+ * stays unallocated.
+ */
+ ret = add_pending_probe(event, event_param->name);
+ if (ret)
+ goto add_pending_error;
+ }
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ }
+ if (event->desc) {
+ ret = _ltt_event_metadata_statedump(chan->session, chan, event);
+ if (ret)
+ goto statedump_error;
+ }
+ cds_list_add(&event->list, &chan->session->events);
+ return event;
+
+statedump_error:
+ if (event->desc) {
+ WARN_ON_ONCE(__tracepoint_probe_unregister(event_param->name,
+ event->desc->probe_callback,
+ event));
+ ltt_event_put(event->desc);
+ }
+add_pending_error:
+register_error:
+ free(event);
+cache_error:
+exist:
+full:
+ return NULL;
+}
+
+/*
+ * Only used internally at session destruction.
+ */
+int _ltt_event_unregister(struct ltt_event *event)
+{
+ int ret = -EINVAL;
+
+ switch (event->instrumentation) {
+ case LTTNG_UST_TRACEPOINT:
+ if (event->desc) {
+ ret = __tracepoint_probe_unregister(event->desc->name,
+ event->desc->probe_callback,
+ event);
+ if (ret)
+ return ret;
+ } else {
+ remove_pending_probe(event->pending_probe);
+ ret = 0;
+ }
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ }
+ return ret;
+}
+
+/*
+ * Only used internally at session destruction.
+ */
+static
+void _ltt_event_destroy(struct ltt_event *event)
+{
+ switch (event->instrumentation) {
+ case LTTNG_UST_TRACEPOINT:
+ if (event->desc) {
+ ltt_event_put(event->desc);
+ }
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ }
+ cds_list_del(&event->list);
+ lttng_destroy_context(event->ctx);
+ free(event);
+}
+
+/*
+ * We have exclusive access to our metadata buffer (protected by the
+ * ust_lock), so we can do racy operations such as looking for
+ * remaining space left in packet and write, since mutual exclusion
+ * protects us from concurrent writes.
+ */
+int lttng_metadata_printf(struct ltt_session *session,
+ const char *fmt, ...)
+{
+ struct lttng_ust_lib_ring_buffer_ctx ctx;
+ struct ltt_channel *chan = session->metadata;
+ char *str = NULL;
+ int ret = 0, waitret;
+ size_t len, reserve_len, pos;
+ va_list ap;
+
+ WARN_ON_ONCE(!CMM_ACCESS_ONCE(session->active));
+
+ va_start(ap, fmt);
+ ret = vasprintf(&str, fmt, ap);
+ va_end(ap);
+ if (ret < 0)
+ return -ENOMEM;
+
+ len = strlen(str);
+ pos = 0;
+
+ for (pos = 0; pos < len; pos += reserve_len) {
+ reserve_len = min_t(size_t,
+ chan->ops->packet_avail_size(chan->chan, chan->handle),
+ len - pos);
+ lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len,
+ sizeof(char), -1, chan->handle);
+ /*
+ * We don't care about metadata buffer's records lost
+ * count, because we always retry here. Report error if
+ * we need to bail out after timeout or being
+ * interrupted.
+ */
+ waitret = wait_cond_interruptible_timeout(
+ ({
+ ret = chan->ops->event_reserve(&ctx, 0);
+ ret != -ENOBUFS || !ret;
+ }),
+ LTTNG_METADATA_TIMEOUT_MSEC);
+ if (waitret == -ETIMEDOUT || waitret == -EINTR || ret) {
+ DBG("LTTng: Failure to write metadata to buffers (%s)\n",
+ waitret == -EINTR ? "interrupted" :
+ (ret == -ENOBUFS ? "timeout" : "I/O error"));
+ if (waitret == -EINTR)
+ ret = waitret;
+ goto end;
+ }
+ chan->ops->event_write(&ctx, &str[pos], reserve_len);
+ chan->ops->event_commit(&ctx);
+ }
+end:
+ free(str);
+ return ret;
+}
+
+static
+int _ltt_field_statedump(struct ltt_session *session,
+ const struct lttng_event_field *field)
+{
+ int ret = 0;
+
+ switch (field->type.atype) {
+ case atype_integer:
+ ret = lttng_metadata_printf(session,
+ " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
+ field->type.u.basic.integer.size,
+ field->type.u.basic.integer.alignment,
+ field->type.u.basic.integer.signedness,
+ (field->type.u.basic.integer.encoding == lttng_encode_none)
+ ? "none"
+ : (field->type.u.basic.integer.encoding == lttng_encode_UTF8)
+ ? "UTF8"
+ : "ASCII",
+ field->type.u.basic.integer.base,
+#if (BYTE_ORDER == BIG_ENDIAN)
+ field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
+#else
+ field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
+#endif
+ field->name);
+ break;
+ case atype_float:
+ ret = lttng_metadata_printf(session,
+ " floating_point { exp_dig = %u; mant_dig = %u; align = %u;%s } _%s;\n",
+ field->type.u.basic._float.exp_dig,
+ field->type.u.basic._float.mant_dig,
+ field->type.u.basic._float.alignment,
+#if (BYTE_ORDER == BIG_ENDIAN)
+ field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
+#else
+ field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
+#endif
+ field->name);
+ break;
+ case atype_enum:
+ ret = lttng_metadata_printf(session,
+ " %s %s;\n",
+ field->type.u.basic.enumeration.name,
+ field->name);
+ break;
+ case atype_array:
+ {
+ const struct lttng_basic_type *elem_type;
+
+ elem_type = &field->type.u.array.elem_type;
+ ret = lttng_metadata_printf(session,
+ " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
+ elem_type->u.basic.integer.size,
+ elem_type->u.basic.integer.alignment,
+ elem_type->u.basic.integer.signedness,
+ (elem_type->u.basic.integer.encoding == lttng_encode_none)
+ ? "none"
+ : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8)
+ ? "UTF8"
+ : "ASCII",
+ elem_type->u.basic.integer.base,
+#if (BYTE_ORDER == BIG_ENDIAN)
+ elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
+#else
+ elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
+#endif
+ field->name, field->type.u.array.length);
+ break;
+ }
+ case atype_sequence:
+ {
+ const struct lttng_basic_type *elem_type;
+ const struct lttng_basic_type *length_type;
+
+ elem_type = &field->type.u.sequence.elem_type;
+ length_type = &field->type.u.sequence.length_type;
+ ret = lttng_metadata_printf(session,
+ " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
+ length_type->u.basic.integer.size,
+ (unsigned int) length_type->u.basic.integer.alignment,
+ length_type->u.basic.integer.signedness,
+ (length_type->u.basic.integer.encoding == lttng_encode_none)
+ ? "none"
+ : ((length_type->u.basic.integer.encoding == lttng_encode_UTF8)
+ ? "UTF8"
+ : "ASCII"),
+ length_type->u.basic.integer.base,
+#if (BYTE_ORDER == BIG_ENDIAN)
+ length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
+#else
+ length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
+#endif
+ field->name);
+ if (ret)
+ return ret;
+
+ ret = lttng_metadata_printf(session,
+ " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
+ elem_type->u.basic.integer.size,
+ (unsigned int) elem_type->u.basic.integer.alignment,
+ elem_type->u.basic.integer.signedness,
+ (elem_type->u.basic.integer.encoding == lttng_encode_none)
+ ? "none"
+ : ((elem_type->u.basic.integer.encoding == lttng_encode_UTF8)
+ ? "UTF8"
+ : "ASCII"),
+ elem_type->u.basic.integer.base,
+#if (BYTE_ORDER == BIG_ENDIAN)
+ elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
+#else
+ elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
+#endif
+ field->name,
+ field->name);
+ break;
+ }
+
+ case atype_string:
+ /* Default encoding is UTF8 */
+ ret = lttng_metadata_printf(session,
+ " string%s _%s;\n",
+ field->type.u.basic.string.encoding == lttng_encode_ASCII ?
+ " { encoding = ASCII; }" : "",
+ field->name);
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return -EINVAL;
+ }
+ return ret;
+}
+
+static
+int _ltt_context_metadata_statedump(struct ltt_session *session,
+ struct lttng_ctx *ctx)
+{
+ int ret = 0;
+ int i;
+
+ if (!ctx)
+ return 0;
+ for (i = 0; i < ctx->nr_fields; i++) {
+ const struct lttng_ctx_field *field = &ctx->fields[i];
+
+ ret = _ltt_field_statedump(session, &field->event_field);
+ if (ret)
+ return ret;
+ }
+ return ret;
+}
+
+static
+int _ltt_fields_metadata_statedump(struct ltt_session *session,
+ struct ltt_event *event)
+{
+ const struct lttng_event_desc *desc = event->desc;
+ int ret = 0;
+ int i;
+
+ for (i = 0; i < desc->nr_fields; i++) {
+ const struct lttng_event_field *field = &desc->fields[i];
+
+ ret = _ltt_field_statedump(session, field);
+ if (ret)
+ return ret;
+ }
+ return ret;
+}
+
+static
+int _ltt_event_metadata_statedump(struct ltt_session *session,
+ struct ltt_channel *chan,
+ struct ltt_event *event)
+{
+ int ret = 0;
+
+ if (event->metadata_dumped || !CMM_ACCESS_ONCE(session->active))
+ return 0;
+ if (chan == session->metadata)
+ return 0;
+ /*
+ * Don't print events for which probe load is pending.
+ */
+ if (!event->desc)
+ return 0;
+
+ ret = lttng_metadata_printf(session,
+ "event {\n"
+ " name = %s;\n"
+ " id = %u;\n"
+ " stream_id = %u;\n",
+ event->desc->name,
+ event->id,
+ event->chan->id);
+ if (ret)
+ goto end;
+
+ if (event->ctx) {
+ ret = lttng_metadata_printf(session,
+ " context := struct {\n");
+ if (ret)
+ goto end;
+ }
+ ret = _ltt_context_metadata_statedump(session, event->ctx);
+ if (ret)
+ goto end;
+ if (event->ctx) {
+ ret = lttng_metadata_printf(session,
+ " };\n");
+ if (ret)
+ goto end;
+ }
+
+ ret = lttng_metadata_printf(session,
+ " fields := struct {\n"
+ );
+ if (ret)
+ goto end;
+
+ ret = _ltt_fields_metadata_statedump(session, event);
+ if (ret)
+ goto end;
+
+ /*
+ * LTTng space reservation can only reserve multiples of the
+ * byte size.
+ */
+ ret = lttng_metadata_printf(session,
+ " };\n"
+ "};\n\n");
+ if (ret)
+ goto end;
+
+ event->metadata_dumped = 1;
+end:
+ return ret;
+
+}
+
+static
+int _ltt_channel_metadata_statedump(struct ltt_session *session,
+ struct ltt_channel *chan)
+{
+ int ret = 0;
+
+ if (chan->metadata_dumped || !CMM_ACCESS_ONCE(session->active))
+ return 0;
+ if (chan == session->metadata)
+ return 0;
+
+ WARN_ON_ONCE(!chan->header_type);
+ ret = lttng_metadata_printf(session,
+ "stream {\n"
+ " id = %u;\n"
+ " event.header := %s;\n"
+ " packet.context := struct packet_context;\n",
+ chan->id,
+ chan->header_type == 1 ? "struct event_header_compact" :
+ "struct event_header_large");
+ if (ret)
+ goto end;
+
+ if (chan->ctx) {
+ ret = lttng_metadata_printf(session,
+ " event.context := struct {\n");
+ if (ret)
+ goto end;
+ }
+ ret = _ltt_context_metadata_statedump(session, chan->ctx);
+ if (ret)
+ goto end;
+ if (chan->ctx) {
+ ret = lttng_metadata_printf(session,
+ " };\n");
+ if (ret)
+ goto end;
+ }
+
+ ret = lttng_metadata_printf(session,
+ "};\n\n");
+
+ chan->metadata_dumped = 1;
+end:
+ return ret;
+}
+
+static
+int _ltt_stream_packet_context_declare(struct ltt_session *session)
+{
+ return lttng_metadata_printf(session,
+ "struct packet_context {\n"
+ " uint64_t timestamp_begin;\n"
+ " uint64_t timestamp_end;\n"
+ " uint32_t events_discarded;\n"
+ " uint32_t content_size;\n"
+ " uint32_t packet_size;\n"
+ " uint32_t cpu_id;\n"
+ "};\n\n"
+ );
+}
+
+/*
+ * Compact header:
+ * id: range: 0 - 30.
+ * id 31 is reserved to indicate an extended header.
+ *
+ * Large header:
+ * id: range: 0 - 65534.
+ * id 65535 is reserved to indicate an extended header.
+ */
+static
+int _ltt_event_header_declare(struct ltt_session *session)
+{
+ return lttng_metadata_printf(session,
+ "struct event_header_compact {\n"
+ " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
+ " variant <id> {\n"
+ " struct {\n"
+ " uint27_t timestamp;\n"
+ " } compact;\n"
+ " struct {\n"
+ " uint32_t id;\n"
+ " uint64_t timestamp;\n"
+ " } extended;\n"
+ " } v;\n"
+ "} align(%u);\n"
+ "\n"
+ "struct event_header_large {\n"
+ " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
+ " variant <id> {\n"
+ " struct {\n"
+ " uint32_t timestamp;\n"
+ " } compact;\n"
+ " struct {\n"
+ " uint32_t id;\n"
+ " uint64_t timestamp;\n"
+ " } extended;\n"
+ " } v;\n"
+ "} align(%u);\n\n",
+ lttng_alignof(uint32_t) * CHAR_BIT,
+ lttng_alignof(uint16_t) * CHAR_BIT
+ );
+}
+
+/*
+ * Output metadata into this session's metadata buffers.
+ */
+static
+int _ltt_session_metadata_statedump(struct ltt_session *session)
+{
+ unsigned char *uuid_c = session->uuid;
+ char uuid_s[37];
+ struct ltt_channel *chan;
+ struct ltt_event *event;
+ int ret = 0;
+
+ if (!CMM_ACCESS_ONCE(session->active))
+ return 0;
+ if (session->metadata_dumped)
+ goto skip_session;
+ if (!session->metadata) {
+ DBG("LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n");
+ return -EPERM;
+ }
+
+ snprintf(uuid_s, sizeof(uuid_s),
+ "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
+ uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
+ uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
+ uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
+ uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
+
+ ret = lttng_metadata_printf(session,
+ "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
+ "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
+ "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
+ "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
+ "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
+ "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
+ "\n"
+ "trace {\n"
+ " major = %u;\n"
+ " minor = %u;\n"
+ " uuid = \"%s\";\n"
+ " byte_order = %s;\n"
+ " packet.header := struct {\n"
+ " uint32_t magic;\n"
+ " uint8_t uuid[16];\n"
+ " uint32_t stream_id;\n"
+ " };\n"
+ "};\n\n",
+ lttng_alignof(uint8_t) * CHAR_BIT,
+ lttng_alignof(uint16_t) * CHAR_BIT,
+ lttng_alignof(uint32_t) * CHAR_BIT,
+ lttng_alignof(uint64_t) * CHAR_BIT,
+ CTF_VERSION_MAJOR,
+ CTF_VERSION_MINOR,
+ uuid_s,
+#if (BYTE_ORDER == BIG_ENDIAN)
+ "be"
+#else
+ "le"
+#endif
+ );
+ if (ret)
+ goto end;
+
+ ret = _ltt_stream_packet_context_declare(session);
+ if (ret)
+ goto end;
+
+ ret = _ltt_event_header_declare(session);
+ if (ret)
+ goto end;
+
+skip_session:
+ cds_list_for_each_entry(chan, &session->chan, list) {
+ ret = _ltt_channel_metadata_statedump(session, chan);
+ if (ret)
+ goto end;
+ }
+
+ cds_list_for_each_entry(event, &session->events, list) {
+ ret = _ltt_event_metadata_statedump(session, event->chan, event);
+ if (ret)
+ goto end;
+ }
+ session->metadata_dumped = 1;
+end:
+ return ret;
+}
+
+/**
+ * ltt_transport_register - LTT transport registration
+ * @transport: transport structure
+ *
+ * Registers a transport which can be used as output to extract the data out of
+ * LTTng. Called with ust_lock held.
+ */
+void ltt_transport_register(struct ltt_transport *transport)
+{
+ cds_list_add_tail(&transport->node, <t_transport_list);
+}
+
+/**
+ * ltt_transport_unregister - LTT transport unregistration
+ * @transport: transport structure
+ * Called with ust_lock held.
+ */
+void ltt_transport_unregister(struct ltt_transport *transport)
+{
+ cds_list_del(&transport->node);
+}
+
+void lttng_ust_events_exit(void)
+{
+ struct ltt_session *session, *tmpsession;
+
+ cds_list_for_each_entry_safe(session, tmpsession, &sessions, list)
+ ltt_session_destroy(session);
+}
projects / ust.git / blobdiff