+++ /dev/null
-/*
- * lttng-events.c
- *
- * Holds LTTng per-session event registry.
- *
- * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; only
- * version 2.1 of the License.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#include <linux/module.h>
-#include <linux/list.h>
-#include <linux/mutex.h>
-#include <linux/sched.h>
-#include <linux/slab.h>
-#include <linux/jiffies.h>
-#include <linux/utsname.h>
-#include "wrapper/uuid.h"
-#include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */
-#include "wrapper/random.h"
-#include "wrapper/tracepoint.h"
-#include "lttng-events.h"
-#include "lttng-tracer.h"
-#include "lttng-abi-old.h"
-
-#define METADATA_CACHE_DEFAULT_SIZE 4096
-
-static LIST_HEAD(sessions);
-static LIST_HEAD(lttng_transport_list);
-/*
- * Protect the sessions and metadata caches.
- */
-static DEFINE_MUTEX(sessions_mutex);
-static struct kmem_cache *event_cache;
-
-static void _lttng_event_destroy(struct lttng_event *event);
-static void _lttng_channel_destroy(struct lttng_channel *chan);
-static int _lttng_event_unregister(struct lttng_event *event);
-static
-int _lttng_event_metadata_statedump(struct lttng_session *session,
- struct lttng_channel *chan,
- struct lttng_event *event);
-static
-int _lttng_session_metadata_statedump(struct lttng_session *session);
-static
-void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream);
-
-void synchronize_trace(void)
-{
- synchronize_sched();
-#ifdef CONFIG_PREEMPT_RT
- synchronize_rcu();
-#endif
-}
-
-struct lttng_session *lttng_session_create(void)
-{
- struct lttng_session *session;
- struct lttng_metadata_cache *metadata_cache;
-
- mutex_lock(&sessions_mutex);
- session = kzalloc(sizeof(struct lttng_session), GFP_KERNEL);
- if (!session)
- goto err;
- INIT_LIST_HEAD(&session->chan);
- INIT_LIST_HEAD(&session->events);
- uuid_le_gen(&session->uuid);
-
- metadata_cache = kzalloc(sizeof(struct lttng_metadata_cache),
- GFP_KERNEL);
- if (!metadata_cache)
- goto err_free_session;
- metadata_cache->data = kzalloc(METADATA_CACHE_DEFAULT_SIZE,
- GFP_KERNEL);
- if (!metadata_cache->data)
- goto err_free_cache;
- metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE;
- kref_init(&metadata_cache->refcount);
- session->metadata_cache = metadata_cache;
- INIT_LIST_HEAD(&metadata_cache->metadata_stream);
- list_add(&session->list, &sessions);
- mutex_unlock(&sessions_mutex);
- return session;
-
-err_free_cache:
- kfree(metadata_cache);
-err_free_session:
- kfree(session);
-err:
- mutex_unlock(&sessions_mutex);
- return NULL;
-}
-
-void metadata_cache_destroy(struct kref *kref)
-{
- struct lttng_metadata_cache *cache =
- container_of(kref, struct lttng_metadata_cache, refcount);
- kfree(cache->data);
- kfree(cache);
-}
-
-void lttng_session_destroy(struct lttng_session *session)
-{
- struct lttng_channel *chan, *tmpchan;
- struct lttng_event *event, *tmpevent;
- struct lttng_metadata_stream *metadata_stream;
- int ret;
-
- mutex_lock(&sessions_mutex);
- ACCESS_ONCE(session->active) = 0;
- list_for_each_entry(chan, &session->chan, list) {
- ret = lttng_syscalls_unregister(chan);
- WARN_ON(ret);
- }
- list_for_each_entry(event, &session->events, list) {
- ret = _lttng_event_unregister(event);
- WARN_ON(ret);
- }
- synchronize_trace(); /* Wait for in-flight events to complete */
- list_for_each_entry_safe(event, tmpevent, &session->events, list)
- _lttng_event_destroy(event);
- list_for_each_entry_safe(chan, tmpchan, &session->chan, list) {
- BUG_ON(chan->channel_type == METADATA_CHANNEL);
- _lttng_channel_destroy(chan);
- }
- list_for_each_entry(metadata_stream, &session->metadata_cache->metadata_stream, list)
- _lttng_metadata_channel_hangup(metadata_stream);
- kref_put(&session->metadata_cache->refcount, metadata_cache_destroy);
- list_del(&session->list);
- mutex_unlock(&sessions_mutex);
- kfree(session);
-}
-
-int lttng_session_enable(struct lttng_session *session)
-{
- int ret = 0;
- struct lttng_channel *chan;
-
- mutex_lock(&sessions_mutex);
- if (session->active) {
- ret = -EBUSY;
- goto end;
- }
-
- /*
- * Snapshot the number of events per channel to know the type of header
- * we need to use.
- */
- 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 */
- }
-
- ACCESS_ONCE(session->active) = 1;
- ACCESS_ONCE(session->been_active) = 1;
- ret = _lttng_session_metadata_statedump(session);
- if (ret) {
- ACCESS_ONCE(session->active) = 0;
- goto end;
- }
- ret = lttng_statedump_start(session);
- if (ret)
- ACCESS_ONCE(session->active) = 0;
-end:
- mutex_unlock(&sessions_mutex);
- return ret;
-}
-
-int lttng_session_disable(struct lttng_session *session)
-{
- int ret = 0;
-
- mutex_lock(&sessions_mutex);
- if (!session->active) {
- ret = -EBUSY;
- goto end;
- }
- ACCESS_ONCE(session->active) = 0;
-end:
- mutex_unlock(&sessions_mutex);
- return ret;
-}
-
-int lttng_channel_enable(struct lttng_channel *channel)
-{
- int old;
-
- if (channel->channel_type == METADATA_CHANNEL)
- return -EPERM;
- old = xchg(&channel->enabled, 1);
- if (old)
- return -EEXIST;
- return 0;
-}
-
-int lttng_channel_disable(struct lttng_channel *channel)
-{
- int old;
-
- if (channel->channel_type == METADATA_CHANNEL)
- return -EPERM;
- old = xchg(&channel->enabled, 0);
- if (!old)
- return -EEXIST;
- return 0;
-}
-
-int lttng_event_enable(struct lttng_event *event)
-{
- int old;
-
- if (event->chan->channel_type == METADATA_CHANNEL)
- return -EPERM;
- old = xchg(&event->enabled, 1);
- if (old)
- return -EEXIST;
- return 0;
-}
-
-int lttng_event_disable(struct lttng_event *event)
-{
- int old;
-
- if (event->chan->channel_type == METADATA_CHANNEL)
- return -EPERM;
- old = xchg(&event->enabled, 0);
- if (!old)
- return -EEXIST;
- return 0;
-}
-
-static struct lttng_transport *lttng_transport_find(const char *name)
-{
- struct lttng_transport *transport;
-
- list_for_each_entry(transport, <tng_transport_list, node) {
- if (!strcmp(transport->name, name))
- return transport;
- }
- return NULL;
-}
-
-struct lttng_channel *lttng_channel_create(struct lttng_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,
- enum channel_type channel_type)
-{
- struct lttng_channel *chan;
- struct lttng_transport *transport = NULL;
-
- mutex_lock(&sessions_mutex);
- if (session->been_active && channel_type != METADATA_CHANNEL)
- goto active; /* Refuse to add channel to active session */
- transport = lttng_transport_find(transport_name);
- if (!transport) {
- printk(KERN_WARNING "LTTng transport %s not found\n",
- transport_name);
- goto notransport;
- }
- if (!try_module_get(transport->owner)) {
- printk(KERN_WARNING "LTT : Can't lock transport module.\n");
- goto notransport;
- }
- chan = kzalloc(sizeof(struct lttng_channel), GFP_KERNEL);
- 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.
- */
- chan->chan = transport->ops.channel_create(transport_name,
- chan, buf_addr, subbuf_size, num_subbuf,
- switch_timer_interval, read_timer_interval);
- if (!chan->chan)
- goto create_error;
- chan->enabled = 1;
- chan->ops = &transport->ops;
- chan->transport = transport;
- chan->channel_type = channel_type;
- list_add(&chan->list, &session->chan);
- mutex_unlock(&sessions_mutex);
- return chan;
-
-create_error:
- kfree(chan);
-nomem:
- if (transport)
- module_put(transport->owner);
-notransport:
-active:
- mutex_unlock(&sessions_mutex);
- return NULL;
-}
-
-/*
- * Only used internally at session destruction for per-cpu channels, and
- * when metadata channel is released.
- * Needs to be called with sessions mutex held.
- */
-static
-void _lttng_channel_destroy(struct lttng_channel *chan)
-{
- chan->ops->channel_destroy(chan->chan);
- module_put(chan->transport->owner);
- list_del(&chan->list);
- lttng_destroy_context(chan->ctx);
- kfree(chan);
-}
-
-void lttng_metadata_channel_destroy(struct lttng_channel *chan)
-{
- BUG_ON(chan->channel_type != METADATA_CHANNEL);
-
- /* Protect the metadata cache with the sessions_mutex. */
- mutex_lock(&sessions_mutex);
- _lttng_channel_destroy(chan);
- mutex_unlock(&sessions_mutex);
-}
-EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy);
-
-static
-void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream)
-{
- stream->finalized = 1;
- wake_up_interruptible(&stream->read_wait);
-}
-
-/*
- * Supports event creation while tracing session is active.
- */
-struct lttng_event *lttng_event_create(struct lttng_channel *chan,
- struct lttng_kernel_event *event_param,
- void *filter,
- const struct lttng_event_desc *internal_desc)
-{
- struct lttng_event *event;
- int ret;
-
- mutex_lock(&sessions_mutex);
- if (chan->free_event_id == -1U)
- 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.
- */
- list_for_each_entry(event, &chan->session->events, list)
- if (!strcmp(event->desc->name, event_param->name))
- goto exist;
- event = kmem_cache_zalloc(event_cache, GFP_KERNEL);
- if (!event)
- goto cache_error;
- event->chan = chan;
- event->filter = filter;
- event->id = chan->free_event_id++;
- event->enabled = 1;
- event->instrumentation = event_param->instrumentation;
- /* Populate lttng_event structure before tracepoint registration. */
- smp_wmb();
- switch (event_param->instrumentation) {
- case LTTNG_KERNEL_TRACEPOINT:
- event->desc = lttng_event_get(event_param->name);
- if (!event->desc)
- goto register_error;
- ret = kabi_2635_tracepoint_probe_register(event_param->name,
- event->desc->probe_callback,
- event);
- if (ret)
- goto register_error;
- break;
- case LTTNG_KERNEL_KPROBE:
- ret = lttng_kprobes_register(event_param->name,
- event_param->u.kprobe.symbol_name,
- event_param->u.kprobe.offset,
- event_param->u.kprobe.addr,
- event);
- if (ret)
- goto register_error;
- ret = try_module_get(event->desc->owner);
- WARN_ON_ONCE(!ret);
- break;
- case LTTNG_KERNEL_KRETPROBE:
- {
- struct lttng_event *event_return;
-
- /* kretprobe defines 2 events */
- event_return =
- kmem_cache_zalloc(event_cache, GFP_KERNEL);
- if (!event_return)
- goto register_error;
- event_return->chan = chan;
- event_return->filter = filter;
- event_return->id = chan->free_event_id++;
- event_return->enabled = 1;
- event_return->instrumentation = event_param->instrumentation;
- /*
- * Populate lttng_event structure before kretprobe registration.
- */
- smp_wmb();
- ret = lttng_kretprobes_register(event_param->name,
- event_param->u.kretprobe.symbol_name,
- event_param->u.kretprobe.offset,
- event_param->u.kretprobe.addr,
- event, event_return);
- if (ret) {
- kmem_cache_free(event_cache, event_return);
- goto register_error;
- }
- /* Take 2 refs on the module: one per event. */
- ret = try_module_get(event->desc->owner);
- WARN_ON_ONCE(!ret);
- ret = try_module_get(event->desc->owner);
- WARN_ON_ONCE(!ret);
- ret = _lttng_event_metadata_statedump(chan->session, chan,
- event_return);
- if (ret) {
- kmem_cache_free(event_cache, event_return);
- module_put(event->desc->owner);
- module_put(event->desc->owner);
- goto statedump_error;
- }
- list_add(&event_return->list, &chan->session->events);
- break;
- }
- case LTTNG_KERNEL_FUNCTION:
- ret = lttng_ftrace_register(event_param->name,
- event_param->u.ftrace.symbol_name,
- event);
- if (ret)
- goto register_error;
- ret = try_module_get(event->desc->owner);
- WARN_ON_ONCE(!ret);
- break;
- case LTTNG_KERNEL_NOOP:
- event->desc = internal_desc;
- if (!event->desc)
- goto register_error;
- break;
- default:
- WARN_ON_ONCE(1);
- }
- ret = _lttng_event_metadata_statedump(chan->session, chan, event);
- if (ret)
- goto statedump_error;
- list_add(&event->list, &chan->session->events);
- mutex_unlock(&sessions_mutex);
- return event;
-
-statedump_error:
- /* If a statedump error occurs, events will not be readable. */
-register_error:
- kmem_cache_free(event_cache, event);
-cache_error:
-exist:
-full:
- mutex_unlock(&sessions_mutex);
- return NULL;
-}
-
-/*
- * Only used internally at session destruction.
- */
-int _lttng_event_unregister(struct lttng_event *event)
-{
- int ret = -EINVAL;
-
- switch (event->instrumentation) {
- case LTTNG_KERNEL_TRACEPOINT:
- ret = kabi_2635_tracepoint_probe_unregister(event->desc->name,
- event->desc->probe_callback,
- event);
- if (ret)
- return ret;
- break;
- case LTTNG_KERNEL_KPROBE:
- lttng_kprobes_unregister(event);
- ret = 0;
- break;
- case LTTNG_KERNEL_KRETPROBE:
- lttng_kretprobes_unregister(event);
- ret = 0;
- break;
- case LTTNG_KERNEL_FUNCTION:
- lttng_ftrace_unregister(event);
- ret = 0;
- break;
- case LTTNG_KERNEL_NOOP:
- ret = 0;
- break;
- default:
- WARN_ON_ONCE(1);
- }
- return ret;
-}
-
-/*
- * Only used internally at session destruction.
- */
-static
-void _lttng_event_destroy(struct lttng_event *event)
-{
- switch (event->instrumentation) {
- case LTTNG_KERNEL_TRACEPOINT:
- lttng_event_put(event->desc);
- break;
- case LTTNG_KERNEL_KPROBE:
- module_put(event->desc->owner);
- lttng_kprobes_destroy_private(event);
- break;
- case LTTNG_KERNEL_KRETPROBE:
- module_put(event->desc->owner);
- lttng_kretprobes_destroy_private(event);
- break;
- case LTTNG_KERNEL_FUNCTION:
- module_put(event->desc->owner);
- lttng_ftrace_destroy_private(event);
- break;
- case LTTNG_KERNEL_NOOP:
- break;
- default:
- WARN_ON_ONCE(1);
- }
- list_del(&event->list);
- lttng_destroy_context(event->ctx);
- kmem_cache_free(event_cache, event);
-}
-
-/*
- * Serialize at most one packet worth of metadata into a metadata
- * channel.
- * We have exclusive access to our metadata buffer (protected by the
- * sessions_mutex), 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_output_channel(struct lttng_channel *chan,
- struct lttng_metadata_stream *stream)
-{
- struct lib_ring_buffer_ctx ctx;
- int ret = 0;
- size_t len, reserve_len;
-
- /*
- * Ensure we support mutiple get_next / put sequences followed
- * by put_next.
- */
- WARN_ON(stream->metadata_in < stream->metadata_out);
- if (stream->metadata_in != stream->metadata_out)
- return 0;
-
- len = stream->metadata_cache->metadata_written -
- stream->metadata_in;
- if (!len)
- return 0;
- reserve_len = min_t(size_t,
- chan->ops->packet_avail_size(chan->chan),
- len);
- lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len,
- sizeof(char), -1);
- /*
- * If reservation failed, return an error to the caller.
- */
- ret = chan->ops->event_reserve(&ctx, 0);
- if (ret != 0) {
- printk(KERN_WARNING "LTTng: Metadata event reservation failed\n");
- goto end;
- }
- chan->ops->event_write(&ctx,
- stream->metadata_cache->data + stream->metadata_in,
- reserve_len);
- chan->ops->event_commit(&ctx);
- stream->metadata_in += reserve_len;
- ret = reserve_len;
-
-end:
- return ret;
-}
-
-/*
- * Write the metadata to the metadata cache.
- * Must be called with sessions_mutex held.
- */
-int lttng_metadata_printf(struct lttng_session *session,
- const char *fmt, ...)
-{
- char *str;
- size_t len;
- va_list ap;
- struct lttng_metadata_stream *stream;
-
- WARN_ON_ONCE(!ACCESS_ONCE(session->active));
-
- va_start(ap, fmt);
- str = kvasprintf(GFP_KERNEL, fmt, ap);
- va_end(ap);
- if (!str)
- return -ENOMEM;
-
- len = strlen(str);
- if (session->metadata_cache->metadata_written + len >
- session->metadata_cache->cache_alloc) {
- char *tmp_cache_realloc;
- unsigned int tmp_cache_alloc_size;
-
- tmp_cache_alloc_size = max_t(unsigned int,
- session->metadata_cache->cache_alloc + len,
- session->metadata_cache->cache_alloc << 1);
- tmp_cache_realloc = krealloc(session->metadata_cache->data,
- tmp_cache_alloc_size, GFP_KERNEL);
- if (!tmp_cache_realloc)
- goto err;
- session->metadata_cache->cache_alloc = tmp_cache_alloc_size;
- session->metadata_cache->data = tmp_cache_realloc;
- }
- memcpy(session->metadata_cache->data +
- session->metadata_cache->metadata_written,
- str, len);
- session->metadata_cache->metadata_written += len;
- kfree(str);
-
- list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list)
- wake_up_interruptible(&stream->read_wait);
-
- return 0;
-
-err:
- kfree(str);
- return -ENOMEM;
-}
-
-/*
- * Must be called with sessions_mutex held.
- */
-static
-int _lttng_field_statedump(struct lttng_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,
-#ifdef __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,
-#ifdef __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,
-#ifdef __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,
-#ifdef __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 _lttng_context_metadata_statedump(struct lttng_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 = _lttng_field_statedump(session, &field->event_field);
- if (ret)
- return ret;
- }
- return ret;
-}
-
-static
-int _lttng_fields_metadata_statedump(struct lttng_session *session,
- struct lttng_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 = _lttng_field_statedump(session, field);
- if (ret)
- return ret;
- }
- return ret;
-}
-
-/*
- * Must be called with sessions_mutex held.
- */
-static
-int _lttng_event_metadata_statedump(struct lttng_session *session,
- struct lttng_channel *chan,
- struct lttng_event *event)
-{
- int ret = 0;
-
- if (event->metadata_dumped || !ACCESS_ONCE(session->active))
- return 0;
- if (chan->channel_type == METADATA_CHANNEL)
- 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 = _lttng_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 = _lttng_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;
-
-}
-
-/*
- * Must be called with sessions_mutex held.
- */
-static
-int _lttng_channel_metadata_statedump(struct lttng_session *session,
- struct lttng_channel *chan)
-{
- int ret = 0;
-
- if (chan->metadata_dumped || !ACCESS_ONCE(session->active))
- return 0;
-
- if (chan->channel_type == METADATA_CHANNEL)
- 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 = _lttng_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;
-}
-
-/*
- * Must be called with sessions_mutex held.
- */
-static
-int _lttng_stream_packet_context_declare(struct lttng_session *session)
-{
- return lttng_metadata_printf(session,
- "struct packet_context {\n"
- " uint64_clock_monotonic_t timestamp_begin;\n"
- " uint64_clock_monotonic_t timestamp_end;\n"
- " uint64_t content_size;\n"
- " uint64_t packet_size;\n"
- " unsigned long events_discarded;\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.
- *
- * Must be called with sessions_mutex held.
- */
-static
-int _lttng_event_header_declare(struct lttng_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_clock_monotonic_t timestamp;\n"
- " } compact;\n"
- " struct {\n"
- " uint32_t id;\n"
- " uint64_clock_monotonic_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_clock_monotonic_t timestamp;\n"
- " } compact;\n"
- " struct {\n"
- " uint32_t id;\n"
- " uint64_clock_monotonic_t timestamp;\n"
- " } extended;\n"
- " } v;\n"
- "} align(%u);\n\n",
- lttng_alignof(uint32_t) * CHAR_BIT,
- lttng_alignof(uint16_t) * CHAR_BIT
- );
-}
-
- /*
- * Approximation of NTP time of day to clock monotonic correlation,
- * taken at start of trace.
- * Yes, this is only an approximation. Yes, we can (and will) do better
- * in future versions.
- */
-static
-uint64_t measure_clock_offset(void)
-{
- uint64_t offset, monotonic[2], realtime;
- struct timespec rts = { 0, 0 };
- unsigned long flags;
-
- /* Disable interrupts to increase correlation precision. */
- local_irq_save(flags);
- monotonic[0] = trace_clock_read64();
- getnstimeofday(&rts);
- monotonic[1] = trace_clock_read64();
- local_irq_restore(flags);
-
- offset = (monotonic[0] + monotonic[1]) >> 1;
- realtime = (uint64_t) rts.tv_sec * NSEC_PER_SEC;
- realtime += rts.tv_nsec;
- offset = realtime - offset;
- return offset;
-}
-
-/*
- * Output metadata into this session's metadata buffers.
- * Must be called with sessions_mutex held.
- */
-static
-int _lttng_session_metadata_statedump(struct lttng_session *session)
-{
- unsigned char *uuid_c = session->uuid.b;
- unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN];
- struct lttng_channel *chan;
- struct lttng_event *event;
- int ret = 0;
-
- if (!ACCESS_ONCE(session->active))
- return 0;
- if (session->metadata_dumped)
- goto skip_session;
-
- 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 = %u; align = %u; signed = false; } := unsigned long;\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,
- sizeof(unsigned long) * CHAR_BIT,
- lttng_alignof(unsigned long) * CHAR_BIT,
- CTF_SPEC_MAJOR,
- CTF_SPEC_MINOR,
- uuid_s,
-#ifdef __BIG_ENDIAN
- "be"
-#else
- "le"
-#endif
- );
- if (ret)
- goto end;
-
- ret = lttng_metadata_printf(session,
- "env {\n"
- " hostname = \"%s\";\n"
- " domain = \"kernel\";\n"
- " sysname = \"%s\";\n"
- " kernel_release = \"%s\";\n"
- " kernel_version = \"%s\";\n"
- " tracer_name = \"lttng-modules\";\n"
- " tracer_major = %d;\n"
- " tracer_minor = %d;\n"
- " tracer_patchlevel = %d;\n"
- "};\n\n",
- current->nsproxy->uts_ns->name.nodename,
- utsname()->sysname,
- utsname()->release,
- utsname()->version,
- LTTNG_MODULES_MAJOR_VERSION,
- LTTNG_MODULES_MINOR_VERSION,
- LTTNG_MODULES_PATCHLEVEL_VERSION
- );
- if (ret)
- goto end;
-
- ret = lttng_metadata_printf(session,
- "clock {\n"
- " name = %s;\n",
- "monotonic"
- );
- if (ret)
- goto end;
-
- if (!trace_clock_uuid(clock_uuid_s)) {
- ret = lttng_metadata_printf(session,
- " uuid = \"%s\";\n",
- clock_uuid_s
- );
- if (ret)
- goto end;
- }
-
- ret = lttng_metadata_printf(session,
- " description = \"Monotonic Clock\";\n"
- " freq = %llu; /* Frequency, in Hz */\n"
- " /* clock value offset from Epoch is: offset * (1/freq) */\n"
- " offset = %llu;\n"
- "};\n\n",
- (unsigned long long) trace_clock_freq(),
- (unsigned long long) measure_clock_offset()
- );
- if (ret)
- goto end;
-
- ret = lttng_metadata_printf(session,
- "typealias integer {\n"
- " size = 27; align = 1; signed = false;\n"
- " map = clock.monotonic.value;\n"
- "} := uint27_clock_monotonic_t;\n"
- "\n"
- "typealias integer {\n"
- " size = 32; align = %u; signed = false;\n"
- " map = clock.monotonic.value;\n"
- "} := uint32_clock_monotonic_t;\n"
- "\n"
- "typealias integer {\n"
- " size = 64; align = %u; signed = false;\n"
- " map = clock.monotonic.value;\n"
- "} := uint64_clock_monotonic_t;\n\n",
- lttng_alignof(uint32_t) * CHAR_BIT,
- lttng_alignof(uint64_t) * CHAR_BIT
- );
- if (ret)
- goto end;
-
- ret = _lttng_stream_packet_context_declare(session);
- if (ret)
- goto end;
-
- ret = _lttng_event_header_declare(session);
- if (ret)
- goto end;
-
-skip_session:
- list_for_each_entry(chan, &session->chan, list) {
- ret = _lttng_channel_metadata_statedump(session, chan);
- if (ret)
- goto end;
- }
-
- list_for_each_entry(event, &session->events, list) {
- ret = _lttng_event_metadata_statedump(session, event->chan, event);
- if (ret)
- goto end;
- }
- session->metadata_dumped = 1;
-end:
- return ret;
-}
-
-/**
- * lttng_transport_register - LTT transport registration
- * @transport: transport structure
- *
- * Registers a transport which can be used as output to extract the data out of
- * LTTng. The module calling this registration function must ensure that no
- * trap-inducing code will be executed by the transport functions. E.g.
- * vmalloc_sync_all() must be called between a vmalloc and the moment the memory
- * is made visible to the transport function. This registration acts as a
- * vmalloc_sync_all. Therefore, only if the module allocates virtual memory
- * after its registration must it synchronize the TLBs.
- */
-void lttng_transport_register(struct lttng_transport *transport)
-{
- /*
- * Make sure no page fault can be triggered by the module about to be
- * registered. We deal with this here so we don't have to call
- * vmalloc_sync_all() in each module's init.
- */
- wrapper_vmalloc_sync_all();
-
- mutex_lock(&sessions_mutex);
- list_add_tail(&transport->node, <tng_transport_list);
- mutex_unlock(&sessions_mutex);
-}
-EXPORT_SYMBOL_GPL(lttng_transport_register);
-
-/**
- * lttng_transport_unregister - LTT transport unregistration
- * @transport: transport structure
- */
-void lttng_transport_unregister(struct lttng_transport *transport)
-{
- mutex_lock(&sessions_mutex);
- list_del(&transport->node);
- mutex_unlock(&sessions_mutex);
-}
-EXPORT_SYMBOL_GPL(lttng_transport_unregister);
-
-static int __init lttng_events_init(void)
-{
- int ret;
-
- event_cache = KMEM_CACHE(lttng_event, 0);
- if (!event_cache)
- return -ENOMEM;
- ret = lttng_abi_init();
- if (ret)
- goto error_abi;
- return 0;
-error_abi:
- kmem_cache_destroy(event_cache);
- return ret;
-}
-
-module_init(lttng_events_init);
-
-static void __exit lttng_events_exit(void)
-{
- struct lttng_session *session, *tmpsession;
-
- lttng_abi_exit();
- list_for_each_entry_safe(session, tmpsession, &sessions, list)
- lttng_session_destroy(session);
- kmem_cache_destroy(event_cache);
-}
-
-module_exit(lttng_events_exit);
-
-MODULE_LICENSE("GPL and additional rights");
-MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
-MODULE_DESCRIPTION("LTTng Events");
projects / lttng-modules.git / blobdiff