+++ /dev/null
-/*
- * lttng-ust-abi.c
- *
- * Copyright 2010-2011 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * LTTng UST ABI
- *
- * Mimic system calls for:
- * - session creation, returns an object descriptor or failure.
- * - channel creation, returns an object descriptor or failure.
- * - Operates on a session object descriptor
- * - Takes all channel options as parameters.
- * - stream get, returns an object descriptor or failure.
- * - Operates on a channel object descriptor.
- * - stream notifier get, returns an object descriptor or failure.
- * - Operates on a channel object descriptor.
- * - event creation, returns an object descriptor or failure.
- * - Operates on a channel object descriptor
- * - Takes an event name as parameter
- * - Takes an instrumentation source as parameter
- * - e.g. tracepoints, dynamic_probes...
- * - Takes instrumentation source specific arguments.
- *
- * Dual LGPL v2.1/GPL v2 license.
- */
-
-#include <lttng/ust-abi.h>
-#include <urcu/compiler.h>
-#include <urcu/list.h>
-#include <lttng/ust-events.h>
-#include <lttng/usterr-signal-safe.h>
-#include "lttng/core.h"
-#include "ltt-tracer.h"
-
-/*
- * Object descriptor table. Should be protected from concurrent access
- * by the caller.
- */
-
-struct lttng_ust_obj {
- union {
- struct {
- void *private_data;
- const struct lttng_ust_objd_ops *ops;
- int f_count;
- } s;
- int freelist_next; /* offset freelist. end is -1. */
- } u;
-};
-
-struct lttng_ust_objd_table {
- struct lttng_ust_obj *array;
- unsigned int len, allocated_len;
- int freelist_head; /* offset freelist head. end is -1 */
-};
-
-static struct lttng_ust_objd_table objd_table = {
- .freelist_head = -1,
-};
-
-static
-int objd_alloc(void *private_data, const struct lttng_ust_objd_ops *ops)
-{
- struct lttng_ust_obj *obj;
-
- if (objd_table.freelist_head != -1) {
- obj = &objd_table.array[objd_table.freelist_head];
- objd_table.freelist_head = obj->u.freelist_next;
- goto end;
- }
-
- if (objd_table.len >= objd_table.allocated_len) {
- unsigned int new_allocated_len, old_allocated_len;
- struct lttng_ust_obj *new_table, *old_table;
-
- old_allocated_len = objd_table.allocated_len;
- old_table = objd_table.array;
- if (!old_allocated_len)
- new_allocated_len = 1;
- else
- new_allocated_len = old_allocated_len << 1;
- new_table = zmalloc(sizeof(struct lttng_ust_obj) * new_allocated_len);
- if (!new_table)
- return -ENOMEM;
- memcpy(new_table, old_table,
- sizeof(struct lttng_ust_obj) * old_allocated_len);
- free(old_table);
- objd_table.array = new_table;
- objd_table.allocated_len = new_allocated_len;
- }
- obj = &objd_table.array[objd_table.len];
- objd_table.len++;
-end:
- obj->u.s.private_data = private_data;
- obj->u.s.ops = ops;
- obj->u.s.f_count = 2; /* count == 1 : object is allocated */
- /* count == 2 : allocated + hold ref */
- return obj - objd_table.array;
-}
-
-static
-struct lttng_ust_obj *_objd_get(int id)
-{
- if (id >= objd_table.len)
- return NULL;
- if (!objd_table.array[id].u.s.f_count)
- return NULL;
- return &objd_table.array[id];
-}
-
-static
-void *objd_private(int id)
-{
- struct lttng_ust_obj *obj = _objd_get(id);
- assert(obj);
- return obj->u.s.private_data;
-}
-
-static
-void objd_set_private(int id, void *private_data)
-{
- struct lttng_ust_obj *obj = _objd_get(id);
- assert(obj);
- obj->u.s.private_data = private_data;
-}
-
-const struct lttng_ust_objd_ops *objd_ops(int id)
-{
- struct lttng_ust_obj *obj = _objd_get(id);
-
- if (!obj)
- return NULL;
- return obj->u.s.ops;
-}
-
-static
-void objd_free(int id)
-{
- struct lttng_ust_obj *obj = _objd_get(id);
-
- assert(obj);
- obj->u.freelist_next = objd_table.freelist_head;
- objd_table.freelist_head = obj - objd_table.array;
- assert(obj->u.s.f_count == 1);
- obj->u.s.f_count = 0; /* deallocated */
-}
-
-static
-void objd_ref(int id)
-{
- struct lttng_ust_obj *obj = _objd_get(id);
- obj->u.s.f_count++;
-}
-
-int lttng_ust_objd_unref(int id)
-{
- struct lttng_ust_obj *obj = _objd_get(id);
-
- if (!obj)
- return -EINVAL;
- if (obj->u.s.f_count == 1) {
- ERR("Reference counting error\n");
- return -EINVAL;
- }
- if ((--obj->u.s.f_count) == 1) {
- const struct lttng_ust_objd_ops *ops = objd_ops(id);
-
- if (ops->release)
- ops->release(id);
- objd_free(id);
- }
- return 0;
-}
-
-static
-void objd_table_destroy(void)
-{
- int i;
-
- for (i = 0; i < objd_table.allocated_len; i++)
- (void) lttng_ust_objd_unref(i);
- free(objd_table.array);
- objd_table.array = NULL;
- objd_table.len = 0;
- objd_table.allocated_len = 0;
- objd_table.freelist_head = -1;
-}
-
-/*
- * This is LTTng's own personal way to create an ABI for sessiond.
- * We send commands over a socket.
- */
-
-static const struct lttng_ust_objd_ops lttng_ops;
-static const struct lttng_ust_objd_ops lttng_session_ops;
-static const struct lttng_ust_objd_ops lttng_channel_ops;
-static const struct lttng_ust_objd_ops lttng_metadata_ops;
-static const struct lttng_ust_objd_ops lttng_event_ops;
-static const struct lttng_ust_objd_ops lib_ring_buffer_objd_ops;
-
-enum channel_type {
- PER_CPU_CHANNEL,
- METADATA_CHANNEL,
-};
-
-int lttng_abi_create_root_handle(void)
-{
- int root_handle;
-
- root_handle = objd_alloc(NULL, <tng_ops);
- return root_handle;
-}
-
-static
-int lttng_abi_create_session(void)
-{
- struct ltt_session *session;
- int session_objd, ret;
-
- session = ltt_session_create();
- if (!session)
- return -ENOMEM;
- session_objd = objd_alloc(session, <tng_session_ops);
- if (session_objd < 0) {
- ret = session_objd;
- goto objd_error;
- }
- session->objd = session_objd;
- return session_objd;
-
-objd_error:
- ltt_session_destroy(session);
- return ret;
-}
-
-#if 0
-static
-int lttng_abi_tracepoint_list(void)
-{
- int list_objd, ret;
-
- /* TODO: Create list private data */
- list_objd = objd_alloc(NULL, <tng_tracepoint_list_ops);
- if (list_objd < 0) {
- ret = list_objd;
- goto objd_error;
- }
-
- return list_objd;
-
-objd_error:
- return ret;
-}
-#endif //0
-
-static
-long lttng_abi_tracer_version(int objd,
- struct lttng_ust_tracer_version *v)
-{
- v->version = LTTNG_UST_VERSION;
- v->patchlevel = LTTNG_UST_PATCHLEVEL;
- v->sublevel = LTTNG_UST_SUBLEVEL;
- return 0;
-}
-
-static
-long lttng_abi_add_context(int objd,
- struct lttng_ust_context *context_param,
- struct lttng_ctx **ctx, struct ltt_session *session)
-{
- if (session->been_active)
- return -EPERM;
-
- switch (context_param->ctx) {
- case LTTNG_UST_CONTEXT_PTHREAD_ID:
- return lttng_add_pthread_id_to_ctx(ctx);
- case LTTNG_UST_CONTEXT_VTID:
- return lttng_add_vtid_to_ctx(ctx);
- case LTTNG_UST_CONTEXT_VPID:
- return lttng_add_vpid_to_ctx(ctx);
- case LTTNG_UST_CONTEXT_PROCNAME:
- return lttng_add_procname_to_ctx(ctx);
- default:
- return -EINVAL;
- }
-}
-
-/**
- * lttng_cmd - lttng control through socket commands
- *
- * @objd: the object descriptor
- * @cmd: the command
- * @arg: command arg
- *
- * This descriptor implements lttng commands:
- * LTTNG_UST_SESSION
- * Returns a LTTng trace session object descriptor
- * LTTNG_UST_TRACER_VERSION
- * Returns the LTTng kernel tracer version
- * LTTNG_UST_TRACEPOINT_LIST
- * Returns a file descriptor listing available tracepoints
- * LTTNG_UST_WAIT_QUIESCENT
- * Returns after all previously running probes have completed
- *
- * The returned session will be deleted when its file descriptor is closed.
- */
-static
-long lttng_cmd(int objd, unsigned int cmd, unsigned long arg)
-{
- switch (cmd) {
- case LTTNG_UST_SESSION:
- return lttng_abi_create_session();
- case LTTNG_UST_TRACER_VERSION:
- return lttng_abi_tracer_version(objd,
- (struct lttng_ust_tracer_version *) arg);
- case LTTNG_UST_TRACEPOINT_LIST:
- return -ENOSYS; //TODO
- //return lttng_abi_tracepoint_list();
- case LTTNG_UST_WAIT_QUIESCENT:
- synchronize_trace();
- return 0;
- default:
- return -EINVAL;
- }
-}
-
-static const struct lttng_ust_objd_ops lttng_ops = {
- .cmd = lttng_cmd,
-};
-
-/*
- * We tolerate no failure in this function (if one happens, we print a dmesg
- * error, but cannot return any error, because the channel information is
- * invariant.
- */
-static
-void lttng_metadata_create_events(int channel_objd)
-{
- struct ltt_channel *channel = objd_private(channel_objd);
- static struct lttng_ust_event metadata_params = {
- .instrumentation = LTTNG_UST_TRACEPOINT,
- .name = "lttng_metadata",
- };
- struct ltt_event *event;
- int ret;
-
- /*
- * We tolerate no failure path after event creation. It will stay
- * invariant for the rest of the session.
- */
- event = ltt_event_create(channel, &metadata_params, NULL);
- if (!event) {
- ret = -EINVAL;
- goto create_error;
- }
- return;
-
-create_error:
- WARN_ON(1);
- return; /* not allowed to return error */
-}
-
-int lttng_abi_create_channel(int session_objd,
- struct lttng_ust_channel *chan_param,
- enum channel_type channel_type)
-{
- struct ltt_session *session = objd_private(session_objd);
- const struct lttng_ust_objd_ops *ops;
- const char *transport_name;
- struct ltt_channel *chan;
- int chan_objd;
- int ret = 0;
-
- chan_objd = objd_alloc(NULL, <tng_channel_ops);
- if (chan_objd < 0) {
- ret = chan_objd;
- goto objd_error;
- }
- switch (channel_type) {
- case PER_CPU_CHANNEL:
- if (chan_param->output == LTTNG_UST_MMAP) {
- transport_name = chan_param->overwrite ?
- "relay-overwrite-mmap" : "relay-discard-mmap";
- } else {
- return -EINVAL;
- }
- ops = <tng_channel_ops;
- break;
- case METADATA_CHANNEL:
- if (chan_param->output == LTTNG_UST_MMAP)
- transport_name = "relay-metadata-mmap";
- else
- return -EINVAL;
- ops = <tng_metadata_ops;
- break;
- default:
- transport_name = "<unknown>";
- break;
- }
- /*
- * We tolerate no failure path after channel creation. It will stay
- * invariant for the rest of the session.
- */
- chan = ltt_channel_create(session, transport_name, NULL,
- chan_param->subbuf_size,
- chan_param->num_subbuf,
- chan_param->switch_timer_interval,
- chan_param->read_timer_interval,
- &chan_param->shm_fd,
- &chan_param->wait_fd,
- &chan_param->memory_map_size);
- if (!chan) {
- ret = -EINVAL;
- goto chan_error;
- }
- objd_set_private(chan_objd, chan);
- chan->objd = chan_objd;
- if (channel_type == METADATA_CHANNEL) {
- session->metadata = chan;
- lttng_metadata_create_events(chan_objd);
- }
-
- /* The channel created holds a reference on the session */
- objd_ref(session_objd);
-
- return chan_objd;
-
-chan_error:
- {
- int err;
-
- err = lttng_ust_objd_unref(chan_objd);
- assert(!err);
- }
-objd_error:
- return ret;
-}
-
-/**
- * lttng_session_cmd - lttng session object command
- *
- * @obj: the object
- * @cmd: the command
- * @arg: command arg
- *
- * This descriptor implements lttng commands:
- * LTTNG_UST_CHANNEL
- * Returns a LTTng channel object descriptor
- * LTTNG_UST_ENABLE
- * Enables tracing for a session (weak enable)
- * LTTNG_UST_DISABLE
- * Disables tracing for a session (strong disable)
- * LTTNG_UST_METADATA
- * Returns a LTTng metadata object descriptor
- *
- * The returned channel will be deleted when its file descriptor is closed.
- */
-static
-long lttng_session_cmd(int objd, unsigned int cmd, unsigned long arg)
-{
- struct ltt_session *session = objd_private(objd);
-
- switch (cmd) {
- case LTTNG_UST_CHANNEL:
- return lttng_abi_create_channel(objd,
- (struct lttng_ust_channel *) arg,
- PER_CPU_CHANNEL);
- case LTTNG_UST_SESSION_START:
- case LTTNG_UST_ENABLE:
- return ltt_session_enable(session);
- case LTTNG_UST_SESSION_STOP:
- case LTTNG_UST_DISABLE:
- return ltt_session_disable(session);
- case LTTNG_UST_METADATA:
- return lttng_abi_create_channel(objd,
- (struct lttng_ust_channel *) arg,
- METADATA_CHANNEL);
- default:
- return -EINVAL;
- }
-}
-
-/*
- * Called when the last file reference is dropped.
- *
- * Big fat note: channels and events are invariant for the whole session after
- * their creation. So this session destruction also destroys all channel and
- * event structures specific to this session (they are not destroyed when their
- * individual file is released).
- */
-static
-int lttng_release_session(int objd)
-{
- struct ltt_session *session = objd_private(objd);
-
- if (session) {
- ltt_session_destroy(session);
- return 0;
- } else {
- return -EINVAL;
- }
-}
-
-static const struct lttng_ust_objd_ops lttng_session_ops = {
- .release = lttng_release_session,
- .cmd = lttng_session_cmd,
-};
-
-struct stream_priv_data {
- struct lttng_ust_lib_ring_buffer *buf;
- struct ltt_channel *ltt_chan;
-};
-
-static
-int lttng_abi_open_stream(int channel_objd, struct lttng_ust_stream *info)
-{
- struct ltt_channel *channel = objd_private(channel_objd);
- struct lttng_ust_lib_ring_buffer *buf;
- struct stream_priv_data *priv;
- int stream_objd, ret;
-
- buf = channel->ops->buffer_read_open(channel->chan, channel->handle,
- &info->shm_fd, &info->wait_fd, &info->memory_map_size);
- if (!buf)
- return -ENOENT;
-
- priv = zmalloc(sizeof(*priv));
- if (!priv) {
- ret = -ENOMEM;
- goto alloc_error;
- }
- priv->buf = buf;
- priv->ltt_chan = channel;
- stream_objd = objd_alloc(priv, &lib_ring_buffer_objd_ops);
- if (stream_objd < 0) {
- ret = stream_objd;
- goto objd_error;
- }
- /* Hold a reference on the channel object descriptor */
- objd_ref(channel_objd);
- return stream_objd;
-
-objd_error:
- free(priv);
-alloc_error:
- channel->ops->buffer_read_close(buf, channel->handle);
- return ret;
-}
-
-static
-int lttng_abi_create_event(int channel_objd,
- struct lttng_ust_event *event_param)
-{
- struct ltt_channel *channel = objd_private(channel_objd);
- struct ltt_event *event;
- int event_objd, ret;
-
- event_param->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
- event_objd = objd_alloc(NULL, <tng_event_ops);
- if (event_objd < 0) {
- ret = event_objd;
- goto objd_error;
- }
- /*
- * We tolerate no failure path after event creation. It will stay
- * invariant for the rest of the session.
- */
- event = ltt_event_create(channel, event_param, NULL);
- if (!event) {
- ret = -EINVAL;
- goto event_error;
- }
- objd_set_private(event_objd, event);
- /* The event holds a reference on the channel */
- objd_ref(channel_objd);
- return event_objd;
-
-event_error:
- {
- int err;
-
- err = lttng_ust_objd_unref(event_objd);
- assert(!err);
- }
-objd_error:
- return ret;
-}
-
-/**
- * lttng_channel_cmd - lttng control through object descriptors
- *
- * @objd: the object descriptor
- * @cmd: the command
- * @arg: command arg
- *
- * This object descriptor implements lttng commands:
- * LTTNG_UST_STREAM
- * Returns an event stream object descriptor or failure.
- * (typically, one event stream records events from one CPU)
- * LTTNG_UST_EVENT
- * Returns an event object descriptor or failure.
- * LTTNG_UST_CONTEXT
- * Prepend a context field to each event in the channel
- * LTTNG_UST_ENABLE
- * Enable recording for events in this channel (weak enable)
- * LTTNG_UST_DISABLE
- * Disable recording for events in this channel (strong disable)
- *
- * Channel and event file descriptors also hold a reference on the session.
- */
-static
-long lttng_channel_cmd(int objd, unsigned int cmd, unsigned long arg)
-{
- struct ltt_channel *channel = objd_private(objd);
-
- switch (cmd) {
- case LTTNG_UST_STREAM:
- {
- struct lttng_ust_stream *stream;
-
- stream = (struct lttng_ust_stream *) arg;
- /* stream used as output */
- return lttng_abi_open_stream(objd, stream);
- }
- case LTTNG_UST_EVENT:
- return lttng_abi_create_event(objd, (struct lttng_ust_event *) arg);
- case LTTNG_UST_CONTEXT:
- return lttng_abi_add_context(objd,
- (struct lttng_ust_context *) arg,
- &channel->ctx, channel->session);
- case LTTNG_UST_ENABLE:
- return ltt_channel_enable(channel);
- case LTTNG_UST_DISABLE:
- return ltt_channel_disable(channel);
- case LTTNG_UST_FLUSH_BUFFER:
- return channel->ops->flush_buffer(channel->chan, channel->handle);
- default:
- return -EINVAL;
- }
-}
-
-/**
- * lttng_metadata_cmd - lttng control through object descriptors
- *
- * @objd: the object descriptor
- * @cmd: the command
- * @arg: command arg
- *
- * This object descriptor implements lttng commands:
- * LTTNG_UST_STREAM
- * Returns an event stream file descriptor or failure.
- *
- * Channel and event file descriptors also hold a reference on the session.
- */
-static
-long lttng_metadata_cmd(int objd, unsigned int cmd, unsigned long arg)
-{
- struct ltt_channel *channel = objd_private(objd);
-
- switch (cmd) {
- case LTTNG_UST_STREAM:
- {
- struct lttng_ust_stream *stream;
-
- stream = (struct lttng_ust_stream *) arg;
- /* stream used as output */
- return lttng_abi_open_stream(objd, stream);
- }
- case LTTNG_UST_FLUSH_BUFFER:
- return channel->ops->flush_buffer(channel->chan, channel->handle);
- default:
- return -EINVAL;
- }
-}
-
-#if 0
-/**
- * lttng_channel_poll - lttng stream addition/removal monitoring
- *
- * @file: the file
- * @wait: poll table
- */
-unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
-{
- struct ltt_channel *channel = file->private_data;
- unsigned int mask = 0;
-
- if (file->f_mode & FMODE_READ) {
- poll_wait_set_exclusive(wait);
- poll_wait(file, channel->ops->get_hp_wait_queue(channel->chan),
- wait);
-
- if (channel->ops->is_disabled(channel->chan))
- return POLLERR;
- if (channel->ops->is_finalized(channel->chan))
- return POLLHUP;
- if (channel->ops->buffer_has_read_closed_stream(channel->chan))
- return POLLIN | POLLRDNORM;
- return 0;
- }
- return mask;
-
-}
-#endif //0
-
-static
-int lttng_channel_release(int objd)
-{
- struct ltt_channel *channel = objd_private(objd);
-
- if (channel)
- return lttng_ust_objd_unref(channel->session->objd);
- return 0;
-}
-
-static const struct lttng_ust_objd_ops lttng_channel_ops = {
- .release = lttng_channel_release,
- //.poll = lttng_channel_poll,
- .cmd = lttng_channel_cmd,
-};
-
-static const struct lttng_ust_objd_ops lttng_metadata_ops = {
- .release = lttng_channel_release,
- .cmd = lttng_metadata_cmd,
-};
-
-/**
- * lttng_rb_cmd - lttng ring buffer control through object descriptors
- *
- * @objd: the object descriptor
- * @cmd: the command
- * @arg: command arg
- *
- * This object descriptor implements lttng commands:
- * (None for now. Access is done directly though shm.)
- */
-static
-long lttng_rb_cmd(int objd, unsigned int cmd, unsigned long arg)
-{
- switch (cmd) {
- default:
- return -EINVAL;
- }
-}
-
-static
-int lttng_rb_release(int objd)
-{
- struct stream_priv_data *priv = objd_private(objd);
- struct lttng_ust_lib_ring_buffer *buf;
- struct ltt_channel *channel;
-
- if (priv) {
- buf = priv->buf;
- channel = priv->ltt_chan;
- free(priv);
- channel->ops->buffer_read_close(buf, channel->handle);
-
- return lttng_ust_objd_unref(channel->objd);
- }
- return 0;
-}
-
-static const struct lttng_ust_objd_ops lib_ring_buffer_objd_ops = {
- .release = lttng_rb_release,
- .cmd = lttng_rb_cmd,
-};
-
-/**
- * lttng_event_cmd - lttng control through object descriptors
- *
- * @objd: the object descriptor
- * @cmd: the command
- * @arg: command arg
- *
- * This object descriptor implements lttng commands:
- * LTTNG_UST_CONTEXT
- * Prepend a context field to each record of this event
- * LTTNG_UST_ENABLE
- * Enable recording for this event (weak enable)
- * LTTNG_UST_DISABLE
- * Disable recording for this event (strong disable)
- */
-static
-long lttng_event_cmd(int objd, unsigned int cmd, unsigned long arg)
-{
- struct ltt_event *event = objd_private(objd);
-
- switch (cmd) {
- case LTTNG_UST_CONTEXT:
- return lttng_abi_add_context(objd,
- (struct lttng_ust_context *) arg,
- &event->ctx, event->chan->session);
- case LTTNG_UST_ENABLE:
- return ltt_event_enable(event);
- case LTTNG_UST_DISABLE:
- return ltt_event_disable(event);
- default:
- return -EINVAL;
- }
-}
-
-static
-int lttng_event_release(int objd)
-{
- struct ltt_event *event = objd_private(objd);
-
- if (event)
- return lttng_ust_objd_unref(event->chan->objd);
- return 0;
-}
-
-/* TODO: filter control ioctl */
-static const struct lttng_ust_objd_ops lttng_event_ops = {
- .release = lttng_event_release,
- .cmd = lttng_event_cmd,
-};
-
-void lttng_ust_abi_exit(void)
-{
- objd_table_destroy();
-}