#include <linux/mutex.h>
#include <linux/sched.h>
#include <linux/slab.h>
-#include <linux/vmalloc.h> /* For vmalloc_sync_all */
+#include <linux/jiffies.h>
+#include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */
#include "ltt-events.h"
+#include "ltt-tracer.h"
static LIST_HEAD(sessions);
static LIST_HEAD(ltt_transport_list);
static DEFINE_MUTEX(sessions_mutex);
static struct kmem_cache *event_cache;
-static void synchronize_trace(void)
+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);
+
+
+static
+void synchronize_trace(void)
{
synchronize_sched();
#ifdef CONFIG_PREEMPT_RT
{
struct ltt_channel *chan, *tmpchan;
struct ltt_event *event, *tmpevent;
+ int ret;
mutex_lock(&sessions_mutex);
- session->active = 0;
+ ACCESS_ONCE(session->active) = 0;
+ 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 */
list_for_each_entry_safe(event, tmpevent, &session->events, list)
_ltt_event_destroy(event);
int ltt_session_start(struct ltt_session *session)
{
int ret = 0;
+ struct ltt_channel *chan;
mutex_lock(&sessions_mutex);
if (session->active) {
ret = -EBUSY;
goto end;
}
- session->active = 1;
+
+ /*
+ * 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;
synchronize_trace(); /* Wait for in-flight events to complete */
+ ret = _ltt_session_metadata_statedump(session);
+ if (ret) {
+ ACCESS_ONCE(session->active) = 0;
+ synchronize_trace(); /* Wait for in-flight events to complete */
+ }
end:
mutex_unlock(&sessions_mutex);
return ret;
ret = -EBUSY;
goto end;
}
- session->active = 0;
+ ACCESS_ONCE(session->active) = 0;
synchronize_trace(); /* Wait for in-flight events to complete */
end:
mutex_unlock(&sessions_mutex);
return ret;
}
-static struct ltt_transport *ltt_transport_find(char *name)
+static struct ltt_transport *ltt_transport_find(const char *name)
{
struct ltt_transport *transport;
}
struct ltt_channel *ltt_channel_create(struct ltt_session *session,
- int overwrite, void *buf_addr,
+ 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)
{
struct ltt_channel *chan;
struct ltt_transport *transport;
- char *transport_name;
mutex_lock(&sessions_mutex);
if (session->active) {
printk(KERN_WARNING "LTTng refusing to add channel to active session\n");
goto active; /* Refuse to add channel to active session */
}
- transport_name = overwrite ? "relay-overwrite" : "relay-discard";
transport = ltt_transport_find(transport_name);
if (!transport) {
printk(KERN_WARNING "LTTng transport %s not found\n",
transport_name);
goto notransport;
}
- printk("got transport\n");
chan = kzalloc(sizeof(struct ltt_channel), GFP_KERNEL);
if (!chan)
goto nomem;
chan->chan = transport->ops.channel_create("[lttng]", session, buf_addr,
subbuf_size, num_subbuf, switch_timer_interval,
read_timer_interval);
- printk("chan create %p\n", chan->chan);
if (!chan->chan)
goto create_error;
+ chan->id = session->free_chan_id++;
chan->ops = &transport->ops;
list_add(&chan->list, &session->chan);
mutex_unlock(&sessions_mutex);
*/
struct ltt_event *ltt_event_create(struct ltt_channel *chan, char *name,
enum instrum_type itype,
- void *probe, void *filter)
+ const struct lttng_event_desc *event_desc,
+ void *filter)
{
struct ltt_event *event;
int ret;
if (chan->free_event_id == -1UL)
goto full;
/*
- * This is O(n^2) (for each event loop called at event creation).
- * Might require a hash if we have lots of events.
+ * 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->name, name))
+ if (!strcmp(event->desc->name, name))
goto exist;
event = kmem_cache_zalloc(event_cache, GFP_KERNEL);
if (!event)
goto cache_error;
- event->name = kmalloc(strlen(name) + 1, GFP_KERNEL);
- if (!event->name)
- goto name_error;
- strcpy(event->name, name);
event->chan = chan;
- event->probe = probe;
+ event->desc = event_desc;
event->filter = filter;
event->id = chan->free_event_id++;
event->itype = itype;
smp_wmb();
switch (itype) {
case INSTRUM_TRACEPOINTS:
- ret = tracepoint_probe_register(name, probe, event);
+ ret = tracepoint_probe_register(name, event_desc->probe_callback,
+ event);
if (ret)
goto register_error;
break;
default:
WARN_ON_ONCE(1);
}
+ ret = _ltt_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:
+ WARN_ON_ONCE(tracepoint_probe_unregister(name, event_desc->probe_callback,
+ event));
register_error:
- kfree(event->name);
-name_error:
kmem_cache_free(event_cache, event);
cache_error:
exist:
/*
* Only used internally at session destruction.
*/
-int _ltt_event_destroy(struct ltt_event *event)
+int _ltt_event_unregister(struct ltt_event *event)
{
int ret = -EINVAL;
switch (event->itype) {
case INSTRUM_TRACEPOINTS:
- ret = tracepoint_probe_unregister(event->name, event->probe,
+ ret = tracepoint_probe_unregister(event->desc->name,
+ event->desc->probe_callback,
event);
if (ret)
return ret;
default:
WARN_ON_ONCE(1);
}
- kfree(event->name);
+ return ret;
+}
+
+/*
+ * Only used internally at session destruction.
+ */
+void _ltt_event_destroy(struct ltt_event *event)
+{
+ ltt_event_put(event->desc);
+ list_del(&event->list);
kmem_cache_free(event_cache, event);
+}
+
+int lttng_metadata_printf(struct ltt_session *session,
+ const char *fmt, ...)
+{
+ struct lib_ring_buffer_ctx ctx;
+ struct ltt_channel *chan = session->metadata;
+ char *str;
+ int ret = 0, waitret;
+ size_t len;
+ va_list ap;
+
+ 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) + 1;
+ lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, len, sizeof(char), -1);
+ /*
+ * 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_event_interruptible_timeout(*chan->ops->get_reader_wait_queue(chan),
+ ({
+ ret = chan->ops->event_reserve(&ctx);
+ ret != -ENOBUFS || !ret;
+ }),
+ msecs_to_jiffies(LTTNG_METADATA_TIMEOUT_MSEC));
+ if (waitret || ret) {
+ printk(KERN_WARNING "LTTng: Failure to write metadata to buffers (%s)\n",
+ waitret == -ERESTARTSYS ? "interrupted" :
+ (ret == -ENOBUFS ? "timeout" : "I/O error"));
+ if (waitret == -ERESTARTSYS)
+ ret = waitret;
+ goto end;
+ }
+ chan->ops->event_write(&ctx, str, len);
+ chan->ops->event_commit(&ctx);
+end:
+ kfree(str);
+ 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];
+
+ switch (field->type.atype) {
+ case atype_integer:
+ ret = lttng_metadata_printf(session,
+ " integer { size = %u; align = %u; signed = %u;%s } %s;\n",
+ field->type.u.basic.integer.size,
+ field->type.u.basic.integer.alignment,
+ field->type.u.basic.integer.signedness,
+#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:
+ break;
+ case atype_sequence:
+ break;
+
+ case atype_string:
+ 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_event_metadata_statedump(struct ltt_session *session,
+ struct ltt_channel *chan,
+ struct ltt_event *event)
+{
+ int ret = 0;
+
+ if (event->metadata_dumped || !ACCESS_ONCE(session->active))
+ return 0;
+ if (chan == session->metadata)
+ return 0;
+
+ ret = lttng_metadata_printf(session,
+ "event {\n"
+ " name = %s;\n"
+ " id = %u;\n"
+ " stream_id = %u;\n"
+ " event.fields := struct {\n",
+ event->desc->name,
+ event->id,
+ event->chan->id);
+ 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,
+ " } aligned(%u);\n"
+ "};\n", ltt_get_header_alignment());
+ 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 || !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",
+ "};\n",
+ chan->id,
+ chan->header_type == 1 ? "struct event_header_compact" :
+ "struct event_header_large");
+ if (ret)
+ goto end;
+
+ chan->metadata_dumped = 1;
+end:
+ return ret;
+}
+
+/*
+ * Output metadata into this session's metadata buffers.
+ */
+static
+int _ltt_session_metadata_statedump(struct ltt_session *session)
+{
+ struct ltt_channel *chan;
+ struct ltt_event *event;
+ int ret = 0;
+
+ if (!ACCESS_ONCE(session->active))
+ return 0;
+ if (session->metadata_dumped)
+ goto skip_session;
+
+
+
+
+skip_session:
+ list_for_each_entry(chan, &session->chan, list) {
+ ret = _ltt_channel_metadata_statedump(session, chan);
+ if (ret)
+ goto end;
+ }
+
+ list_for_each_entry(event, &session->events, list) {
+ ret = _ltt_event_metadata_statedump(session, chan, event);
+ if (ret)
+ goto end;
+ }
+ session->metadata_dumped = 1;
+end:
return ret;
}
* registered. We deal with this here so we don't have to call
* vmalloc_sync_all() in each module's init.
*/
- vmalloc_sync_all();
+ wrapper_vmalloc_sync_all();
mutex_lock(&sessions_mutex);
list_add_tail(&transport->node, <t_transport_list);
}
EXPORT_SYMBOL_GPL(ltt_transport_unregister);
-
static int __init ltt_events_init(void)
{
int ret;
return -ENOMEM;
ret = ltt_debugfs_abi_init();
if (ret)
- goto error;
+ goto error_abi;
return 0;
-error:
+error_abi:
kmem_cache_destroy(event_cache);
return ret;
}