X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=ltt-events.c;h=03dbb2036af923e3c60841783bca3f46ac528c00;hb=edb5c2da83545004c5f556accb79d010a6b1e3a9;hp=ffcc61ec65d5657fb03a0e0ca7958cb1df43f60f;hpb=17baffe29814f2508556e498ab8c41a192e76b67;p=lttng-modules.git

diff --git a/ltt-events.c b/ltt-events.c
index ffcc61ec..03dbb203 100644
--- a/ltt-events.c
+++ b/ltt-events.c
@@ -14,7 +14,7 @@
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/jiffies.h>
-#include <linux/uuid.h>
+#include "wrapper/uuid.h"
 #include "wrapper/vmalloc.h"	/* for wrapper_vmalloc_sync_all() */
 #include "ltt-events.h"
 #include "ltt-tracer.h"
@@ -34,8 +34,6 @@ int _ltt_event_metadata_statedump(struct ltt_session *session,
 static
 int _ltt_session_metadata_statedump(struct ltt_session *session);
 
-
-static
 void synchronize_trace(void)
 {
 	synchronize_sched();
@@ -68,6 +66,10 @@ void ltt_session_destroy(struct ltt_session *session)
 
 	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 = _ltt_event_unregister(event);
 		WARN_ON(ret);
@@ -82,7 +84,7 @@ void ltt_session_destroy(struct ltt_session *session)
 	kfree(session);
 }
 
-int ltt_session_start(struct ltt_session *session)
+int ltt_session_enable(struct ltt_session *session)
 {
 	int ret = 0;
 	struct ltt_channel *chan;
@@ -108,18 +110,15 @@ int ltt_session_start(struct ltt_session *session)
 
 	ACCESS_ONCE(session->active) = 1;
 	ACCESS_ONCE(session->been_active) = 1;
-	synchronize_trace();	/* Wait for in-flight events to complete */
 	ret = _ltt_session_metadata_statedump(session);
-	if (ret) {
+	if (ret)
 		ACCESS_ONCE(session->active) = 0;
-		synchronize_trace();	/* Wait for in-flight events to complete */
-	}
 end:
 	mutex_unlock(&sessions_mutex);
 	return ret;
 }
 
-int ltt_session_stop(struct ltt_session *session)
+int ltt_session_disable(struct ltt_session *session)
 {
 	int ret = 0;
 
@@ -129,12 +128,59 @@ int ltt_session_stop(struct ltt_session *session)
 		goto end;
 	}
 	ACCESS_ONCE(session->active) = 0;
-	synchronize_trace();	/* Wait for in-flight events to complete */
 end:
 	mutex_unlock(&sessions_mutex);
 	return ret;
 }
 
+int ltt_channel_enable(struct ltt_channel *channel)
+{
+	int old;
+
+	if (channel == channel->session->metadata)
+		return -EPERM;
+	old = 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 = 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 = 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 = xchg(&event->enabled, 0);
+	if (!old)
+		return -EEXIST;
+	return 0;
+}
+
 static struct ltt_transport *ltt_transport_find(const char *name)
 {
 	struct ltt_transport *transport;
@@ -154,7 +200,7 @@ struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 				       unsigned int read_timer_interval)
 {
 	struct ltt_channel *chan;
-	struct ltt_transport *transport;
+	struct ltt_transport *transport = NULL;
 
 	mutex_lock(&sessions_mutex);
 	if (session->been_active)
@@ -165,11 +211,14 @@ struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 		       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 ltt_channel), GFP_KERNEL);
 	if (!chan)
 		goto nomem;
 	chan->session = session;
-	init_waitqueue_head(&chan->notify_wait);
 	chan->id = session->free_chan_id++;
 	/*
 	 * Note: the channel creation op already writes into the packet
@@ -181,7 +230,9 @@ struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 			read_timer_interval);
 	if (!chan->chan)
 		goto create_error;
+	chan->enabled = 1;
 	chan->ops = &transport->ops;
+	chan->transport = transport;
 	list_add(&chan->list, &session->chan);
 	mutex_unlock(&sessions_mutex);
 	return chan;
@@ -189,6 +240,8 @@ struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 create_error:
 	kfree(chan);
 nomem:
+	if (transport)
+		module_put(transport->owner);
 notransport:
 active:
 	mutex_unlock(&sessions_mutex);
@@ -202,6 +255,7 @@ static
 void _ltt_channel_destroy(struct ltt_channel *chan)
 {
 	chan->ops->channel_destroy(chan->chan);
+	module_put(chan->transport->owner);
 	list_del(&chan->list);
 	lttng_destroy_context(chan->ctx);
 	kfree(chan);
@@ -212,7 +266,8 @@ void _ltt_channel_destroy(struct ltt_channel *chan)
  */
 struct ltt_event *ltt_event_create(struct ltt_channel *chan,
 				   struct lttng_kernel_event *event_param,
-				   void *filter)
+				   void *filter,
+				   const struct lttng_event_desc *internal_desc)
 {
 	struct ltt_event *event;
 	int ret;
@@ -233,6 +288,7 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan,
 	event->chan = chan;
 	event->filter = filter;
 	event->id = chan->free_event_id++;
+	event->enabled = 1;
 	event->instrumentation = event_param->instrumentation;
 	/* Populate ltt_event structure before tracepoint registration. */
 	smp_wmb();
@@ -258,6 +314,49 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan,
 		ret = try_module_get(event->desc->owner);
 		WARN_ON_ONCE(!ret);
 		break;
+	case LTTNG_KERNEL_KRETPROBE:
+	{
+		struct ltt_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 ltt_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 = _ltt_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,
@@ -267,6 +366,11 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan,
 		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);
 	}
@@ -278,10 +382,7 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan,
 	return event;
 
 statedump_error:
-	WARN_ON_ONCE(tracepoint_probe_unregister(event_param->name,
-				event->desc->probe_callback,
-				event));
-	ltt_event_put(event->desc);
+	/* If a statedump error occurs, events will not be readable. */
 register_error:
 	kmem_cache_free(event_cache, event);
 cache_error:
@@ -310,10 +411,17 @@ int _ltt_event_unregister(struct ltt_event *event)
 		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);
 	}
@@ -334,10 +442,16 @@ void _ltt_event_destroy(struct ltt_event *event)
 		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);
 	}
@@ -385,7 +499,7 @@ int lttng_metadata_printf(struct ltt_session *session,
 		 * we need to bail out after timeout or being
 		 * interrupted.
 		 */
-		waitret = wait_event_interruptible_timeout(*chan->ops->get_reader_wait_queue(chan),
+		waitret = wait_event_interruptible_timeout(*chan->ops->get_writer_buf_wait_queue(chan->chan, -1),
 			({
 				ret = chan->ops->event_reserve(&ctx, 0);
 				ret != -ENOBUFS || !ret;
@@ -399,7 +513,7 @@ int lttng_metadata_printf(struct ltt_session *session,
 				ret = waitret;
 			goto end;
 		}
-		chan->ops->event_write(&ctx, &str[pos], len);
+		chan->ops->event_write(&ctx, &str[pos], reserve_len);
 		chan->ops->event_commit(&ctx);
 	}
 end:
@@ -416,7 +530,7 @@ int _ltt_field_statedump(struct ltt_session *session,
 	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",
+			"		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,
@@ -435,7 +549,7 @@ int _ltt_field_statedump(struct ltt_session *session,
 		break;
 	case atype_enum:
 		ret = lttng_metadata_printf(session,
-			"		%s %s;\n",
+			"		%s _%s;\n",
 			field->type.u.basic.enumeration.name,
 			field->name);
 		break;
@@ -445,7 +559,7 @@ int _ltt_field_statedump(struct ltt_session *session,
 
 		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",
+			"		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,
@@ -491,7 +605,7 @@ int _ltt_field_statedump(struct ltt_session *session,
 			return ret;
 
 		ret = lttng_metadata_printf(session,
-			"		integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s[ __%s_length ];\n",
+			"		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,
@@ -514,7 +628,7 @@ int _ltt_field_statedump(struct ltt_session *session,
 	case atype_string:
 		/* Default encoding is UTF8 */
 		ret = lttng_metadata_printf(session,
-			"		string%s %s;\n",
+			"		string%s _%s;\n",
 			field->type.u.basic.string.encoding == lttng_encode_ASCII ?
 				" { encoding = ASCII; }" : "",
 			field->name);
@@ -867,7 +981,7 @@ static int __init ltt_events_init(void)
 	event_cache = KMEM_CACHE(ltt_event, 0);
 	if (!event_cache)
 		return -ENOMEM;
-	ret = ltt_debugfs_abi_init();
+	ret = lttng_abi_init();
 	if (ret)
 		goto error_abi;
 	return 0;
@@ -882,7 +996,7 @@ static void __exit ltt_events_exit(void)
 {
 	struct ltt_session *session, *tmpsession;
 
-	ltt_debugfs_abi_exit();
+	lttng_abi_exit();
 	list_for_each_entry_safe(session, tmpsession, &sessions, list)
 		ltt_session_destroy(session);
 	kmem_cache_destroy(event_cache);