X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fkernel.c;h=646da3ba83affd3463a30dd7e2efb7a43b05535c;hp=4ee4bea64ff630abae9617624f86ce21cc87950d;hb=1831ae68b70dece8e9b847081526495adbbf05e5;hpb=25357057de5ae4dd2a572e8f9b893c1b90cbd60a

diff --git a/src/bin/lttng-sessiond/kernel.c b/src/bin/lttng-sessiond/kernel.c
index 4ee4bea64..646da3ba8 100644
--- a/src/bin/lttng-sessiond/kernel.c
+++ b/src/bin/lttng-sessiond/kernel.c
@@ -15,11 +15,20 @@
 #include <sys/types.h>
 
 #include <common/common.h>
+#include <common/hashtable/utils.h>
 #include <common/trace-chunk.h>
 #include <common/kernel-ctl/kernel-ctl.h>
 #include <common/kernel-ctl/kernel-ioctl.h>
 #include <common/sessiond-comm/sessiond-comm.h>
 
+#include <lttng/userspace-probe.h>
+#include <lttng/userspace-probe-internal.h>
+#include <lttng/condition/event-rule.h>
+#include <lttng/condition/event-rule-internal.h>
+#include <lttng/event-rule/event-rule.h>
+#include <lttng/event-rule/event-rule-internal.h>
+#include <lttng/event-rule/uprobe-internal.h>
+
 #include "lttng-sessiond.h"
 #include "lttng-syscall.h"
 #include "consumer.h"
@@ -29,6 +38,7 @@
 #include "utils.h"
 #include "rotate.h"
 #include "modprobe.h"
+#include "notification-thread-commands.h"
 
 /*
  * Key used to reference a channel between the sessiond and the consumer. This
@@ -39,9 +49,10 @@ static uint64_t next_kernel_channel_key;
 static const char *module_proc_lttng = "/proc/lttng";
 
 static int kernel_tracer_fd = -1;
+static int kernel_tracer_trigger_group_fd = -1;
+static int kernel_tracer_trigger_group_notification_fd = -1;
+static struct ltt_kernel_token_event_rule_list kernel_tracer_token_list;
 
-#include <lttng/userspace-probe.h>
-#include <lttng/userspace-probe-internal.h>
 /*
  * Add context on a kernel channel.
  *
@@ -213,6 +224,44 @@ error:
 	return -1;
 }
 
+/*
+ * Create a kernel channel, register it to the kernel tracer and add it to the
+ * kernel session.
+ */
+static
+int kernel_create_trigger_group(int *trigger_group_fd)
+{
+	int ret;
+	int local_fd = -1;
+
+	assert(trigger_group_fd);
+
+	/* Kernel tracer channel creation */
+	ret = kernctl_create_trigger_group(kernel_tracer_fd);
+	if (ret < 0) {
+		PERROR("ioctl kernel create trigger group");
+		ret = -1;
+		goto error;
+	}
+
+	/* Store locally */
+	local_fd = ret;
+
+	/* Prevent fd duplication after execlp() */
+	ret = fcntl(local_fd, F_SETFD, FD_CLOEXEC);
+	if (ret < 0) {
+		PERROR("fcntl session fd");
+	}
+
+	DBG("Kernel trigger group created (fd: %d)",
+			local_fd);
+	ret = 0;
+
+error:
+	*trigger_group_fd = local_fd;
+	return ret;
+}
+
 /*
  * Compute the offset of the instrumentation byte in the binary based on the
  * function probe location using the ELF lookup method.
@@ -224,7 +273,7 @@ error:
 static
 int extract_userspace_probe_offset_function_elf(
 		const struct lttng_userspace_probe_location *probe_location,
-		struct ltt_kernel_session *session, uint64_t *offset)
+		uid_t uid, gid_t gid, uint64_t *offset)
 {
 	int fd;
 	int ret = 0;
@@ -261,8 +310,7 @@ int extract_userspace_probe_offset_function_elf(
 		goto end;
 	}
 
-	ret = run_as_extract_elf_symbol_offset(fd, symbol, session->uid,
-			session->gid, offset);
+	ret = run_as_extract_elf_symbol_offset(fd, symbol, uid, gid, offset);
 	if (ret < 0) {
 		DBG("userspace probe offset calculation failed for "
 				"function %s", symbol);
@@ -286,7 +334,7 @@ end:
 static
 int extract_userspace_probe_offset_tracepoint_sdt(
 		const struct lttng_userspace_probe_location *probe_location,
-		struct ltt_kernel_session *session, uint64_t **offsets,
+		uid_t uid, gid_t gid, uint64_t **offsets,
 		uint32_t *offsets_count)
 {
 	enum lttng_userspace_probe_location_lookup_method_type lookup_method_type;
@@ -332,7 +380,7 @@ int extract_userspace_probe_offset_tracepoint_sdt(
 	}
 
 	ret = run_as_extract_sdt_probe_offsets(fd, provider_name, probe_name,
-			session->uid, session->gid, offsets, offsets_count);
+			uid, gid, offsets, offsets_count);
 	if (ret < 0) {
 		DBG("userspace probe offset calculation failed for sdt "
 				"probe %s:%s", provider_name, probe_name);
@@ -353,29 +401,16 @@ end:
 	return ret;
 }
 
-/*
- * Extract the offsets of the instrumentation point for the different lookup
- * methods.
- */
 static
-int userspace_probe_add_callsites(struct lttng_event *ev,
-			struct ltt_kernel_session *session, int fd)
+int userspace_probe_add_callsite(
+		const struct lttng_userspace_probe_location *location,
+		uid_t uid, gid_t gid, int fd)
 {
 	const struct lttng_userspace_probe_location_lookup_method *lookup_method = NULL;
 	enum lttng_userspace_probe_location_lookup_method_type type;
-	const struct lttng_userspace_probe_location *location = NULL;
 	int ret;
 
-	assert(ev);
-	assert(ev->type == LTTNG_EVENT_USERSPACE_PROBE);
-
-	location = lttng_event_get_userspace_probe_location(ev);
-	if (!location) {
-		ret = -1;
-		goto end;
-	}
-	lookup_method =
-			lttng_userspace_probe_location_get_lookup_method(location);
+	lookup_method = lttng_userspace_probe_location_get_lookup_method(location);
 	if (!lookup_method) {
 		ret = -1;
 		goto end;
@@ -388,7 +423,8 @@ int userspace_probe_add_callsites(struct lttng_event *ev,
 		struct lttng_kernel_event_callsite callsite;
 		uint64_t offset;
 
-		ret = extract_userspace_probe_offset_function_elf(location, session, &offset);
+		ret = extract_userspace_probe_offset_function_elf(location,
+				uid, gid, &offset);
 		if (ret) {
 			ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
 			goto end;
@@ -397,8 +433,7 @@ int userspace_probe_add_callsites(struct lttng_event *ev,
 		callsite.u.uprobe.offset = offset;
 		ret = kernctl_add_callsite(fd, &callsite);
 		if (ret) {
-			WARN("Adding callsite to userspace probe "
-					"event %s failed.", ev->name);
+			WARN("Adding callsite to ELF userspace probe failed.");
 			ret = LTTNG_ERR_KERN_ENABLE_FAIL;
 			goto end;
 		}
@@ -415,8 +450,8 @@ int userspace_probe_add_callsites(struct lttng_event *ev,
 		 * This call allocates the offsets buffer. This buffer must be freed
 		 * by the caller
 		 */
-		ret = extract_userspace_probe_offset_tracepoint_sdt(location, session,
-				&offsets, &offsets_count);
+		ret = extract_userspace_probe_offset_tracepoint_sdt(location,
+				uid, gid, &offsets, &offsets_count);
 		if (ret) {
 			ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
 			goto end;
@@ -425,8 +460,8 @@ int userspace_probe_add_callsites(struct lttng_event *ev,
 			callsite.u.uprobe.offset = offsets[i];
 			ret = kernctl_add_callsite(fd, &callsite);
 			if (ret) {
-				WARN("Adding callsite to userspace probe "
-						"event %s failed.", ev->name);
+				WARN("Adding callsite to SDT userspace probe "
+					"failed.");
 				ret = LTTNG_ERR_KERN_ENABLE_FAIL;
 				free(offsets);
 				goto end;
@@ -443,6 +478,71 @@ end:
 	return ret;
 }
 
+/*
+ * Extract the offsets of the instrumentation point for the different lookup
+ * methods.
+ */
+static
+int userspace_probe_event_add_callsites(struct lttng_event *ev,
+			struct ltt_kernel_session *session, int fd)
+{
+	const struct lttng_userspace_probe_location *location = NULL;
+	int ret;
+
+	assert(ev);
+	assert(ev->type == LTTNG_EVENT_USERSPACE_PROBE);
+
+	location = lttng_event_get_userspace_probe_location(ev);
+	if (!location) {
+		ret = -1;
+		goto end;
+	}
+
+	ret = userspace_probe_add_callsite(location, session->uid, session->gid,
+		fd);
+	if (ret) {
+		WARN("Adding callsite to userspace probe event \"%s\" "
+			"failed.", ev->name);
+	}
+
+end:
+	return ret;
+}
+
+/*
+ * Extract the offsets of the instrumentation point for the different lookup
+ * methods.
+ */
+static int userspace_probe_event_rule_add_callsites(
+		const struct lttng_event_rule *rule,
+		const struct lttng_credentials *creds,
+		int fd)
+{
+	const struct lttng_userspace_probe_location *location = NULL;
+	enum lttng_event_rule_status status;
+	int ret;
+
+	assert(rule);
+	assert(creds);
+	assert(lttng_event_rule_get_type(rule) == LTTNG_EVENT_RULE_TYPE_UPROBE);
+
+	status = lttng_event_rule_uprobe_get_location(rule, &location);
+	if (status != LTTNG_EVENT_RULE_STATUS_OK || !location) {
+		ret = -1;
+		goto end;
+	}
+
+	ret = userspace_probe_add_callsite(location, creds->uid, creds->gid,
+		fd);
+	if (ret) {
+		WARN("Adding callsite to userspace probe object %d"
+			"failed.", fd);
+	}
+
+end:
+	return ret;
+}
+
 /*
  * Create a kernel event, enable it to the kernel tracer and add it to the
  * channel event list of the kernel session.
@@ -512,7 +612,8 @@ int kernel_create_event(struct lttng_event *ev,
 	}
 
 	if (ev->type == LTTNG_EVENT_USERSPACE_PROBE) {
-		ret = userspace_probe_add_callsites(ev, channel->session, event->fd);
+		ret = userspace_probe_event_add_callsites(ev, channel->session,
+			event->fd);
 		if (ret) {
 			goto add_callsite_error;
 		}
@@ -669,6 +770,36 @@ error:
 	return ret;
 }
 
+/*
+ * Disable a kernel trigger.
+ */
+int kernel_disable_token_event_rule(struct ltt_kernel_token_event_rule *event)
+{
+	int ret;
+
+	assert(event);
+
+	ret = kernctl_disable(event->fd);
+	if (ret < 0) {
+		switch (-ret) {
+		case EEXIST:
+			ret = LTTNG_ERR_KERN_EVENT_EXIST;
+			break;
+		default:
+			PERROR("disable kernel event");
+			break;
+		}
+		goto error;
+	}
+
+	event->enabled = 0;
+	DBG("Kernel trigger token %" PRIu64" disabled (fd: %d)", event->token, event->fd);
+
+	return 0;
+
+error:
+	return ret;
+}
 static struct lttng_tracker_list *get_id_tracker_list(
 		struct ltt_kernel_session *session,
 		enum lttng_tracker_type tracker_type)
@@ -1732,20 +1863,37 @@ int init_kernel_tracer(void)
 	if (ret < 0) {
 		goto error_modules;
 	}
-
 	if (ret < 1) {
 		WARN("Kernel tracer does not support buffer monitoring. "
 			"The monitoring timer of channels in the kernel domain "
 			"will be set to 0 (disabled).");
 	}
 
+	ret = kernel_create_trigger_group(&kernel_tracer_trigger_group_fd);
+	if (ret < 0) {
+		/* TODO: error handling if it is not supported etc. */
+		WARN("Failed trigger group creation");
+		kernel_tracer_trigger_group_fd = -1;
+		/* This is not fatal */
+	} else {
+		ret = kernel_create_trigger_group_notification_fd(&kernel_tracer_trigger_group_notification_fd);
+		if (ret < 0) {
+			goto error_modules;
+		}
+	}
+
+	CDS_INIT_LIST_HEAD(&kernel_tracer_token_list.head);
+
 	DBG("Kernel tracer fd %d", kernel_tracer_fd);
+	DBG("Kernel tracer trigger group fd %d", kernel_tracer_trigger_group_fd);
+	DBG("Kernel tracer trigger group notificationi fd %d", kernel_tracer_trigger_group_notification_fd);
 
 	ret = syscall_init_table(kernel_tracer_fd);
 	if (ret < 0) {
 		ERR("Unable to populate syscall table. Syscall tracing won't "
 			"work for this session daemon.");
 	}
+
 	return 0;
 
 error_version:
@@ -1781,6 +1929,31 @@ void cleanup_kernel_tracer(void)
 {
 	int ret;
 
+	struct ltt_kernel_token_event_rule *rule, *rtmp;
+        cds_list_for_each_entry_safe(rule, rtmp, &kernel_tracer_token_list.head, list) {
+		kernel_disable_token_event_rule(rule);
+		trace_kernel_destroy_token_event_rule(rule);
+	}
+
+	DBG2("Closing kernel trigger group notification fd");
+	if (kernel_tracer_trigger_group_notification_fd >= 0) {
+		ret = close(kernel_tracer_trigger_group_notification_fd);
+		if (ret) {
+			PERROR("close");
+		}
+		kernel_tracer_trigger_group_notification_fd = -1;
+	}
+
+	/* TODO: do we iterate over the list to remove all token? */
+	DBG2("Closing kernel trigger group fd");
+	if (kernel_tracer_trigger_group_fd >= 0) {
+		ret = close(kernel_tracer_trigger_group_fd);
+		if (ret) {
+			PERROR("close");
+		}
+		kernel_tracer_trigger_group_fd = -1;
+	}
+
 	DBG2("Closing kernel fd");
 	if (kernel_tracer_fd >= 0) {
 		ret = close(kernel_tracer_fd);
@@ -1789,6 +1962,8 @@ void cleanup_kernel_tracer(void)
 		}
 		kernel_tracer_fd = -1;
 	}
+
+	
 	DBG("Unloading kernel modules");
 	modprobe_remove_lttng_all();
 	free(syscall_table);
@@ -1879,3 +2054,274 @@ end:
 	rcu_read_unlock();
 	return status;
 }
+
+enum lttng_error_code kernel_create_trigger_group_notification_fd(
+		int *trigger_group_notification_fd)
+{
+	enum lttng_error_code ret = LTTNG_OK;
+	int local_fd = -1;
+
+	assert(trigger_group_notification_fd);
+
+	ret = kernctl_create_trigger_group_notification_fd(kernel_tracer_trigger_group_fd);
+	if (ret < 0) {
+		PERROR("ioctl kernel create trigger group");
+		ret = -1;
+		goto error;
+	}
+
+	/* Store locally */
+	local_fd = ret;
+
+	/* Prevent fd duplication after execlp() */
+	ret = fcntl(local_fd, F_SETFD, FD_CLOEXEC);
+	if (ret < 0) {
+		PERROR("fcntl session fd");
+	}
+
+	DBG("Kernel trigger group notification created (fd: %d)",
+			local_fd);
+	ret = 0;
+
+error:
+	*trigger_group_notification_fd = local_fd;
+	return ret;
+}
+
+enum lttng_error_code kernel_destroy_trigger_group_notification_fd(
+		int trigger_group_notification_fd)
+{
+	enum lttng_error_code ret = LTTNG_OK;
+	DBG("Closing trigger group notification fd %d", trigger_group_notification_fd);
+	if (trigger_group_notification_fd >= 0) {
+		ret = close(trigger_group_notification_fd);
+		if (ret) {
+			PERROR("close");
+		}
+	}
+	return ret;
+}
+
+static int kernel_create_token_event_rule(struct lttng_event_rule *rule,
+		const struct lttng_credentials *creds, uint64_t token)
+{
+	int err, fd;
+	enum lttng_error_code ret;
+	struct ltt_kernel_token_event_rule *event;
+	struct lttng_kernel_trigger trigger;
+
+	assert(rule);
+
+	ret = trace_kernel_create_token_event_rule(rule, token, &event);
+	if (ret != LTTNG_OK) {
+		goto error;
+	}
+	
+	trace_kernel_init_trigger_from_event_rule(event->event_rule, &trigger);
+	trigger.id = event->token;
+
+	fd = kernctl_create_trigger(kernel_tracer_trigger_group_fd, &trigger);
+	if (fd < 0) {
+		switch (-fd) {
+		case EEXIST:
+			ret = LTTNG_ERR_KERN_EVENT_EXIST;
+			break;
+		case ENOSYS:
+			WARN("Trigger type not implemented");
+			ret = LTTNG_ERR_KERN_EVENT_ENOSYS;
+			break;
+		case ENOENT:
+			WARN("Event %s not found!", trigger.name);
+			ret = LTTNG_ERR_KERN_ENABLE_FAIL;
+			break;
+		default:
+			ret = LTTNG_ERR_KERN_ENABLE_FAIL;
+			PERROR("create trigger ioctl");
+		}
+		goto free_event;
+	}
+
+	event->fd = fd;
+	/* Prevent fd duplication after execlp() */
+	err = fcntl(event->fd, F_SETFD, FD_CLOEXEC);
+	if (err < 0) {
+		PERROR("fcntl session fd");
+	}
+
+	if (event->filter) {
+		err = kernctl_filter(event->fd, event->filter);
+		if (err < 0) {
+			switch (-err) {
+			case ENOMEM:
+				ret = LTTNG_ERR_FILTER_NOMEM;
+				break;
+			default:
+				ret = LTTNG_ERR_FILTER_INVAL;
+				break;
+			}
+			goto filter_error;
+		}
+	}
+
+	if (lttng_event_rule_get_type(event->event_rule) ==
+			LTTNG_EVENT_RULE_TYPE_UPROBE) {
+		ret = userspace_probe_event_rule_add_callsites(
+				rule, creds, event->fd);
+		if (ret) {
+			goto add_callsite_error;
+		}
+	}
+
+	err = kernctl_enable(event->fd);
+	if (err < 0) {
+		switch (-err) {
+		case EEXIST:
+			ret = LTTNG_ERR_KERN_EVENT_EXIST;
+			break;
+		default:
+			PERROR("enable kernel trigger");
+			ret = LTTNG_ERR_KERN_ENABLE_FAIL;
+			break;
+		}
+		goto enable_error;
+	}
+
+	/* Add event to event list */
+	cds_list_add(&event->list, &kernel_tracer_token_list.head);
+
+	DBG("Trigger %s created (fd: %d)", trigger.name, event->fd);
+
+	return 0;
+
+add_callsite_error:
+enable_error:
+filter_error:
+	{
+		int closeret;
+
+		closeret = close(event->fd);
+		if (closeret) {
+			PERROR("close event fd");
+		}
+	}
+free_event:
+	free(event);
+error:
+	return ret;
+}
+
+enum lttng_error_code kernel_update_tokens(void)
+{
+	enum lttng_error_code ret = LTTNG_OK;
+	enum lttng_trigger_status t_status;
+	struct ltt_kernel_token_event_rule *token_event_rule_element;
+	struct lttng_triggers *triggers;
+	unsigned int count;
+	
+	/* TODO error handling */
+
+	/* Get list of token trigger from the notification thread here */
+	rcu_read_lock();
+	pthread_mutex_lock(&notification_trigger_tokens_ht_lock);
+	ret = notification_thread_command_get_tokens(notification_thread_handle, &triggers);
+	if (ret != LTTNG_OK) {
+		ret = -1;
+		goto end;
+	}
+
+	assert(triggers);
+
+	t_status = lttng_triggers_get_count(triggers, &count);
+	if (t_status != LTTNG_TRIGGER_STATUS_OK) {
+		ret = -1;
+		goto end;
+	}
+
+	for (unsigned int i = 0; i < count; i++) {
+		struct lttng_condition *condition;
+		struct lttng_event_rule *event_rule;
+		struct lttng_trigger *trigger;
+		struct ltt_kernel_token_event_rule *k_token;
+		const struct lttng_credentials *creds;
+		uint64_t token;
+
+		trigger = lttng_triggers_get_pointer_of_index(triggers, i);
+		assert(trigger);
+
+		/* TODO: error checking and type checking */
+		token = lttng_trigger_get_key(trigger);
+		condition = lttng_trigger_get_condition(trigger);
+		(void) lttng_condition_event_rule_get_rule_no_const(condition, &event_rule);
+
+		if (lttng_event_rule_get_domain_type(event_rule) != LTTNG_DOMAIN_KERNEL) {
+			/* Skip ust related trigger */
+			continue;
+		}
+
+		creds = lttng_trigger_get_credentials(trigger);
+		/* Iterate over all known token trigger */
+		k_token = trace_kernel_find_trigger_by_token(&kernel_tracer_token_list, token);
+		if (!k_token) {
+			ret = kernel_create_token_event_rule(event_rule, creds, token);
+			if (ret < 0) {
+				goto end;
+			}
+		}
+	}
+
+	/* Remove all unknown trigger from the app
+	 * TODO find a way better way then this, do it on the unregister command
+	 * and be specific on the token to remove instead of going over all
+	 * trigger known to the app. This is sub optimal.
+	 */
+	cds_list_for_each_entry (token_event_rule_element, &kernel_tracer_token_list.head,
+			list) {
+		uint64_t token;
+		bool found = false;
+
+		token = token_event_rule_element->token;
+
+	/*
+		 * Check if the app event trigger still exists on the
+		 * notification side.
+		 * TODO: might want to change the backing data struct of the
+		 * lttng_triggers object to allow quick lookup?
+		 * For kernel mostly all of this can be removed once we delete
+		 * on a per trigger basis.
+		 */
+
+		for (unsigned int i = 0; i < count; i++) {
+			struct lttng_trigger *trigger;
+			uint64_t inner_token;
+
+			trigger = lttng_triggers_get_pointer_of_index(
+					triggers, i);
+			assert(trigger);
+
+			inner_token = lttng_trigger_get_key(trigger);
+
+			if (inner_token == token) {
+				found = true;
+				break;
+			}
+		}
+
+		if (found) {
+			/* Still valid */
+			continue;
+		}
+
+		kernel_disable_token_event_rule(token_event_rule_element);
+		trace_kernel_destroy_token_event_rule(token_event_rule_element);
+	}
+end:
+	rcu_read_unlock();
+	pthread_mutex_unlock(&notification_trigger_tokens_ht_lock);
+	return ret;
+
+}
+
+int kernel_get_notification_fd(void)
+{
+	return kernel_tracer_trigger_group_notification_fd;
+}