From: David Goulet <david.goulet@polymtl.ca>
Date: Tue, 24 May 2011 15:32:17 +0000 (-0400)
Subject: Add kernel enable event support
X-Git-Tag: v2.0-pre1~126
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=f34daff7d0139d162e949f1b4fbb4cd003746b15;p=lttng-tools.git

Add kernel enable event support

Signed-off-by: David Goulet <david.goulet@polymtl.ca>
---

diff --git a/liblttsessiondcomm/liblttsessiondcomm.c b/liblttsessiondcomm/liblttsessiondcomm.c
index 19bda8388..5cd0f1203 100644
--- a/liblttsessiondcomm/liblttsessiondcomm.c
+++ b/liblttsessiondcomm/liblttsessiondcomm.c
@@ -51,6 +51,8 @@ static const char *lttcomm_readable_code[] = {
 	[ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_NA) ] = "Kernel tracer not available",
 	[ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_SESS_FAIL) ] = "Kernel create session failed",
 	[ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CHAN_FAIL) ] = "Kernel create channel failed",
+	[ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_ENABLE_FAIL) ] = "Enable kernel event failed",
+	[ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_DISABLE_FAIL) ] = "Disable kernel event failed",
 	[ LTTCOMM_ERR_INDEX(KCONSUMERD_COMMAND_SOCK_READY) ] = "Kconsumerd command socket ready",
 	[ LTTCOMM_ERR_INDEX(KCONSUMERD_SUCCESS_RECV_FD) ] = "Kconsumerd success on receiving fds",
 	[ LTTCOMM_ERR_INDEX(KCONSUMERD_ERROR_RECV_FD) ] = "Kconsumerd error on receiving fds",
diff --git a/liblttsessiondcomm/liblttsessiondcomm.h b/liblttsessiondcomm/liblttsessiondcomm.h
index 580d4c2c7..879982101 100644
--- a/liblttsessiondcomm/liblttsessiondcomm.h
+++ b/liblttsessiondcomm/liblttsessiondcomm.h
@@ -103,6 +103,8 @@ enum lttcomm_return_code {
 	LTTCOMM_KERN_NA,				/* Kernel tracer unavalable */
 	LTTCOMM_KERN_SESS_FAIL,			/* Kernel create session failed */
 	LTTCOMM_KERN_CHAN_FAIL,			/* Kernel create channel failed */
+	LTTCOMM_KERN_ENABLE_FAIL,		/* Kernel enable event failed */
+	LTTCOMM_KERN_DISABLE_FAIL,		/* Kernel disable event failed */
 	KCONSUMERD_COMMAND_SOCK_READY,	/* when kconsumerd command socket ready */
 	KCONSUMERD_SUCCESS_RECV_FD,		/* success on receiving fds */
 	KCONSUMERD_ERROR_RECV_FD,		/* error on receiving fds */
diff --git a/ltt-sessiond/kernel-ctl.c b/ltt-sessiond/kernel-ctl.c
index 5d70296ea..02e87e340 100644
--- a/ltt-sessiond/kernel-ctl.c
+++ b/ltt-sessiond/kernel-ctl.c
@@ -19,6 +19,7 @@
 #include <errno.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
 
 #include "ltt-sessiond.h"
 #include "libkernelctl.h"
@@ -101,3 +102,42 @@ int kernel_create_channel(struct command_ctx *cmd_ctx)
 error:
 	return ret;
 }
+
+/*
+ *  kernel_enable_event
+ *
+ *  Enable kernel event.
+ */
+int kernel_enable_event(struct ltt_kernel_channel *channel, char *name)
+{
+	int ret;
+	struct ltt_kernel_event *event;
+	struct lttng_kernel_event *lke;
+
+	event = malloc(sizeof(struct ltt_kernel_event));
+	lke = malloc(sizeof(struct lttng_kernel_event));
+
+	if (event == NULL || lke == NULL) {
+		perror("kernel enable event malloc");
+		ret = -errno;
+		goto error;
+	}
+
+	/* Setting up a kernel event */
+	strncpy(lke->name, name, LTTNG_SYM_NAME_LEN);
+	lke->instrumentation = LTTNG_KERNEL_TRACEPOINTS;
+	event->event = lke;
+
+	ret = kernctl_create_event(channel->fd, lke);
+	if (ret < 0) {
+		goto error;
+	}
+
+	/* Add event to event list */
+	cds_list_add(&event->list, &channel->events_list.head);
+
+	return 0;
+
+error:
+	return ret;
+}
diff --git a/ltt-sessiond/kernel-ctl.h b/ltt-sessiond/kernel-ctl.h
index 35057be08..b8f41e7d9 100644
--- a/ltt-sessiond/kernel-ctl.h
+++ b/ltt-sessiond/kernel-ctl.h
@@ -19,7 +19,10 @@
 #ifndef _LTT_KERNEL_CTL_H
 #define _LTT_KERNEL_CTL_H
 
+#include "trace.h"
+
 int kernel_create_session(struct command_ctx *cmd_ctx, int tracer_fd);
 int kernel_create_channel(struct command_ctx *cmd_ctx);
+int kernel_enable_event(struct ltt_kernel_channel *channel, char *name);
 
 #endif /* _LTT_KERNEL_CTL_H */
diff --git a/ltt-sessiond/main.c b/ltt-sessiond/main.c
index 5b7fb0c21..88a43d968 100644
--- a/ltt-sessiond/main.c
+++ b/ltt-sessiond/main.c
@@ -526,6 +526,12 @@ static int process_client_msg(struct command_ctx *cmd_ctx)
 
 		DBG("Enabling kernel event %s", cmd_ctx->lsm->u.event.event_name);
 
+		ret = kernel_enable_event(cmd_ctx->session->kernel_session->channel, cmd_ctx->lsm->u.event.event_name);
+		if (ret < 0) {
+			ret = LTTCOMM_KERN_ENABLE_FAIL;
+			goto error;
+		}
+
 		ret = LTTCOMM_OK;
 		break;
 	}
diff --git a/ltt-sessiond/trace.h b/ltt-sessiond/trace.h
index 9cfbd84ab..5b4ff68ff 100644
--- a/ltt-sessiond/trace.h
+++ b/ltt-sessiond/trace.h
@@ -30,8 +30,8 @@ struct ltt_kernel_event_list {
 
 /* Kernel event */
 struct ltt_kernel_event {
-	char name[NAME_MAX];
 	int fd;
+	struct lttng_kernel_event *event;
 	struct cds_list_head list;
 };
 
diff --git a/lttng/lttng.c b/lttng/lttng.c
index beb67ffb4..c7c88f631 100644
--- a/lttng/lttng.c
+++ b/lttng/lttng.c
@@ -131,11 +131,12 @@ static int process_client_opt(void)
 
 		if (opt_event_list != NULL) {
 			ret = process_opt_kernel_event();
+			if (ret < 0) {
+				goto end;
+			}
 		} else {
 			// Enable all events
 		}
-
-		goto error;
 	}
 
 	if (opt_trace_pid != 0) {
@@ -521,7 +522,7 @@ static int validate_options(void)
 	}
 
 	/* If start trace, auto start tracing */
-	if (opt_start_trace) {
+	if (opt_start_trace || opt_event_list != NULL) {
 		DBG("Requesting auto tracing");
 		auto_trace = 1;
 	}