X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fkernel.c;h=dee065460b1e661f8dca9f32a9070f3b876b24bc;hp=59d86f45ae1b399866d8656228cedb9c49ce5a37;hb=521dd13449ffb95328746403b460f2a7f5f7ba59;hpb=a5dfbb9db7ba31913657ed921006b13977b7b426

diff --git a/src/bin/lttng-sessiond/kernel.c b/src/bin/lttng-sessiond/kernel.c
index 59d86f45a..dee065460 100644
--- a/src/bin/lttng-sessiond/kernel.c
+++ b/src/bin/lttng-sessiond/kernel.c
@@ -15,7 +15,6 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
 #define _LGPL_SOURCE
 #include <errno.h>
 #include <fcntl.h>
@@ -50,17 +49,24 @@ int kernel_add_channel_context(struct ltt_kernel_channel *chan,
 	DBG("Adding context to channel %s", chan->channel->name);
 	ret = kernctl_add_context(chan->fd, &ctx->ctx);
 	if (ret < 0) {
-		if (errno != EEXIST) {
-			PERROR("add context ioctl");
-		} else {
+		switch (errno) {
+		case ENOSYS:
+			/* Exists but not available for this kernel */
+			ret = LTTNG_ERR_KERN_CONTEXT_UNAVAILABLE;
+			goto error;
+		case EEXIST:
 			/* If EEXIST, we just ignore the error */
 			ret = 0;
+			goto end;
+		default:
+			PERROR("add context ioctl");
+			ret = LTTNG_ERR_KERN_CONTEXT_FAIL;
+			goto error;
 		}
-		goto error;
 	}
 
+end:
 	cds_list_add_tail(&ctx->list, &chan->ctx_list);
-
 	return 0;
 
 error:
@@ -177,7 +183,9 @@ error:
  * We own filter_expression and filter.
  */
 int kernel_create_event(struct lttng_event *ev,
-		struct ltt_kernel_channel *channel)
+		struct ltt_kernel_channel *channel,
+		char *filter_expression,
+		struct lttng_filter_bytecode *filter)
 {
 	int ret;
 	struct ltt_kernel_event *event;
@@ -185,7 +193,9 @@ int kernel_create_event(struct lttng_event *ev,
 	assert(ev);
 	assert(channel);
 
-	event = trace_kernel_create_event(ev);
+	/* We pass ownership of filter_expression and filter */
+	event = trace_kernel_create_event(ev, filter_expression,
+			filter);
 	if (event == NULL) {
 		ret = -1;
 		goto error;
@@ -209,19 +219,7 @@ int kernel_create_event(struct lttng_event *ev,
 		goto free_event;
 	}
 
-	/*
-	 * LTTNG_KERNEL_SYSCALL event creation will return 0 on success.
-	 */
-	if (ret == 0 && event->event->instrumentation == LTTNG_KERNEL_SYSCALL) {
-		DBG2("Kernel event syscall creation success");
-		/*
-		 * We use fd == -1 to ensure that we never trigger a close of fd
-		 * 0.
-		 */
-		event->fd = -1;
-		goto add_list;
-	}
-
+	event->type = ev->type;
 	event->fd = ret;
 	/* Prevent fd duplication after execlp() */
 	ret = fcntl(event->fd, F_SETFD, FD_CLOEXEC);
@@ -229,7 +227,26 @@ int kernel_create_event(struct lttng_event *ev,
 		PERROR("fcntl session fd");
 	}
 
-add_list:
+	if (filter) {
+		ret = kernctl_filter(event->fd, filter);
+		if (ret) {
+			goto filter_error;
+		}
+	}
+
+	ret = kernctl_enable(event->fd);
+	if (ret < 0) {
+		switch (errno) {
+		case EEXIST:
+			ret = LTTNG_ERR_KERN_EVENT_EXIST;
+			break;
+		default:
+			PERROR("enable kernel event");
+			break;
+		}
+		goto enable_error;
+	}
+
 	/* Add event to event list */
 	cds_list_add(&event->list, &channel->events_list.head);
 	channel->event_count++;
@@ -238,6 +255,16 @@ add_list:
 
 	return 0;
 
+enable_error:
+filter_error:
+	{
+		int closeret;
+
+		closeret = close(event->fd);
+		if (closeret) {
+			PERROR("close event fd");
+		}
+	}
 free_event:
 	free(event);
 error:
@@ -355,30 +382,49 @@ error:
 	return ret;
 }
 
-int kernel_enable_syscall(const char *syscall_name,
-		struct ltt_kernel_channel *channel)
-{
-	return kernctl_enable_syscall(channel->fd, syscall_name);
-}
-
-int kernel_disable_syscall(const char *syscall_name,
-		struct ltt_kernel_channel *channel)
-{
-	return kernctl_disable_syscall(channel->fd, syscall_name);
-}
 
 int kernel_track_pid(struct ltt_kernel_session *session, int pid)
 {
+	int ret;
+
 	DBG("Kernel track PID %d for session id %" PRIu64 ".",
 			pid, session->id);
-	return kernctl_track_pid(session->fd, pid);
+	ret = kernctl_track_pid(session->fd, pid);
+	if (!ret) {
+		return LTTNG_OK;
+	}
+	switch (errno) {
+	case EINVAL:
+		return LTTNG_ERR_INVALID;
+	case ENOMEM:
+		return LTTNG_ERR_NOMEM;
+	case EEXIST:
+		return LTTNG_ERR_PID_TRACKED;
+	default:
+		return LTTNG_ERR_UNK;
+	}
 }
 
 int kernel_untrack_pid(struct ltt_kernel_session *session, int pid)
 {
+	int ret;
+
 	DBG("Kernel untrack PID %d for session id %" PRIu64 ".",
 			pid, session->id);
-	return kernctl_untrack_pid(session->fd, pid);
+	ret = kernctl_untrack_pid(session->fd, pid);
+	if (!ret) {
+		return LTTNG_OK;
+	}
+	switch (errno) {
+	case EINVAL:
+		return LTTNG_ERR_INVALID;
+	case ENOMEM:
+		return LTTNG_ERR_NOMEM;
+	case ENOENT:
+		return LTTNG_ERR_PID_NOT_TRACKED;
+	default:
+		return LTTNG_ERR_UNK;
+	}
 }
 
 ssize_t kernel_list_tracker_pids(struct ltt_kernel_session *session,
@@ -790,7 +836,7 @@ int kernel_validate_version(int tracer_fd)
 
 	ret = kernctl_tracer_version(tracer_fd, &version);
 	if (ret < 0) {
-		ERR("Failed at getting the lttng-modules version");
+		ERR("Failed to retrieve the lttng-modules version");
 		goto error;
 	}
 
@@ -802,11 +848,11 @@ int kernel_validate_version(int tracer_fd)
 	}
 	ret = kernctl_tracer_abi_version(tracer_fd, &abi_version);
 	if (ret < 0) {
-		ERR("Failed at getting lttng-modules ABI version");
+		ERR("Failed to retrieve lttng-modules ABI version");
 		goto error;
 	}
 	if (abi_version.major != LTTNG_MODULES_ABI_MAJOR_VERSION) {
-		ERR("Kernel tracer ABI version (%d.%d) is not compatible with expected ABI major version (%d.*)",
+		ERR("Kernel tracer ABI version (%d.%d) does not match the expected ABI major version (%d.*)",
 			abi_version.major, abi_version.minor,
 			LTTNG_MODULES_ABI_MAJOR_VERSION);
 		goto error;
@@ -820,6 +866,7 @@ error_version:
 	ret = -1;
 
 error:
+	ERR("Kernel tracer version check failed; kernel tracing will not be available");
 	return ret;
 }