X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fkernel.c;h=a72fe7f5c977ac76cd351555ec170b5781977191;hb=de04bbc88637bb336255f6cc7c7e4f4ea179f40d;hp=faf35cc7fc8f8a42c927325a15a161bd69215148;hpb=15dc512ac8cf2f59c8779f442f116a23975c950c;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/kernel.c b/src/bin/lttng-sessiond/kernel.c
index faf35cc7f..a72fe7f5c 100644
--- a/src/bin/lttng-sessiond/kernel.c
+++ b/src/bin/lttng-sessiond/kernel.c
@@ -15,8 +15,7 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
-#include <errno.h>
+#define _LGPL_SOURCE
 #include <fcntl.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -26,18 +25,22 @@
 
 #include <common/common.h>
 #include <common/kernel-ctl/kernel-ctl.h>
+#include <common/kernel-ctl/kernel-ioctl.h>
 #include <common/sessiond-comm/sessiond-comm.h>
 
 #include "consumer.h"
 #include "kernel.h"
 #include "kernel-consumer.h"
 #include "kern-modules.h"
+#include "utils.h"
 
 /*
  * Add context on a kernel channel.
+ *
+ * Assumes the ownership of ctx.
  */
 int kernel_add_channel_context(struct ltt_kernel_channel *chan,
-		struct lttng_kernel_context *ctx)
+		struct ltt_kernel_context *ctx)
 {
 	int ret;
 
@@ -45,28 +48,32 @@ int kernel_add_channel_context(struct ltt_kernel_channel *chan,
 	assert(ctx);
 
 	DBG("Adding context to channel %s", chan->channel->name);
-	ret = kernctl_add_context(chan->fd, ctx);
+	ret = kernctl_add_context(chan->fd, &ctx->ctx);
 	if (ret < 0) {
-		if (errno != EEXIST) {
-			PERROR("add context ioctl");
-		} else {
+		switch (-ret) {
+		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;
 	}
 
-	chan->ctx = zmalloc(sizeof(struct lttng_kernel_context));
-	if (chan->ctx == NULL) {
-		PERROR("zmalloc event context");
-		goto error;
-	}
-
-	memcpy(chan->ctx, ctx, sizeof(struct lttng_kernel_context));
-
-	return 0;
-
+end:
+	cds_list_add_tail(&ctx->list, &chan->ctx_list);
+	ctx->in_list = true;
+	ctx = NULL;
 error:
+	if (ctx) {
+		trace_kernel_destroy_context(ctx);
+	}
 	return ret;
 }
 
@@ -177,9 +184,12 @@ error:
 /*
  * Create a kernel event, enable it to the kernel tracer and add it to the
  * channel event list of the kernel session.
+ * 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;
@@ -187,7 +197,9 @@ 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;
@@ -195,32 +207,22 @@ int kernel_create_event(struct lttng_event *ev,
 
 	ret = kernctl_create_event(channel->fd, event->event);
 	if (ret < 0) {
-		switch (errno) {
+		switch (-ret) {
 		case EEXIST:
 			break;
 		case ENOSYS:
 			WARN("Event type not implemented");
 			break;
+		case ENOENT:
+			WARN("Event %s not found!", ev->name);
+			break;
 		default:
 			PERROR("create event ioctl");
 		}
-		ret = -errno;
 		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);
@@ -228,7 +230,26 @@ 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 (-ret) {
+		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++;
@@ -237,6 +258,16 @@ 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:
@@ -255,7 +286,6 @@ int kernel_disable_channel(struct ltt_kernel_channel *chan)
 	ret = kernctl_disable(chan->fd);
 	if (ret < 0) {
 		PERROR("disable chan ioctl");
-		ret = errno;
 		goto error;
 	}
 
@@ -278,7 +308,7 @@ int kernel_enable_channel(struct ltt_kernel_channel *chan)
 	assert(chan);
 
 	ret = kernctl_enable(chan->fd);
-	if (ret < 0 && errno != EEXIST) {
+	if (ret < 0 && ret != -EEXIST) {
 		PERROR("Enable kernel chan");
 		goto error;
 	}
@@ -303,7 +333,7 @@ int kernel_enable_event(struct ltt_kernel_event *event)
 
 	ret = kernctl_enable(event->fd);
 	if (ret < 0) {
-		switch (errno) {
+		switch (-ret) {
 		case EEXIST:
 			ret = LTTNG_ERR_KERN_EVENT_EXIST;
 			break;
@@ -334,7 +364,7 @@ int kernel_disable_event(struct ltt_kernel_event *event)
 
 	ret = kernctl_disable(event->fd);
 	if (ret < 0) {
-		switch (errno) {
+		switch (-ret) {
 		case EEXIST:
 			ret = LTTNG_ERR_KERN_EVENT_EXIST;
 			break;
@@ -354,6 +384,276 @@ error:
 	return ret;
 }
 
+static
+struct lttng_tracker_list *get_id_tracker_list(struct ltt_kernel_session *session,
+		enum lttng_tracker_type tracker_type)
+{
+	switch (tracker_type) {
+	case LTTNG_TRACKER_PID:
+		return session->tracker_list_pid;
+	case LTTNG_TRACKER_VPID:
+		return session->tracker_list_vpid;
+	case LTTNG_TRACKER_UID:
+		return session->tracker_list_uid;
+	case LTTNG_TRACKER_VUID:
+		return session->tracker_list_vuid;
+	case LTTNG_TRACKER_GID:
+		return session->tracker_list_gid;
+	case LTTNG_TRACKER_VGID:
+		return session->tracker_list_vgid;
+	default:
+		return NULL;
+	}
+}
+
+int kernel_track_id(enum lttng_tracker_type tracker_type,
+		struct ltt_kernel_session *session,
+		struct lttng_tracker_id *id)
+{
+	int ret, value;
+	struct lttng_tracker_list *tracker_list;
+	struct lttng_tracker_id *saved_ids;
+	ssize_t saved_ids_count, i;
+
+	ret = lttng_tracker_id_lookup_string(tracker_type,
+			id, &value);
+	if (ret != LTTNG_OK) {
+		return ret;
+	}
+
+	tracker_list = get_id_tracker_list(session, tracker_type);
+	if (!tracker_list) {
+		return LTTNG_ERR_INVALID;
+	}
+	/* Save list for restore on error. */
+	saved_ids_count = lttng_tracker_id_get_list(tracker_list, &saved_ids);
+	if (saved_ids_count < 0) {
+		return LTTNG_ERR_INVALID;
+	}
+	/* Add to list. */
+	ret = lttng_tracker_list_add(tracker_list, id);
+	if (ret != LTTNG_OK) {
+		goto end;
+	}
+
+	switch (tracker_type) {
+	case LTTNG_TRACKER_PID:
+		DBG("Kernel track PID %d for session id %" PRIu64 ".",
+				value, session->id);
+		ret = kernctl_track_pid(session->fd, value);
+		if (!ret) {
+			ret = LTTNG_OK;
+			goto end;
+		}
+		break;
+	case LTTNG_TRACKER_VPID:
+		DBG("Kernel track VPID %d for session id %" PRIu64 ".",
+				value, session->id);
+		ret = kernctl_track_id(session->fd, LTTNG_TRACKER_VPID, value);
+		if (!ret) {
+			ret = LTTNG_OK;
+			goto end;
+		}
+		break;
+	case LTTNG_TRACKER_UID:
+		DBG("Kernel track UID %d for session id %" PRIu64 ".",
+				value, session->id);
+		ret = kernctl_track_id(session->fd, LTTNG_TRACKER_UID, value);
+		if (!ret) {
+			ret = LTTNG_OK;
+			goto end;
+		}
+		break;
+	case LTTNG_TRACKER_GID:
+		DBG("Kernel track GID %d for session id %" PRIu64 ".",
+				value, session->id);
+		ret = kernctl_track_id(session->fd, LTTNG_TRACKER_GID, value);
+		if (!ret) {
+			ret = LTTNG_OK;
+			goto end;
+		}
+		break;
+	case LTTNG_TRACKER_VUID:
+		DBG("Kernel track VUID %d for session id %" PRIu64 ".",
+				value, session->id);
+		ret = kernctl_track_id(session->fd, LTTNG_TRACKER_VUID, value);
+		if (!ret) {
+			ret = LTTNG_OK;
+			goto end;
+		}
+		break;
+	case LTTNG_TRACKER_VGID:
+		DBG("Kernel track VGID %d for session id %" PRIu64 ".",
+				value, session->id);
+		ret = kernctl_track_id(session->fd, LTTNG_TRACKER_VGID, value);
+		if (!ret) {
+			ret = LTTNG_OK;
+			goto end;
+		}
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+	/* Error handling. */
+	switch (-ret) {
+	case EINVAL:
+		ret = LTTNG_ERR_INVALID;
+		break;
+	case ENOMEM:
+		ret = LTTNG_ERR_NOMEM;
+		break;
+	case EEXIST:
+		ret = LTTNG_ERR_ID_TRACKED;
+		break;
+	default:
+		ret = LTTNG_ERR_UNK;
+		break;
+	}
+	if (lttng_tracker_id_set_list(tracker_list, saved_ids, saved_ids_count) != LTTNG_OK) {
+		ERR("Error on tracker add error handling.\n");
+	}
+end:
+	for (i = 0; i < saved_ids_count; i++) {
+		free(saved_ids[i].string);
+	}
+	free(saved_ids);
+	return ret;
+}
+
+int kernel_untrack_id(enum lttng_tracker_type tracker_type,
+		struct ltt_kernel_session *session,
+		struct lttng_tracker_id *id)
+{
+	int ret, value;
+	struct lttng_tracker_list *tracker_list;
+	struct lttng_tracker_id *saved_ids;
+	ssize_t saved_ids_count, i;
+
+	ret = lttng_tracker_id_lookup_string(tracker_type,
+			id, &value);
+	if (ret != LTTNG_OK) {
+		return ret;
+	}
+
+	tracker_list = get_id_tracker_list(session, tracker_type);
+	if (!tracker_list) {
+		return LTTNG_ERR_INVALID;
+	}
+	/* Save list for restore on error. */
+	saved_ids_count = lttng_tracker_id_get_list(tracker_list, &saved_ids);
+	if (saved_ids_count < 0) {
+		return LTTNG_ERR_INVALID;
+	}
+	/* Remove from list. */
+	ret = lttng_tracker_list_remove(tracker_list, id);
+	if (ret != LTTNG_OK) {
+		goto end;
+	}
+
+	switch (tracker_type) {
+	case LTTNG_TRACKER_PID:
+		DBG("Kernel untrack PID %d for session id %" PRIu64 ".",
+				value, session->id);
+		ret = kernctl_untrack_pid(session->fd, value);
+		if (!ret) {
+			ret = LTTNG_OK;
+			goto end;
+		}
+		break;
+	case LTTNG_TRACKER_VPID:
+		DBG("Kernel untrack VPID %d for session id %" PRIu64 ".",
+				value, session->id);
+		ret = kernctl_untrack_id(session->fd, LTTNG_TRACKER_VPID, value);
+		if (!ret) {
+			ret = LTTNG_OK;
+			goto end;
+		}
+		break;
+	case LTTNG_TRACKER_UID:
+		DBG("Kernel untrack UID %d for session id %" PRIu64 ".",
+				value, session->id);
+		ret = kernctl_untrack_id(session->fd, LTTNG_TRACKER_UID, value);
+		if (!ret) {
+			ret = LTTNG_OK;
+			goto end;
+		}
+		break;
+	case LTTNG_TRACKER_GID:
+		DBG("Kernel untrack GID %d for session id %" PRIu64 ".",
+				value, session->id);
+		ret = kernctl_untrack_id(session->fd, LTTNG_TRACKER_GID, value);
+		if (!ret) {
+			ret = LTTNG_OK;
+			goto end;
+		}
+		break;
+	case LTTNG_TRACKER_VUID:
+		DBG("Kernel untrack VUID %d for session id %" PRIu64 ".",
+				value, session->id);
+		ret = kernctl_untrack_id(session->fd, LTTNG_TRACKER_VUID, value);
+		if (!ret) {
+			ret = LTTNG_OK;
+			goto end;
+		}
+		break;
+	case LTTNG_TRACKER_VGID:
+		DBG("Kernel untrack VGID %d for session id %" PRIu64 ".",
+				value, session->id);
+		ret = kernctl_untrack_id(session->fd, LTTNG_TRACKER_VGID, value);
+		if (!ret) {
+			ret = LTTNG_OK;
+			goto end;
+		}
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	/* Error handling. */
+	switch (-ret) {
+	case EINVAL:
+		ret = LTTNG_ERR_INVALID;
+		break;
+	case ENOMEM:
+		ret = LTTNG_ERR_NOMEM;
+		break;
+	case EEXIST:
+		ret = LTTNG_ERR_ID_TRACKED;
+		break;
+	default:
+		ret = LTTNG_ERR_UNK;
+		break;
+	}
+
+	if (lttng_tracker_id_set_list(tracker_list, saved_ids, saved_ids_count) != LTTNG_OK) {
+		ERR("Error on tracker remove error handling.\n");
+	}
+end:
+	for (i = 0; i < saved_ids_count; i++) {
+		free(saved_ids[i].string);
+	}
+	free(saved_ids);
+	return ret;
+}
+
+/*
+ * Called with session lock held.
+ */
+ssize_t kernel_list_tracker_ids(enum lttng_tracker_type tracker_type,
+		struct ltt_kernel_session *session,
+		struct lttng_tracker_id **_ids)
+{
+	struct lttng_tracker_list *tracker_list;
+
+	tracker_list = get_id_tracker_list(session, tracker_type);
+	if (!tracker_list) {
+		return -LTTNG_ERR_INVALID;
+	}
+	return lttng_tracker_id_get_list(tracker_list, _ids);
+}
+
 /*
  * Create kernel metadata, open from the kernel tracer and add it to the
  * kernel session.
@@ -435,25 +735,6 @@ void kernel_wait_quiescent(int fd)
 	}
 }
 
-/*
- * Kernel calibrate
- */
-int kernel_calibrate(int fd, struct lttng_kernel_calibrate *calibrate)
-{
-	int ret;
-
-	assert(calibrate);
-
-	ret = kernctl_calibrate(fd, calibrate);
-	if (ret < 0) {
-		PERROR("calibrate ioctl");
-		return -1;
-	}
-
-	return 0;
-}
-
-
 /*
  *  Force flush buffer of metadata.
  */
@@ -522,17 +803,22 @@ error:
  * Open stream of channel, register it to the kernel tracer and add it
  * to the stream list of the channel.
  *
+ * Note: given that the streams may appear in random order wrt CPU
+ * number (e.g. cpu hotplug), the index value of the stream number in
+ * the stream name is not necessarily linked to the CPU number.
+ *
  * Return the number of created stream. Else, a negative value.
  */
 int kernel_open_channel_stream(struct ltt_kernel_channel *channel)
 {
-	int ret, count = 0;
+	int ret;
 	struct ltt_kernel_stream *lks;
 
 	assert(channel);
 
 	while ((ret = kernctl_create_stream(channel->fd)) >= 0) {
-		lks = trace_kernel_create_stream(channel->channel->name, count);
+		lks = trace_kernel_create_stream(channel->channel->name,
+				channel->stream_count);
 		if (lks == NULL) {
 			ret = close(ret);
 			if (ret) {
@@ -551,13 +837,10 @@ int kernel_open_channel_stream(struct ltt_kernel_channel *channel)
 		lks->tracefile_size = channel->channel->attr.tracefile_size;
 		lks->tracefile_count = channel->channel->attr.tracefile_count;
 
-		/* Add stream to channe stream list */
+		/* Add stream to channel stream list */
 		cds_list_add(&lks->list, &channel->stream_list.head);
 		channel->stream_count++;
 
-		/* Increment counter which represent CPU number. */
-		count++;
-
 		DBG("Kernel stream %s created (fd: %d, state: %d)", lks->name, lks->fd,
 				lks->state);
 	}
@@ -688,28 +971,41 @@ int kernel_validate_version(int tracer_fd)
 {
 	int ret;
 	struct lttng_kernel_tracer_version version;
+	struct lttng_kernel_tracer_abi_version abi_version;
 
 	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;
 	}
 
 	/* Validate version */
-	if (version.major != KERN_MODULES_PRE_MAJOR
-		&& version.major != KERN_MODULES_MAJOR) {
+	if (version.major != VERSION_MAJOR) {
+		ERR("Kernel tracer major version (%d) is not compatible with lttng-tools major version (%d)",
+			version.major, VERSION_MAJOR);
 		goto error_version;
 	}
-
-	DBG2("Kernel tracer version validated (major version %d)", version.major);
+	ret = kernctl_tracer_abi_version(tracer_fd, &abi_version);
+	if (ret < 0) {
+		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) does not match the expected ABI major version (%d.*)",
+			abi_version.major, abi_version.minor,
+			LTTNG_MODULES_ABI_MAJOR_VERSION);
+		goto error;
+	}
+	DBG2("Kernel tracer version validated (%d.%d, ABI %d.%d)",
+			version.major, version.minor,
+			abi_version.major, abi_version.minor);
 	return 0;
 
 error_version:
-	ERR("Kernel major version %d is not compatible (supporting <= %d)",
-			version.major, KERN_MODULES_MAJOR)
 	ret = -1;
 
 error:
+	ERR("Kernel tracer version check failed; kernel tracing will not be available");
 	return ret;
 }
 
@@ -769,6 +1065,7 @@ void kernel_destroy_session(struct ltt_kernel_session *ksess)
 		struct lttng_ht_iter iter;
 
 		/* For each consumer socket. */
+		rcu_read_lock();
 		cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
 				socket, node.node) {
 			struct ltt_kernel_channel *chan;
@@ -782,6 +1079,7 @@ void kernel_destroy_session(struct ltt_kernel_session *ksess)
 				}
 			}
 		}
+		rcu_read_unlock();
 	}
 
 	/* Close any relayd session */
@@ -826,13 +1124,13 @@ void kernel_destroy_channel(struct ltt_kernel_channel *kchan)
  * Return 0 on success or else return a LTTNG_ERR code.
  */
 int kernel_snapshot_record(struct ltt_kernel_session *ksess,
-		struct snapshot_output *output, int wait, unsigned int nb_streams)
+		struct snapshot_output *output, int wait,
+		uint64_t nb_packets_per_stream)
 {
 	int err, ret, saved_metadata_fd;
 	struct consumer_socket *socket;
 	struct lttng_ht_iter iter;
 	struct ltt_kernel_metadata *saved_metadata;
-	uint64_t max_size_per_stream = 0;
 
 	assert(ksess);
 	assert(ksess->consumer);
@@ -858,10 +1156,6 @@ int kernel_snapshot_record(struct ltt_kernel_session *ksess,
 		goto error_open_stream;
 	}
 
-	if (output->max_size > 0 && nb_streams > 0) {
-		max_size_per_stream = output->max_size / nb_streams;
-	}
-
 	/* Send metadata to consumer and snapshot everything. */
 	cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
 			socket, node.node) {
@@ -888,23 +1182,10 @@ int kernel_snapshot_record(struct ltt_kernel_session *ksess,
 
 		/* For each channel, ask the consumer to snapshot it. */
 		cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
-			if (max_size_per_stream &&
-					chan->channel->attr.subbuf_size > max_size_per_stream) {
-				ret = LTTNG_ERR_INVALID;
-				DBG3("Kernel snapshot record maximum stream size %" PRIu64
-						" is smaller than subbuffer size of %" PRIu64,
-						max_size_per_stream, chan->channel->attr.subbuf_size);
-				(void) kernel_consumer_destroy_metadata(socket,
-						ksess->metadata);
-				goto error_consumer;
-			}
-
-			pthread_mutex_lock(socket->lock);
 			ret = consumer_snapshot_channel(socket, chan->fd, output, 0,
 					ksess->uid, ksess->gid,
 					DEFAULT_KERNEL_TRACE_DIR, wait,
-					max_size_per_stream);
-			pthread_mutex_unlock(socket->lock);
+					nb_packets_per_stream);
 			if (ret < 0) {
 				ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
 				(void) kernel_consumer_destroy_metadata(socket,
@@ -914,11 +1195,9 @@ int kernel_snapshot_record(struct ltt_kernel_session *ksess,
 		}
 
 		/* Snapshot metadata, */
-		pthread_mutex_lock(socket->lock);
 		ret = consumer_snapshot_channel(socket, ksess->metadata->fd, output,
 				1, ksess->uid, ksess->gid,
-				DEFAULT_KERNEL_TRACE_DIR, wait, max_size_per_stream);
-		pthread_mutex_unlock(socket->lock);
+				DEFAULT_KERNEL_TRACE_DIR, wait, 0);
 		if (ret < 0) {
 			ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
 			goto error_consumer;
@@ -950,3 +1229,17 @@ error:
 	rcu_read_unlock();
 	return ret;
 }
+
+/*
+ * Get the syscall mask array from the kernel tracer.
+ *
+ * Return 0 on success else a negative value. In both case, syscall_mask should
+ * be freed.
+ */
+int kernel_syscall_mask(int chan_fd, char **syscall_mask, uint32_t *nr_bits)
+{
+	assert(syscall_mask);
+	assert(nr_bits);
+
+	return kernctl_syscall_mask(chan_fd, syscall_mask, nr_bits);
+}