X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=lttng-sessiond%2Fkernel-ctl.c;fp=lttng-sessiond%2Fkernel-ctl.c;h=203c01050e82199f34128d09b9c5dd95ca6fb0a4;hb=322585731ced1adba36cddcb8bdd5d997d1b2e3e;hp=0000000000000000000000000000000000000000;hpb=1316184615e422526ef4fae68f980443414969c1;p=lttng-tools.git

diff --git a/lttng-sessiond/kernel-ctl.c b/lttng-sessiond/kernel-ctl.c
new file mode 100644
index 000000000..203c01050
--- /dev/null
+++ b/lttng-sessiond/kernel-ctl.c
@@ -0,0 +1,607 @@
+/*
+ * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; only version 2
+ * of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <lttng-kernel-ctl.h>
+#include <lttngerr.h>
+
+#include "kernel-ctl.h"
+
+/*
+ * Add context on a kernel channel.
+ */
+int kernel_add_channel_context(struct ltt_kernel_channel *chan,
+		struct lttng_kernel_context *ctx)
+{
+	int ret;
+
+	DBG("Adding context to channel %s", chan->channel->name);
+	ret = kernctl_add_context(chan->fd, ctx);
+	if (ret < 0) {
+		if (errno != EEXIST) {
+			perror("add context ioctl");
+		} else {
+			/* If EEXIST, we just ignore the error */
+			ret = 0;
+		}
+		goto error;
+	}
+
+	chan->ctx = malloc(sizeof(struct lttng_kernel_context));
+	if (chan->ctx == NULL) {
+		perror("malloc event context");
+		goto error;
+	}
+
+	memcpy(chan->ctx, ctx, sizeof(struct lttng_kernel_context));
+
+	return 0;
+
+error:
+	return ret;
+}
+
+/*
+ * Add context on a kernel event.
+ */
+int kernel_add_event_context(struct ltt_kernel_event *event,
+		struct lttng_kernel_context *ctx)
+{
+	int ret;
+
+	DBG("Adding context to event %s", event->event->name);
+	ret = kernctl_add_context(event->fd, ctx);
+	if (ret < 0) {
+		perror("add context ioctl");
+		goto error;
+	}
+
+	event->ctx = malloc(sizeof(struct lttng_kernel_context));
+	if (event->ctx == NULL) {
+		perror("malloc event context");
+		goto error;
+	}
+
+	memcpy(event->ctx, ctx, sizeof(struct lttng_kernel_context));
+
+	return 0;
+
+error:
+	return ret;
+}
+
+/*
+ * Create a new kernel session, register it to the kernel tracer and add it to
+ * the session daemon session.
+ */
+int kernel_create_session(struct ltt_session *session, int tracer_fd)
+{
+	int ret;
+	struct ltt_kernel_session *lks;
+
+	/* Allocate data structure */
+	lks = trace_kernel_create_session(session->path);
+	if (lks == NULL) {
+		ret = -1;
+		goto error;
+	}
+
+	/* Kernel tracer session creation */
+	ret = kernctl_create_session(tracer_fd);
+	if (ret < 0) {
+		perror("ioctl kernel create session");
+		goto error;
+	}
+
+	lks->fd = ret;
+	/* Prevent fd duplication after execlp() */
+	ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC);
+	if (ret < 0) {
+		perror("fcntl session fd");
+	}
+
+	lks->consumer_fds_sent = 0;
+	session->kernel_session = lks;
+
+	DBG("Kernel session created (fd: %d)", lks->fd);
+
+	return 0;
+
+error:
+	return ret;
+}
+
+/*
+ * Create a kernel channel, register it to the kernel tracer and add it to the
+ * kernel session.
+ */
+int kernel_create_channel(struct ltt_kernel_session *session,
+		struct lttng_channel *chan, char *path)
+{
+	int ret;
+	struct ltt_kernel_channel *lkc;
+
+	/* Allocate kernel channel */
+	lkc = trace_kernel_create_channel(chan, path);
+	if (lkc == NULL) {
+		goto error;
+	}
+
+	/* Kernel tracer channel creation */
+	ret = kernctl_create_channel(session->fd, &lkc->channel->attr);
+	if (ret < 0) {
+		perror("ioctl kernel create channel");
+		goto error;
+	}
+
+	/* Setup the channel fd */
+	lkc->fd = ret;
+	/* Prevent fd duplication after execlp() */
+	ret = fcntl(lkc->fd, F_SETFD, FD_CLOEXEC);
+	if (ret < 0) {
+		perror("fcntl session fd");
+	}
+
+	/* Add channel to session */
+	cds_list_add(&lkc->list, &session->channel_list.head);
+	session->channel_count++;
+
+	DBG("Kernel channel %s created (fd: %d and path: %s)",
+			lkc->channel->name, lkc->fd, lkc->pathname);
+
+	return 0;
+
+error:
+	return -1;
+}
+
+/*
+ * Create a kernel event, enable it to the kernel tracer and add it to the
+ * channel event list of the kernel session.
+ */
+int kernel_create_event(struct lttng_event *ev,
+		struct ltt_kernel_channel *channel)
+{
+	int ret;
+	struct ltt_kernel_event *event;
+
+	event = trace_kernel_create_event(ev);
+	if (event == NULL) {
+		ret = -1;
+		goto error;
+	}
+
+	ret = kernctl_create_event(channel->fd, event->event);
+	if (ret < 0) {
+		if (errno != EEXIST) {
+			PERROR("create event ioctl");
+		}
+		ret = -errno;
+		goto free_event;
+	}
+
+	/*
+	 * LTTNG_KERNEL_SYSCALL event creation will return 0 on success. However
+	 * this FD must not be added to the event list.
+	 */
+	if (ret == 0 && event->event->instrumentation == LTTNG_KERNEL_SYSCALL) {
+		DBG2("Kernel event syscall creation success");
+		goto end;
+	}
+
+	event->fd = ret;
+	/* Prevent fd duplication after execlp() */
+	ret = fcntl(event->fd, F_SETFD, FD_CLOEXEC);
+	if (ret < 0) {
+		perror("fcntl session fd");
+	}
+
+	/* Add event to event list */
+	cds_list_add(&event->list, &channel->events_list.head);
+	channel->event_count++;
+
+	DBG("Event %s created (fd: %d)", ev->name, event->fd);
+
+end:
+	return 0;
+
+free_event:
+	free(event);
+error:
+	return ret;
+}
+
+/*
+ * Disable a kernel channel.
+ */
+int kernel_disable_channel(struct ltt_kernel_channel *chan)
+{
+	int ret;
+
+	ret = kernctl_disable(chan->fd);
+	if (ret < 0) {
+		perror("disable chan ioctl");
+		ret = errno;
+		goto error;
+	}
+
+	chan->enabled = 0;
+	DBG("Kernel channel %s disabled (fd: %d)", chan->channel->name, chan->fd);
+
+	return 0;
+
+error:
+	return ret;
+}
+
+/*
+ * Enable a kernel channel.
+ */
+int kernel_enable_channel(struct ltt_kernel_channel *chan)
+{
+	int ret;
+
+	ret = kernctl_enable(chan->fd);
+	if (ret < 0 && errno != EEXIST) {
+		perror("Enable kernel chan");
+		goto error;
+	}
+
+	chan->enabled = 1;
+	DBG("Kernel channel %s enabled (fd: %d)", chan->channel->name, chan->fd);
+
+	return 0;
+
+error:
+	return ret;
+}
+
+/*
+ * Enable a kernel event.
+ */
+int kernel_enable_event(struct ltt_kernel_event *event)
+{
+	int ret;
+
+	ret = kernctl_enable(event->fd);
+	if (ret < 0 && errno != EEXIST) {
+		perror("enable kernel event");
+		goto error;
+	}
+
+	event->enabled = 1;
+	DBG("Kernel event %s enabled (fd: %d)", event->event->name, event->fd);
+
+	return 0;
+
+error:
+	return ret;
+}
+
+/*
+ * Disable a kernel event.
+ */
+int kernel_disable_event(struct ltt_kernel_event *event)
+{
+	int ret;
+
+	ret = kernctl_disable(event->fd);
+	if (ret < 0 && errno != EEXIST) {
+		perror("disable kernel event");
+		goto error;
+	}
+
+	event->enabled = 0;
+	DBG("Kernel event %s disabled (fd: %d)", event->event->name, event->fd);
+
+	return 0;
+
+error:
+	return ret;
+}
+
+/*
+ * Create kernel metadata, open from the kernel tracer and add it to the
+ * kernel session.
+ */
+int kernel_open_metadata(struct ltt_kernel_session *session, char *path)
+{
+	int ret;
+	struct ltt_kernel_metadata *lkm;
+
+	/* Allocate kernel metadata */
+	lkm = trace_kernel_create_metadata(path);
+	if (lkm == NULL) {
+		goto error;
+	}
+
+	/* Kernel tracer metadata creation */
+	ret = kernctl_open_metadata(session->fd, &lkm->conf->attr);
+	if (ret < 0) {
+		goto error;
+	}
+
+	lkm->fd = ret;
+	/* Prevent fd duplication after execlp() */
+	ret = fcntl(lkm->fd, F_SETFD, FD_CLOEXEC);
+	if (ret < 0) {
+		perror("fcntl session fd");
+	}
+
+	session->metadata = lkm;
+
+	DBG("Kernel metadata opened (fd: %d and path: %s)", lkm->fd, lkm->pathname);
+
+	return 0;
+
+error:
+	return -1;
+}
+
+/*
+ * Start tracing session.
+ */
+int kernel_start_session(struct ltt_kernel_session *session)
+{
+	int ret;
+
+	ret = kernctl_start_session(session->fd);
+	if (ret < 0) {
+		perror("ioctl start session");
+		goto error;
+	}
+
+	DBG("Kernel session started");
+
+	return 0;
+
+error:
+	return ret;
+}
+
+/*
+ * Make a kernel wait to make sure in-flight probe have completed.
+ */
+void kernel_wait_quiescent(int fd)
+{
+	int ret;
+
+	DBG("Kernel quiescent wait on %d", fd);
+
+	ret = kernctl_wait_quiescent(fd);
+	if (ret < 0) {
+		perror("wait quiescent ioctl");
+		ERR("Kernel quiescent wait failed");
+	}
+}
+
+/*
+ * Kernel calibrate
+ */
+int kernel_calibrate(int fd, struct lttng_kernel_calibrate *calibrate)
+{
+	int ret;
+
+	ret = kernctl_calibrate(fd, calibrate);
+	if (ret < 0) {
+		perror("calibrate ioctl");
+		return -1;
+	}
+
+	return 0;
+}
+
+
+/*
+ *  Force flush buffer of metadata.
+ */
+int kernel_metadata_flush_buffer(int fd)
+{
+	int ret;
+
+	ret = kernctl_buffer_flush(fd);
+	if (ret < 0) {
+		ERR("Fail to flush metadata buffers %d (ret: %d", fd, ret);
+	}
+
+	return 0;
+}
+
+/*
+ * Force flush buffer for channel.
+ */
+int kernel_flush_buffer(struct ltt_kernel_channel *channel)
+{
+	int ret;
+	struct ltt_kernel_stream *stream;
+
+	DBG("Flush buffer for channel %s", channel->channel->name);
+
+	cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
+		DBG("Flushing channel stream %d", stream->fd);
+		ret = kernctl_buffer_flush(stream->fd);
+		if (ret < 0) {
+			perror("ioctl");
+			ERR("Fail to flush buffer for stream %d (ret: %d)",
+					stream->fd, ret);
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Stop tracing session.
+ */
+int kernel_stop_session(struct ltt_kernel_session *session)
+{
+	int ret;
+
+	ret = kernctl_stop_session(session->fd);
+	if (ret < 0) {
+		goto error;
+	}
+
+	DBG("Kernel session stopped");
+
+	return 0;
+
+error:
+	return ret;
+}
+
+/*
+ * Open stream of channel, register it to the kernel tracer and add it
+ * to the stream list of the channel.
+ *
+ * Return the number of created stream. Else, a negative value.
+ */
+int kernel_open_channel_stream(struct ltt_kernel_channel *channel)
+{
+	int ret;
+	struct ltt_kernel_stream *lks;
+
+	while ((ret = kernctl_create_stream(channel->fd)) > 0) {
+		lks = trace_kernel_create_stream();
+		if (lks == NULL) {
+			close(ret);
+			goto error;
+		}
+
+		lks->fd = ret;
+		/* Prevent fd duplication after execlp() */
+		ret = fcntl(lks->fd, F_SETFD, FD_CLOEXEC);
+		if (ret < 0) {
+			perror("fcntl session fd");
+		}
+
+		ret = asprintf(&lks->pathname, "%s/%s_%d",
+				channel->pathname, channel->channel->name, channel->stream_count);
+		if (ret < 0) {
+			perror("asprintf kernel create stream");
+			goto error;
+		}
+
+		/* Add stream to channe stream list */
+		cds_list_add(&lks->list, &channel->stream_list.head);
+		channel->stream_count++;
+
+		DBG("Kernel stream %d created (fd: %d, state: %d, path: %s)",
+				channel->stream_count, lks->fd, lks->state, lks->pathname);
+	}
+
+	return channel->stream_count;
+
+error:
+	return -1;
+}
+
+/*
+ * Open the metadata stream and set it to the kernel session.
+ */
+int kernel_open_metadata_stream(struct ltt_kernel_session *session)
+{
+	int ret;
+
+	ret = kernctl_create_stream(session->metadata->fd);
+	if (ret < 0) {
+		perror("kernel create metadata stream");
+		goto error;
+	}
+
+	DBG("Kernel metadata stream created (fd: %d)", ret);
+	session->metadata_stream_fd = ret;
+	/* Prevent fd duplication after execlp() */
+	ret = fcntl(session->metadata_stream_fd, F_SETFD, FD_CLOEXEC);
+	if (ret < 0) {
+		perror("fcntl session fd");
+	}
+
+	return 0;
+
+error:
+	return -1;
+}
+
+/*
+ * Get the event list from the kernel tracer and return the number of elements.
+ */
+ssize_t kernel_list_events(int tracer_fd, struct lttng_event **events)
+{
+	int fd, pos;
+	char *event;
+	size_t nbmem, count = 0;
+	ssize_t size;
+	FILE *fp;
+	struct lttng_event *elist;
+
+	fd = kernctl_tracepoint_list(tracer_fd);
+	if (fd < 0) {
+		perror("kernel tracepoint list");
+		goto error;
+	}
+
+	fp = fdopen(fd, "r");
+	if (fp == NULL) {
+		perror("kernel tracepoint list fdopen");
+		goto error_fp;
+	}
+
+	/*
+	 * Init memory size counter
+	 * See kernel-ctl.h for explanation of this value
+	 */
+	nbmem = KERNEL_EVENT_LIST_SIZE;
+	elist = malloc(sizeof(struct lttng_event) * nbmem);
+
+	while ((size = fscanf(fp, "event { name = %m[^;]; };%n\n", &event, &pos)) == 1) {
+		if (count > nbmem) {
+			DBG("Reallocating event list from %zu to %zu bytes", nbmem,
+					nbmem + KERNEL_EVENT_LIST_SIZE);
+			/* Adding the default size again */
+			nbmem += KERNEL_EVENT_LIST_SIZE;
+			elist = realloc(elist, nbmem);
+			if (elist == NULL) {
+				perror("realloc list events");
+				count = -ENOMEM;
+				goto end;
+			}
+		}
+		strncpy(elist[count].name, event, LTTNG_SYMBOL_NAME_LEN);
+		elist[count].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
+		count++;
+	}
+
+	*events = elist;
+	DBG("Kernel list events done (%zu events)", count);
+end:
+	fclose(fp);	/* closes both fp and fd */
+	return count;
+
+error_fp:
+	close(fd);
+error:
+	return -1;
+}