#include <string.h>
#include <unistd.h>
#include <inttypes.h>
+#include <sys/types.h>
#include <common/common.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-sessiond.h"
+#include "lttng-syscall.h"
#include "consumer.h"
#include "kernel.h"
#include "kernel-consumer.h"
#include "kern-modules.h"
#include "utils.h"
#include "rotate.h"
+#include "modprobe.h"
/*
* Key used to reference a channel between the sessiond and the consumer. This
*/
static uint64_t next_kernel_channel_key;
+static const char *module_proc_lttng = "/proc/lttng";
+
+static int kernel_tracer_fd = -1;
+
#include <lttng/userspace-probe.h>
#include <lttng/userspace-probe-internal.h>
/*
* 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 kernel_create_session(struct ltt_session *session)
{
int ret;
struct ltt_kernel_session *lks;
}
/* Kernel tracer session creation */
- ret = kernctl_create_session(tracer_fd);
+ ret = kernctl_create_session(kernel_tracer_fd);
if (ret < 0) {
PERROR("ioctl kernel create session");
goto error;
DBG("Kernel session created (fd: %d)", lks->fd);
+ /*
+ * This is necessary since the creation time is present in the session
+ * name when it is generated.
+ */
+ if (session->has_auto_generated_name) {
+ ret = kernctl_session_set_name(lks->fd, DEFAULT_SESSION_NAME);
+ } else {
+ ret = kernctl_session_set_name(lks->fd, session->name);
+ }
+ if (ret) {
+ WARN("Could not set kernel session name for session %" PRIu64 " name: %s",
+ session->id, session->name);
+ }
+
+ ret = kernctl_session_set_creation_time(lks->fd, session->creation_time);
+ if (ret) {
+ WARN("Could not set kernel session creation time for session %" PRIu64 " name: %s",
+ session->id, session->name);
+ }
+
return 0;
error:
if (lks) {
trace_kernel_destroy_session(lks);
+ trace_kernel_free_session(lks);
}
return ret;
}
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_pid(struct ltt_kernel_session *session, int pid)
+int kernel_track_id(enum lttng_tracker_type tracker_type,
+ struct ltt_kernel_session *session,
+ const struct lttng_tracker_id *id)
{
- int ret;
+ int ret, value;
+ struct lttng_tracker_list *tracker_list;
+ struct lttng_tracker_id **saved_ids;
+ ssize_t saved_ids_count;
- DBG("Kernel track PID %d for session id %" PRIu64 ".",
- pid, session->id);
- ret = kernctl_track_pid(session->fd, pid);
- if (!ret) {
- return LTTNG_OK;
+ ret = lttng_tracker_id_lookup_string(tracker_type, id, &value);
+ if (ret != LTTNG_OK) {
+ return ret;
}
- switch (-ret) {
- case EINVAL:
+
+ tracker_list = get_id_tracker_list(session, tracker_type);
+ if (!tracker_list) {
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;
+ /* 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;
+ }
- DBG("Kernel untrack PID %d for session id %" PRIu64 ".",
- pid, session->id);
- ret = kernctl_untrack_pid(session->fd, pid);
- if (!ret) {
- return LTTNG_OK;
+ /* 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:
- return LTTNG_ERR_INVALID;
+ ret = LTTNG_ERR_INVALID;
+ break;
case ENOMEM:
- return LTTNG_ERR_NOMEM;
- case ENOENT:
- return LTTNG_ERR_PID_NOT_TRACKED;
+ ret = LTTNG_ERR_NOMEM;
+ break;
+ case EEXIST:
+ ret = LTTNG_ERR_ID_TRACKED;
+ break;
default:
- return LTTNG_ERR_UNK;
+ 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:
+ lttng_tracker_ids_destroy(saved_ids, saved_ids_count);
+ free(saved_ids);
+ return ret;
}
-ssize_t kernel_list_tracker_pids(struct ltt_kernel_session *session,
- int **_pids)
+int kernel_untrack_id(enum lttng_tracker_type tracker_type,
+ struct ltt_kernel_session *session,
+ const struct lttng_tracker_id *id)
{
- int fd, ret;
- int pid;
- ssize_t nbmem, count = 0;
- FILE *fp;
- int *pids;
+ int ret, value;
+ struct lttng_tracker_list *tracker_list;
+ struct lttng_tracker_id **saved_ids;
+ ssize_t saved_ids_count;
- fd = kernctl_list_tracker_pids(session->fd);
- if (fd < 0) {
- PERROR("kernel tracker pids list");
- goto error;
+ ret = lttng_tracker_id_lookup_string(tracker_type, id, &value);
+ if (ret != LTTNG_OK) {
+ return ret;
}
- fp = fdopen(fd, "r");
- if (fp == NULL) {
- PERROR("kernel tracker pids list fdopen");
- goto error_fp;
+ tracker_list = get_id_tracker_list(session, tracker_type);
+ if (!tracker_list) {
+ return LTTNG_ERR_INVALID;
}
-
- nbmem = KERNEL_TRACKER_PIDS_INIT_LIST_SIZE;
- pids = zmalloc(sizeof(*pids) * nbmem);
- if (pids == NULL) {
- PERROR("alloc list pids");
- count = -ENOMEM;
+ /* 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;
}
- while (fscanf(fp, "process { pid = %u; };\n", &pid) == 1) {
- if (count >= nbmem) {
- int *new_pids;
- size_t new_nbmem;
-
- new_nbmem = nbmem << 1;
- DBG("Reallocating pids list from %zu to %zu entries",
- nbmem, new_nbmem);
- new_pids = realloc(pids, new_nbmem * sizeof(*new_pids));
- if (new_pids == NULL) {
- PERROR("realloc list events");
- free(pids);
- count = -ENOMEM;
- goto end;
- }
- /* Zero the new memory */
- memset(new_pids + nbmem, 0,
- (new_nbmem - nbmem) * sizeof(*new_pids));
- nbmem = new_nbmem;
- pids = new_pids;
+ 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;
}
- pids[count++] = pid;
+ break;
+ default:
+ ret = -EINVAL;
+ break;
}
- *_pids = pids;
- DBG("Kernel list tracker pids done (%zd pids)", count);
-end:
- ret = fclose(fp); /* closes both fp and fd */
- if (ret) {
- PERROR("fclose");
+ /* 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;
}
- return count;
-error_fp:
- ret = close(fd);
- if (ret) {
- PERROR("close");
+ if (lttng_tracker_id_set_list(tracker_list, saved_ids,
+ saved_ids_count) != LTTNG_OK) {
+ ERR("Error on tracker remove error handling.\n");
}
-error:
- return -1;
+end:
+ lttng_tracker_ids_destroy(saved_ids, saved_ids_count);
+ 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);
}
/*
/*
* Make a kernel wait to make sure in-flight probe have completed.
*/
-void kernel_wait_quiescent(int fd)
+void kernel_wait_quiescent(void)
{
int ret;
+ int fd = kernel_tracer_fd;
DBG("Kernel quiescent wait on %d", fd);
/*
* 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)
+ssize_t kernel_list_events(struct lttng_event **events)
{
int fd, ret;
char *event;
assert(events);
- fd = kernctl_tracepoint_list(tracer_fd);
+ fd = kernctl_tracepoint_list(kernel_tracer_fd);
if (fd < 0) {
PERROR("kernel tracepoint list");
goto error;
/*
* Get kernel version and validate it.
*/
-int kernel_validate_version(int tracer_fd,
- struct lttng_kernel_tracer_version *version,
+int kernel_validate_version(struct lttng_kernel_tracer_version *version,
struct lttng_kernel_tracer_abi_version *abi_version)
{
int ret;
- ret = kernctl_tracer_version(tracer_fd, version);
+ ret = kernctl_tracer_version(kernel_tracer_fd, version);
if (ret < 0) {
ERR("Failed to retrieve the lttng-modules version");
goto error;
version->major, VERSION_MAJOR);
goto error_version;
}
- ret = kernctl_tracer_abi_version(tracer_fd, abi_version);
+ ret = kernctl_tracer_abi_version(kernel_tracer_fd, abi_version);
if (ret < 0) {
ERR("Failed to retrieve lttng-modules ABI version");
goto error;
}
/*
- * Complete teardown of a kernel session.
+ * Teardown of a kernel session, keeping data required by destroy notifiers.
*/
void kernel_destroy_session(struct ltt_kernel_session *ksess)
{
+ struct lttng_trace_chunk *trace_chunk;
+
if (ksess == NULL) {
DBG3("No kernel session when tearing down session");
return;
}
DBG("Tearing down kernel session");
+ trace_chunk = ksess->current_trace_chunk;
/*
* Destroy channels on the consumer if at least one FD has been sent and we
consumer_output_send_destroy_relayd(ksess->consumer);
trace_kernel_destroy_session(ksess);
+ lttng_trace_chunk_put(trace_chunk);
+}
+
+/* Teardown of data required by destroy notifiers. */
+void kernel_free_session(struct ltt_kernel_session *ksess)
+{
+ if (ksess == NULL) {
+ return;
+ }
+ trace_kernel_free_session(ksess);
}
/*
*
* Return LTTNG_OK on success or else return a LTTNG_ERR code.
*/
-enum lttng_error_code kernel_snapshot_record(struct ltt_kernel_session *ksess,
- struct snapshot_output *output, int wait,
+enum lttng_error_code kernel_snapshot_record(
+ struct ltt_kernel_session *ksess,
+ const struct consumer_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;
- struct ltt_session *session;
- uint64_t trace_archive_id;
+ char *trace_path = NULL;
+ size_t consumer_path_offset = 0;
assert(ksess);
assert(ksess->consumer);
DBG("Kernel snapshot record started");
- session = session_find_by_id(ksess->id);
- assert(session);
- assert(pthread_mutex_trylock(&session->lock));
- assert(session_trylock_list());
- trace_archive_id = session->current_archive_id;
-
/* Save current metadata since the following calls will change it. */
saved_metadata = ksess->metadata;
saved_metadata_fd = ksess->metadata_stream_fd;
goto error_open_stream;
}
+ trace_path = setup_channel_trace_path(ksess->consumer,
+ DEFAULT_KERNEL_TRACE_DIR, &consumer_path_offset);
+ if (!trace_path) {
+ status = LTTNG_ERR_INVALID;
+ goto error;
+ }
/* Send metadata to consumer and snapshot everything. */
- cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
+ cds_lfht_for_each_entry(output->socks->ht, &iter.iter,
socket, node.node) {
- struct consumer_output *saved_output;
struct ltt_kernel_channel *chan;
- /*
- * Temporarly switch consumer output for our snapshot output. As long
- * as the session lock is taken, this is safe.
- */
- saved_output = ksess->consumer;
- ksess->consumer = output->consumer;
-
pthread_mutex_lock(socket->lock);
/* This stream must not be monitored by the consumer. */
ret = kernel_consumer_add_metadata(socket, ksess, 0);
pthread_mutex_unlock(socket->lock);
- /* Put back the saved consumer output into the session. */
- ksess->consumer = saved_output;
if (ret < 0) {
- status = LTTNG_ERR_KERN_CONSUMER_FAIL;
+ status = LTTNG_ERR_KERN_META_FAIL;
goto error_consumer;
}
cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
status = consumer_snapshot_channel(socket, chan->key, output, 0,
ksess->uid, ksess->gid,
- DEFAULT_KERNEL_TRACE_DIR, wait,
- nb_packets_per_stream,
- trace_archive_id);
+ &trace_path[consumer_path_offset], wait,
+ nb_packets_per_stream);
if (status != LTTNG_OK) {
(void) kernel_consumer_destroy_metadata(socket,
ksess->metadata);
/* Snapshot metadata, */
status = consumer_snapshot_channel(socket, ksess->metadata->key, output,
- 1, ksess->uid, ksess->gid,
- DEFAULT_KERNEL_TRACE_DIR, wait, 0,
- trace_archive_id);
+ 1, ksess->uid, ksess->gid, &trace_path[consumer_path_offset],
+ wait, 0);
if (status != LTTNG_OK) {
goto error_consumer;
}
/* Restore metadata state.*/
ksess->metadata = saved_metadata;
ksess->metadata_stream_fd = saved_metadata_fd;
-
rcu_read_unlock();
+ free(trace_path);
return status;
}
* Return 1 on success, 0 when feature is not supported, negative value in case
* of errors.
*/
-int kernel_supports_ring_buffer_snapshot_sample_positions(int tracer_fd)
+int kernel_supports_ring_buffer_snapshot_sample_positions(void)
{
int ret = 0; // Not supported by default
struct lttng_kernel_tracer_abi_version abi;
- ret = kernctl_tracer_abi_version(tracer_fd, &abi);
+ ret = kernctl_tracer_abi_version(kernel_tracer_fd, &abi);
if (ret < 0) {
ERR("Failed to retrieve lttng-modules ABI version");
goto error;
return ret;
}
+/*
+ * Check for the support of the packet sequence number via abi version number.
+ *
+ * Return 1 on success, 0 when feature is not supported, negative value in case
+ * of errors.
+ */
+int kernel_supports_ring_buffer_packet_sequence_number(void)
+{
+ int ret = 0; // Not supported by default
+ struct lttng_kernel_tracer_abi_version abi;
+
+ ret = kernctl_tracer_abi_version(kernel_tracer_fd, &abi);
+ if (ret < 0) {
+ ERR("Failed to retrieve lttng-modules ABI version");
+ goto error;
+ }
+
+ /*
+ * Packet sequence number was introduced in LTTng 2.8,
+ * lttng-modules ABI 2.1.
+ */
+ if (abi.major >= 2 && abi.minor >= 1) {
+ /* Supported */
+ ret = 1;
+ } else {
+ /* Not supported */
+ ret = 0;
+ }
+error:
+ return ret;
+}
+
/*
* Rotate a kernel session.
*
socket, node.node) {
struct ltt_kernel_channel *chan;
- /* For each channel, ask the consumer to rotate it. */
+ /* For each channel, ask the consumer to rotate it. */
cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
DBG("Rotate kernel channel %" PRIu64 ", session %s",
chan->key, session->name);
ret = consumer_rotate_channel(socket, chan->key,
ksess->uid, ksess->gid, ksess->consumer,
- ksess->consumer->subdir,
- /* is_metadata_channel */ false,
- session->current_archive_id);
+ /* is_metadata_channel */ false);
if (ret < 0) {
status = LTTNG_ERR_KERN_CONSUMER_FAIL;
goto error;
*/
ret = consumer_rotate_channel(socket, ksess->metadata->key,
ksess->uid, ksess->gid, ksess->consumer,
- ksess->consumer->subdir,
- /* is_metadata_channel */ true,
- session->current_archive_id);
+ /* is_metadata_channel */ true);
if (ret < 0) {
status = LTTNG_ERR_KERN_CONSUMER_FAIL;
goto error;
rcu_read_unlock();
return status;
}
+
+enum lttng_error_code kernel_create_channel_subdirectories(
+ const struct ltt_kernel_session *ksess)
+{
+ enum lttng_error_code ret = LTTNG_OK;
+ enum lttng_trace_chunk_status chunk_status;
+
+ rcu_read_lock();
+ assert(ksess->current_trace_chunk);
+
+ /*
+ * Create the index subdirectory which will take care
+ * of implicitly creating the channel's path.
+ */
+ chunk_status = lttng_trace_chunk_create_subdirectory(
+ ksess->current_trace_chunk,
+ DEFAULT_KERNEL_TRACE_DIR "/" DEFAULT_INDEX_DIR);
+ if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
+ ret = LTTNG_ERR_CREATE_DIR_FAIL;
+ goto error;
+ }
+error:
+ rcu_read_unlock();
+ return ret;
+}
+
+/*
+ * Setup necessary data for kernel tracer action.
+ */
+LTTNG_HIDDEN
+int init_kernel_tracer(void)
+{
+ int ret;
+ bool is_root = !getuid();
+
+ /* Modprobe lttng kernel modules */
+ ret = modprobe_lttng_control();
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* Open debugfs lttng */
+ kernel_tracer_fd = open(module_proc_lttng, O_RDWR);
+ if (kernel_tracer_fd < 0) {
+ DBG("Failed to open %s", module_proc_lttng);
+ goto error_open;
+ }
+
+ /* Validate kernel version */
+ ret = kernel_validate_version(&kernel_tracer_version,
+ &kernel_tracer_abi_version);
+ if (ret < 0) {
+ goto error_version;
+ }
+
+ ret = modprobe_lttng_data();
+ if (ret < 0) {
+ goto error_modules;
+ }
+
+ ret = kernel_supports_ring_buffer_snapshot_sample_positions();
+ 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).");
+ }
+
+ DBG("Kernel tracer fd %d", kernel_tracer_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:
+ modprobe_remove_lttng_control();
+ ret = close(kernel_tracer_fd);
+ if (ret) {
+ PERROR("close");
+ }
+ kernel_tracer_fd = -1;
+ return LTTNG_ERR_KERN_VERSION;
+
+error_modules:
+ ret = close(kernel_tracer_fd);
+ if (ret) {
+ PERROR("close");
+ }
+
+error_open:
+ modprobe_remove_lttng_control();
+
+error:
+ WARN("No kernel tracer available");
+ kernel_tracer_fd = -1;
+ if (!is_root) {
+ return LTTNG_ERR_NEED_ROOT_SESSIOND;
+ } else {
+ return LTTNG_ERR_KERN_NA;
+ }
+}
+
+LTTNG_HIDDEN
+void cleanup_kernel_tracer(void)
+{
+ int ret;
+
+ DBG2("Closing kernel fd");
+ if (kernel_tracer_fd >= 0) {
+ ret = close(kernel_tracer_fd);
+ if (ret) {
+ PERROR("close");
+ }
+ kernel_tracer_fd = -1;
+ }
+ DBG("Unloading kernel modules");
+ modprobe_remove_lttng_all();
+ free(syscall_table);
+}
+
+LTTNG_HIDDEN
+bool kernel_tracer_is_initialized(void)
+{
+ return kernel_tracer_fd >= 0;
+}
+
+/*
+ * Clear a kernel session.
+ *
+ * Return LTTNG_OK on success or else an LTTng error code.
+ */
+enum lttng_error_code kernel_clear_session(struct ltt_session *session)
+{
+ int ret;
+ enum lttng_error_code status = LTTNG_OK;
+ struct consumer_socket *socket;
+ struct lttng_ht_iter iter;
+ struct ltt_kernel_session *ksess = session->kernel_session;
+
+ assert(ksess);
+ assert(ksess->consumer);
+
+ DBG("Clear kernel session %s (session %" PRIu64 ")",
+ session->name, session->id);
+
+ rcu_read_lock();
+
+ if (ksess->active) {
+ ERR("Expecting inactive session %s (%" PRIu64 ")", session->name, session->id);
+ status = LTTNG_ERR_FATAL;
+ goto end;
+ }
+
+ /*
+ * Note that this loop will end after one iteration given that there is
+ * only one kernel consumer.
+ */
+ cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
+ socket, node.node) {
+ struct ltt_kernel_channel *chan;
+
+ /* For each channel, ask the consumer to clear it. */
+ cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
+ DBG("Clear kernel channel %" PRIu64 ", session %s",
+ chan->key, session->name);
+ ret = consumer_clear_channel(socket, chan->key);
+ if (ret < 0) {
+ goto error;
+ }
+ }
+
+ if (!ksess->metadata) {
+ /*
+ * Nothing to do for the metadata.
+ * This is a snapshot session.
+ * The metadata is genererated on the fly.
+ */
+ continue;
+ }
+
+ /*
+ * Clear the metadata channel.
+ * Metadata channel is not cleared per se but we still need to
+ * perform a rotation operation on it behind the scene.
+ */
+ ret = consumer_clear_channel(socket, ksess->metadata->key);
+ if (ret < 0) {
+ goto error;
+ }
+ }
+
+ goto end;
+error:
+ switch (-ret) {
+ case LTTCOMM_CONSUMERD_RELAYD_CLEAR_DISALLOWED:
+ status = LTTNG_ERR_CLEAR_RELAY_DISALLOWED;
+ break;
+ default:
+ status = LTTNG_ERR_CLEAR_FAIL_CONSUMER;
+ break;
+ }
+end:
+ rcu_read_unlock();
+ return status;
+}
projects / lttng-tools.git / blobdiff