#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-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;
}
/*
* 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)
{
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);
+}
+
/*
* Destroy a kernel channel object. It does not do anything on the tracer side.
*/
struct consumer_socket *socket;
struct lttng_ht_iter iter;
struct ltt_kernel_metadata *saved_metadata;
+ char *trace_path = NULL;
+ size_t consumer_path_offset = 0;
assert(ksess);
assert(ksess->consumer);
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(output->socks->ht, &iter.iter,
socket, node.node) {
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,
+ &trace_path[consumer_path_offset], wait,
nb_packets_per_stream);
if (status != LTTNG_OK) {
(void) kernel_consumer_destroy_metadata(socket,
/* Snapshot metadata, */
status = consumer_snapshot_channel(socket, ksess->metadata->key, output,
- 1, ksess->uid, ksess->gid,
- DEFAULT_KERNEL_TRACE_DIR, wait, 0);
+ 1, ksess->uid, ksess->gid, &trace_path[consumer_path_offset],
+ wait, 0);
if (status != LTTNG_OK) {
goto error_consumer;
}
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.
*
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