/*
- * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
+ * 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, version 2 only,
- * as published by the Free Software Foundation.
+ * SPDX-License-Identifier: GPL-2.0-only
*
- * 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.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#define _LGPL_SOURCE
#include <common/kernel-ctl/kernel-ctl.h>
#include <common/kernel-ctl/kernel-ioctl.h>
#include <common/sessiond-comm/sessiond-comm.h>
+#include <common/tracker.h>
+#include <common/utils.h>
+#include <lttng/event.h>
+#include <lttng/lttng-error.h>
+#include <lttng/tracker.h>
#include "lttng-sessiond.h"
#include "lttng-syscall.h"
#include "utils.h"
#include "rotate.h"
#include "modprobe.h"
+#include "tracker.h"
/*
* Key used to reference a channel between the sessiond and the consumer. This
static
int extract_userspace_probe_offset_function_elf(
const struct lttng_userspace_probe_location *probe_location,
- struct ltt_kernel_session *session, uint64_t *offset)
+ uid_t uid, gid_t gid, uint64_t *offset)
{
int fd;
int ret = 0;
goto end;
}
- ret = run_as_extract_elf_symbol_offset(fd, symbol, session->uid,
- session->gid, offset);
+ ret = run_as_extract_elf_symbol_offset(fd, symbol, uid, gid, offset);
if (ret < 0) {
DBG("userspace probe offset calculation failed for "
"function %s", symbol);
static
int extract_userspace_probe_offset_tracepoint_sdt(
const struct lttng_userspace_probe_location *probe_location,
- struct ltt_kernel_session *session, uint64_t **offsets,
+ uid_t uid, gid_t gid, uint64_t **offsets,
uint32_t *offsets_count)
{
enum lttng_userspace_probe_location_lookup_method_type lookup_method_type;
}
ret = run_as_extract_sdt_probe_offsets(fd, provider_name, probe_name,
- session->uid, session->gid, offsets, offsets_count);
+ uid, gid, offsets, offsets_count);
if (ret < 0) {
DBG("userspace probe offset calculation failed for sdt "
"probe %s:%s", provider_name, probe_name);
return ret;
}
-/*
- * Extract the offsets of the instrumentation point for the different lookup
- * methods.
- */
static
-int userspace_probe_add_callsites(struct lttng_event *ev,
- struct ltt_kernel_session *session, int fd)
+int userspace_probe_add_callsite(
+ const struct lttng_userspace_probe_location *location,
+ uid_t uid, gid_t gid, int fd)
{
const struct lttng_userspace_probe_location_lookup_method *lookup_method = NULL;
enum lttng_userspace_probe_location_lookup_method_type type;
- const struct lttng_userspace_probe_location *location = NULL;
int ret;
- assert(ev);
- assert(ev->type == LTTNG_EVENT_USERSPACE_PROBE);
-
- location = lttng_event_get_userspace_probe_location(ev);
- if (!location) {
- ret = -1;
- goto end;
- }
- lookup_method =
- lttng_userspace_probe_location_get_lookup_method(location);
+ lookup_method = lttng_userspace_probe_location_get_lookup_method(location);
if (!lookup_method) {
ret = -1;
goto end;
struct lttng_kernel_event_callsite callsite;
uint64_t offset;
- ret = extract_userspace_probe_offset_function_elf(location, session, &offset);
+ ret = extract_userspace_probe_offset_function_elf(location,
+ uid, gid, &offset);
if (ret) {
ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
goto end;
callsite.u.uprobe.offset = offset;
ret = kernctl_add_callsite(fd, &callsite);
if (ret) {
- WARN("Adding callsite to userspace probe "
- "event %s failed.", ev->name);
+ WARN("Failed to add callsite to ELF userspace probe.");
ret = LTTNG_ERR_KERN_ENABLE_FAIL;
goto end;
}
* This call allocates the offsets buffer. This buffer must be freed
* by the caller
*/
- ret = extract_userspace_probe_offset_tracepoint_sdt(location, session,
- &offsets, &offsets_count);
+ ret = extract_userspace_probe_offset_tracepoint_sdt(location,
+ uid, gid, &offsets, &offsets_count);
if (ret) {
ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
goto end;
callsite.u.uprobe.offset = offsets[i];
ret = kernctl_add_callsite(fd, &callsite);
if (ret) {
- WARN("Adding callsite to userspace probe "
- "event %s failed.", ev->name);
+ WARN("Failed to add callsite to SDT userspace probe");
ret = LTTNG_ERR_KERN_ENABLE_FAIL;
free(offsets);
goto end;
return ret;
}
+/*
+ * Extract the offsets of the instrumentation point for the different lookup
+ * methods.
+ */
+static
+int userspace_probe_event_add_callsites(struct lttng_event *ev,
+ struct ltt_kernel_session *session, int fd)
+{
+ int ret;
+ const struct lttng_userspace_probe_location *location = NULL;
+
+ assert(ev);
+ assert(ev->type == LTTNG_EVENT_USERSPACE_PROBE);
+
+ location = lttng_event_get_userspace_probe_location(ev);
+ if (!location) {
+ ret = -1;
+ goto end;
+ }
+
+ ret = userspace_probe_add_callsite(location, session->uid, session->gid,
+ fd);
+ if (ret) {
+ WARN("Failed to add callsite to userspace probe event '%s'",
+ ev->name);
+ }
+
+end:
+ return ret;
+}
+
/*
* Create a kernel event, enable it to the kernel tracer and add it to the
* channel event list of the kernel session.
}
if (ev->type == LTTNG_EVENT_USERSPACE_PROBE) {
- ret = userspace_probe_add_callsites(ev, channel->session, event->fd);
+ ret = userspace_probe_event_add_callsites(ev, channel->session,
+ event->fd);
if (ret) {
goto add_callsite_error;
}
return ret;
}
+static
+struct process_attr_tracker *_kernel_get_process_attr_tracker(
+ struct ltt_kernel_session *session,
+ enum lttng_process_attr process_attr)
+{
+ switch (process_attr) {
+ case LTTNG_PROCESS_ATTR_PROCESS_ID:
+ return session->tracker_pid;
+ case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
+ return session->tracker_vpid;
+ case LTTNG_PROCESS_ATTR_USER_ID:
+ return session->tracker_uid;
+ case LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID:
+ return session->tracker_vuid;
+ case LTTNG_PROCESS_ATTR_GROUP_ID:
+ return session->tracker_gid;
+ case LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID:
+ return session->tracker_vgid;
+ default:
+ return NULL;
+ }
+}
+
+const struct process_attr_tracker *kernel_get_process_attr_tracker(
+ struct ltt_kernel_session *session,
+ enum lttng_process_attr process_attr)
+{
+ return (const struct process_attr_tracker *)
+ _kernel_get_process_attr_tracker(session, process_attr);
+}
-int kernel_track_pid(struct ltt_kernel_session *session, int pid)
+enum lttng_error_code kernel_process_attr_tracker_set_tracking_policy(
+ struct ltt_kernel_session *session,
+ enum lttng_process_attr process_attr,
+ enum lttng_tracking_policy policy)
{
int ret;
+ enum lttng_error_code ret_code = LTTNG_OK;
+ struct process_attr_tracker *tracker =
+ _kernel_get_process_attr_tracker(session, process_attr);
+ enum lttng_tracking_policy previous_policy;
- DBG("Kernel track PID %d for session id %" PRIu64 ".",
- pid, session->id);
- ret = kernctl_track_pid(session->fd, pid);
- if (!ret) {
- return LTTNG_OK;
+ if (!tracker) {
+ ret_code = LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ previous_policy = process_attr_tracker_get_tracking_policy(tracker);
+ ret = process_attr_tracker_set_tracking_policy(tracker, policy);
+ if (ret) {
+ ret_code = LTTNG_ERR_UNK;
+ goto end;
}
+
+ if (previous_policy == policy) {
+ goto end;
+ }
+
+ switch (policy) {
+ case LTTNG_TRACKING_POLICY_INCLUDE_ALL:
+ if (process_attr == LTTNG_PROCESS_ATTR_PROCESS_ID) {
+ /*
+ * Maintain a special case for the process ID process
+ * attribute tracker as it was the only supported
+ * attribute prior to 2.12.
+ */
+ ret = kernctl_track_pid(session->fd, -1);
+ } else {
+ ret = kernctl_track_id(session->fd, process_attr, -1);
+ }
+ break;
+ case LTTNG_TRACKING_POLICY_EXCLUDE_ALL:
+ case LTTNG_TRACKING_POLICY_INCLUDE_SET:
+ /* fall-through. */
+ if (process_attr == LTTNG_PROCESS_ATTR_PROCESS_ID) {
+ /*
+ * Maintain a special case for the process ID process
+ * attribute tracker as it was the only supported
+ * attribute prior to 2.12.
+ */
+ ret = kernctl_untrack_pid(session->fd, -1);
+ } else {
+ ret = kernctl_untrack_id(session->fd, process_attr, -1);
+ }
+ break;
+ default:
+ abort();
+ }
+ /* kern-ctl error handling */
switch (-ret) {
+ case 0:
+ ret_code = LTTNG_OK;
+ break;
case EINVAL:
- return LTTNG_ERR_INVALID;
+ ret_code = LTTNG_ERR_INVALID;
+ break;
case ENOMEM:
- return LTTNG_ERR_NOMEM;
+ ret_code = LTTNG_ERR_NOMEM;
+ break;
case EEXIST:
- return LTTNG_ERR_PID_TRACKED;
+ ret_code = LTTNG_ERR_PROCESS_ATTR_EXISTS;
+ break;
default:
- return LTTNG_ERR_UNK;
+ ret_code = LTTNG_ERR_UNK;
+ break;
}
+end:
+ return ret_code;
}
-int kernel_untrack_pid(struct ltt_kernel_session *session, int pid)
+enum lttng_error_code kernel_process_attr_tracker_inclusion_set_add_value(
+ struct ltt_kernel_session *session,
+ enum lttng_process_attr process_attr,
+ const struct process_attr_value *value)
{
- int ret;
+ int ret, integral_value;
+ enum lttng_error_code ret_code;
+ struct process_attr_tracker *tracker;
+ enum process_attr_tracker_status status;
- DBG("Kernel untrack PID %d for session id %" PRIu64 ".",
- pid, session->id);
- ret = kernctl_untrack_pid(session->fd, pid);
- if (!ret) {
- return LTTNG_OK;
+ /*
+ * Convert process attribute tracker value to the integral
+ * representation required by the kern-ctl API.
+ */
+ switch (process_attr) {
+ case LTTNG_PROCESS_ATTR_PROCESS_ID:
+ case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
+ integral_value = (int) value->value.pid;
+ break;
+ case LTTNG_PROCESS_ATTR_USER_ID:
+ case LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID:
+ if (value->type == LTTNG_PROCESS_ATTR_VALUE_TYPE_USER_NAME) {
+ uid_t uid;
+
+ ret_code = utils_user_id_from_name(
+ value->value.user_name, &uid);
+ if (ret_code != LTTNG_OK) {
+ goto end;
+ }
+ integral_value = (int) uid;
+ } else {
+ integral_value = (int) value->value.uid;
+ }
+ break;
+ case LTTNG_PROCESS_ATTR_GROUP_ID:
+ case LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID:
+ if (value->type == LTTNG_PROCESS_ATTR_VALUE_TYPE_GROUP_NAME) {
+ gid_t gid;
+
+ ret_code = utils_group_id_from_name(
+ value->value.group_name, &gid);
+ if (ret_code != LTTNG_OK) {
+ goto end;
+ }
+ integral_value = (int) gid;
+ } else {
+ integral_value = (int) value->value.gid;
+ }
+ break;
+ default:
+ ret_code = LTTNG_ERR_INVALID;
+ goto end;
}
+
+ tracker = _kernel_get_process_attr_tracker(session, process_attr);
+ if (!tracker) {
+ ret_code = LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ status = process_attr_tracker_inclusion_set_add_value(tracker, value);
+ if (status != PROCESS_ATTR_TRACKER_STATUS_OK) {
+ switch (status) {
+ case PROCESS_ATTR_TRACKER_STATUS_EXISTS:
+ ret_code = LTTNG_ERR_PROCESS_ATTR_EXISTS;
+ break;
+ case PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY:
+ ret_code = LTTNG_ERR_PROCESS_ATTR_TRACKER_INVALID_TRACKING_POLICY;
+ break;
+ case PROCESS_ATTR_TRACKER_STATUS_ERROR:
+ default:
+ ret_code = LTTNG_ERR_UNK;
+ break;
+ }
+ goto end;
+ }
+
+ DBG("Kernel track %s %d for session id %" PRIu64,
+ lttng_process_attr_to_string(process_attr),
+ integral_value, session->id);
+ if (process_attr == LTTNG_PROCESS_ATTR_PROCESS_ID) {
+ /*
+ * Maintain a special case for the process ID process attribute
+ * tracker as it was the only supported attribute prior to 2.12.
+ */
+ ret = kernctl_track_pid(session->fd, integral_value);
+ } else {
+ ret = kernctl_track_id(
+ session->fd, process_attr, integral_value);
+ }
+ if (ret == 0) {
+ ret_code = LTTNG_OK;
+ goto end;
+ }
+
+ kernel_wait_quiescent();
+
+ /* kern-ctl error handling */
switch (-ret) {
+ case 0:
+ ret_code = LTTNG_OK;
+ break;
case EINVAL:
- return LTTNG_ERR_INVALID;
+ ret_code = LTTNG_ERR_INVALID;
+ break;
case ENOMEM:
- return LTTNG_ERR_NOMEM;
- case ENOENT:
- return LTTNG_ERR_PID_NOT_TRACKED;
+ ret_code = LTTNG_ERR_NOMEM;
+ break;
+ case EEXIST:
+ ret_code = LTTNG_ERR_PROCESS_ATTR_EXISTS;
+ break;
default:
- return LTTNG_ERR_UNK;
+ ret_code = LTTNG_ERR_UNK;
+ break;
}
+
+ /* Attempt to remove the value from the tracker. */
+ status = process_attr_tracker_inclusion_set_remove_value(
+ tracker, value);
+ if (status != PROCESS_ATTR_TRACKER_STATUS_OK) {
+ ERR("Failed to roll-back the tracking of kernel %s process attribute %d while handling a kern-ctl error",
+ lttng_process_attr_to_string(process_attr),
+ integral_value);
+ }
+end:
+ return ret_code;
}
-ssize_t kernel_list_tracker_pids(struct ltt_kernel_session *session,
- int **_pids)
+enum lttng_error_code kernel_process_attr_tracker_inclusion_set_remove_value(
+ struct ltt_kernel_session *session,
+ enum lttng_process_attr process_attr,
+ const struct process_attr_value *value)
{
- int fd, ret;
- int pid;
- ssize_t nbmem, count = 0;
- FILE *fp;
- int *pids;
+ int ret, integral_value;
+ enum lttng_error_code ret_code;
+ struct process_attr_tracker *tracker;
+ enum process_attr_tracker_status status;
- fd = kernctl_list_tracker_pids(session->fd);
- if (fd < 0) {
- PERROR("kernel tracker pids list");
- goto error;
+ /*
+ * Convert process attribute tracker value to the integral
+ * representation required by the kern-ctl API.
+ */
+ switch (process_attr) {
+ case LTTNG_PROCESS_ATTR_PROCESS_ID:
+ case LTTNG_PROCESS_ATTR_VIRTUAL_PROCESS_ID:
+ integral_value = (int) value->value.pid;
+ break;
+ case LTTNG_PROCESS_ATTR_USER_ID:
+ case LTTNG_PROCESS_ATTR_VIRTUAL_USER_ID:
+ if (value->type == LTTNG_PROCESS_ATTR_VALUE_TYPE_USER_NAME) {
+ uid_t uid;
+
+ ret_code = utils_user_id_from_name(
+ value->value.user_name, &uid);
+ if (ret_code != LTTNG_OK) {
+ goto end;
+ }
+ integral_value = (int) uid;
+ } else {
+ integral_value = (int) value->value.uid;
+ }
+ break;
+ case LTTNG_PROCESS_ATTR_GROUP_ID:
+ case LTTNG_PROCESS_ATTR_VIRTUAL_GROUP_ID:
+ if (value->type == LTTNG_PROCESS_ATTR_VALUE_TYPE_GROUP_NAME) {
+ gid_t gid;
+
+ ret_code = utils_group_id_from_name(
+ value->value.group_name, &gid);
+ if (ret_code != LTTNG_OK) {
+ goto end;
+ }
+ integral_value = (int) gid;
+ } else {
+ integral_value = (int) value->value.gid;
+ }
+ break;
+ default:
+ ret_code = LTTNG_ERR_INVALID;
+ goto end;
}
- fp = fdopen(fd, "r");
- if (fp == NULL) {
- PERROR("kernel tracker pids list fdopen");
- goto error_fp;
+ tracker = _kernel_get_process_attr_tracker(session, process_attr);
+ if (!tracker) {
+ ret_code = LTTNG_ERR_INVALID;
+ goto end;
}
- nbmem = KERNEL_TRACKER_PIDS_INIT_LIST_SIZE;
- pids = zmalloc(sizeof(*pids) * nbmem);
- if (pids == NULL) {
- PERROR("alloc list pids");
- count = -ENOMEM;
+ status = process_attr_tracker_inclusion_set_remove_value(
+ tracker, value);
+ if (status != PROCESS_ATTR_TRACKER_STATUS_OK) {
+ switch (status) {
+ case PROCESS_ATTR_TRACKER_STATUS_MISSING:
+ ret_code = LTTNG_ERR_PROCESS_ATTR_MISSING;
+ break;
+ case PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY:
+ ret_code = LTTNG_ERR_PROCESS_ATTR_TRACKER_INVALID_TRACKING_POLICY;
+ break;
+ case PROCESS_ATTR_TRACKER_STATUS_ERROR:
+ default:
+ ret_code = LTTNG_ERR_UNK;
+ break;
+ }
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;
- }
- pids[count++] = pid;
+ DBG("Kernel track %s %d for session id %" PRIu64,
+ lttng_process_attr_to_string(process_attr),
+ integral_value, session->id);
+ if (process_attr == LTTNG_PROCESS_ATTR_PROCESS_ID) {
+ /*
+ * Maintain a special case for the process ID process attribute
+ * tracker as it was the only supported attribute prior to 2.12.
+ */
+ ret = kernctl_untrack_pid(session->fd, integral_value);
+ } else {
+ ret = kernctl_untrack_id(
+ session->fd, process_attr, integral_value);
+ }
+ if (ret == 0) {
+ ret_code = LTTNG_OK;
+ goto end;
}
+ kernel_wait_quiescent();
- *_pids = pids;
- DBG("Kernel list tracker pids done (%zd pids)", count);
-end:
- ret = fclose(fp); /* closes both fp and fd */
- if (ret) {
- PERROR("fclose");
+ /* kern-ctl error handling */
+ switch (-ret) {
+ case 0:
+ ret_code = LTTNG_OK;
+ break;
+ case EINVAL:
+ ret_code = LTTNG_ERR_INVALID;
+ break;
+ case ENOMEM:
+ ret_code = LTTNG_ERR_NOMEM;
+ break;
+ case ENOENT:
+ ret_code = LTTNG_ERR_PROCESS_ATTR_MISSING;
+ break;
+ default:
+ ret_code = LTTNG_ERR_UNK;
+ break;
}
- return count;
-error_fp:
- ret = close(fd);
- if (ret) {
- PERROR("close");
+ /* Attempt to add the value to the tracker. */
+ status = process_attr_tracker_inclusion_set_add_value(
+ tracker, value);
+ if (status != PROCESS_ATTR_TRACKER_STATUS_OK) {
+ ERR("Failed to roll-back the tracking of kernel %s process attribute %d while handling a kern-ctl error",
+ lttng_process_attr_to_string(process_attr),
+ integral_value);
}
-error:
- return -1;
+end:
+ return ret_code;
}
/*
return kernctl_syscall_mask(chan_fd, syscall_mask, nr_bits);
}
-/*
- * Check for the support of the RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS 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_snapshot_sample_positions(void)
+static
+int kernel_tracer_abi_greater_or_equal(unsigned int major, unsigned int minor)
{
- int ret = 0; // Not supported by default
+ int ret;
struct lttng_kernel_tracer_abi_version abi;
ret = kernctl_tracer_abi_version(kernel_tracer_fd, &abi);
goto error;
}
+ ret = abi.major > major || (abi.major == major && abi.minor >= minor);
+error:
+ return ret;
+}
+
+/*
+ * Check for the support of the RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS 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_snapshot_sample_positions(void)
+{
/*
* RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS was introduced in 2.3
*/
- if (abi.major >= 2 && abi.minor >= 3) {
- /* Supported */
- ret = 1;
- } else {
- /* Not supported */
- ret = 0;
- }
-error:
- return ret;
+ return kernel_tracer_abi_greater_or_equal(2, 3);
}
/*
*/
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.
+ */
+ return kernel_tracer_abi_greater_or_equal(2, 1);
+}
+/*
+ * Check for the support of event notifiers via abi version number.
+ *
+ * Return 1 on success, 0 when feature is not supported, negative value in case
+ * of errors.
+ */
+int kernel_supports_event_notifiers(void)
+{
/*
- * Packet sequence number was introduced in 2.8
+ * Event notifiers were introduced in LTTng 2.13, lttng-modules ABI 2.6.
*/
- if (abi.major >= 2 && abi.minor >= 8) {
- /* Supported */
- ret = 1;
- } else {
- /* Not supported */
- ret = 0;
- }
-error:
- return ret;
+ return kernel_tracer_abi_greater_or_equal(2, 6);
}
/*
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);
ksess->uid, ksess->gid, ksess->consumer,
/* is_metadata_channel */ false);
if (ret < 0) {
- status = LTTNG_ERR_KERN_CONSUMER_FAIL;
+ status = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
goto error;
}
}
ksess->uid, ksess->gid, ksess->consumer,
/* is_metadata_channel */ true);
if (ret < 0) {
- status = LTTNG_ERR_KERN_CONSUMER_FAIL;
+ status = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
goto error;
}
}
{
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;
+}