+++ /dev/null
-/*
- * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
- *
- * SPDX-License-Identifier: GPL-2.0-only
- *
- */
-
-#define _LGPL_SOURCE
-#include <fcntl.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#include <unistd.h>
-#include <inttypes.h>
-#include <sys/types.h>
-
-#include <common/common.h>
-#include <common/hashtable/utils.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 <common/tracker.h>
-#include <common/utils.h>
-#include <lttng/event.h>
-#include <lttng/lttng-error.h>
-#include <lttng/tracker.h>
-
-#include <lttng/userspace-probe.h>
-#include <lttng/userspace-probe-internal.h>
-#include <lttng/condition/event-rule-matches.h>
-#include <lttng/condition/event-rule-matches-internal.h>
-#include <lttng/event-rule/event-rule.h>
-#include <lttng/event-rule/event-rule-internal.h>
-#include <lttng/event-rule/kernel-uprobe-internal.h>
-
-#include "event-notifier-error-accounting.h"
-#include "lttng-sessiond.h"
-#include "lttng-syscall.h"
-#include "condition-internal.h"
-#include "consumer.h"
-#include "kernel.h"
-#include "kernel-consumer.h"
-#include "kern-modules.h"
-#include "sessiond-config.h"
-#include "utils.h"
-#include "rotate.h"
-#include "modprobe.h"
-#include "tracker.h"
-#include "notification-thread-commands.h"
-
-/*
- * Key used to reference a channel between the sessiond and the consumer. This
- * is only read and updated with the session_list lock held.
- */
-static uint64_t next_kernel_channel_key;
-
-static const char *module_proc_lttng = "/proc/lttng";
-
-static int kernel_tracer_fd = -1;
-static int kernel_tracer_event_notifier_group_fd = -1;
-static int kernel_tracer_event_notifier_group_notification_fd = -1;
-static struct cds_lfht *kernel_token_to_event_notifier_rule_ht;
-
-/*
- * Add context on a kernel channel.
- *
- * Assumes the ownership of ctx.
- */
-int kernel_add_channel_context(struct ltt_kernel_channel *chan,
- struct ltt_kernel_context *ctx)
-{
- int ret;
-
- LTTNG_ASSERT(chan);
- LTTNG_ASSERT(ctx);
-
- DBG("Adding context to channel %s", chan->channel->name);
- ret = kernctl_add_context(chan->fd, &ctx->ctx);
- if (ret < 0) {
- 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;
- }
- }
- ret = 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;
-}
-
-/*
- * 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 ret;
- struct ltt_kernel_session *lks;
-
- LTTNG_ASSERT(session);
-
- /* Allocate data structure */
- lks = trace_kernel_create_session();
- if (lks == NULL) {
- ret = -1;
- goto error;
- }
-
- /* Kernel tracer session creation */
- ret = kernctl_create_session(kernel_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->id = session->id;
- lks->consumer_fds_sent = 0;
- session->kernel_session = lks;
-
- 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;
-}
-
-/*
- * 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)
-{
- int ret;
- struct ltt_kernel_channel *lkc;
-
- LTTNG_ASSERT(session);
- LTTNG_ASSERT(chan);
-
- /* Allocate kernel channel */
- lkc = trace_kernel_create_channel(chan);
- if (lkc == NULL) {
- goto error;
- }
-
- DBG3("Kernel create channel %s with attr: %d, %" PRIu64 ", %" PRIu64 ", %u, %u, %d, %d",
- chan->name, lkc->channel->attr.overwrite,
- lkc->channel->attr.subbuf_size, lkc->channel->attr.num_subbuf,
- lkc->channel->attr.switch_timer_interval, lkc->channel->attr.read_timer_interval,
- lkc->channel->attr.live_timer_interval, lkc->channel->attr.output);
-
- /* 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++;
- lkc->session = session;
- lkc->key = ++next_kernel_channel_key;
-
- DBG("Kernel channel %s created (fd: %d, key: %" PRIu64 ")",
- lkc->channel->name, lkc->fd, lkc->key);
-
- return 0;
-
-error:
- if (lkc) {
- free(lkc->channel);
- free(lkc);
- }
- return -1;
-}
-
-/*
- * Create a kernel event notifier group, register it to the kernel tracer and
- * add it to the kernel session.
- */
-static int kernel_create_event_notifier_group(int *event_notifier_group_fd)
-{
- int ret;
- int local_fd = -1;
-
- LTTNG_ASSERT(event_notifier_group_fd);
-
- /* Kernel event notifier group creation. */
- ret = kernctl_create_event_notifier_group(kernel_tracer_fd);
- if (ret < 0) {
- PERROR("Failed to create kernel event notifier group");
- ret = -1;
- goto error;
- }
-
- local_fd = ret;
-
- /* Prevent fd duplication after execlp(). */
- ret = fcntl(local_fd, F_SETFD, FD_CLOEXEC);
- if (ret < 0) {
- PERROR("Failed to set FD_CLOEXEC on kernel event notifier group file descriptor: fd = %d",
- local_fd);
- goto error;
- }
-
- DBG("Created kernel event notifier group: fd = %d", local_fd);
- *event_notifier_group_fd = local_fd;
- local_fd = -1;
- ret = 0;
-error:
- if (local_fd >= 0) {
- ret = close(local_fd);
- if (ret) {
- PERROR("Failed to close kernel event notifier group file descriptor: fd = %d",
- local_fd);
- }
- }
-
- return ret;
-}
-
-/*
- * Compute the offset of the instrumentation byte in the binary based on the
- * function probe location using the ELF lookup method.
- *
- * Returns 0 on success and set the offset out parameter to the offset of the
- * elf symbol
- * Returns -1 on error
- */
-static
-int extract_userspace_probe_offset_function_elf(
- const struct lttng_userspace_probe_location *probe_location,
- uid_t uid, gid_t gid, uint64_t *offset)
-{
- int fd;
- int ret = 0;
- const char *symbol = NULL;
- const struct lttng_userspace_probe_location_lookup_method *lookup = NULL;
- enum lttng_userspace_probe_location_lookup_method_type lookup_method_type;
-
- LTTNG_ASSERT(lttng_userspace_probe_location_get_type(probe_location) ==
- LTTNG_USERSPACE_PROBE_LOCATION_TYPE_FUNCTION);
-
- lookup = lttng_userspace_probe_location_get_lookup_method(
- probe_location);
- if (!lookup) {
- ret = -1;
- goto end;
- }
-
- lookup_method_type =
- lttng_userspace_probe_location_lookup_method_get_type(lookup);
-
- LTTNG_ASSERT(lookup_method_type ==
- LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF);
-
- symbol = lttng_userspace_probe_location_function_get_function_name(
- probe_location);
- if (!symbol) {
- ret = -1;
- goto end;
- }
-
- fd = lttng_userspace_probe_location_function_get_binary_fd(probe_location);
- if (fd < 0) {
- ret = -1;
- goto end;
- }
-
- 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);
- goto end;
- }
-
- DBG("userspace probe elf offset for %s is 0x%jd", symbol, (intmax_t)(*offset));
-end:
- return ret;
-}
-
-/*
- * Compute the offsets of the instrumentation bytes in the binary based on the
- * tracepoint probe location using the SDT lookup method. This function
- * allocates the offsets buffer, the caller must free it.
- *
- * Returns 0 on success and set the offset out parameter to the offsets of the
- * SDT tracepoint.
- * Returns -1 on error.
- */
-static
-int extract_userspace_probe_offset_tracepoint_sdt(
- const struct lttng_userspace_probe_location *probe_location,
- uid_t uid, gid_t gid, uint64_t **offsets,
- uint32_t *offsets_count)
-{
- enum lttng_userspace_probe_location_lookup_method_type lookup_method_type;
- const struct lttng_userspace_probe_location_lookup_method *lookup = NULL;
- const char *probe_name = NULL, *provider_name = NULL;
- int ret = 0;
- int fd, i;
-
- LTTNG_ASSERT(lttng_userspace_probe_location_get_type(probe_location) ==
- LTTNG_USERSPACE_PROBE_LOCATION_TYPE_TRACEPOINT);
-
- lookup = lttng_userspace_probe_location_get_lookup_method(probe_location);
- if (!lookup) {
- ret = -1;
- goto end;
- }
-
- lookup_method_type =
- lttng_userspace_probe_location_lookup_method_get_type(lookup);
-
- LTTNG_ASSERT(lookup_method_type ==
- LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT);
-
-
- probe_name = lttng_userspace_probe_location_tracepoint_get_probe_name(
- probe_location);
- if (!probe_name) {
- ret = -1;
- goto end;
- }
-
- provider_name = lttng_userspace_probe_location_tracepoint_get_provider_name(
- probe_location);
- if (!provider_name) {
- ret = -1;
- goto end;
- }
-
- fd = lttng_userspace_probe_location_tracepoint_get_binary_fd(probe_location);
- if (fd < 0) {
- ret = -1;
- goto end;
- }
-
- ret = run_as_extract_sdt_probe_offsets(fd, provider_name, probe_name,
- uid, gid, offsets, offsets_count);
- if (ret < 0) {
- DBG("userspace probe offset calculation failed for sdt "
- "probe %s:%s", provider_name, probe_name);
- goto end;
- }
-
- if (*offsets_count == 0) {
- DBG("no userspace probe offset found");
- goto end;
- }
-
- DBG("%u userspace probe SDT offsets found for %s:%s at:",
- *offsets_count, provider_name, probe_name);
- for (i = 0; i < *offsets_count; i++) {
- DBG("\t0x%jd", (intmax_t)((*offsets)[i]));
- }
-end:
- return ret;
-}
-
-static
-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;
- int ret;
-
- lookup_method = lttng_userspace_probe_location_get_lookup_method(location);
- if (!lookup_method) {
- ret = -1;
- goto end;
- }
-
- type = lttng_userspace_probe_location_lookup_method_get_type(lookup_method);
- switch (type) {
- case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF:
- {
- struct lttng_kernel_abi_event_callsite callsite;
- uint64_t 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("Failed to add callsite to ELF userspace probe.");
- ret = LTTNG_ERR_KERN_ENABLE_FAIL;
- goto end;
- }
- break;
- }
- case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT:
- {
- int i;
- uint64_t *offsets = NULL;
- uint32_t offsets_count;
- struct lttng_kernel_abi_event_callsite callsite;
-
- /*
- * This call allocates the offsets buffer. This buffer must be freed
- * by the caller
- */
- ret = extract_userspace_probe_offset_tracepoint_sdt(location,
- uid, gid, &offsets, &offsets_count);
- if (ret) {
- ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
- goto end;
- }
- for (i = 0; i < offsets_count; i++) {
- callsite.u.uprobe.offset = offsets[i];
- ret = kernctl_add_callsite(fd, &callsite);
- if (ret) {
- WARN("Failed to add callsite to SDT userspace probe");
- ret = LTTNG_ERR_KERN_ENABLE_FAIL;
- free(offsets);
- goto end;
- }
- }
- free(offsets);
- break;
- }
- default:
- ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
- goto end;
- }
-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;
-
- LTTNG_ASSERT(ev);
- LTTNG_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;
-}
-
-/*
- * Extract the offsets of the instrumentation point for the different look-up
- * methods.
- */
-static int userspace_probe_event_rule_add_callsites(
- const struct lttng_event_rule *rule,
- const struct lttng_credentials *creds,
- int fd)
-{
- int ret;
- enum lttng_event_rule_status status;
- enum lttng_event_rule_type event_rule_type;
- const struct lttng_userspace_probe_location *location = NULL;
-
- LTTNG_ASSERT(rule);
- LTTNG_ASSERT(creds);
-
- event_rule_type = lttng_event_rule_get_type(rule);
- LTTNG_ASSERT(event_rule_type == LTTNG_EVENT_RULE_TYPE_KERNEL_UPROBE);
-
- status = lttng_event_rule_kernel_uprobe_get_location(rule, &location);
- if (status != LTTNG_EVENT_RULE_STATUS_OK || !location) {
- ret = -1;
- goto end;
- }
-
- ret = userspace_probe_add_callsite(location,
- lttng_credentials_get_uid(creds),
- lttng_credentials_get_gid(creds), fd);
- if (ret) {
- WARN("Failed to add callsite to user space probe object: fd = %d",
- fd);
- }
-
-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.
- * We own filter_expression and filter.
- */
-int kernel_create_event(struct lttng_event *ev,
- struct ltt_kernel_channel *channel,
- char *filter_expression,
- struct lttng_bytecode *filter)
-{
- int err, fd;
- enum lttng_error_code ret;
- struct ltt_kernel_event *event;
-
- LTTNG_ASSERT(ev);
- LTTNG_ASSERT(channel);
-
- /* We pass ownership of filter_expression and filter */
- ret = trace_kernel_create_event(ev, filter_expression,
- filter, &event);
- if (ret != LTTNG_OK) {
- goto error;
- }
-
- fd = kernctl_create_event(channel->fd, event->event);
- if (fd < 0) {
- switch (-fd) {
- case EEXIST:
- ret = LTTNG_ERR_KERN_EVENT_EXIST;
- break;
- case ENOSYS:
- WARN("Event type not implemented");
- ret = LTTNG_ERR_KERN_EVENT_ENOSYS;
- break;
- case ENOENT:
- WARN("Event %s not found!", ev->name);
- ret = LTTNG_ERR_KERN_ENABLE_FAIL;
- break;
- default:
- ret = LTTNG_ERR_KERN_ENABLE_FAIL;
- PERROR("create event ioctl");
- }
- goto free_event;
- }
-
- event->type = ev->type;
- event->fd = fd;
- /* Prevent fd duplication after execlp() */
- err = fcntl(event->fd, F_SETFD, FD_CLOEXEC);
- if (err < 0) {
- PERROR("fcntl session fd");
- }
-
- if (filter) {
- err = kernctl_filter(event->fd, filter);
- if (err < 0) {
- switch (-err) {
- case ENOMEM:
- ret = LTTNG_ERR_FILTER_NOMEM;
- break;
- default:
- ret = LTTNG_ERR_FILTER_INVAL;
- break;
- }
- goto filter_error;
- }
- }
-
- if (ev->type == LTTNG_EVENT_USERSPACE_PROBE) {
- ret = userspace_probe_event_add_callsites(ev, channel->session,
- event->fd);
- if (ret) {
- goto add_callsite_error;
- }
- }
-
- err = kernctl_enable(event->fd);
- if (err < 0) {
- switch (-err) {
- case EEXIST:
- ret = LTTNG_ERR_KERN_EVENT_EXIST;
- break;
- default:
- PERROR("enable kernel event");
- ret = LTTNG_ERR_KERN_ENABLE_FAIL;
- break;
- }
- goto enable_error;
- }
-
- /* 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);
-
- return 0;
-
-add_callsite_error:
-enable_error:
-filter_error:
- {
- int closeret;
-
- closeret = close(event->fd);
- if (closeret) {
- PERROR("close event fd");
- }
- }
-free_event:
- free(event);
-error:
- return ret;
-}
-
-/*
- * Disable a kernel channel.
- */
-int kernel_disable_channel(struct ltt_kernel_channel *chan)
-{
- int ret;
-
- LTTNG_ASSERT(chan);
-
- ret = kernctl_disable(chan->fd);
- if (ret < 0) {
- PERROR("disable chan ioctl");
- goto error;
- }
-
- chan->enabled = 0;
- DBG("Kernel channel %s disabled (fd: %d, key: %" PRIu64 ")",
- chan->channel->name, chan->fd, chan->key);
-
- return 0;
-
-error:
- return ret;
-}
-
-/*
- * Enable a kernel channel.
- */
-int kernel_enable_channel(struct ltt_kernel_channel *chan)
-{
- int ret;
-
- LTTNG_ASSERT(chan);
-
- ret = kernctl_enable(chan->fd);
- if (ret < 0 && ret != -EEXIST) {
- PERROR("Enable kernel chan");
- goto error;
- }
-
- chan->enabled = 1;
- DBG("Kernel channel %s enabled (fd: %d, key: %" PRIu64 ")",
- chan->channel->name, chan->fd, chan->key);
-
- return 0;
-
-error:
- return ret;
-}
-
-/*
- * Enable a kernel event.
- */
-int kernel_enable_event(struct ltt_kernel_event *event)
-{
- int ret;
-
- LTTNG_ASSERT(event);
-
- 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 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;
-
- LTTNG_ASSERT(event);
-
- ret = kernctl_disable(event->fd);
- if (ret < 0) {
- PERROR("Failed to disable kernel event: name = '%s', fd = %d",
- event->event->name, event->fd);
- goto error;
- }
-
- event->enabled = 0;
- DBG("Kernel event %s disabled (fd: %d)", event->event->name, event->fd);
-
- return 0;
-
-error:
- return ret;
-}
-
-/*
- * Disable a kernel event notifier.
- */
-static
-int kernel_disable_event_notifier_rule(struct ltt_kernel_event_notifier_rule *event)
-{
- int ret;
-
- LTTNG_ASSERT(event);
-
- rcu_read_lock();
- cds_lfht_del(kernel_token_to_event_notifier_rule_ht, &event->ht_node);
- rcu_read_unlock();
-
- ret = kernctl_disable(event->fd);
- if (ret < 0) {
- PERROR("Failed to disable kernel event notifier: fd = %d, token = %" PRIu64,
- event->fd, event->token);
- goto error;
- }
-
- event->enabled = 0;
- DBG("Disabled kernel event notifier: fd = %d, token = %" PRIu64,
- event->fd, event->token);
-
-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);
-}
-
-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;
-
- 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:
- ret_code = LTTNG_ERR_INVALID;
- break;
- case ENOMEM:
- ret_code = LTTNG_ERR_NOMEM;
- break;
- case EEXIST:
- ret_code = LTTNG_ERR_PROCESS_ATTR_EXISTS;
- break;
- default:
- ret_code = LTTNG_ERR_UNK;
- break;
- }
-end:
- return ret_code;
-}
-
-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, integral_value;
- enum lttng_error_code ret_code;
- struct process_attr_tracker *tracker;
- enum process_attr_tracker_status status;
-
- /*
- * 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:
- ret_code = LTTNG_ERR_INVALID;
- break;
- case ENOMEM:
- ret_code = LTTNG_ERR_NOMEM;
- break;
- case EEXIST:
- ret_code = LTTNG_ERR_PROCESS_ATTR_EXISTS;
- break;
- default:
- 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;
-}
-
-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 ret, integral_value;
- enum lttng_error_code ret_code;
- struct process_attr_tracker *tracker;
- enum process_attr_tracker_status status;
-
- /*
- * 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_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;
- }
-
- 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();
-
- /* 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;
- }
-
- /* 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);
- }
-end:
- return ret_code;
-}
-
-/*
- * Create kernel metadata, open from the kernel tracer and add it to the
- * kernel session.
- */
-int kernel_open_metadata(struct ltt_kernel_session *session)
-{
- int ret;
- struct ltt_kernel_metadata *lkm = NULL;
-
- LTTNG_ASSERT(session);
-
- /* Allocate kernel metadata */
- lkm = trace_kernel_create_metadata();
- if (lkm == NULL) {
- goto error;
- }
-
- /* Kernel tracer metadata creation */
- ret = kernctl_open_metadata(session->fd, &lkm->conf->attr);
- if (ret < 0) {
- goto error_open;
- }
-
- lkm->fd = ret;
- lkm->key = ++next_kernel_channel_key;
- /* 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)", lkm->fd);
-
- return 0;
-
-error_open:
- trace_kernel_destroy_metadata(lkm);
-error:
- return -1;
-}
-
-/*
- * Start tracing session.
- */
-int kernel_start_session(struct ltt_kernel_session *session)
-{
- int ret;
-
- LTTNG_ASSERT(session);
-
- 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(void)
-{
- int ret;
- int fd = kernel_tracer_fd;
-
- DBG("Kernel quiescent wait on %d", fd);
-
- ret = kernctl_wait_quiescent(fd);
- if (ret < 0) {
- PERROR("wait quiescent ioctl");
- ERR("Kernel quiescent wait failed");
- }
-}
-
-/*
- * Force flush buffer of metadata.
- */
-int kernel_metadata_flush_buffer(int fd)
-{
- int ret;
-
- DBG("Kernel flushing metadata buffer on fd %d", fd);
-
- 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;
-
- LTTNG_ASSERT(channel);
-
- 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;
-
- LTTNG_ASSERT(session);
-
- 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.
- *
- * 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;
- struct ltt_kernel_stream *lks;
-
- LTTNG_ASSERT(channel);
-
- while ((ret = kernctl_create_stream(channel->fd)) >= 0) {
- lks = trace_kernel_create_stream(channel->channel->name,
- channel->stream_count);
- if (lks == NULL) {
- ret = close(ret);
- if (ret) {
- PERROR("close");
- }
- 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->tracefile_size = channel->channel->attr.tracefile_size;
- lks->tracefile_count = channel->channel->attr.tracefile_count;
-
- /* Add stream to channel stream list */
- cds_list_add(&lks->list, &channel->stream_list.head);
- channel->stream_count++;
-
- DBG("Kernel stream %s created (fd: %d, state: %d)", lks->name, lks->fd,
- lks->state);
- }
-
- 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;
-
- LTTNG_ASSERT(session);
-
- 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(struct lttng_event **events)
-{
- int fd, ret;
- char *event;
- size_t nbmem, count = 0;
- FILE *fp;
- struct lttng_event *elist;
-
- LTTNG_ASSERT(events);
-
- fd = kernctl_tracepoint_list(kernel_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_INIT_LIST_SIZE;
- elist = zmalloc(sizeof(struct lttng_event) * nbmem);
- if (elist == NULL) {
- PERROR("alloc list events");
- count = -ENOMEM;
- goto end;
- }
-
- while (fscanf(fp, "event { name = %m[^;]; };\n", &event) == 1) {
- if (count >= nbmem) {
- struct lttng_event *new_elist;
- size_t new_nbmem;
-
- new_nbmem = nbmem << 1;
- DBG("Reallocating event list from %zu to %zu bytes",
- nbmem, new_nbmem);
- new_elist = realloc(elist, new_nbmem * sizeof(struct lttng_event));
- if (new_elist == NULL) {
- PERROR("realloc list events");
- free(event);
- free(elist);
- count = -ENOMEM;
- goto end;
- }
- /* Zero the new memory */
- memset(new_elist + nbmem, 0,
- (new_nbmem - nbmem) * sizeof(struct lttng_event));
- nbmem = new_nbmem;
- elist = new_elist;
- }
- strncpy(elist[count].name, event, LTTNG_SYMBOL_NAME_LEN);
- elist[count].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
- elist[count].enabled = -1;
- count++;
- free(event);
- }
-
- *events = elist;
- DBG("Kernel list events done (%zu events)", count);
-end:
- ret = fclose(fp); /* closes both fp and fd */
- if (ret) {
- PERROR("fclose");
- }
- return count;
-
-error_fp:
- ret = close(fd);
- if (ret) {
- PERROR("close");
- }
-error:
- return -1;
-}
-
-/*
- * Get kernel version and validate it.
- */
-int kernel_validate_version(struct lttng_kernel_abi_tracer_version *version,
- struct lttng_kernel_abi_tracer_abi_version *abi_version)
-{
- int ret;
-
- ret = kernctl_tracer_version(kernel_tracer_fd, version);
- if (ret < 0) {
- ERR("Failed to retrieve the lttng-modules version");
- goto error;
- }
-
- /* Validate version */
- 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;
- }
- ret = kernctl_tracer_abi_version(kernel_tracer_fd, abi_version);
- if (ret < 0) {
- ERR("Failed to retrieve lttng-modules ABI version");
- goto error;
- }
- if (abi_version->major != LTTNG_KERNEL_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_KERNEL_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:
- ret = -1;
-
-error:
- ERR("Kernel tracer version check failed; kernel tracing will not be available");
- return ret;
-}
-
-/*
- * Kernel work-arounds called at the start of sessiond main().
- */
-int init_kernel_workarounds(void)
-{
- int ret;
- FILE *fp;
-
- /*
- * boot_id needs to be read once before being used concurrently
- * to deal with a Linux kernel race. A fix is proposed for
- * upstream, but the work-around is needed for older kernels.
- */
- fp = fopen("/proc/sys/kernel/random/boot_id", "r");
- if (!fp) {
- goto end_boot_id;
- }
- while (!feof(fp)) {
- char buf[37] = "";
-
- ret = fread(buf, 1, sizeof(buf), fp);
- if (ret < 0) {
- /* Ignore error, we don't really care */
- }
- }
- ret = fclose(fp);
- if (ret) {
- PERROR("fclose");
- }
-end_boot_id:
- return 0;
-}
-
-/*
- * 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
- * are in no output mode because the streams are in *no* monitor mode so we
- * have to send a command to clean them up or else they leaked.
- */
- if (!ksess->output_traces && ksess->consumer_fds_sent) {
- int ret;
- struct consumer_socket *socket;
- 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;
-
- /* For each channel, ask the consumer to destroy it. */
- cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
- ret = kernel_consumer_destroy_channel(socket, chan);
- if (ret < 0) {
- /* Consumer is probably dead. Use next socket. */
- continue;
- }
- }
- }
- rcu_read_unlock();
- }
-
- /* Close any relayd session */
- 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);
-}
-
-/*
- * Destroy a kernel channel object. It does not do anything on the tracer side.
- */
-void kernel_destroy_channel(struct ltt_kernel_channel *kchan)
-{
- struct ltt_kernel_session *ksess = NULL;
-
- LTTNG_ASSERT(kchan);
- LTTNG_ASSERT(kchan->channel);
-
- DBG3("Kernel destroy channel %s", kchan->channel->name);
-
- /* Update channel count of associated session. */
- if (kchan->session) {
- /* Keep pointer reference so we can update it after the destroy. */
- ksess = kchan->session;
- }
-
- trace_kernel_destroy_channel(kchan);
-
- /*
- * At this point the kernel channel is not visible anymore. This is safe
- * since in order to work on a visible kernel session, the tracing session
- * lock (ltt_session.lock) MUST be acquired.
- */
- if (ksess) {
- ksess->channel_count--;
- }
-}
-
-/*
- * Take a snapshot for a given kernel session.
- *
- * Return LTTNG_OK on success or else return a LTTNG_ERR code.
- */
-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;
- enum lttng_error_code status = LTTNG_OK;
- 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;
-
- LTTNG_ASSERT(ksess);
- LTTNG_ASSERT(ksess->consumer);
- LTTNG_ASSERT(output);
-
- DBG("Kernel snapshot record started");
-
- /* Save current metadata since the following calls will change it. */
- saved_metadata = ksess->metadata;
- saved_metadata_fd = ksess->metadata_stream_fd;
-
- rcu_read_lock();
-
- ret = kernel_open_metadata(ksess);
- if (ret < 0) {
- status = LTTNG_ERR_KERN_META_FAIL;
- goto error;
- }
-
- ret = kernel_open_metadata_stream(ksess);
- if (ret < 0) {
- status = LTTNG_ERR_KERN_META_FAIL;
- goto error_open_stream;
- }
-
- trace_path = setup_channel_trace_path(ksess->consumer,
- "", &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) {
- struct ltt_kernel_channel *chan;
-
- 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);
- if (ret < 0) {
- status = LTTNG_ERR_KERN_META_FAIL;
- goto error_consumer;
- }
-
- /* For each channel, ask the consumer to snapshot it. */
- cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
- status = consumer_snapshot_channel(socket, chan->key, output, 0,
- ksess->uid, ksess->gid,
- &trace_path[consumer_path_offset], wait,
- nb_packets_per_stream);
- if (status != LTTNG_OK) {
- (void) kernel_consumer_destroy_metadata(socket,
- ksess->metadata);
- goto error_consumer;
- }
- }
-
- /* Snapshot metadata, */
- status = consumer_snapshot_channel(socket, ksess->metadata->key, output,
- 1, ksess->uid, ksess->gid, &trace_path[consumer_path_offset],
- wait, 0);
- if (status != LTTNG_OK) {
- goto error_consumer;
- }
-
- /*
- * The metadata snapshot is done, ask the consumer to destroy it since
- * it's not monitored on the consumer side.
- */
- (void) kernel_consumer_destroy_metadata(socket, ksess->metadata);
- }
-
-error_consumer:
- /* Close newly opened metadata stream. It's now on the consumer side. */
- err = close(ksess->metadata_stream_fd);
- if (err < 0) {
- PERROR("close snapshot kernel");
- }
-
-error_open_stream:
- trace_kernel_destroy_metadata(ksess->metadata);
-error:
- /* Restore metadata state.*/
- ksess->metadata = saved_metadata;
- ksess->metadata_stream_fd = saved_metadata_fd;
- rcu_read_unlock();
- free(trace_path);
- return status;
-}
-
-/*
- * 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)
-{
- LTTNG_ASSERT(syscall_mask);
- LTTNG_ASSERT(nr_bits);
-
- return kernctl_syscall_mask(chan_fd, syscall_mask, nr_bits);
-}
-
-static
-int kernel_tracer_abi_greater_or_equal(unsigned int major, unsigned int minor)
-{
- int ret;
- struct lttng_kernel_abi_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;
- }
-
- 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
- */
- return kernel_tracer_abi_greater_or_equal(2, 3);
-}
-
-/*
- * 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)
-{
- /*
- * 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)
-{
- /*
- * Event notifiers were introduced in LTTng 2.13, lttng-modules ABI 2.6.
- */
- return kernel_tracer_abi_greater_or_equal(2, 6);
-}
-
-/*
- * Rotate a kernel session.
- *
- * Return LTTNG_OK on success or else an LTTng error code.
- */
-enum lttng_error_code kernel_rotate_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;
-
- LTTNG_ASSERT(ksess);
- LTTNG_ASSERT(ksess->consumer);
-
- DBG("Rotate kernel session %s started (session %" PRIu64 ")",
- session->name, session->id);
-
- rcu_read_lock();
-
- /*
- * 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 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,
- /* is_metadata_channel */ false);
- if (ret < 0) {
- status = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
- goto error;
- }
- }
-
- /*
- * Rotate the metadata channel.
- */
- ret = consumer_rotate_channel(socket, ksess->metadata->key,
- ksess->uid, ksess->gid, ksess->consumer,
- /* is_metadata_channel */ true);
- if (ret < 0) {
- status = LTTNG_ERR_ROTATION_FAIL_CONSUMER;
- goto error;
- }
- }
-
-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();
- LTTNG_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.
- */
-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(&the_kernel_tracer_version,
- &the_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).");
- }
-
- ret = kernel_supports_event_notifiers();
- if (ret < 0) {
- ERR("Failed to check for kernel tracer event notifier support");
- goto error_modules;
- }
- ret = kernel_create_event_notifier_group(&kernel_tracer_event_notifier_group_fd);
- if (ret < 0) {
- /* This is not fatal. */
- WARN("Failed to create kernel event notifier group");
- kernel_tracer_event_notifier_group_fd = -1;
- } else {
- enum event_notifier_error_accounting_status error_accounting_status;
- enum lttng_error_code error_code_ret =
- kernel_create_event_notifier_group_notification_fd(
- &kernel_tracer_event_notifier_group_notification_fd);
-
- if (error_code_ret != LTTNG_OK) {
- goto error_modules;
- }
-
- error_accounting_status = event_notifier_error_accounting_register_kernel(
- kernel_tracer_event_notifier_group_fd);
- if (error_accounting_status != EVENT_NOTIFIER_ERROR_ACCOUNTING_STATUS_OK) {
- ERR("Failed to initialize event notifier error accounting for kernel tracer");
- error_code_ret = LTTNG_ERR_EVENT_NOTIFIER_ERROR_ACCOUNTING;
- goto error_modules;
- }
-
- kernel_token_to_event_notifier_rule_ht = cds_lfht_new(
- DEFAULT_HT_SIZE, 1, 0,
- CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING,
- NULL);
- if (!kernel_token_to_event_notifier_rule_ht) {
- goto error_token_ht;
- }
- }
-
- DBG("Kernel tracer initialized: kernel tracer fd = %d, event notifier group fd = %d, event notifier group notification fd = %d",
- kernel_tracer_fd, kernel_tracer_event_notifier_group_fd,
- kernel_tracer_event_notifier_group_notification_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("Failed to close kernel tracer file descriptor: fd = %d",
- kernel_tracer_fd);
- }
-
- kernel_tracer_fd = -1;
- return LTTNG_ERR_KERN_VERSION;
-
-
-error_token_ht:
- ret = close(kernel_tracer_event_notifier_group_notification_fd);
- if (ret) {
- PERROR("Failed to close kernel tracer event notifier group notification file descriptor: fd = %d",
- kernel_tracer_event_notifier_group_notification_fd);
- }
-
- kernel_tracer_event_notifier_group_notification_fd = -1;
-
-error_modules:
- ret = close(kernel_tracer_event_notifier_group_fd);
- if (ret) {
- PERROR("Failed to close kernel tracer event notifier group file descriptor: fd = %d",
- kernel_tracer_event_notifier_group_fd);
- }
-
- kernel_tracer_event_notifier_group_fd = -1;
-
- ret = close(kernel_tracer_fd);
- if (ret) {
- PERROR("Failed to close kernel tracer file descriptor: fd = %d",
- kernel_tracer_fd);
- }
-
- kernel_tracer_fd = -1;
-
-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;
- }
-}
-
-void cleanup_kernel_tracer(void)
-{
- DBG2("Closing kernel event notifier group notification file descriptor");
- if (kernel_tracer_event_notifier_group_notification_fd >= 0) {
- int ret = notification_thread_command_remove_tracer_event_source(
- the_notification_thread_handle,
- kernel_tracer_event_notifier_group_notification_fd);
- if (ret != LTTNG_OK) {
- ERR("Failed to remove kernel event notifier notification from notification thread");
- }
-
- ret = close(kernel_tracer_event_notifier_group_notification_fd);
- if (ret) {
- PERROR("Failed to close kernel event notifier group notification file descriptor: fd = %d",
- kernel_tracer_event_notifier_group_notification_fd);
- }
-
- kernel_tracer_event_notifier_group_notification_fd = -1;
- }
-
- if (kernel_token_to_event_notifier_rule_ht) {
- const int ret = cds_lfht_destroy(
- kernel_token_to_event_notifier_rule_ht, NULL);
- LTTNG_ASSERT(ret == 0);
- }
-
- DBG2("Closing kernel event notifier group file descriptor");
- if (kernel_tracer_event_notifier_group_fd >= 0) {
- const int ret = close(kernel_tracer_event_notifier_group_fd);
-
- if (ret) {
- PERROR("Failed to close kernel event notifier group file descriptor: fd = %d",
- kernel_tracer_event_notifier_group_fd);
- }
-
- kernel_tracer_event_notifier_group_fd = -1;
- }
-
- DBG2("Closing kernel fd");
- if (kernel_tracer_fd >= 0) {
- const int ret = close(kernel_tracer_fd);
-
- if (ret) {
- PERROR("Failed to close kernel tracer file descriptor: fd = %d",
- kernel_tracer_fd);
- }
-
- kernel_tracer_fd = -1;
- }
-
- free(syscall_table);
-}
-
-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;
-
- LTTNG_ASSERT(ksess);
- LTTNG_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;
-}
-
-enum lttng_error_code kernel_create_event_notifier_group_notification_fd(
- int *event_notifier_group_notification_fd)
-{
- int local_fd = -1, ret;
- enum lttng_error_code error_code_ret;
-
- LTTNG_ASSERT(event_notifier_group_notification_fd);
-
- ret = kernctl_create_event_notifier_group_notification_fd(
- kernel_tracer_event_notifier_group_fd);
- if (ret < 0) {
- PERROR("Failed to create kernel event notifier group notification file descriptor");
- error_code_ret = LTTNG_ERR_EVENT_NOTIFIER_GROUP_NOTIFICATION_FD;
- goto error;
- }
-
- local_fd = ret;
-
- /* Prevent fd duplication after execlp(). */
- ret = fcntl(local_fd, F_SETFD, FD_CLOEXEC);
- if (ret < 0) {
- PERROR("Failed to set FD_CLOEXEC on kernel event notifier group notification file descriptor: fd = %d",
- local_fd);
- error_code_ret = LTTNG_ERR_EVENT_NOTIFIER_GROUP_NOTIFICATION_FD;
- goto error;
- }
-
- DBG("Created kernel notifier group notification file descriptor: fd = %d",
- local_fd);
- error_code_ret = LTTNG_OK;
- *event_notifier_group_notification_fd = local_fd;
- local_fd = -1;
-
-error:
- if (local_fd >= 0) {
- ret = close(local_fd);
- if (ret) {
- PERROR("Failed to close kernel event notifier group notification file descriptor: fd = %d",
- local_fd);
- }
- }
-
- return error_code_ret;
-}
-
-enum lttng_error_code kernel_destroy_event_notifier_group_notification_fd(
- int event_notifier_group_notification_fd)
-{
- enum lttng_error_code ret_code = LTTNG_OK;
-
- DBG("Closing event notifier group notification file descriptor: fd = %d",
- event_notifier_group_notification_fd);
- if (event_notifier_group_notification_fd >= 0) {
- const int ret = close(event_notifier_group_notification_fd);
- if (ret) {
- PERROR("Failed to close event notifier group notification file descriptor: fd = %d",
- event_notifier_group_notification_fd);
- }
- }
-
- return ret_code;
-}
-
-static
-unsigned long hash_trigger(const struct lttng_trigger *trigger)
-{
- const struct lttng_condition *condition =
- lttng_trigger_get_const_condition(trigger);
-
- return lttng_condition_hash(condition);
-}
-
-static
-int match_trigger(struct cds_lfht_node *node, const void *key)
-{
- const struct ltt_kernel_event_notifier_rule *event_notifier_rule;
- const struct lttng_trigger *trigger = key;
-
- event_notifier_rule = caa_container_of(node,
- const struct ltt_kernel_event_notifier_rule, ht_node);
-
- return lttng_trigger_is_equal(trigger, event_notifier_rule->trigger);
-}
-
-static enum lttng_error_code kernel_create_event_notifier_rule(
- struct lttng_trigger *trigger,
- const struct lttng_credentials *creds, uint64_t token)
-{
- int err, fd, ret = 0;
- enum lttng_error_code error_code_ret;
- enum lttng_condition_status condition_status;
- enum lttng_condition_type condition_type;
- enum lttng_event_rule_type event_rule_type;
- struct ltt_kernel_event_notifier_rule *event_notifier_rule;
- struct lttng_kernel_abi_event_notifier kernel_event_notifier = {};
- unsigned int capture_bytecode_count = 0, i;
- const struct lttng_condition *condition = NULL;
- const struct lttng_event_rule *event_rule = NULL;
- enum lttng_condition_status cond_status;
-
- LTTNG_ASSERT(trigger);
-
- condition = lttng_trigger_get_const_condition(trigger);
- LTTNG_ASSERT(condition);
-
- condition_type = lttng_condition_get_type(condition);
- LTTNG_ASSERT(condition_type == LTTNG_CONDITION_TYPE_EVENT_RULE_MATCHES);
-
- /* Does not acquire a reference. */
- condition_status = lttng_condition_event_rule_matches_get_rule(
- condition, &event_rule);
- LTTNG_ASSERT(condition_status == LTTNG_CONDITION_STATUS_OK);
- LTTNG_ASSERT(event_rule);
-
- event_rule_type = lttng_event_rule_get_type(event_rule);
- LTTNG_ASSERT(event_rule_type != LTTNG_EVENT_RULE_TYPE_UNKNOWN);
-
- error_code_ret = trace_kernel_create_event_notifier_rule(trigger, token,
- lttng_condition_event_rule_matches_get_error_counter_index(
- condition),
- &event_notifier_rule);
- if (error_code_ret != LTTNG_OK) {
- goto error;
- }
-
- error_code_ret = trace_kernel_init_event_notifier_from_event_rule(
- event_rule, &kernel_event_notifier);
- if (error_code_ret != LTTNG_OK) {
- goto free_event;
- }
-
- kernel_event_notifier.event.token = event_notifier_rule->token;
- kernel_event_notifier.error_counter_idx =
- lttng_condition_event_rule_matches_get_error_counter_index(
- condition);
-
- fd = kernctl_create_event_notifier(
- kernel_tracer_event_notifier_group_fd,
- &kernel_event_notifier);
- if (fd < 0) {
- switch (-fd) {
- case EEXIST:
- error_code_ret = LTTNG_ERR_KERN_EVENT_EXIST;
- break;
- case ENOSYS:
- WARN("Failed to create kernel event notifier: not notifier type not implemented");
- error_code_ret = LTTNG_ERR_KERN_EVENT_ENOSYS;
- break;
- case ENOENT:
- WARN("Failed to create kernel event notifier: not found: name = '%s'",
- kernel_event_notifier.event.name);
- error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
- break;
- default:
- PERROR("Failed to create kernel event notifier: error code = %d, name = '%s'",
- fd, kernel_event_notifier.event.name);
- error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
- }
- goto free_event;
- }
-
- event_notifier_rule->fd = fd;
- /* Prevent fd duplication after execlp(). */
- err = fcntl(event_notifier_rule->fd, F_SETFD, FD_CLOEXEC);
- if (err < 0) {
- PERROR("Failed to set FD_CLOEXEC on kernel event notifier file descriptor: fd = %d",
- fd);
- error_code_ret = LTTNG_ERR_FATAL;
- goto set_cloexec_error;
- }
-
- if (event_notifier_rule->filter) {
- err = kernctl_filter(event_notifier_rule->fd, event_notifier_rule->filter);
- if (err < 0) {
- switch (-err) {
- case ENOMEM:
- error_code_ret = LTTNG_ERR_FILTER_NOMEM;
- break;
- default:
- error_code_ret = LTTNG_ERR_FILTER_INVAL;
- break;
- }
- goto filter_error;
- }
- }
-
- if (lttng_event_rule_get_type(event_rule) ==
- LTTNG_EVENT_RULE_TYPE_KERNEL_UPROBE) {
- ret = userspace_probe_event_rule_add_callsites(
- event_rule, creds, event_notifier_rule->fd);
- if (ret) {
- error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
- goto add_callsite_error;
- }
- }
-
- /* Set the capture bytecode if any. */
- cond_status = lttng_condition_event_rule_matches_get_capture_descriptor_count(
- condition, &capture_bytecode_count);
- LTTNG_ASSERT(cond_status == LTTNG_CONDITION_STATUS_OK);
-
- for (i = 0; i < capture_bytecode_count; i++) {
- const struct lttng_bytecode *capture_bytecode =
- lttng_condition_event_rule_matches_get_capture_bytecode_at_index(
- condition, i);
-
- if (capture_bytecode == NULL) {
- ERR("Unexpected NULL capture bytecode on condition");
- error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
- goto capture_error;
- }
-
- ret = kernctl_capture(event_notifier_rule->fd, capture_bytecode);
- if (ret < 0) {
- ERR("Failed to set capture bytecode on event notifier rule fd: fd = %d",
- event_notifier_rule->fd);
- error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
- goto capture_error;
- }
- }
-
- err = kernctl_enable(event_notifier_rule->fd);
- if (err < 0) {
- switch (-err) {
- case EEXIST:
- error_code_ret = LTTNG_ERR_KERN_EVENT_EXIST;
- break;
- default:
- PERROR("enable kernel event notifier");
- error_code_ret = LTTNG_ERR_KERN_ENABLE_FAIL;
- break;
- }
- goto enable_error;
- }
-
- /* Add trigger to kernel token mapping in the hash table. */
- rcu_read_lock();
- cds_lfht_add(kernel_token_to_event_notifier_rule_ht, hash_trigger(trigger),
- &event_notifier_rule->ht_node);
- rcu_read_unlock();
-
- DBG("Created kernel event notifier: name = '%s', fd = %d",
- kernel_event_notifier.event.name,
- event_notifier_rule->fd);
-
- return LTTNG_OK;
-
-capture_error:
-add_callsite_error:
-enable_error:
-set_cloexec_error:
-filter_error:
- {
- const int close_ret = close(event_notifier_rule->fd);
-
- if (close_ret) {
- PERROR("Failed to close kernel event notifier file descriptor: fd = %d",
- event_notifier_rule->fd);
- }
- }
-free_event:
- free(event_notifier_rule);
-error:
- return error_code_ret;
-}
-
-enum lttng_error_code kernel_register_event_notifier(
- struct lttng_trigger *trigger,
- const struct lttng_credentials *cmd_creds)
-{
- enum lttng_error_code ret;
- enum lttng_condition_status status;
- enum lttng_domain_type domain_type;
- const struct lttng_event_rule *event_rule;
- const struct lttng_condition *const condition =
- lttng_trigger_get_const_condition(trigger);
- const uint64_t token = lttng_trigger_get_tracer_token(trigger);
-
- LTTNG_ASSERT(condition);
-
- /* Does not acquire a reference to the event rule. */
- status = lttng_condition_event_rule_matches_get_rule(
- condition, &event_rule);
- LTTNG_ASSERT(status == LTTNG_CONDITION_STATUS_OK);
-
- domain_type = lttng_event_rule_get_domain_type(event_rule);
- LTTNG_ASSERT(domain_type == LTTNG_DOMAIN_KERNEL);
-
- ret = kernel_create_event_notifier_rule(trigger, cmd_creds, token);
- if (ret != LTTNG_OK) {
- ERR("Failed to create kernel event notifier rule");
- }
-
- return ret;
-}
-
-enum lttng_error_code kernel_unregister_event_notifier(
- const struct lttng_trigger *trigger)
-{
- struct ltt_kernel_event_notifier_rule *token_event_rule_element;
- struct cds_lfht_node *node;
- struct cds_lfht_iter iter;
- enum lttng_error_code error_code_ret;
- int ret;
-
- rcu_read_lock();
-
- cds_lfht_lookup(kernel_token_to_event_notifier_rule_ht,
- hash_trigger(trigger), match_trigger, trigger, &iter);
-
- node = cds_lfht_iter_get_node(&iter);
- if (!node) {
- error_code_ret = LTTNG_ERR_TRIGGER_NOT_FOUND;
- goto error;
- }
-
- token_event_rule_element = caa_container_of(node,
- struct ltt_kernel_event_notifier_rule, ht_node);
-
- ret = kernel_disable_event_notifier_rule(token_event_rule_element);
- if (ret) {
- error_code_ret = LTTNG_ERR_FATAL;
- goto error;
- }
-
- trace_kernel_destroy_event_notifier_rule(token_event_rule_element);
- error_code_ret = LTTNG_OK;
-
-error:
- rcu_read_unlock();
-
- return error_code_ret;
-}
-
-int kernel_get_notification_fd(void)
-{
- return kernel_tracer_event_notifier_group_notification_fd;
-}
projects / lttng-tools.git / blobdiff