* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
+/*
+ * This page_alloc.h wrapper needs to be included before gfpflags.h because it
+ * overrides a function with a define.
+ */
+#include "wrapper/page_alloc.h"
+
#include <linux/module.h>
-#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/utsname.h>
#include <linux/err.h>
+#include <linux/seq_file.h>
+#include <linux/file.h>
+#include <linux/anon_inodes.h>
+#include "wrapper/file.h"
+#include <linux/jhash.h>
+#include <linux/uaccess.h>
+#include <linux/vmalloc.h>
+
#include "wrapper/uuid.h"
#include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */
#include "wrapper/random.h"
#include "wrapper/tracepoint.h"
+#include "wrapper/list.h"
#include "lttng-kernel-version.h"
#include "lttng-events.h"
#include "lttng-tracer.h"
#include "lttng-abi-old.h"
+#include "lttng-endian.h"
+#include "wrapper/vzalloc.h"
+#include "wrapper/ringbuffer/backend.h"
+#include "wrapper/ringbuffer/frontend.h"
#define METADATA_CACHE_DEFAULT_SIZE 4096
static DEFINE_MUTEX(sessions_mutex);
static struct kmem_cache *event_cache;
+static void lttng_session_lazy_sync_enablers(struct lttng_session *session);
+static void lttng_session_sync_enablers(struct lttng_session *session);
+static void lttng_enabler_destroy(struct lttng_enabler *enabler);
+
static void _lttng_event_destroy(struct lttng_event *event);
static void _lttng_channel_destroy(struct lttng_channel *chan);
static int _lttng_event_unregister(struct lttng_event *event);
#endif /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */
}
+void lttng_lock_sessions(void)
+{
+ mutex_lock(&sessions_mutex);
+}
+
+void lttng_unlock_sessions(void)
+{
+ mutex_unlock(&sessions_mutex);
+}
+
+/*
+ * Called with sessions lock held.
+ */
+int lttng_session_active(void)
+{
+ struct lttng_session *iter;
+
+ list_for_each_entry(iter, &sessions, list) {
+ if (iter->active)
+ return 1;
+ }
+ return 0;
+}
+
struct lttng_session *lttng_session_create(void)
{
struct lttng_session *session;
struct lttng_metadata_cache *metadata_cache;
+ int i;
mutex_lock(&sessions_mutex);
session = kzalloc(sizeof(struct lttng_session), GFP_KERNEL);
GFP_KERNEL);
if (!metadata_cache)
goto err_free_session;
- metadata_cache->data = kzalloc(METADATA_CACHE_DEFAULT_SIZE,
- GFP_KERNEL);
+ metadata_cache->data = lttng_vzalloc(METADATA_CACHE_DEFAULT_SIZE);
if (!metadata_cache->data)
goto err_free_cache;
metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE;
kref_init(&metadata_cache->refcount);
+ mutex_init(&metadata_cache->lock);
session->metadata_cache = metadata_cache;
INIT_LIST_HEAD(&metadata_cache->metadata_stream);
memcpy(&metadata_cache->uuid, &session->uuid,
sizeof(metadata_cache->uuid));
+ INIT_LIST_HEAD(&session->enablers_head);
+ for (i = 0; i < LTTNG_EVENT_HT_SIZE; i++)
+ INIT_HLIST_HEAD(&session->events_ht.table[i]);
list_add(&session->list, &sessions);
mutex_unlock(&sessions_mutex);
return session;
{
struct lttng_metadata_cache *cache =
container_of(kref, struct lttng_metadata_cache, refcount);
- kfree(cache->data);
+ vfree(cache->data);
kfree(cache);
}
struct lttng_channel *chan, *tmpchan;
struct lttng_event *event, *tmpevent;
struct lttng_metadata_stream *metadata_stream;
+ struct lttng_enabler *enabler, *tmpenabler;
int ret;
mutex_lock(&sessions_mutex);
WARN_ON(ret);
}
synchronize_trace(); /* Wait for in-flight events to complete */
+ list_for_each_entry_safe(enabler, tmpenabler,
+ &session->enablers_head, node)
+ lttng_enabler_destroy(enabler);
list_for_each_entry_safe(event, tmpevent, &session->events, list)
_lttng_event_destroy(event);
list_for_each_entry_safe(chan, tmpchan, &session->chan, list) {
}
list_for_each_entry(metadata_stream, &session->metadata_cache->metadata_stream, list)
_lttng_metadata_channel_hangup(metadata_stream);
+ if (session->pid_tracker)
+ lttng_pid_tracker_destroy(session->pid_tracker);
kref_put(&session->metadata_cache->refcount, metadata_cache_destroy);
list_del(&session->list);
mutex_unlock(&sessions_mutex);
goto end;
}
+ /* Set transient enabler state to "enabled" */
+ session->tstate = 1;
+
/*
* Snapshot the number of events per channel to know the type of header
* we need to use.
chan->header_type = 2; /* large */
}
+ /* We need to sync enablers with session before activation. */
+ lttng_session_sync_enablers(session);
+
+ /* Clear each stream's quiescent state. */
+ list_for_each_entry(chan, &session->chan, list) {
+ if (chan->channel_type != METADATA_CHANNEL)
+ lib_ring_buffer_clear_quiescent_channel(chan->chan);
+ }
+
ACCESS_ONCE(session->active) = 1;
ACCESS_ONCE(session->been_active) = 1;
ret = _lttng_session_metadata_statedump(session);
int lttng_session_disable(struct lttng_session *session)
{
int ret = 0;
+ struct lttng_channel *chan;
mutex_lock(&sessions_mutex);
if (!session->active) {
goto end;
}
ACCESS_ONCE(session->active) = 0;
+
+ /* Set transient enabler state to "disabled" */
+ session->tstate = 0;
+ lttng_session_sync_enablers(session);
+
+ /* Set each stream's quiescent state. */
+ list_for_each_entry(chan, &session->chan, list) {
+ if (chan->channel_type != METADATA_CHANNEL)
+ lib_ring_buffer_set_quiescent_channel(chan->chan);
+ }
end:
mutex_unlock(&sessions_mutex);
return ret;
int lttng_channel_enable(struct lttng_channel *channel)
{
- int old;
+ int ret = 0;
- if (channel->channel_type == METADATA_CHANNEL)
- return -EPERM;
- old = xchg(&channel->enabled, 1);
- if (old)
- return -EEXIST;
- return 0;
+ mutex_lock(&sessions_mutex);
+ if (channel->channel_type == METADATA_CHANNEL) {
+ ret = -EPERM;
+ goto end;
+ }
+ if (channel->enabled) {
+ ret = -EEXIST;
+ goto end;
+ }
+ /* Set transient enabler state to "enabled" */
+ channel->tstate = 1;
+ lttng_session_sync_enablers(channel->session);
+ /* Set atomically the state to "enabled" */
+ ACCESS_ONCE(channel->enabled) = 1;
+end:
+ mutex_unlock(&sessions_mutex);
+ return ret;
}
int lttng_channel_disable(struct lttng_channel *channel)
{
- int old;
+ int ret = 0;
- if (channel->channel_type == METADATA_CHANNEL)
- return -EPERM;
- old = xchg(&channel->enabled, 0);
- if (!old)
- return -EEXIST;
- return 0;
+ mutex_lock(&sessions_mutex);
+ if (channel->channel_type == METADATA_CHANNEL) {
+ ret = -EPERM;
+ goto end;
+ }
+ if (!channel->enabled) {
+ ret = -EEXIST;
+ goto end;
+ }
+ /* Set atomically the state to "disabled" */
+ ACCESS_ONCE(channel->enabled) = 0;
+ /* Set transient enabler state to "enabled" */
+ channel->tstate = 0;
+ lttng_session_sync_enablers(channel->session);
+end:
+ mutex_unlock(&sessions_mutex);
+ return ret;
}
int lttng_event_enable(struct lttng_event *event)
{
- int old;
+ int ret = 0;
- if (event->chan->channel_type == METADATA_CHANNEL)
- return -EPERM;
- old = xchg(&event->enabled, 1);
- if (old)
- return -EEXIST;
- return 0;
+ mutex_lock(&sessions_mutex);
+ if (event->chan->channel_type == METADATA_CHANNEL) {
+ ret = -EPERM;
+ goto end;
+ }
+ if (event->enabled) {
+ ret = -EEXIST;
+ goto end;
+ }
+ switch (event->instrumentation) {
+ case LTTNG_KERNEL_TRACEPOINT:
+ case LTTNG_KERNEL_SYSCALL:
+ ret = -EINVAL;
+ break;
+ case LTTNG_KERNEL_KPROBE:
+ case LTTNG_KERNEL_FUNCTION:
+ case LTTNG_KERNEL_NOOP:
+ ACCESS_ONCE(event->enabled) = 1;
+ break;
+ case LTTNG_KERNEL_KRETPROBE:
+ ret = lttng_kretprobes_event_enable_state(event, 1);
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ ret = -EINVAL;
+ }
+end:
+ mutex_unlock(&sessions_mutex);
+ return ret;
}
int lttng_event_disable(struct lttng_event *event)
{
- int old;
+ int ret = 0;
- if (event->chan->channel_type == METADATA_CHANNEL)
- return -EPERM;
- old = xchg(&event->enabled, 0);
- if (!old)
- return -EEXIST;
- return 0;
+ mutex_lock(&sessions_mutex);
+ if (event->chan->channel_type == METADATA_CHANNEL) {
+ ret = -EPERM;
+ goto end;
+ }
+ if (!event->enabled) {
+ ret = -EEXIST;
+ goto end;
+ }
+ switch (event->instrumentation) {
+ case LTTNG_KERNEL_TRACEPOINT:
+ case LTTNG_KERNEL_SYSCALL:
+ ret = -EINVAL;
+ break;
+ case LTTNG_KERNEL_KPROBE:
+ case LTTNG_KERNEL_FUNCTION:
+ case LTTNG_KERNEL_NOOP:
+ ACCESS_ONCE(event->enabled) = 0;
+ break;
+ case LTTNG_KERNEL_KRETPROBE:
+ ret = lttng_kretprobes_event_enable_state(event, 0);
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ ret = -EINVAL;
+ }
+end:
+ mutex_unlock(&sessions_mutex);
+ return ret;
}
static struct lttng_transport *lttng_transport_find(const char *name)
switch_timer_interval, read_timer_interval);
if (!chan->chan)
goto create_error;
+ chan->tstate = 1;
chan->enabled = 1;
chan->transport = transport;
chan->channel_type = channel_type;
/*
* Supports event creation while tracing session is active.
+ * Needs to be called with sessions mutex held.
*/
-struct lttng_event *lttng_event_create(struct lttng_channel *chan,
- struct lttng_kernel_event *event_param,
- void *filter,
- const struct lttng_event_desc *internal_desc)
+struct lttng_event *_lttng_event_create(struct lttng_channel *chan,
+ struct lttng_kernel_event *event_param,
+ void *filter,
+ const struct lttng_event_desc *event_desc,
+ enum lttng_kernel_instrumentation itype)
{
+ struct lttng_session *session = chan->session;
struct lttng_event *event;
+ const char *event_name;
+ struct hlist_head *head;
+ size_t name_len;
+ uint32_t hash;
int ret;
- mutex_lock(&sessions_mutex);
if (chan->free_event_id == -1U) {
ret = -EMFILE;
goto full;
}
- /*
- * This is O(n^2) (for each event, the loop is called at event
- * creation). Might require a hash if we have lots of events.
- */
- list_for_each_entry(event, &chan->session->events, list) {
- if (!strcmp(event->desc->name, event_param->name)) {
+
+ switch (itype) {
+ case LTTNG_KERNEL_TRACEPOINT:
+ event_name = event_desc->name;
+ break;
+ case LTTNG_KERNEL_KPROBE:
+ case LTTNG_KERNEL_KRETPROBE:
+ case LTTNG_KERNEL_FUNCTION:
+ case LTTNG_KERNEL_NOOP:
+ case LTTNG_KERNEL_SYSCALL:
+ event_name = event_param->name;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ ret = -EINVAL;
+ goto type_error;
+ }
+ name_len = strlen(event_name);
+ hash = jhash(event_name, name_len, 0);
+ head = &session->events_ht.table[hash & (LTTNG_EVENT_HT_SIZE - 1)];
+ lttng_hlist_for_each_entry(event, head, hlist) {
+ WARN_ON_ONCE(!event->desc);
+ if (!strncmp(event->desc->name, event_name,
+ LTTNG_KERNEL_SYM_NAME_LEN - 1)
+ && chan == event->chan) {
ret = -EEXIST;
goto exist;
}
}
+
event = kmem_cache_zalloc(event_cache, GFP_KERNEL);
if (!event) {
ret = -ENOMEM;
event->chan = chan;
event->filter = filter;
event->id = chan->free_event_id++;
- event->enabled = 1;
- event->instrumentation = event_param->instrumentation;
- /* Populate lttng_event structure before tracepoint registration. */
- smp_wmb();
- switch (event_param->instrumentation) {
+ event->instrumentation = itype;
+ event->evtype = LTTNG_TYPE_EVENT;
+ INIT_LIST_HEAD(&event->bytecode_runtime_head);
+ INIT_LIST_HEAD(&event->enablers_ref_head);
+
+ switch (itype) {
case LTTNG_KERNEL_TRACEPOINT:
- event->desc = lttng_event_get(event_param->name);
+ /* Event will be enabled by enabler sync. */
+ event->enabled = 0;
+ event->registered = 0;
+ event->desc = lttng_event_get(event_name);
if (!event->desc) {
ret = -ENOENT;
goto register_error;
}
- ret = lttng_wrapper_tracepoint_probe_register(event->desc->kname,
- event->desc->probe_callback,
- event);
- if (ret) {
- ret = -EINVAL;
- goto register_error;
- }
+ /* Populate lttng_event structure before event registration. */
+ smp_wmb();
break;
case LTTNG_KERNEL_KPROBE:
- ret = lttng_kprobes_register(event_param->name,
+ /*
+ * Needs to be explicitly enabled after creation, since
+ * we may want to apply filters.
+ */
+ event->enabled = 0;
+ event->registered = 1;
+ /*
+ * Populate lttng_event structure before event
+ * registration.
+ */
+ smp_wmb();
+ ret = lttng_kprobes_register(event_name,
event_param->u.kprobe.symbol_name,
event_param->u.kprobe.offset,
event_param->u.kprobe.addr,
struct lttng_event *event_return;
/* kretprobe defines 2 events */
+ /*
+ * Needs to be explicitly enabled after creation, since
+ * we may want to apply filters.
+ */
+ event->enabled = 0;
+ event->registered = 1;
event_return =
kmem_cache_zalloc(event_cache, GFP_KERNEL);
if (!event_return) {
event_return->chan = chan;
event_return->filter = filter;
event_return->id = chan->free_event_id++;
- event_return->enabled = 1;
- event_return->instrumentation = event_param->instrumentation;
+ event_return->enabled = 0;
+ event_return->registered = 1;
+ event_return->instrumentation = itype;
/*
* Populate lttng_event structure before kretprobe registration.
*/
smp_wmb();
- ret = lttng_kretprobes_register(event_param->name,
+ ret = lttng_kretprobes_register(event_name,
event_param->u.kretprobe.symbol_name,
event_param->u.kretprobe.offset,
event_param->u.kretprobe.addr,
break;
}
case LTTNG_KERNEL_FUNCTION:
- ret = lttng_ftrace_register(event_param->name,
+ /*
+ * Needs to be explicitly enabled after creation, since
+ * we may want to apply filters.
+ */
+ event->enabled = 0;
+ event->registered = 1;
+ /*
+ * Populate lttng_event structure before event
+ * registration.
+ */
+ smp_wmb();
+ ret = lttng_ftrace_register(event_name,
event_param->u.ftrace.symbol_name,
event);
if (ret) {
WARN_ON_ONCE(!ret);
break;
case LTTNG_KERNEL_NOOP:
- event->desc = internal_desc;
+ case LTTNG_KERNEL_SYSCALL:
+ /*
+ * Needs to be explicitly enabled after creation, since
+ * we may want to apply filters.
+ */
+ event->enabled = 0;
+ event->registered = 0;
+ event->desc = event_desc;
if (!event->desc) {
ret = -EINVAL;
goto register_error;
if (ret) {
goto statedump_error;
}
+ hlist_add_head(&event->hlist, head);
list_add(&event->list, &chan->session->events);
- mutex_unlock(&sessions_mutex);
return event;
statedump_error:
kmem_cache_free(event_cache, event);
cache_error:
exist:
+type_error:
full:
- mutex_unlock(&sessions_mutex);
return ERR_PTR(ret);
}
+struct lttng_event *lttng_event_create(struct lttng_channel *chan,
+ struct lttng_kernel_event *event_param,
+ void *filter,
+ const struct lttng_event_desc *event_desc,
+ enum lttng_kernel_instrumentation itype)
+{
+ struct lttng_event *event;
+
+ mutex_lock(&sessions_mutex);
+ event = _lttng_event_create(chan, event_param, filter, event_desc,
+ itype);
+ mutex_unlock(&sessions_mutex);
+ return event;
+}
+
+/* Only used for tracepoints for now. */
+static
+void register_event(struct lttng_event *event)
+{
+ const struct lttng_event_desc *desc;
+ int ret = -EINVAL;
+
+ if (event->registered)
+ return;
+
+ desc = event->desc;
+ switch (event->instrumentation) {
+ case LTTNG_KERNEL_TRACEPOINT:
+ ret = lttng_wrapper_tracepoint_probe_register(desc->kname,
+ desc->probe_callback,
+ event);
+ break;
+ case LTTNG_KERNEL_SYSCALL:
+ ret = lttng_syscall_filter_enable(event->chan,
+ desc->name);
+ break;
+ case LTTNG_KERNEL_KPROBE:
+ case LTTNG_KERNEL_KRETPROBE:
+ case LTTNG_KERNEL_FUNCTION:
+ case LTTNG_KERNEL_NOOP:
+ ret = 0;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ }
+ if (!ret)
+ event->registered = 1;
+}
+
/*
* Only used internally at session destruction.
*/
int _lttng_event_unregister(struct lttng_event *event)
{
+ const struct lttng_event_desc *desc;
int ret = -EINVAL;
+ if (!event->registered)
+ return 0;
+
+ desc = event->desc;
switch (event->instrumentation) {
case LTTNG_KERNEL_TRACEPOINT:
ret = lttng_wrapper_tracepoint_probe_unregister(event->desc->kname,
event->desc->probe_callback,
event);
- if (ret)
- return ret;
break;
case LTTNG_KERNEL_KPROBE:
lttng_kprobes_unregister(event);
lttng_ftrace_unregister(event);
ret = 0;
break;
+ case LTTNG_KERNEL_SYSCALL:
+ ret = lttng_syscall_filter_disable(event->chan,
+ desc->name);
+ break;
case LTTNG_KERNEL_NOOP:
ret = 0;
break;
default:
WARN_ON_ONCE(1);
}
+ if (!ret)
+ event->registered = 0;
return ret;
}
lttng_ftrace_destroy_private(event);
break;
case LTTNG_KERNEL_NOOP:
+ case LTTNG_KERNEL_SYSCALL:
break;
default:
WARN_ON_ONCE(1);
kmem_cache_free(event_cache, event);
}
+int lttng_session_track_pid(struct lttng_session *session, int pid)
+{
+ int ret;
+
+ if (pid < -1)
+ return -EINVAL;
+ mutex_lock(&sessions_mutex);
+ if (pid == -1) {
+ /* track all pids: destroy tracker. */
+ if (session->pid_tracker) {
+ struct lttng_pid_tracker *lpf;
+
+ lpf = session->pid_tracker;
+ rcu_assign_pointer(session->pid_tracker, NULL);
+ synchronize_trace();
+ lttng_pid_tracker_destroy(lpf);
+ }
+ ret = 0;
+ } else {
+ if (!session->pid_tracker) {
+ struct lttng_pid_tracker *lpf;
+
+ lpf = lttng_pid_tracker_create();
+ if (!lpf) {
+ ret = -ENOMEM;
+ goto unlock;
+ }
+ ret = lttng_pid_tracker_add(lpf, pid);
+ rcu_assign_pointer(session->pid_tracker, lpf);
+ } else {
+ ret = lttng_pid_tracker_add(session->pid_tracker, pid);
+ }
+ }
+unlock:
+ mutex_unlock(&sessions_mutex);
+ return ret;
+}
+
+int lttng_session_untrack_pid(struct lttng_session *session, int pid)
+{
+ int ret;
+
+ if (pid < -1)
+ return -EINVAL;
+ mutex_lock(&sessions_mutex);
+ if (pid == -1) {
+ /* untrack all pids: replace by empty tracker. */
+ struct lttng_pid_tracker *old_lpf = session->pid_tracker;
+ struct lttng_pid_tracker *lpf;
+
+ lpf = lttng_pid_tracker_create();
+ if (!lpf) {
+ ret = -ENOMEM;
+ goto unlock;
+ }
+ rcu_assign_pointer(session->pid_tracker, lpf);
+ synchronize_trace();
+ if (old_lpf)
+ lttng_pid_tracker_destroy(old_lpf);
+ ret = 0;
+ } else {
+ if (!session->pid_tracker) {
+ ret = -ENOENT;
+ goto unlock;
+ }
+ ret = lttng_pid_tracker_del(session->pid_tracker, pid);
+ }
+unlock:
+ mutex_unlock(&sessions_mutex);
+ return ret;
+}
+
+static
+void *pid_list_start(struct seq_file *m, loff_t *pos)
+{
+ struct lttng_session *session = m->private;
+ struct lttng_pid_tracker *lpf;
+ struct lttng_pid_hash_node *e;
+ int iter = 0, i;
+
+ mutex_lock(&sessions_mutex);
+ lpf = session->pid_tracker;
+ if (lpf) {
+ for (i = 0; i < LTTNG_PID_TABLE_SIZE; i++) {
+ struct hlist_head *head = &lpf->pid_hash[i];
+
+ lttng_hlist_for_each_entry(e, head, hlist) {
+ if (iter++ >= *pos)
+ return e;
+ }
+ }
+ } else {
+ /* PID tracker disabled. */
+ if (iter >= *pos && iter == 0) {
+ return session; /* empty tracker */
+ }
+ iter++;
+ }
+ /* End of list */
+ return NULL;
+}
+
+/* Called with sessions_mutex held. */
+static
+void *pid_list_next(struct seq_file *m, void *p, loff_t *ppos)
+{
+ struct lttng_session *session = m->private;
+ struct lttng_pid_tracker *lpf;
+ struct lttng_pid_hash_node *e;
+ int iter = 0, i;
+
+ (*ppos)++;
+ lpf = session->pid_tracker;
+ if (lpf) {
+ for (i = 0; i < LTTNG_PID_TABLE_SIZE; i++) {
+ struct hlist_head *head = &lpf->pid_hash[i];
+
+ lttng_hlist_for_each_entry(e, head, hlist) {
+ if (iter++ >= *ppos)
+ return e;
+ }
+ }
+ } else {
+ /* PID tracker disabled. */
+ if (iter >= *ppos && iter == 0)
+ return session; /* empty tracker */
+ iter++;
+ }
+
+ /* End of list */
+ return NULL;
+}
+
+static
+void pid_list_stop(struct seq_file *m, void *p)
+{
+ mutex_unlock(&sessions_mutex);
+}
+
+static
+int pid_list_show(struct seq_file *m, void *p)
+{
+ int pid;
+
+ if (p == m->private) {
+ /* Tracker disabled. */
+ pid = -1;
+ } else {
+ const struct lttng_pid_hash_node *e = p;
+
+ pid = lttng_pid_tracker_get_node_pid(e);
+ }
+ seq_printf(m, "process { pid = %d; };\n", pid);
+ return 0;
+}
+
+static
+const struct seq_operations lttng_tracker_pids_list_seq_ops = {
+ .start = pid_list_start,
+ .next = pid_list_next,
+ .stop = pid_list_stop,
+ .show = pid_list_show,
+};
+
+static
+int lttng_tracker_pids_list_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, <tng_tracker_pids_list_seq_ops);
+}
+
+static
+int lttng_tracker_pids_list_release(struct inode *inode, struct file *file)
+{
+ struct seq_file *m = file->private_data;
+ struct lttng_session *session = m->private;
+ int ret;
+
+ WARN_ON_ONCE(!session);
+ ret = seq_release(inode, file);
+ if (!ret && session)
+ fput(session->file);
+ return ret;
+}
+
+const struct file_operations lttng_tracker_pids_list_fops = {
+ .owner = THIS_MODULE,
+ .open = lttng_tracker_pids_list_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = lttng_tracker_pids_list_release,
+};
+
+int lttng_session_list_tracker_pids(struct lttng_session *session)
+{
+ struct file *tracker_pids_list_file;
+ struct seq_file *m;
+ int file_fd, ret;
+
+ file_fd = lttng_get_unused_fd();
+ if (file_fd < 0) {
+ ret = file_fd;
+ goto fd_error;
+ }
+
+ tracker_pids_list_file = anon_inode_getfile("[lttng_tracker_pids_list]",
+ <tng_tracker_pids_list_fops,
+ NULL, O_RDWR);
+ if (IS_ERR(tracker_pids_list_file)) {
+ ret = PTR_ERR(tracker_pids_list_file);
+ goto file_error;
+ }
+ if (atomic_long_add_unless(&session->file->f_count,
+ 1, INT_MAX) == INT_MAX) {
+ goto refcount_error;
+ }
+ ret = lttng_tracker_pids_list_fops.open(NULL, tracker_pids_list_file);
+ if (ret < 0)
+ goto open_error;
+ m = tracker_pids_list_file->private_data;
+ m->private = session;
+ fd_install(file_fd, tracker_pids_list_file);
+
+ return file_fd;
+
+open_error:
+ atomic_long_dec(&session->file->f_count);
+refcount_error:
+ fput(tracker_pids_list_file);
+file_error:
+ put_unused_fd(file_fd);
+fd_error:
+ return ret;
+}
+
+/*
+ * Enabler management.
+ */
+static
+int lttng_match_enabler_wildcard(const char *desc_name,
+ const char *name)
+{
+ /* Compare excluding final '*' */
+ if (strncmp(desc_name, name, strlen(name) - 1))
+ return 0;
+ return 1;
+}
+
+static
+int lttng_match_enabler_name(const char *desc_name,
+ const char *name)
+{
+ if (strcmp(desc_name, name))
+ return 0;
+ return 1;
+}
+
+static
+int lttng_desc_match_enabler(const struct lttng_event_desc *desc,
+ struct lttng_enabler *enabler)
+{
+ const char *desc_name, *enabler_name;
+
+ enabler_name = enabler->event_param.name;
+ switch (enabler->event_param.instrumentation) {
+ case LTTNG_KERNEL_TRACEPOINT:
+ desc_name = desc->name;
+ break;
+ case LTTNG_KERNEL_SYSCALL:
+ desc_name = desc->name;
+ if (!strncmp(desc_name, "compat_", strlen("compat_")))
+ desc_name += strlen("compat_");
+ if (!strncmp(desc_name, "syscall_exit_",
+ strlen("syscall_exit_"))) {
+ desc_name += strlen("syscall_exit_");
+ } else if (!strncmp(desc_name, "syscall_entry_",
+ strlen("syscall_entry_"))) {
+ desc_name += strlen("syscall_entry_");
+ } else {
+ WARN_ON_ONCE(1);
+ return -EINVAL;
+ }
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return -EINVAL;
+ }
+ switch (enabler->type) {
+ case LTTNG_ENABLER_WILDCARD:
+ return lttng_match_enabler_wildcard(desc_name, enabler_name);
+ case LTTNG_ENABLER_NAME:
+ return lttng_match_enabler_name(desc_name, enabler_name);
+ default:
+ return -EINVAL;
+ }
+}
+
+static
+int lttng_event_match_enabler(struct lttng_event *event,
+ struct lttng_enabler *enabler)
+{
+ if (enabler->event_param.instrumentation != event->instrumentation)
+ return 0;
+ if (lttng_desc_match_enabler(event->desc, enabler)
+ && event->chan == enabler->chan)
+ return 1;
+ else
+ return 0;
+}
+
+static
+struct lttng_enabler_ref *lttng_event_enabler_ref(struct lttng_event *event,
+ struct lttng_enabler *enabler)
+{
+ struct lttng_enabler_ref *enabler_ref;
+
+ list_for_each_entry(enabler_ref,
+ &event->enablers_ref_head, node) {
+ if (enabler_ref->ref == enabler)
+ return enabler_ref;
+ }
+ return NULL;
+}
+
+static
+void lttng_create_tracepoint_if_missing(struct lttng_enabler *enabler)
+{
+ struct lttng_session *session = enabler->chan->session;
+ struct lttng_probe_desc *probe_desc;
+ const struct lttng_event_desc *desc;
+ int i;
+ struct list_head *probe_list;
+
+ probe_list = lttng_get_probe_list_head();
+ /*
+ * For each probe event, if we find that a probe event matches
+ * our enabler, create an associated lttng_event if not
+ * already present.
+ */
+ list_for_each_entry(probe_desc, probe_list, head) {
+ for (i = 0; i < probe_desc->nr_events; i++) {
+ int found = 0;
+ struct hlist_head *head;
+ const char *event_name;
+ size_t name_len;
+ uint32_t hash;
+ struct lttng_event *event;
+
+ desc = probe_desc->event_desc[i];
+ if (!lttng_desc_match_enabler(desc, enabler))
+ continue;
+ event_name = desc->name;
+ name_len = strlen(event_name);
+
+ /*
+ * Check if already created.
+ */
+ hash = jhash(event_name, name_len, 0);
+ head = &session->events_ht.table[hash & (LTTNG_EVENT_HT_SIZE - 1)];
+ lttng_hlist_for_each_entry(event, head, hlist) {
+ if (event->desc == desc
+ && event->chan == enabler->chan)
+ found = 1;
+ }
+ if (found)
+ continue;
+
+ /*
+ * We need to create an event for this
+ * event probe.
+ */
+ event = _lttng_event_create(enabler->chan,
+ NULL, NULL, desc,
+ LTTNG_KERNEL_TRACEPOINT);
+ if (!event) {
+ printk(KERN_INFO "Unable to create event %s\n",
+ probe_desc->event_desc[i]->name);
+ }
+ }
+ }
+}
+
+static
+void lttng_create_syscall_if_missing(struct lttng_enabler *enabler)
+{
+ int ret;
+
+ ret = lttng_syscalls_register(enabler->chan, NULL);
+ WARN_ON_ONCE(ret);
+}
+
+/*
+ * Create struct lttng_event if it is missing and present in the list of
+ * tracepoint probes.
+ * Should be called with sessions mutex held.
+ */
+static
+void lttng_create_event_if_missing(struct lttng_enabler *enabler)
+{
+ switch (enabler->event_param.instrumentation) {
+ case LTTNG_KERNEL_TRACEPOINT:
+ lttng_create_tracepoint_if_missing(enabler);
+ break;
+ case LTTNG_KERNEL_SYSCALL:
+ lttng_create_syscall_if_missing(enabler);
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ break;
+ }
+}
+
+/*
+ * Create events associated with an enabler (if not already present),
+ * and add backward reference from the event to the enabler.
+ * Should be called with sessions mutex held.
+ */
+static
+int lttng_enabler_ref_events(struct lttng_enabler *enabler)
+{
+ struct lttng_session *session = enabler->chan->session;
+ struct lttng_event *event;
+
+ /* First ensure that probe events are created for this enabler. */
+ lttng_create_event_if_missing(enabler);
+
+ /* For each event matching enabler in session event list. */
+ list_for_each_entry(event, &session->events, list) {
+ struct lttng_enabler_ref *enabler_ref;
+
+ if (!lttng_event_match_enabler(event, enabler))
+ continue;
+ enabler_ref = lttng_event_enabler_ref(event, enabler);
+ if (!enabler_ref) {
+ /*
+ * If no backward ref, create it.
+ * Add backward ref from event to enabler.
+ */
+ enabler_ref = kzalloc(sizeof(*enabler_ref), GFP_KERNEL);
+ if (!enabler_ref)
+ return -ENOMEM;
+ enabler_ref->ref = enabler;
+ list_add(&enabler_ref->node,
+ &event->enablers_ref_head);
+ }
+
+ /*
+ * Link filter bytecodes if not linked yet.
+ */
+ lttng_enabler_event_link_bytecode(event, enabler);
+
+ /* TODO: merge event context. */
+ }
+ return 0;
+}
+
+/*
+ * Called at module load: connect the probe on all enablers matching
+ * this event.
+ * Called with sessions lock held.
+ */
+int lttng_fix_pending_events(void)
+{
+ struct lttng_session *session;
+
+ list_for_each_entry(session, &sessions, list)
+ lttng_session_lazy_sync_enablers(session);
+ return 0;
+}
+
+struct lttng_enabler *lttng_enabler_create(enum lttng_enabler_type type,
+ struct lttng_kernel_event *event_param,
+ struct lttng_channel *chan)
+{
+ struct lttng_enabler *enabler;
+
+ enabler = kzalloc(sizeof(*enabler), GFP_KERNEL);
+ if (!enabler)
+ return NULL;
+ enabler->type = type;
+ INIT_LIST_HEAD(&enabler->filter_bytecode_head);
+ memcpy(&enabler->event_param, event_param,
+ sizeof(enabler->event_param));
+ enabler->chan = chan;
+ /* ctx left NULL */
+ enabler->enabled = 0;
+ enabler->evtype = LTTNG_TYPE_ENABLER;
+ mutex_lock(&sessions_mutex);
+ list_add(&enabler->node, &enabler->chan->session->enablers_head);
+ lttng_session_lazy_sync_enablers(enabler->chan->session);
+ mutex_unlock(&sessions_mutex);
+ return enabler;
+}
+
+int lttng_enabler_enable(struct lttng_enabler *enabler)
+{
+ mutex_lock(&sessions_mutex);
+ enabler->enabled = 1;
+ lttng_session_lazy_sync_enablers(enabler->chan->session);
+ mutex_unlock(&sessions_mutex);
+ return 0;
+}
+
+int lttng_enabler_disable(struct lttng_enabler *enabler)
+{
+ mutex_lock(&sessions_mutex);
+ enabler->enabled = 0;
+ lttng_session_lazy_sync_enablers(enabler->chan->session);
+ mutex_unlock(&sessions_mutex);
+ return 0;
+}
+
+int lttng_enabler_attach_bytecode(struct lttng_enabler *enabler,
+ struct lttng_kernel_filter_bytecode __user *bytecode)
+{
+ struct lttng_filter_bytecode_node *bytecode_node;
+ uint32_t bytecode_len;
+ int ret;
+
+ ret = get_user(bytecode_len, &bytecode->len);
+ if (ret)
+ return ret;
+ bytecode_node = kzalloc(sizeof(*bytecode_node) + bytecode_len,
+ GFP_KERNEL);
+ if (!bytecode_node)
+ return -ENOMEM;
+ ret = copy_from_user(&bytecode_node->bc, bytecode,
+ sizeof(*bytecode) + bytecode_len);
+ if (ret)
+ goto error_free;
+ bytecode_node->enabler = enabler;
+ /* Enforce length based on allocated size */
+ bytecode_node->bc.len = bytecode_len;
+ list_add_tail(&bytecode_node->node, &enabler->filter_bytecode_head);
+ lttng_session_lazy_sync_enablers(enabler->chan->session);
+ return 0;
+
+error_free:
+ kfree(bytecode_node);
+ return ret;
+}
+
+int lttng_enabler_attach_context(struct lttng_enabler *enabler,
+ struct lttng_kernel_context *context_param)
+{
+ return -ENOSYS;
+}
+
+static
+void lttng_enabler_destroy(struct lttng_enabler *enabler)
+{
+ struct lttng_filter_bytecode_node *filter_node, *tmp_filter_node;
+
+ /* Destroy filter bytecode */
+ list_for_each_entry_safe(filter_node, tmp_filter_node,
+ &enabler->filter_bytecode_head, node) {
+ kfree(filter_node);
+ }
+
+ /* Destroy contexts */
+ lttng_destroy_context(enabler->ctx);
+
+ list_del(&enabler->node);
+ kfree(enabler);
+}
+
+/*
+ * lttng_session_sync_enablers should be called just before starting a
+ * session.
+ * Should be called with sessions mutex held.
+ */
+static
+void lttng_session_sync_enablers(struct lttng_session *session)
+{
+ struct lttng_enabler *enabler;
+ struct lttng_event *event;
+
+ list_for_each_entry(enabler, &session->enablers_head, node)
+ lttng_enabler_ref_events(enabler);
+ /*
+ * For each event, if at least one of its enablers is enabled,
+ * and its channel and session transient states are enabled, we
+ * enable the event, else we disable it.
+ */
+ list_for_each_entry(event, &session->events, list) {
+ struct lttng_enabler_ref *enabler_ref;
+ struct lttng_bytecode_runtime *runtime;
+ int enabled = 0, has_enablers_without_bytecode = 0;
+
+ switch (event->instrumentation) {
+ case LTTNG_KERNEL_TRACEPOINT:
+ case LTTNG_KERNEL_SYSCALL:
+ /* Enable events */
+ list_for_each_entry(enabler_ref,
+ &event->enablers_ref_head, node) {
+ if (enabler_ref->ref->enabled) {
+ enabled = 1;
+ break;
+ }
+ }
+ break;
+ default:
+ /* Not handled with lazy sync. */
+ continue;
+ }
+ /*
+ * Enabled state is based on union of enablers, with
+ * intesection of session and channel transient enable
+ * states.
+ */
+ enabled = enabled && session->tstate && event->chan->tstate;
+
+ ACCESS_ONCE(event->enabled) = enabled;
+ /*
+ * Sync tracepoint registration with event enabled
+ * state.
+ */
+ if (enabled) {
+ register_event(event);
+ } else {
+ _lttng_event_unregister(event);
+ }
+
+ /* Check if has enablers without bytecode enabled */
+ list_for_each_entry(enabler_ref,
+ &event->enablers_ref_head, node) {
+ if (enabler_ref->ref->enabled
+ && list_empty(&enabler_ref->ref->filter_bytecode_head)) {
+ has_enablers_without_bytecode = 1;
+ break;
+ }
+ }
+ event->has_enablers_without_bytecode =
+ has_enablers_without_bytecode;
+
+ /* Enable filters */
+ list_for_each_entry(runtime,
+ &event->bytecode_runtime_head, node)
+ lttng_filter_sync_state(runtime);
+ }
+}
+
+/*
+ * Apply enablers to session events, adding events to session if need
+ * be. It is required after each modification applied to an active
+ * session, and right before session "start".
+ * "lazy" sync means we only sync if required.
+ * Should be called with sessions mutex held.
+ */
+static
+void lttng_session_lazy_sync_enablers(struct lttng_session *session)
+{
+ /* We can skip if session is not active */
+ if (!session->active)
+ return;
+ lttng_session_sync_enablers(session);
+}
+
/*
* Serialize at most one packet worth of metadata into a metadata
* channel.
- * We have exclusive access to our metadata buffer (protected by the
- * sessions_mutex), so we can do racy operations such as looking for
- * remaining space left in packet and write, since mutual exclusion
- * protects us from concurrent writes.
+ * We grab the metadata cache mutex to get exclusive access to our metadata
+ * buffer and to the metadata cache. Exclusive access to the metadata buffer
+ * allows us to do racy operations such as looking for remaining space left in
+ * packet and write, since mutual exclusion protects us from concurrent writes.
+ * Mutual exclusion on the metadata cache allow us to read the cache content
+ * without racing against reallocation of the cache by updates.
* Returns the number of bytes written in the channel, 0 if no data
* was written and a negative value on error.
*/
size_t len, reserve_len;
/*
- * Ensure we support mutiple get_next / put sequences followed
- * by put_next. The metadata stream lock internally protects
- * reading the metadata cache. It can indeed be read
- * concurrently by "get_next_subbuf" and "flush" operations on
- * the buffer invoked by different processes.
+ * Ensure we support mutiple get_next / put sequences followed by
+ * put_next. The metadata cache lock protects reading the metadata
+ * cache. It can indeed be read concurrently by "get_next_subbuf" and
+ * "flush" operations on the buffer invoked by different processes.
+ * Moreover, since the metadata cache memory can be reallocated, we
+ * need to have exclusive access against updates even though we only
+ * read it.
*/
- mutex_lock(&stream->lock);
+ mutex_lock(&stream->metadata_cache->lock);
WARN_ON(stream->metadata_in < stream->metadata_out);
if (stream->metadata_in != stream->metadata_out)
goto end;
ret = reserve_len;
end:
- mutex_unlock(&stream->lock);
+ mutex_unlock(&stream->metadata_cache->lock);
return ret;
}
/*
* Write the metadata to the metadata cache.
* Must be called with sessions_mutex held.
+ * The metadata cache lock protects us from concurrent read access from
+ * thread outputting metadata content to ring buffer.
*/
int lttng_metadata_printf(struct lttng_session *session,
const char *fmt, ...)
return -ENOMEM;
len = strlen(str);
+ mutex_lock(&session->metadata_cache->lock);
if (session->metadata_cache->metadata_written + len >
session->metadata_cache->cache_alloc) {
char *tmp_cache_realloc;
tmp_cache_alloc_size = max_t(unsigned int,
session->metadata_cache->cache_alloc + len,
session->metadata_cache->cache_alloc << 1);
- tmp_cache_realloc = krealloc(session->metadata_cache->data,
- tmp_cache_alloc_size, GFP_KERNEL);
+ tmp_cache_realloc = lttng_vzalloc(tmp_cache_alloc_size);
if (!tmp_cache_realloc)
goto err;
+ if (session->metadata_cache->data) {
+ memcpy(tmp_cache_realloc,
+ session->metadata_cache->data,
+ session->metadata_cache->cache_alloc);
+ vfree(session->metadata_cache->data);
+ }
+
session->metadata_cache->cache_alloc = tmp_cache_alloc_size;
session->metadata_cache->data = tmp_cache_realloc;
}
session->metadata_cache->metadata_written,
str, len);
session->metadata_cache->metadata_written += len;
+ mutex_unlock(&session->metadata_cache->lock);
kfree(str);
list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list)
return 0;
err:
+ mutex_unlock(&session->metadata_cache->lock);
kfree(str);
return -ENOMEM;
}
? "UTF8"
: "ASCII",
field->type.u.basic.integer.base,
-#ifdef __BIG_ENDIAN
+#if __BYTE_ORDER == __BIG_ENDIAN
field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
#else
field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
? "UTF8"
: "ASCII",
elem_type->u.basic.integer.base,
-#ifdef __BIG_ENDIAN
+#if __BYTE_ORDER == __BIG_ENDIAN
elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
#else
elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
? "UTF8"
: "ASCII"),
length_type->u.basic.integer.base,
-#ifdef __BIG_ENDIAN
+#if __BYTE_ORDER == __BIG_ENDIAN
length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
#else
length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
? "UTF8"
: "ASCII"),
elem_type->u.basic.integer.base,
-#ifdef __BIG_ENDIAN
+#if __BYTE_ORDER == __BIG_ENDIAN
elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
#else
elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
* taken at start of trace.
* Yes, this is only an approximation. Yes, we can (and will) do better
* in future versions.
+ * Return 0 if offset is negative. It may happen if the system sets
+ * the REALTIME clock to 0 after boot.
*/
static
uint64_t measure_clock_offset(void)
{
- uint64_t offset, monotonic[2], realtime;
+ uint64_t monotonic_avg, monotonic[2], realtime;
+ int64_t offset;
struct timespec rts = { 0, 0 };
unsigned long flags;
monotonic[1] = trace_clock_read64();
local_irq_restore(flags);
- offset = (monotonic[0] + monotonic[1]) >> 1;
+ monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
realtime = (uint64_t) rts.tv_sec * NSEC_PER_SEC;
realtime += rts.tv_nsec;
- offset = realtime - offset;
+ offset = (int64_t) realtime - monotonic_avg;
+ if (offset < 0)
+ return 0;
return offset;
}
CTF_SPEC_MAJOR,
CTF_SPEC_MINOR,
uuid_s,
-#ifdef __BIG_ENDIAN
+#if __BYTE_ORDER == __BIG_ENDIAN
"be"
#else
"le"
ret = wrapper_lttng_fixup_sig(THIS_MODULE);
if (ret)
return ret;
-
- ret = lttng_tracepoint_init();
+ ret = wrapper_get_pfnblock_flags_mask_init();
if (ret)
return ret;
+ ret = wrapper_get_pageblock_flags_mask_init();
+ if (ret)
+ return ret;
+ ret = lttng_context_init();
+ if (ret)
+ return ret;
+ ret = lttng_tracepoint_init();
+ if (ret)
+ goto error_tp;
event_cache = KMEM_CACHE(lttng_event, 0);
if (!event_cache) {
ret = -ENOMEM;
kmem_cache_destroy(event_cache);
error_kmem:
lttng_tracepoint_exit();
+error_tp:
+ lttng_context_exit();
return ret;
}
lttng_session_destroy(session);
kmem_cache_destroy(event_cache);
lttng_tracepoint_exit();
+ lttng_context_exit();
}
module_exit(lttng_events_exit);
projects / lttng-modules.git / blobdiff