#define _LGPL_SOURCE
#include <errno.h>
-#include <ust/tracepoint.h>
-#include <ust/tracepoint-internal.h>
-#include <ust/core.h>
-#include <ust/kcompat/kcompat.h>
+#include <lttng/tracepoint.h>
+#include <lttng/tracepoint-internal.h>
+#include <lttng/core.h>
+#include <lttng/kcompat/kcompat.h>
#include <urcu-bp.h>
#include <urcu/hlist.h>
+#include <urcu/uatomic.h>
-#include "usterr_signal_safe.h"
-
-extern struct tracepoint * const __start___tracepoints_ptrs[]
- __attribute__((visibility("hidden")));
-extern struct tracepoint * const __stop___tracepoints_ptrs[]
- __attribute__((visibility("hidden")));
-
-static struct tracepoint * __tracepoint_ptr_dummy
- __attribute__((used, section("__tracepoints_ptrs")));
+#include <lttng/usterr-signal-safe.h>
+#include "ltt-tracer-core.h"
/* Set to 1 to enable tracepoint debug output */
static const int tracepoint_debug;
static CDS_LIST_HEAD(libs);
/*
- * Allow nested mutex for mutex listing and nested enable.
- */
-static __thread int nested_mutex;
-
-/*
- * Tracepoints mutex protects the library tracepoints, the hash table,
- * and the library list.
+ * The UST lock protects the library tracepoints, the hash table, and
+ * the library list.
+ * All calls to the tracepoint API must be protected by the UST lock,
+ * excepts calls to tracepoint_register_lib and
+ * tracepoint_unregister_lib, which take the UST lock themselves.
*/
-static pthread_mutex_t tracepoints_mutex;
-
-static
-void lock_tracepoints(void)
-{
- if (!(nested_mutex++))
- pthread_mutex_lock(&tracepoints_mutex);
-}
-
-static
-void unlock_tracepoints(void)
-{
- if (!(--nested_mutex))
- pthread_mutex_unlock(&tracepoints_mutex);
-}
/*
* Tracepoint hash table, containing the active tracepoints.
/*
* Remove the tracepoint from the tracepoint hash table. Must be called with
- * mutex_lock held.
+ * ust_lock held.
*/
static inline void remove_tracepoint(struct tracepoint_entry *e)
{
{
struct tracepoint_lib *lib;
- lock_tracepoints();
cds_list_for_each_entry(lib, &libs, list) {
tracepoint_update_probe_range(lib->tracepoints_start,
lib->tracepoints_start + lib->tracepoints_count);
}
- unlock_tracepoints();
}
/*
*
* Returns 0 if ok, error value on error.
* The probe address must at least be aligned on the architecture pointer size.
+ * Called with the UST lock held.
*/
int __tracepoint_probe_register(const char *name, void *probe, void *data)
{
void *old;
- lock_tracepoints();
old = tracepoint_add_probe(name, probe, data);
- unlock_tracepoints();
if (IS_ERR(old))
return PTR_ERR(old);
* @probe: probe function pointer
* @probe: probe data pointer
*
- * We do not need to call a synchronize_sched to make sure the probes have
- * finished running before doing a module unload, because the module unload
- * itself uses stop_machine(), which insures that every preempt disabled section
- * have finished.
+ * Called with the UST lock held.
*/
int __tracepoint_probe_unregister(const char *name, void *probe, void *data)
{
void *old;
- lock_tracepoints();
old = tracepoint_remove_probe(name, probe, data);
- unlock_tracepoints();
if (IS_ERR(old))
return PTR_ERR(old);
* @probe: probe handler
*
* caller must call tracepoint_probe_update_all()
+ * Called with the UST lock held.
*/
int tracepoint_probe_register_noupdate(const char *name, void *probe,
void *data)
{
void *old;
- lock_tracepoints();
old = tracepoint_add_probe(name, probe, data);
if (IS_ERR(old)) {
- unlock_tracepoints();
return PTR_ERR(old);
}
tracepoint_add_old_probes(old);
- unlock_tracepoints();
return 0;
}
* @probe: probe function pointer
*
* caller must call tracepoint_probe_update_all()
+ * Called with the UST lock held.
*/
int tracepoint_probe_unregister_noupdate(const char *name, void *probe,
void *data)
{
void *old;
- lock_tracepoints();
old = tracepoint_remove_probe(name, probe, data);
if (IS_ERR(old)) {
- unlock_tracepoints();
return PTR_ERR(old);
}
tracepoint_add_old_probes(old);
- unlock_tracepoints();
return 0;
}
/**
* tracepoint_probe_update_all - update tracepoints
+ * Called with the UST lock held.
*/
void tracepoint_probe_update_all(void)
{
CDS_LIST_HEAD(release_probes);
struct tp_probes *pos, *next;
- lock_tracepoints();
if (!need_update) {
- unlock_tracepoints();
return;
}
if (!cds_list_empty(&old_probes))
cds_list_replace_init(&old_probes, &release_probes);
need_update = 0;
- unlock_tracepoints();
tracepoint_update_probes();
cds_list_for_each_entry_safe(pos, next, &release_probes, u.list) {
tracepoint_iter_reset(iter);
}
+/*
+ * Called with UST lock held.
+ */
void tracepoint_iter_start(struct tracepoint_iter *iter)
{
- lock_tracepoints();
tracepoint_get_iter(iter);
}
/*
- * Called with tracepoint mutex held.
+ * Called with UST lock held.
*/
void tracepoint_iter_next(struct tracepoint_iter *iter)
{
tracepoint_get_iter(iter);
}
+/*
+ * Called with UST lock held.
+ */
void tracepoint_iter_stop(struct tracepoint_iter *iter)
{
- unlock_tracepoints();
}
void tracepoint_iter_reset(struct tracepoint_iter *iter)
{
struct tracepoint_lib *pl, *iter;
+ init_tracepoint();
+
pl = (struct tracepoint_lib *) zmalloc(sizeof(struct tracepoint_lib));
pl->tracepoints_start = tracepoints_start;
pl->tracepoints_count = tracepoints_count;
- lock_tracepoints();
+ ust_lock();
/*
* We sort the libs by struct lib pointer address.
*/
/* We should be added at the head of the list */
cds_list_add(&pl->list, &libs);
lib_added:
- unlock_tracepoints();
-
new_tracepoints(tracepoints_start, tracepoints_start + tracepoints_count);
/* TODO: update just the loaded lib */
lib_update_tracepoints();
+ ust_unlock();
- /* tracepoints_count - 1: skip dummy */
- DBG("just registered a tracepoints section from %p and having %d tracepoints (minus dummy tracepoints)", tracepoints_start, tracepoints_count);
+ DBG("just registered a tracepoints section from %p and having %d tracepoints",
+ tracepoints_start, tracepoints_count);
return 0;
}
{
struct tracepoint_lib *lib;
- lock_tracepoints();
+ ust_lock();
cds_list_for_each_entry(lib, &libs, list) {
if (lib->tracepoints_start == tracepoints_start) {
struct tracepoint_lib *lib2free = lib;
break;
}
}
- unlock_tracepoints();
+ ust_unlock();
return 0;
}
-void __attribute__((constructor)) init_tracepoint(void)
+void init_tracepoint(void)
{
- if (!initialized) {
- tracepoint_register_lib(__start___tracepoints_ptrs,
- __stop___tracepoints_ptrs
- - __start___tracepoints_ptrs);
- initialized = 1;
- }
+ if (uatomic_xchg(&initialized, 1) == 1)
+ return;
+ init_usterr();
}
-void __attribute__((destructor)) destroy_tracepoint(void)
+void exit_tracepoint(void)
{
- tracepoint_unregister_lib(__start___tracepoints_ptrs);
+ initialized = 0;
}
projects / lttng-ust.git / blobdiff