/*
- * Copyright (C) 2008 Mathieu Desnoyers
+ * Copyright (C) 2008-2011 Mathieu Desnoyers
* Copyright (C) 2009 Pierre-Marc Fournier
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* Ported to userspace by Pierre-Marc Fournier.
*/
+#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 "usterr.h"
-
-#define _LGPL_SOURCE
#include <urcu-bp.h>
#include <urcu/hlist.h>
-//extern struct tracepoint __start___tracepoints[] __attribute__((visibility("hidden")));
-//extern struct tracepoint __stop___tracepoints[] __attribute__((visibility("hidden")));
+#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")));
/* Set to 1 to enable tracepoint debug output */
static const int tracepoint_debug;
+static int initialized;
+static void (*new_tracepoint_cb)(struct tracepoint *);
/* libraries that contain tracepoints (struct tracepoint_lib) */
static CDS_LIST_HEAD(libs);
/*
- * tracepoints_mutex nests inside module_mutex. Tracepoints mutex protects the
- * builtin and module tracepoints and the hash table.
+ * Allow nested mutex for mutex listing and nested enable.
*/
-static DEFINE_MUTEX(tracepoints_mutex);
+static __thread int nested_mutex;
+
+/*
+ * Tracepoints mutex protects the library tracepoints, the hash table,
+ * and the library list.
+ */
+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.
#define TRACEPOINT_TABLE_SIZE (1 << TRACEPOINT_HASH_BITS)
static struct cds_hlist_head tracepoint_table[TRACEPOINT_TABLE_SIZE];
+static CDS_LIST_HEAD(old_probes);
+static int need_update;
+
/*
* Note about RCU :
* It is used to to delay the free of multiple probes array until a quiescent
*/
struct tracepoint_entry {
struct cds_hlist_node hlist;
- struct probe *probes;
+ struct tracepoint_probe *probes;
int refcount; /* Number of times armed. 0 if disarmed. */
char name[0];
};
struct tp_probes {
union {
-//ust// struct rcu_head rcu;
struct cds_list_head list;
} u;
- struct probe probes[0];
+ struct tracepoint_probe probes[0];
};
static inline void *allocate_probes(int count)
{
- struct tp_probes *p = zmalloc(count * sizeof(struct probe)
+ struct tp_probes *p = zmalloc(count * sizeof(struct tracepoint_probe)
+ sizeof(struct tp_probes));
return p == NULL ? NULL : p->probes;
}
-//ust// static void rcu_free_old_probes(struct rcu_head *head)
-//ust// {
-//ust// kfree(container_of(head, struct tp_probes, u.rcu));
-//ust// }
-
static inline void release_probes(void *old)
{
if (old) {
struct tp_probes *tp_probes = _ust_container_of(old,
struct tp_probes, probes[0]);
-//ust// call_rcu_sched(&tp_probes->u.rcu, rcu_free_old_probes);
synchronize_rcu();
free(tp_probes);
}
void *probe, void *data)
{
int nr_probes = 0;
- struct probe *old, *new;
+ struct tracepoint_probe *old, *new;
WARN_ON(!probe);
if (new == NULL)
return ERR_PTR(-ENOMEM);
if (old)
- memcpy(new, old, nr_probes * sizeof(struct probe));
+ memcpy(new, old, nr_probes * sizeof(struct tracepoint_probe));
new[nr_probes].func = probe;
new[nr_probes].data = data;
new[nr_probes + 1].func = NULL;
void *data)
{
int nr_probes = 0, nr_del = 0, i;
- struct probe *old, *new;
+ struct tracepoint_probe *old, *new;
old = entry->probes;
* is used.
*/
rcu_assign_pointer(elem->probes, (*entry)->probes);
- elem->state__imv = active;
+ elem->state = active;
}
/*
*/
static void disable_tracepoint(struct tracepoint *elem)
{
- elem->state__imv = 0;
+ elem->state = 0;
rcu_assign_pointer(elem->probes, NULL);
}
*
* Updates the probe callback corresponding to a range of tracepoints.
*/
+static
void tracepoint_update_probe_range(struct tracepoint * const *begin,
struct tracepoint * const *end)
{
struct tracepoint * const *iter;
struct tracepoint_entry *mark_entry;
- pthread_mutex_lock(&tracepoints_mutex);
for (iter = begin; iter < end; iter++) {
if (!*iter)
continue; /* skip dummy */
disable_tracepoint(*iter);
}
}
- pthread_mutex_unlock(&tracepoints_mutex);
}
static void lib_update_tracepoints(void)
{
struct tracepoint_lib *lib;
-//ust// pthread_mutex_lock(&module_mutex);
- cds_list_for_each_entry(lib, &libs, list)
+ lock_tracepoints();
+ cds_list_for_each_entry(lib, &libs, list) {
tracepoint_update_probe_range(lib->tracepoints_start,
lib->tracepoints_start + lib->tracepoints_count);
-//ust// pthread_mutex_unlock(&module_mutex);
+ }
+ unlock_tracepoints();
}
/*
*/
static void tracepoint_update_probes(void)
{
- /* Core kernel tracepoints */
-//ust// tracepoint_update_probe_range(__start___tracepoints,
-//ust// __stop___tracepoints);
- /* tracepoints in modules. */
+ /* tracepoints registered from libraries and executable. */
lib_update_tracepoints();
- /* Update immediate values */
- core_imv_update();
-//ust// module_imv_update();
}
-static struct probe *
+static struct tracepoint_probe *
tracepoint_add_probe(const char *name, void *probe, void *data)
{
struct tracepoint_entry *entry;
- struct probe *old;
+ struct tracepoint_probe *old;
entry = get_tracepoint(name);
if (!entry) {
entry = add_tracepoint(name);
if (IS_ERR(entry))
- return (struct probe *)entry;
+ return (struct tracepoint_probe *)entry;
}
old = tracepoint_entry_add_probe(entry, probe, data);
if (IS_ERR(old) && !entry->refcount)
}
/**
- * tracepoint_probe_register - Connect a probe to a tracepoint
+ * __tracepoint_probe_register - Connect a probe to a tracepoint
* @name: tracepoint name
* @probe: probe handler
*
* Returns 0 if ok, error value on error.
* The probe address must at least be aligned on the architecture pointer size.
*/
-int tracepoint_probe_register(const char *name, void *probe, void *data)
+int __tracepoint_probe_register(const char *name, void *probe, void *data)
{
void *old;
- pthread_mutex_lock(&tracepoints_mutex);
+ lock_tracepoints();
old = tracepoint_add_probe(name, probe, data);
- pthread_mutex_unlock(&tracepoints_mutex);
+ unlock_tracepoints();
if (IS_ERR(old))
return PTR_ERR(old);
release_probes(old);
return 0;
}
-//ust// EXPORT_SYMBOL_GPL(tracepoint_probe_register);
static void *tracepoint_remove_probe(const char *name, void *probe, void *data)
{
* itself uses stop_machine(), which insures that every preempt disabled section
* have finished.
*/
-int tracepoint_probe_unregister(const char *name, void *probe, void *data)
+int __tracepoint_probe_unregister(const char *name, void *probe, void *data)
{
void *old;
- pthread_mutex_lock(&tracepoints_mutex);
+ lock_tracepoints();
old = tracepoint_remove_probe(name, probe, data);
- pthread_mutex_unlock(&tracepoints_mutex);
+ unlock_tracepoints();
if (IS_ERR(old))
return PTR_ERR(old);
release_probes(old);
return 0;
}
-//ust// EXPORT_SYMBOL_GPL(tracepoint_probe_unregister);
-
-static CDS_LIST_HEAD(old_probes);
-static int need_update;
static void tracepoint_add_old_probes(void *old)
{
{
void *old;
- pthread_mutex_lock(&tracepoints_mutex);
+ lock_tracepoints();
old = tracepoint_add_probe(name, probe, data);
if (IS_ERR(old)) {
- pthread_mutex_unlock(&tracepoints_mutex);
+ unlock_tracepoints();
return PTR_ERR(old);
}
tracepoint_add_old_probes(old);
- pthread_mutex_unlock(&tracepoints_mutex);
+ unlock_tracepoints();
return 0;
}
-//ust// EXPORT_SYMBOL_GPL(tracepoint_probe_register_noupdate);
/**
* tracepoint_probe_unregister_noupdate - remove a probe but not disconnect
{
void *old;
- pthread_mutex_lock(&tracepoints_mutex);
+ lock_tracepoints();
old = tracepoint_remove_probe(name, probe, data);
if (IS_ERR(old)) {
- pthread_mutex_unlock(&tracepoints_mutex);
+ unlock_tracepoints();
return PTR_ERR(old);
}
tracepoint_add_old_probes(old);
- pthread_mutex_unlock(&tracepoints_mutex);
+ unlock_tracepoints();
return 0;
}
-//ust// EXPORT_SYMBOL_GPL(tracepoint_probe_unregister_noupdate);
/**
* tracepoint_probe_update_all - update tracepoints
CDS_LIST_HEAD(release_probes);
struct tp_probes *pos, *next;
- pthread_mutex_lock(&tracepoints_mutex);
+ lock_tracepoints();
if (!need_update) {
- pthread_mutex_unlock(&tracepoints_mutex);
+ unlock_tracepoints();
return;
}
if (!cds_list_empty(&old_probes))
cds_list_replace_init(&old_probes, &release_probes);
need_update = 0;
- pthread_mutex_unlock(&tracepoints_mutex);
+ unlock_tracepoints();
tracepoint_update_probes();
cds_list_for_each_entry_safe(pos, next, &release_probes, u.list) {
cds_list_del(&pos->u.list);
-//ust// call_rcu_sched(&pos->u.rcu, rcu_free_old_probes);
synchronize_rcu();
free(pos);
}
}
-//ust// EXPORT_SYMBOL_GPL(tracepoint_probe_update_all);
/*
* Returns 0 if current not found.
* Returns 1 if current found.
+ *
+ * Called with tracepoint mutex held
*/
int lib_get_iter_tracepoints(struct tracepoint_iter *iter)
{
struct tracepoint_lib *iter_lib;
int found = 0;
-//ust// pthread_mutex_lock(&module_mutex);
cds_list_for_each_entry(iter_lib, &libs, list) {
if (iter_lib < iter->lib)
continue;
break;
}
}
-//ust// pthread_mutex_unlock(&module_mutex);
return found;
}
* Returns whether a next tracepoint has been found (1) or not (0).
* Will return the first tracepoint in the range if the input tracepoint is
* NULL.
+ * Called with tracepoint mutex held.
*/
int tracepoint_get_iter_range(struct tracepoint * const **tracepoint,
struct tracepoint * const *begin, struct tracepoint * const *end)
}
return 0;
}
-//ust// EXPORT_SYMBOL_GPL(tracepoint_get_iter_range);
+/*
+ * Called with tracepoint mutex held.
+ */
static void tracepoint_get_iter(struct tracepoint_iter *iter)
{
int found = 0;
-//ust// /* Core kernel tracepoints */
-//ust// if (!iter->module) {
-//ust// found = tracepoint_get_iter_range(&iter->tracepoint,
-//ust// __start___tracepoints, __stop___tracepoints);
-//ust// if (found)
-//ust// goto end;
-//ust// }
/* tracepoints in libs. */
found = lib_get_iter_tracepoints(iter);
-//ust// end:
if (!found)
tracepoint_iter_reset(iter);
}
void tracepoint_iter_start(struct tracepoint_iter *iter)
{
+ lock_tracepoints();
tracepoint_get_iter(iter);
}
-//ust// EXPORT_SYMBOL_GPL(tracepoint_iter_start);
+/*
+ * Called with tracepoint mutex held.
+ */
void tracepoint_iter_next(struct tracepoint_iter *iter)
{
iter->tracepoint++;
*/
tracepoint_get_iter(iter);
}
-//ust// EXPORT_SYMBOL_GPL(tracepoint_iter_next);
void tracepoint_iter_stop(struct tracepoint_iter *iter)
{
+ unlock_tracepoints();
}
-//ust// EXPORT_SYMBOL_GPL(tracepoint_iter_stop);
void tracepoint_iter_reset(struct tracepoint_iter *iter)
{
-//ust// iter->module = NULL;
iter->tracepoint = NULL;
}
-//ust// EXPORT_SYMBOL_GPL(tracepoint_iter_reset);
-
-//ust// #ifdef CONFIG_MODULES
-
-//ust// int tracepoint_module_notify(struct notifier_block *self,
-//ust// unsigned long val, void *data)
-//ust// {
-//ust// struct module *mod = data;
-//ust//
-//ust// switch (val) {
-//ust// case MODULE_STATE_COMING:
-//ust// tracepoint_update_probe_range(mod->tracepoints,
-//ust// mod->tracepoints + mod->num_tracepoints);
-//ust// break;
-//ust// case MODULE_STATE_GOING:
-//ust// tracepoint_update_probe_range(mod->tracepoints,
-//ust// mod->tracepoints + mod->num_tracepoints);
-//ust// break;
-//ust// }
-//ust// return 0;
-//ust// }
-
-//ust// struct notifier_block tracepoint_module_nb = {
-//ust// .notifier_call = tracepoint_module_notify,
-//ust// .priority = 0,
-//ust// };
-
-//ust// static int init_tracepoints(void)
-//ust// {
-//ust// return register_module_notifier(&tracepoint_module_nb);
-//ust// }
-//ust// __initcall(init_tracepoints);
-
-//ust// #endif /* CONFIG_MODULES */
-
-static void (*new_tracepoint_cb)(struct tracepoint *) = NULL;
void tracepoint_set_new_tracepoint_cb(void (*cb)(struct tracepoint *))
{
if (new_tracepoint_cb) {
struct tracepoint * const *t;
- for(t = start; t < end; t++) {
+ for (t = start; t < end; t++) {
if (*t)
new_tracepoint_cb(*t);
}
}
}
-int tracepoint_register_lib(struct tracepoint * const *tracepoints_start, int tracepoints_count)
+int tracepoint_register_lib(struct tracepoint * const *tracepoints_start,
+ int tracepoints_count)
{
struct tracepoint_lib *pl, *iter;
pl->tracepoints_start = tracepoints_start;
pl->tracepoints_count = tracepoints_count;
- /* FIXME: maybe protect this with its own mutex? */
- pthread_mutex_lock(&tracepoints_mutex);
+ lock_tracepoints();
/*
* 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:
- pthread_mutex_unlock(&tracepoints_mutex);
+ unlock_tracepoints();
new_tracepoints(tracepoints_start, tracepoints_start + tracepoints_count);
- /* FIXME: update just the loaded lib */
+ /* TODO: update just the loaded lib */
lib_update_tracepoints();
/* tracepoints_count - 1: skip dummy */
- DBG("just registered a tracepoints section from %p and having %d tracepoints", tracepoints_start, tracepoints_count - 1);
+ DBG("just registered a tracepoints section from %p and having %d tracepoints (minus dummy tracepoints)", tracepoints_start, tracepoints_count);
return 0;
}
{
struct tracepoint_lib *lib;
- pthread_mutex_lock(&tracepoints_mutex);
-
+ lock_tracepoints();
cds_list_for_each_entry(lib, &libs, list) {
if (lib->tracepoints_start == tracepoints_start) {
struct tracepoint_lib *lib2free = lib;
break;
}
}
-
- pthread_mutex_unlock(&tracepoints_mutex);
+ unlock_tracepoints();
return 0;
}
+
+void __attribute__((constructor)) init_tracepoint(void)
+{
+ if (!initialized) {
+ tracepoint_register_lib(__start___tracepoints_ptrs,
+ __stop___tracepoints_ptrs
+ - __start___tracepoints_ptrs);
+ initialized = 1;
+ }
+}
+
+void __attribute__((destructor)) destroy_tracepoint(void)
+{
+ tracepoint_unregister_lib(__start___tracepoints_ptrs);
+}
projects / ust.git / blobdiff