tracepoint: Remove unused API functions

After the following commit:

commit b75ef8b44b1cb95f5a26484b0e2fe37a63b12b44
Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date:   Wed Aug 10 15:18:39 2011 -0400

    Tracepoint: Dissociate from module mutex

The following functions became unnecessary:

- tracepoint_probe_register_noupdate,
- tracepoint_probe_unregister_noupdate,
- tracepoint_probe_update_all.

In fact, none of the in-kernel tracers, nor LTTng, nor SystemTAP use
them. Remove those.

Moreover, the functions:

- tracepoint_iter_start,
- tracepoint_iter_next,
- tracepoint_iter_stop,
- tracepoint_iter_reset.

are unused by in-kernel tracers, LTTng and SystemTAP. Remove those too.

Link: http://lkml.kernel.org/r/1395379142-2118-2-git-send-email-mathieu.desnoyers@efficios.com

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

2 files changed, 5 insertions, 235 deletions

diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index accc497f8d72..a3b2837d8dd1 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -48,12 +48,6 @@ extern int tracepoint_probe_register(const char *name, void *probe, void *data);
 extern int
 tracepoint_probe_unregister(const char *name, void *probe, void *data);
 
-extern int tracepoint_probe_register_noupdate(const char *name, void *probe,
-                                              void *data);
-extern int tracepoint_probe_unregister_noupdate(const char *name, void *probe,
-                                                void *data);
-extern void tracepoint_probe_update_all(void);
-
 #ifdef CONFIG_MODULES
 struct tp_module {
         struct list_head list;
@@ -62,18 +56,6 @@ struct tp_module {
 };
 #endif /* CONFIG_MODULES */
 
-struct tracepoint_iter {
-#ifdef CONFIG_MODULES
-        struct tp_module *module;
-#endif /* CONFIG_MODULES */
-        struct tracepoint * const *tracepoint;
-};
-
-extern void tracepoint_iter_start(struct tracepoint_iter *iter);
-extern void tracepoint_iter_next(struct tracepoint_iter *iter);
-extern void tracepoint_iter_stop(struct tracepoint_iter *iter);
-extern void tracepoint_iter_reset(struct tracepoint_iter *iter);
-
 /*
  * tracepoint_synchronize_unregister must be called between the last tracepoint
  * probe unregistration and the end of module exit to make sure there is no
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index e2a58a22b0f4..65d9f9459a75 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -67,10 +67,7 @@ struct tracepoint_entry {
 };
 
 struct tp_probes {
-        union {
-                struct rcu_head rcu;
-                struct list_head list;
-        } u;
+        struct rcu_head rcu;
         struct tracepoint_func probes[0];
 };
 
@@ -83,7 +80,7 @@ static inline void *allocate_probes(int count)
 
 static void rcu_free_old_probes(struct rcu_head *head)
 {
-        kfree(container_of(head, struct tp_probes, u.rcu));
+        kfree(container_of(head, struct tp_probes, rcu));
 }
 
 static inline void release_probes(struct tracepoint_func *old)
@@ -91,7 +88,7 @@ static inline void release_probes(struct tracepoint_func *old)
         if (old) {
                 struct tp_probes *tp_probes = container_of(old,
                         struct tp_probes, probes[0]);
-                call_rcu_sched(&tp_probes->u.rcu, rcu_free_old_probes);
+                call_rcu_sched(&tp_probes->rcu, rcu_free_old_probes);
         }
 }
 
@@ -459,204 +456,11 @@ int tracepoint_probe_unregister(const char *name, void *probe, void *data)
 }
 EXPORT_SYMBOL_GPL(tracepoint_probe_unregister);
 
-static LIST_HEAD(old_probes);
-static int need_update;
-
-static void tracepoint_add_old_probes(void *old)
-{
-        need_update = 1;
-        if (old) {
-                struct tp_probes *tp_probes = container_of(old,
-                        struct tp_probes, probes[0]);
-                list_add(&tp_probes->u.list, &old_probes);
-        }
-}
-
-/**
- * tracepoint_probe_register_noupdate -  register a probe but not connect
- * @name: tracepoint name
- * @probe: probe handler
- * @data: probe private data
- *
- * caller must call tracepoint_probe_update_all()
- */
-int tracepoint_probe_register_noupdate(const char *name, void *probe,
-                                       void *data)
-{
-        struct tracepoint_func *old;
-
-        mutex_lock(&tracepoints_mutex);
-        old = tracepoint_add_probe(name, probe, data);
-        if (IS_ERR(old)) {
-                mutex_unlock(&tracepoints_mutex);
-                return PTR_ERR(old);
-        }
-        tracepoint_add_old_probes(old);
-        mutex_unlock(&tracepoints_mutex);
-        return 0;
-}
-EXPORT_SYMBOL_GPL(tracepoint_probe_register_noupdate);
-
-/**
- * tracepoint_probe_unregister_noupdate -  remove a probe but not disconnect
- * @name: tracepoint name
- * @probe: probe function pointer
- * @data: probe private data
- *
- * caller must call tracepoint_probe_update_all()
- */
-int tracepoint_probe_unregister_noupdate(const char *name, void *probe,
-                                         void *data)
-{
-        struct tracepoint_func *old;
-
-        mutex_lock(&tracepoints_mutex);
-        old = tracepoint_remove_probe(name, probe, data);
-        if (IS_ERR(old)) {
-                mutex_unlock(&tracepoints_mutex);
-                return PTR_ERR(old);
-        }
-        tracepoint_add_old_probes(old);
-        mutex_unlock(&tracepoints_mutex);
-        return 0;
-}
-EXPORT_SYMBOL_GPL(tracepoint_probe_unregister_noupdate);
-
-/**
- * tracepoint_probe_update_all -  update tracepoints
- */
-void tracepoint_probe_update_all(void)
-{
-        LIST_HEAD(release_probes);
-        struct tp_probes *pos, *next;
-
-        mutex_lock(&tracepoints_mutex);
-        if (!need_update) {
-                mutex_unlock(&tracepoints_mutex);
-                return;
-        }
-        if (!list_empty(&old_probes))
-                list_replace_init(&old_probes, &release_probes);
-        need_update = 0;
-        tracepoint_update_probes();
-        mutex_unlock(&tracepoints_mutex);
-        list_for_each_entry_safe(pos, next, &release_probes, u.list) {
-                list_del(&pos->u.list);
-                call_rcu_sched(&pos->u.rcu, rcu_free_old_probes);
-        }
-}
-EXPORT_SYMBOL_GPL(tracepoint_probe_update_all);
-
-/**
- * tracepoint_get_iter_range - Get a next tracepoint iterator given a range.
- * @tracepoint: current tracepoints (in), next tracepoint (out)
- * @begin: beginning of the range
- * @end: end of the range
- *
- * 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.
- */
-static int tracepoint_get_iter_range(struct tracepoint * const **tracepoint,
-        struct tracepoint * const *begin, struct tracepoint * const *end)
-{
-        if (!*tracepoint && begin != end) {
-                *tracepoint = begin;
-                return 1;
-        }
-        if (*tracepoint >= begin && *tracepoint < end)
-                return 1;
-        return 0;
-}
-
-#ifdef CONFIG_MODULES
-static void tracepoint_get_iter(struct tracepoint_iter *iter)
-{
-        int found = 0;
-        struct tp_module *iter_mod;
-
-        /* Core kernel tracepoints */
-        if (!iter->module) {
-                found = tracepoint_get_iter_range(&iter->tracepoint,
-                                __start___tracepoints_ptrs,
-                                __stop___tracepoints_ptrs);
-                if (found)
-                        goto end;
-        }
-        /* Tracepoints in modules */
-        mutex_lock(&tracepoints_mutex);
-        list_for_each_entry(iter_mod, &tracepoint_module_list, list) {
-                /*
-                 * Sorted module list
-                 */
-                if (iter_mod < iter->module)
-                        continue;
-                else if (iter_mod > iter->module)
-                        iter->tracepoint = NULL;
-                found = tracepoint_get_iter_range(&iter->tracepoint,
-                        iter_mod->tracepoints_ptrs,
-                        iter_mod->tracepoints_ptrs
-                                + iter_mod->num_tracepoints);
-                if (found) {
-                        iter->module = iter_mod;
-                        break;
-                }
-        }
-        mutex_unlock(&tracepoints_mutex);
-end:
-        if (!found)
-                tracepoint_iter_reset(iter);
-}
-#else /* CONFIG_MODULES */
-static void tracepoint_get_iter(struct tracepoint_iter *iter)
-{
-        int found = 0;
-
-        /* Core kernel tracepoints */
-        found = tracepoint_get_iter_range(&iter->tracepoint,
-                        __start___tracepoints_ptrs,
-                        __stop___tracepoints_ptrs);
-        if (!found)
-                tracepoint_iter_reset(iter);
-}
-#endif /* CONFIG_MODULES */
-
-void tracepoint_iter_start(struct tracepoint_iter *iter)
-{
-        tracepoint_get_iter(iter);
-}
-EXPORT_SYMBOL_GPL(tracepoint_iter_start);
-
-void tracepoint_iter_next(struct tracepoint_iter *iter)
-{
-        iter->tracepoint++;
-        /*
-         * iter->tracepoint may be invalid because we blindly incremented it.
-         * Make sure it is valid by marshalling on the tracepoints, getting the
-         * tracepoints from following modules if necessary.
-         */
-        tracepoint_get_iter(iter);
-}
-EXPORT_SYMBOL_GPL(tracepoint_iter_next);
-
-void tracepoint_iter_stop(struct tracepoint_iter *iter)
-{
-}
-EXPORT_SYMBOL_GPL(tracepoint_iter_stop);
-
-void tracepoint_iter_reset(struct tracepoint_iter *iter)
-{
-#ifdef CONFIG_MODULES
-        iter->module = NULL;
-#endif /* CONFIG_MODULES */
-        iter->tracepoint = NULL;
-}
-EXPORT_SYMBOL_GPL(tracepoint_iter_reset);
 
 #ifdef CONFIG_MODULES
 static int tracepoint_module_coming(struct module *mod)
 {
-        struct tp_module *tp_mod, *iter;
+        struct tp_module *tp_mod;
         int ret = 0;
 
         if (!mod->num_tracepoints)
@@ -677,23 +481,7 @@ static int tracepoint_module_coming(struct module *mod)
         }
         tp_mod->num_tracepoints = mod->num_tracepoints;
         tp_mod->tracepoints_ptrs = mod->tracepoints_ptrs;
-
-        /*
-         * tracepoint_module_list is kept sorted by struct module pointer
-         * address for iteration on tracepoints from a seq_file that can release
-         * the mutex between calls.
-         */
-        list_for_each_entry_reverse(iter, &tracepoint_module_list, list) {
-                BUG_ON(iter == tp_mod); /* Should never be in the list twice */
-                if (iter < tp_mod) {
-                        /* We belong to the location right after iter. */
-                        list_add(&tp_mod->list, &iter->list);
-                        goto module_added;
-                }
-        }
-        /* We belong to the beginning of the list */
-        list_add(&tp_mod->list, &tracepoint_module_list);
-module_added:
+        list_add_tail(&tp_mod->list, &tracepoint_module_list);
         tracepoint_update_probe_range(mod->tracepoints_ptrs,
                 mod->tracepoints_ptrs + mod->num_tracepoints);
 end: