static const int tracepoint_debug;
/*
- * tracepoints_mutex nests inside module_mutex. Tracepoints mutex protects the
- * builtin and module tracepoints and the hash table.
+ * Tracepoints mutex protects the builtin and module tracepoints and the hash
+ * table, as well as the local module list.
*/
static DEFINE_MUTEX(tracepoints_mutex);
+#ifdef CONFIG_MODULES
+/* Local list of struct module */
+static LIST_HEAD(tracepoint_module_list);
+#endif /* CONFIG_MODULES */
+
/*
* Tracepoint hash table, containing the active tracepoints.
* Protected by tracepoints_mutex.
* @end: end of the range
*
* Updates the probe callback corresponding to a range of tracepoints.
+ * Called with tracepoints_mutex held.
*/
-void tracepoint_update_probe_range(struct tracepoint * const *begin,
- struct tracepoint * const *end)
+static void tracepoint_update_probe_range(struct tracepoint * const *begin,
+ struct tracepoint * const *end)
{
struct tracepoint * const *iter;
struct tracepoint_entry *mark_entry;
if (!begin)
return;
- mutex_lock(&tracepoints_mutex);
for (iter = begin; iter < end; iter++) {
mark_entry = get_tracepoint((*iter)->name);
if (mark_entry) {
disable_tracepoint(*iter);
}
}
- mutex_unlock(&tracepoints_mutex);
}
+#ifdef CONFIG_MODULES
+void module_update_tracepoints(void)
+{
+ struct tp_module *tp_mod;
+
+ list_for_each_entry(tp_mod, &tracepoint_module_list, list)
+ tracepoint_update_probe_range(tp_mod->tracepoints_ptrs,
+ tp_mod->tracepoints_ptrs + tp_mod->num_tracepoints);
+}
+#else /* CONFIG_MODULES */
+void module_update_tracepoints(void)
+{
+}
+#endif /* CONFIG_MODULES */
+
+
/*
* Update probes, removing the faulty probes.
+ * Called with tracepoints_mutex held.
*/
static void tracepoint_update_probes(void)
{
mutex_lock(&tracepoints_mutex);
old = tracepoint_add_probe(name, probe, data);
- mutex_unlock(&tracepoints_mutex);
- if (IS_ERR(old))
+ if (IS_ERR(old)) {
+ mutex_unlock(&tracepoints_mutex);
return PTR_ERR(old);
-
+ }
tracepoint_update_probes(); /* may update entry */
+ mutex_unlock(&tracepoints_mutex);
release_probes(old);
return 0;
}
mutex_lock(&tracepoints_mutex);
old = tracepoint_remove_probe(name, probe, data);
- mutex_unlock(&tracepoints_mutex);
- if (IS_ERR(old))
+ if (IS_ERR(old)) {
+ mutex_unlock(&tracepoints_mutex);
return PTR_ERR(old);
-
+ }
tracepoint_update_probes(); /* may update entry */
+ mutex_unlock(&tracepoints_mutex);
release_probes(old);
return 0;
}
if (!list_empty(&old_probes))
list_replace_init(&old_probes, &release_probes);
need_update = 0;
- mutex_unlock(&tracepoints_mutex);
-
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);
* Will return the first tracepoint in the range if the input tracepoint is
* NULL.
*/
-int tracepoint_get_iter_range(struct tracepoint * const **tracepoint,
+static int tracepoint_get_iter_range(struct tracepoint * const **tracepoint,
struct tracepoint * const *begin, struct tracepoint * const *end)
{
if (!*tracepoint && begin != end) {
return 1;
return 0;
}
-EXPORT_SYMBOL_GPL(tracepoint_get_iter_range);
+#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) {
if (found)
goto end;
}
- /* tracepoints in modules. */
- found = module_get_iter_tracepoints(iter);
+ /* 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)
{
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;
+ int ret = 0;
+
+ /*
+ * We skip modules that tain the kernel, especially those with different
+ * module header (for forced load), to make sure we don't cause a crash.
+ */
+ if (mod->taints)
+ return 0;
+ mutex_lock(&tracepoints_mutex);
+ tp_mod = kmalloc(sizeof(struct tp_module), GFP_KERNEL);
+ if (!tp_mod) {
+ ret = -ENOMEM;
+ goto end;
+ }
+ 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:
+ tracepoint_update_probe_range(mod->tracepoints_ptrs,
+ mod->tracepoints_ptrs + mod->num_tracepoints);
+end:
+ mutex_unlock(&tracepoints_mutex);
+ return ret;
+}
+
+static int tracepoint_module_going(struct module *mod)
+{
+ struct tp_module *pos;
+
+ mutex_lock(&tracepoints_mutex);
+ tracepoint_update_probe_range(mod->tracepoints_ptrs,
+ mod->tracepoints_ptrs + mod->num_tracepoints);
+ list_for_each_entry(pos, &tracepoint_module_list, list) {
+ if (pos->tracepoints_ptrs == mod->tracepoints_ptrs) {
+ list_del(&pos->list);
+ kfree(pos);
+ break;
+ }
+ }
+ /*
+ * In the case of modules that were tainted at "coming", we'll simply
+ * walk through the list without finding it. We cannot use the "tainted"
+ * flag on "going", in case a module taints the kernel only after being
+ * loaded.
+ */
+ mutex_unlock(&tracepoints_mutex);
+ return 0;
+}
int tracepoint_module_notify(struct notifier_block *self,
unsigned long val, void *data)
{
struct module *mod = data;
+ int ret = 0;
switch (val) {
case MODULE_STATE_COMING:
+ ret = tracepoint_module_coming(mod);
+ break;
+ case MODULE_STATE_LIVE:
+ break;
case MODULE_STATE_GOING:
- tracepoint_update_probe_range(mod->tracepoints_ptrs,
- mod->tracepoints_ptrs + mod->num_tracepoints);
+ ret = tracepoint_module_going(mod);
break;
}
- return 0;
+ return ret;
}
struct notifier_block tracepoint_module_nb = {
return register_module_notifier(&tracepoint_module_nb);
}
__initcall(init_tracepoints);
-
#endif /* CONFIG_MODULES */
#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
projects / platform / upstream / kernel-adaptation-pc.git / commitdiff