EXPORT_SYMBOL_GPL(event_storage);
LIST_HEAD(ftrace_events);
-LIST_HEAD(ftrace_common_fields);
+static LIST_HEAD(ftrace_common_fields);
+
+#define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
+
+static struct kmem_cache *field_cachep;
+static struct kmem_cache *file_cachep;
/* Double loops, do not use break, only goto's work */
#define do_for_each_event_file(tr, file) \
#define while_for_each_event_file() \
}
-struct list_head *
+static struct list_head *
trace_get_fields(struct ftrace_event_call *event_call)
{
if (!event_call->class->get_fields)
return event_call->class->get_fields(event_call);
}
+static struct ftrace_event_field *
+__find_event_field(struct list_head *head, char *name)
+{
+ struct ftrace_event_field *field;
+
+ list_for_each_entry(field, head, link) {
+ if (!strcmp(field->name, name))
+ return field;
+ }
+
+ return NULL;
+}
+
+struct ftrace_event_field *
+trace_find_event_field(struct ftrace_event_call *call, char *name)
+{
+ struct ftrace_event_field *field;
+ struct list_head *head;
+
+ field = __find_event_field(&ftrace_common_fields, name);
+ if (field)
+ return field;
+
+ head = trace_get_fields(call);
+ return __find_event_field(head, name);
+}
+
static int __trace_define_field(struct list_head *head, const char *type,
const char *name, int offset, int size,
int is_signed, int filter_type)
{
struct ftrace_event_field *field;
- field = kzalloc(sizeof(*field), GFP_KERNEL);
+ field = kmem_cache_alloc(field_cachep, GFP_TRACE);
if (!field)
goto err;
- field->name = kstrdup(name, GFP_KERNEL);
- if (!field->name)
- goto err;
-
- field->type = kstrdup(type, GFP_KERNEL);
- if (!field->type)
- goto err;
+ field->name = name;
+ field->type = type;
if (filter_type == FILTER_OTHER)
field->filter_type = filter_assign_type(type);
return 0;
err:
- if (field)
- kfree(field->name);
- kfree(field);
+ kmem_cache_free(field_cachep, field);
return -ENOMEM;
}
return ret;
}
-void trace_destroy_fields(struct ftrace_event_call *call)
+static void trace_destroy_fields(struct ftrace_event_call *call)
{
struct ftrace_event_field *field, *next;
struct list_head *head;
head = trace_get_fields(call);
list_for_each_entry_safe(field, next, head, link) {
list_del(&field->link);
- kfree(field->type);
- kfree(field->name);
- kfree(field);
+ kmem_cache_free(field_cachep, field);
}
}
if (enable) {
tracing_start_cmdline_record();
- file->flags |= FTRACE_EVENT_FL_RECORDED_CMD;
+ set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
} else {
tracing_stop_cmdline_record();
- file->flags &= ~FTRACE_EVENT_FL_RECORDED_CMD;
+ clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
}
} while_for_each_event_file();
mutex_unlock(&event_mutex);
}
-static int ftrace_event_enable_disable(struct ftrace_event_file *file,
- int enable)
+static int __ftrace_event_enable_disable(struct ftrace_event_file *file,
+ int enable, int soft_disable)
{
struct ftrace_event_call *call = file->event_call;
int ret = 0;
+ int disable;
switch (enable) {
case 0:
- if (file->flags & FTRACE_EVENT_FL_ENABLED) {
- file->flags &= ~FTRACE_EVENT_FL_ENABLED;
+ /*
+ * When soft_disable is set and enable is cleared, we want
+ * to clear the SOFT_DISABLED flag but leave the event in the
+ * state that it was. That is, if the event was enabled and
+ * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
+ * is set we do not want the event to be enabled before we
+ * clear the bit.
+ *
+ * When soft_disable is not set but the SOFT_MODE flag is,
+ * we do nothing. Do not disable the tracepoint, otherwise
+ * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
+ */
+ if (soft_disable) {
+ disable = file->flags & FTRACE_EVENT_FL_SOFT_DISABLED;
+ clear_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
+ } else
+ disable = !(file->flags & FTRACE_EVENT_FL_SOFT_MODE);
+
+ if (disable && (file->flags & FTRACE_EVENT_FL_ENABLED)) {
+ clear_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
if (file->flags & FTRACE_EVENT_FL_RECORDED_CMD) {
tracing_stop_cmdline_record();
- file->flags &= ~FTRACE_EVENT_FL_RECORDED_CMD;
+ clear_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
}
call->class->reg(call, TRACE_REG_UNREGISTER, file);
}
+ /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT */
+ if (file->flags & FTRACE_EVENT_FL_SOFT_MODE)
+ set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
break;
case 1:
+ /*
+ * When soft_disable is set and enable is set, we want to
+ * register the tracepoint for the event, but leave the event
+ * as is. That means, if the event was already enabled, we do
+ * nothing (but set SOFT_MODE). If the event is disabled, we
+ * set SOFT_DISABLED before enabling the event tracepoint, so
+ * it still seems to be disabled.
+ */
+ if (!soft_disable)
+ clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
+ else
+ set_bit(FTRACE_EVENT_FL_SOFT_MODE_BIT, &file->flags);
+
if (!(file->flags & FTRACE_EVENT_FL_ENABLED)) {
+
+ /* Keep the event disabled, when going to SOFT_MODE. */
+ if (soft_disable)
+ set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
+
if (trace_flags & TRACE_ITER_RECORD_CMD) {
tracing_start_cmdline_record();
- file->flags |= FTRACE_EVENT_FL_RECORDED_CMD;
+ set_bit(FTRACE_EVENT_FL_RECORDED_CMD_BIT, &file->flags);
}
ret = call->class->reg(call, TRACE_REG_REGISTER, file);
if (ret) {
"%s\n", call->name);
break;
}
- file->flags |= FTRACE_EVENT_FL_ENABLED;
+ set_bit(FTRACE_EVENT_FL_ENABLED_BIT, &file->flags);
+
+ /* WAS_ENABLED gets set but never cleared. */
+ call->flags |= TRACE_EVENT_FL_WAS_ENABLED;
}
break;
}
return ret;
}
+static int ftrace_event_enable_disable(struct ftrace_event_file *file,
+ int enable)
+{
+ return __ftrace_event_enable_disable(file, enable, 0);
+}
+
static void ftrace_clear_events(struct trace_array *tr)
{
struct ftrace_event_file *file;
kfree(filter->filter_string);
kfree(filter);
}
- kfree(system->name);
kfree(system);
}
struct ftrace_event_file *file = filp->private_data;
char *buf;
- if (file->flags & FTRACE_EVENT_FL_ENABLED)
- buf = "1\n";
- else
+ if (file->flags & FTRACE_EVENT_FL_ENABLED) {
+ if (file->flags & FTRACE_EVENT_FL_SOFT_DISABLED)
+ buf = "0*\n";
+ else
+ buf = "1\n";
+ } else
buf = "0\n";
- return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
}
static ssize_t
return NULL;
system->ref_count = 1;
- system->name = kstrdup(name, GFP_KERNEL);
-
- if (!system->name)
- goto out_free;
+ system->name = name;
system->filter = NULL;
return system;
out_free:
- kfree(system->name);
kfree(system);
return NULL;
}
list_del(&file->list);
debugfs_remove_recursive(file->dir);
remove_subsystem(file->system);
- kfree(file);
+ kmem_cache_free(file_cachep, file);
/*
* The do_for_each_event_file_safe() is
{
struct ftrace_event_file *file;
- file = kzalloc(sizeof(*file), GFP_KERNEL);
+ file = kmem_cache_alloc(file_cachep, GFP_TRACE);
if (!file)
return -ENOMEM;
return event_create_dir(tr->event_dir, file, id, enable, filter, format);
}
+/*
+ * Just create a decriptor for early init. A descriptor is required
+ * for enabling events at boot. We want to enable events before
+ * the filesystem is initialized.
+ */
+static __init int
+__trace_early_add_new_event(struct ftrace_event_call *call,
+ struct trace_array *tr)
+{
+ struct ftrace_event_file *file;
+
+ file = kmem_cache_alloc(file_cachep, GFP_TRACE);
+ if (!file)
+ return -ENOMEM;
+
+ file->event_call = call;
+ file->tr = tr;
+ list_add(&file->list, &tr->events);
+
+ return 0;
+}
+
struct ftrace_module_file_ops;
static void __add_event_to_tracers(struct ftrace_event_call *call,
struct ftrace_module_file_ops *file_ops);
}
/*
- * Must be called under locking both of event_mutex and trace_event_mutex.
+ * Must be called under locking both of event_mutex and trace_event_sem.
*/
static void __trace_remove_event_call(struct ftrace_event_call *call)
{
void trace_remove_event_call(struct ftrace_event_call *call)
{
mutex_lock(&event_mutex);
- down_write(&trace_event_mutex);
+ down_write(&trace_event_sem);
__trace_remove_event_call(call);
- up_write(&trace_event_mutex);
+ up_write(&trace_event_sem);
mutex_unlock(&event_mutex);
}
struct file_operations filter;
};
-static struct ftrace_module_file_ops *find_ftrace_file_ops(struct module *mod)
+static struct ftrace_module_file_ops *
+find_ftrace_file_ops(struct ftrace_module_file_ops *file_ops, struct module *mod)
{
- struct ftrace_module_file_ops *file_ops;
+ /*
+ * As event_calls are added in groups by module,
+ * when we find one file_ops, we don't need to search for
+ * each call in that module, as the rest should be the
+ * same. Only search for a new one if the last one did
+ * not match.
+ */
+ if (file_ops && mod == file_ops->mod)
+ return file_ops;
list_for_each_entry(file_ops, &ftrace_module_file_list, list) {
if (file_ops->mod == mod)
{
struct ftrace_module_file_ops *file_ops;
struct ftrace_event_call *call, *p;
- bool found = false;
+ bool clear_trace = false;
- down_write(&trace_event_mutex);
+ down_write(&trace_event_sem);
list_for_each_entry_safe(call, p, &ftrace_events, list) {
if (call->mod == mod) {
- found = true;
+ if (call->flags & TRACE_EVENT_FL_WAS_ENABLED)
+ clear_trace = true;
__trace_remove_event_call(call);
}
}
list_del(&file_ops->list);
kfree(file_ops);
}
+ up_write(&trace_event_sem);
/*
* It is safest to reset the ring buffer if the module being unloaded
- * registered any events.
+ * registered any events that were used. The only worry is if
+ * a new module gets loaded, and takes on the same id as the events
+ * of this module. When printing out the buffer, traced events left
+ * over from this module may be passed to the new module events and
+ * unexpected results may occur.
*/
- if (found)
- tracing_reset_current_online_cpus();
- up_write(&trace_event_mutex);
+ if (clear_trace)
+ tracing_reset_all_online_cpus();
}
static int trace_module_notify(struct notifier_block *self,
return 0;
}
+
+static int
+__trace_add_new_mod_event(struct ftrace_event_call *call,
+ struct trace_array *tr,
+ struct ftrace_module_file_ops *file_ops)
+{
+ return __trace_add_new_event(call, tr,
+ &file_ops->id, &file_ops->enable,
+ &file_ops->filter, &file_ops->format);
+}
+
#else
-static struct ftrace_module_file_ops *find_ftrace_file_ops(struct module *mod)
+static inline struct ftrace_module_file_ops *
+find_ftrace_file_ops(struct ftrace_module_file_ops *file_ops, struct module *mod)
{
return NULL;
}
-static int trace_module_notify(struct notifier_block *self,
- unsigned long val, void *data)
+static inline int trace_module_notify(struct notifier_block *self,
+ unsigned long val, void *data)
{
return 0;
}
+static inline int
+__trace_add_new_mod_event(struct ftrace_event_call *call,
+ struct trace_array *tr,
+ struct ftrace_module_file_ops *file_ops)
+{
+ return -ENODEV;
+}
#endif /* CONFIG_MODULES */
/* Create a new event directory structure for a trace directory. */
* want the module to disappear when reading one
* of these files). The file_ops keep account of
* the module ref count.
- *
- * As event_calls are added in groups by module,
- * when we find one file_ops, we don't need to search for
- * each call in that module, as the rest should be the
- * same. Only search for a new one if the last one did
- * not match.
*/
- if (!file_ops || call->mod != file_ops->mod)
- file_ops = find_ftrace_file_ops(call->mod);
+ file_ops = find_ftrace_file_ops(file_ops, call->mod);
if (!file_ops)
continue; /* Warn? */
- ret = __trace_add_new_event(call, tr,
- &file_ops->id, &file_ops->enable,
- &file_ops->filter, &file_ops->format);
+ ret = __trace_add_new_mod_event(call, tr, file_ops);
if (ret < 0)
pr_warning("Could not create directory for event %s\n",
call->name);
}
}
+#ifdef CONFIG_DYNAMIC_FTRACE
+
+/* Avoid typos */
+#define ENABLE_EVENT_STR "enable_event"
+#define DISABLE_EVENT_STR "disable_event"
+
+struct event_probe_data {
+ struct ftrace_event_file *file;
+ unsigned long count;
+ int ref;
+ bool enable;
+};
+
+static struct ftrace_event_file *
+find_event_file(struct trace_array *tr, const char *system, const char *event)
+{
+ struct ftrace_event_file *file;
+ struct ftrace_event_call *call;
+
+ list_for_each_entry(file, &tr->events, list) {
+
+ call = file->event_call;
+
+ if (!call->name || !call->class || !call->class->reg)
+ continue;
+
+ if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
+ continue;
+
+ if (strcmp(event, call->name) == 0 &&
+ strcmp(system, call->class->system) == 0)
+ return file;
+ }
+ return NULL;
+}
+
+static void
+event_enable_probe(unsigned long ip, unsigned long parent_ip, void **_data)
+{
+ struct event_probe_data **pdata = (struct event_probe_data **)_data;
+ struct event_probe_data *data = *pdata;
+
+ if (!data)
+ return;
+
+ if (data->enable)
+ clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
+ else
+ set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &data->file->flags);
+}
+
+static void
+event_enable_count_probe(unsigned long ip, unsigned long parent_ip, void **_data)
+{
+ struct event_probe_data **pdata = (struct event_probe_data **)_data;
+ struct event_probe_data *data = *pdata;
+
+ if (!data)
+ return;
+
+ if (!data->count)
+ return;
+
+ /* Skip if the event is in a state we want to switch to */
+ if (data->enable == !(data->file->flags & FTRACE_EVENT_FL_SOFT_DISABLED))
+ return;
+
+ if (data->count != -1)
+ (data->count)--;
+
+ event_enable_probe(ip, parent_ip, _data);
+}
+
+static int
+event_enable_print(struct seq_file *m, unsigned long ip,
+ struct ftrace_probe_ops *ops, void *_data)
+{
+ struct event_probe_data *data = _data;
+
+ seq_printf(m, "%ps:", (void *)ip);
+
+ seq_printf(m, "%s:%s:%s",
+ data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
+ data->file->event_call->class->system,
+ data->file->event_call->name);
+
+ if (data->count == -1)
+ seq_printf(m, ":unlimited\n");
+ else
+ seq_printf(m, ":count=%ld\n", data->count);
+
+ return 0;
+}
+
+static int
+event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
+ void **_data)
+{
+ struct event_probe_data **pdata = (struct event_probe_data **)_data;
+ struct event_probe_data *data = *pdata;
+
+ data->ref++;
+ return 0;
+}
+
+static void
+event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
+ void **_data)
+{
+ struct event_probe_data **pdata = (struct event_probe_data **)_data;
+ struct event_probe_data *data = *pdata;
+
+ if (WARN_ON_ONCE(data->ref <= 0))
+ return;
+
+ data->ref--;
+ if (!data->ref) {
+ /* Remove the SOFT_MODE flag */
+ __ftrace_event_enable_disable(data->file, 0, 1);
+ module_put(data->file->event_call->mod);
+ kfree(data);
+ }
+ *pdata = NULL;
+}
+
+static struct ftrace_probe_ops event_enable_probe_ops = {
+ .func = event_enable_probe,
+ .print = event_enable_print,
+ .init = event_enable_init,
+ .free = event_enable_free,
+};
+
+static struct ftrace_probe_ops event_enable_count_probe_ops = {
+ .func = event_enable_count_probe,
+ .print = event_enable_print,
+ .init = event_enable_init,
+ .free = event_enable_free,
+};
+
+static struct ftrace_probe_ops event_disable_probe_ops = {
+ .func = event_enable_probe,
+ .print = event_enable_print,
+ .init = event_enable_init,
+ .free = event_enable_free,
+};
+
+static struct ftrace_probe_ops event_disable_count_probe_ops = {
+ .func = event_enable_count_probe,
+ .print = event_enable_print,
+ .init = event_enable_init,
+ .free = event_enable_free,
+};
+
+static int
+event_enable_func(struct ftrace_hash *hash,
+ char *glob, char *cmd, char *param, int enabled)
+{
+ struct trace_array *tr = top_trace_array();
+ struct ftrace_event_file *file;
+ struct ftrace_probe_ops *ops;
+ struct event_probe_data *data;
+ const char *system;
+ const char *event;
+ char *number;
+ bool enable;
+ int ret;
+
+ /* hash funcs only work with set_ftrace_filter */
+ if (!enabled)
+ return -EINVAL;
+
+ if (!param)
+ return -EINVAL;
+
+ system = strsep(¶m, ":");
+ if (!param)
+ return -EINVAL;
+
+ event = strsep(¶m, ":");
+
+ mutex_lock(&event_mutex);
+
+ ret = -EINVAL;
+ file = find_event_file(tr, system, event);
+ if (!file)
+ goto out;
+
+ enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
+
+ if (enable)
+ ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
+ else
+ ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
+
+ if (glob[0] == '!') {
+ unregister_ftrace_function_probe_func(glob+1, ops);
+ ret = 0;
+ goto out;
+ }
+
+ ret = -ENOMEM;
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ goto out;
+
+ data->enable = enable;
+ data->count = -1;
+ data->file = file;
+
+ if (!param)
+ goto out_reg;
+
+ number = strsep(¶m, ":");
+
+ ret = -EINVAL;
+ if (!strlen(number))
+ goto out_free;
+
+ /*
+ * We use the callback data field (which is a pointer)
+ * as our counter.
+ */
+ ret = kstrtoul(number, 0, &data->count);
+ if (ret)
+ goto out_free;
+
+ out_reg:
+ /* Don't let event modules unload while probe registered */
+ ret = try_module_get(file->event_call->mod);
+ if (!ret)
+ goto out_free;
+
+ ret = __ftrace_event_enable_disable(file, 1, 1);
+ if (ret < 0)
+ goto out_put;
+ ret = register_ftrace_function_probe(glob, ops, data);
+ if (!ret)
+ goto out_disable;
+ out:
+ mutex_unlock(&event_mutex);
+ return ret;
+
+ out_disable:
+ __ftrace_event_enable_disable(file, 0, 1);
+ out_put:
+ module_put(file->event_call->mod);
+ out_free:
+ kfree(data);
+ goto out;
+}
+
+static struct ftrace_func_command event_enable_cmd = {
+ .name = ENABLE_EVENT_STR,
+ .func = event_enable_func,
+};
+
+static struct ftrace_func_command event_disable_cmd = {
+ .name = DISABLE_EVENT_STR,
+ .func = event_enable_func,
+};
+
+static __init int register_event_cmds(void)
+{
+ int ret;
+
+ ret = register_ftrace_command(&event_enable_cmd);
+ if (WARN_ON(ret < 0))
+ return ret;
+ ret = register_ftrace_command(&event_disable_cmd);
+ if (WARN_ON(ret < 0))
+ unregister_ftrace_command(&event_enable_cmd);
+ return ret;
+}
+#else
+static inline int register_event_cmds(void) { return 0; }
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+/*
+ * The top level array has already had its ftrace_event_file
+ * descriptors created in order to allow for early events to
+ * be recorded. This function is called after the debugfs has been
+ * initialized, and we now have to create the files associated
+ * to the events.
+ */
+static __init void
+__trace_early_add_event_dirs(struct trace_array *tr)
+{
+ struct ftrace_event_file *file;
+ int ret;
+
+
+ list_for_each_entry(file, &tr->events, list) {
+ ret = event_create_dir(tr->event_dir, file,
+ &ftrace_event_id_fops,
+ &ftrace_enable_fops,
+ &ftrace_event_filter_fops,
+ &ftrace_event_format_fops);
+ if (ret < 0)
+ pr_warning("Could not create directory for event %s\n",
+ file->event_call->name);
+ }
+}
+
+/*
+ * For early boot up, the top trace array requires to have
+ * a list of events that can be enabled. This must be done before
+ * the filesystem is set up in order to allow events to be traced
+ * early.
+ */
+static __init void
+__trace_early_add_events(struct trace_array *tr)
+{
+ struct ftrace_event_call *call;
+ int ret;
+
+ list_for_each_entry(call, &ftrace_events, list) {
+ /* Early boot up should not have any modules loaded */
+ if (WARN_ON_ONCE(call->mod))
+ continue;
+
+ ret = __trace_early_add_new_event(call, tr);
+ if (ret < 0)
+ pr_warning("Could not create early event %s\n",
+ call->name);
+ }
+}
+
+/* Remove the event directory structure for a trace directory. */
+static void
+__trace_remove_event_dirs(struct trace_array *tr)
+{
+ struct ftrace_event_file *file, *next;
+
+ list_for_each_entry_safe(file, next, &tr->events, list) {
+ list_del(&file->list);
+ debugfs_remove_recursive(file->dir);
+ remove_subsystem(file->system);
+ kmem_cache_free(file_cachep, file);
+ }
+}
+
static void
__add_event_to_tracers(struct ftrace_event_call *call,
struct ftrace_module_file_ops *file_ops)
list_for_each_entry(tr, &ftrace_trace_arrays, list) {
if (file_ops)
- __trace_add_new_event(call, tr,
- &file_ops->id, &file_ops->enable,
- &file_ops->filter, &file_ops->format);
+ __trace_add_new_mod_event(call, tr, file_ops);
else
__trace_add_new_event(call, tr,
&ftrace_event_id_fops,
static __init int setup_trace_event(char *str)
{
strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
- ring_buffer_expanded = 1;
- tracing_selftest_disabled = 1;
+ ring_buffer_expanded = true;
+ tracing_selftest_disabled = true;
return 1;
}
__setup("trace_event=", setup_trace_event);
-int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
+/* Expects to have event_mutex held when called */
+static int
+create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
{
struct dentry *d_events;
struct dentry *entry;
}
d_events = debugfs_create_dir("events", parent);
- if (!d_events)
+ if (!d_events) {
pr_warning("Could not create debugfs 'events' directory\n");
+ return -ENOMEM;
+ }
/* ring buffer internal formats */
trace_create_file("header_page", 0444, d_events,
tr, &ftrace_tr_enable_fops);
tr->event_dir = d_events;
+
+ return 0;
+}
+
+/**
+ * event_trace_add_tracer - add a instance of a trace_array to events
+ * @parent: The parent dentry to place the files/directories for events in
+ * @tr: The trace array associated with these events
+ *
+ * When a new instance is created, it needs to set up its events
+ * directory, as well as other files associated with events. It also
+ * creates the event hierachry in the @parent/events directory.
+ *
+ * Returns 0 on success.
+ */
+int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
+{
+ int ret;
+
+ mutex_lock(&event_mutex);
+
+ ret = create_event_toplevel_files(parent, tr);
+ if (ret)
+ goto out_unlock;
+
+ down_write(&trace_event_sem);
__trace_add_event_dirs(tr);
+ up_write(&trace_event_sem);
+
+ out_unlock:
+ mutex_unlock(&event_mutex);
+
+ return ret;
+}
+/*
+ * The top trace array already had its file descriptors created.
+ * Now the files themselves need to be created.
+ */
+static __init int
+early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
+{
+ int ret;
+
+ mutex_lock(&event_mutex);
+
+ ret = create_event_toplevel_files(parent, tr);
+ if (ret)
+ goto out_unlock;
+
+ down_write(&trace_event_sem);
+ __trace_early_add_event_dirs(tr);
+ up_write(&trace_event_sem);
+
+ out_unlock:
+ mutex_unlock(&event_mutex);
+
+ return ret;
+}
+
+int event_trace_del_tracer(struct trace_array *tr)
+{
+ /* Disable any running events */
+ __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
+
+ mutex_lock(&event_mutex);
+
+ down_write(&trace_event_sem);
+ __trace_remove_event_dirs(tr);
+ debugfs_remove_recursive(tr->event_dir);
+ up_write(&trace_event_sem);
+
+ tr->event_dir = NULL;
+
+ mutex_unlock(&event_mutex);
+
+ return 0;
+}
+
+static __init int event_trace_memsetup(void)
+{
+ field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
+ file_cachep = KMEM_CACHE(ftrace_event_file, SLAB_PANIC);
return 0;
}
list_add(&call->list, &ftrace_events);
}
+ /*
+ * We need the top trace array to have a working set of trace
+ * points at early init, before the debug files and directories
+ * are created. Create the file entries now, and attach them
+ * to the actual file dentries later.
+ */
+ __trace_early_add_events(tr);
+
while (true) {
token = strsep(&buf, ",");
trace_printk_start_comm();
+ register_event_cmds();
+
return 0;
}
if (trace_define_common_fields())
pr_warning("tracing: Failed to allocate common fields");
- ret = event_trace_add_tracer(d_tracer, tr);
+ ret = early_event_add_tracer(d_tracer, tr);
if (ret)
return ret;
return 0;
}
+early_initcall(event_trace_memsetup);
core_initcall(event_trace_enable);
fs_initcall(event_trace_init);
projects / platform / adaptation / renesas_rcar / renesas_kernel.git / blobdiff