tracing: Add 'enable_event' and 'disable_event' event trigger commands
Add 'enable_event' and 'disable_event' event_command commands. enable_event and disable_event event triggers are added by the user via these commands in a similar way and using practically the same syntax as the analagous 'enable_event' and 'disable_event' ftrace function commands, but instead of writing to the set_ftrace_filter file, the enable_event and disable_event triggers are written to the per-event 'trigger' files: echo 'enable_event:system:event' > .../othersys/otherevent/trigger echo 'disable_event:system:event' > .../othersys/otherevent/trigger The above commands will enable or disable the 'system:event' trace events whenever the othersys:otherevent events are hit. This also adds a 'count' version that limits the number of times the command will be invoked: echo 'enable_event:system:event:N' > .../othersys/otherevent/trigger echo 'disable_event:system:event:N' > .../othersys/otherevent/trigger Where N is the number of times the command will be invoked. The above commands will will enable or disable the 'system:event' trace events whenever the othersys:otherevent events are hit, but only N times. This also makes the find_event_file() helper function extern, since it's useful to use from other places, such as the event triggers code, so make it accessible. Link: http://lkml.kernel.org/r/f825f3048c3f6b026ee37ae5825f9fc373451828.1382622043.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
parent
f21ecbb35f
commit
7862ad1846
|
@ -348,6 +348,7 @@ enum event_trigger_type {
|
||||||
ETT_TRACE_ONOFF = (1 << 0),
|
ETT_TRACE_ONOFF = (1 << 0),
|
||||||
ETT_SNAPSHOT = (1 << 1),
|
ETT_SNAPSHOT = (1 << 1),
|
||||||
ETT_STACKTRACE = (1 << 2),
|
ETT_STACKTRACE = (1 << 2),
|
||||||
|
ETT_EVENT_ENABLE = (1 << 3),
|
||||||
};
|
};
|
||||||
|
|
||||||
extern void destroy_preds(struct ftrace_event_file *file);
|
extern void destroy_preds(struct ftrace_event_file *file);
|
||||||
|
|
|
@ -1028,6 +1028,10 @@ extern void trace_event_enable_cmd_record(bool enable);
|
||||||
extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
|
extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
|
||||||
extern int event_trace_del_tracer(struct trace_array *tr);
|
extern int event_trace_del_tracer(struct trace_array *tr);
|
||||||
|
|
||||||
|
extern struct ftrace_event_file *find_event_file(struct trace_array *tr,
|
||||||
|
const char *system,
|
||||||
|
const char *event);
|
||||||
|
|
||||||
static inline void *event_file_data(struct file *filp)
|
static inline void *event_file_data(struct file *filp)
|
||||||
{
|
{
|
||||||
return ACCESS_ONCE(file_inode(filp)->i_private);
|
return ACCESS_ONCE(file_inode(filp)->i_private);
|
||||||
|
|
|
@ -1868,7 +1868,7 @@ struct event_probe_data {
|
||||||
bool enable;
|
bool enable;
|
||||||
};
|
};
|
||||||
|
|
||||||
static struct ftrace_event_file *
|
struct ftrace_event_file *
|
||||||
find_event_file(struct trace_array *tr, const char *system, const char *event)
|
find_event_file(struct trace_array *tr, const char *system, const char *event)
|
||||||
{
|
{
|
||||||
struct ftrace_event_file *file;
|
struct ftrace_event_file *file;
|
||||||
|
|
|
@ -864,6 +864,364 @@ static __init void unregister_trigger_traceon_traceoff_cmds(void)
|
||||||
unregister_event_command(&trigger_traceoff_cmd);
|
unregister_event_command(&trigger_traceoff_cmd);
|
||||||
}
|
}
|
||||||
|
|
||||||
|
/* Avoid typos */
|
||||||
|
#define ENABLE_EVENT_STR "enable_event"
|
||||||
|
#define DISABLE_EVENT_STR "disable_event"
|
||||||
|
|
||||||
|
struct enable_trigger_data {
|
||||||
|
struct ftrace_event_file *file;
|
||||||
|
bool enable;
|
||||||
|
};
|
||||||
|
|
||||||
|
static void
|
||||||
|
event_enable_trigger(struct event_trigger_data *data)
|
||||||
|
{
|
||||||
|
struct enable_trigger_data *enable_data = data->private_data;
|
||||||
|
|
||||||
|
if (enable_data->enable)
|
||||||
|
clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
|
||||||
|
else
|
||||||
|
set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &enable_data->file->flags);
|
||||||
|
}
|
||||||
|
|
||||||
|
static void
|
||||||
|
event_enable_count_trigger(struct event_trigger_data *data)
|
||||||
|
{
|
||||||
|
struct enable_trigger_data *enable_data = data->private_data;
|
||||||
|
|
||||||
|
if (!data->count)
|
||||||
|
return;
|
||||||
|
|
||||||
|
/* Skip if the event is in a state we want to switch to */
|
||||||
|
if (enable_data->enable == !(enable_data->file->flags & FTRACE_EVENT_FL_SOFT_DISABLED))
|
||||||
|
return;
|
||||||
|
|
||||||
|
if (data->count != -1)
|
||||||
|
(data->count)--;
|
||||||
|
|
||||||
|
event_enable_trigger(data);
|
||||||
|
}
|
||||||
|
|
||||||
|
static int
|
||||||
|
event_enable_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
|
||||||
|
struct event_trigger_data *data)
|
||||||
|
{
|
||||||
|
struct enable_trigger_data *enable_data = data->private_data;
|
||||||
|
|
||||||
|
seq_printf(m, "%s:%s:%s",
|
||||||
|
enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
|
||||||
|
enable_data->file->event_call->class->system,
|
||||||
|
enable_data->file->event_call->name);
|
||||||
|
|
||||||
|
if (data->count == -1)
|
||||||
|
seq_puts(m, ":unlimited");
|
||||||
|
else
|
||||||
|
seq_printf(m, ":count=%ld", data->count);
|
||||||
|
|
||||||
|
if (data->filter_str)
|
||||||
|
seq_printf(m, " if %s\n", data->filter_str);
|
||||||
|
else
|
||||||
|
seq_puts(m, "\n");
|
||||||
|
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
static void
|
||||||
|
event_enable_trigger_free(struct event_trigger_ops *ops,
|
||||||
|
struct event_trigger_data *data)
|
||||||
|
{
|
||||||
|
struct enable_trigger_data *enable_data = data->private_data;
|
||||||
|
|
||||||
|
if (WARN_ON_ONCE(data->ref <= 0))
|
||||||
|
return;
|
||||||
|
|
||||||
|
data->ref--;
|
||||||
|
if (!data->ref) {
|
||||||
|
/* Remove the SOFT_MODE flag */
|
||||||
|
trace_event_enable_disable(enable_data->file, 0, 1);
|
||||||
|
module_put(enable_data->file->event_call->mod);
|
||||||
|
trigger_data_free(data);
|
||||||
|
kfree(enable_data);
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
static struct event_trigger_ops event_enable_trigger_ops = {
|
||||||
|
.func = event_enable_trigger,
|
||||||
|
.print = event_enable_trigger_print,
|
||||||
|
.init = event_trigger_init,
|
||||||
|
.free = event_enable_trigger_free,
|
||||||
|
};
|
||||||
|
|
||||||
|
static struct event_trigger_ops event_enable_count_trigger_ops = {
|
||||||
|
.func = event_enable_count_trigger,
|
||||||
|
.print = event_enable_trigger_print,
|
||||||
|
.init = event_trigger_init,
|
||||||
|
.free = event_enable_trigger_free,
|
||||||
|
};
|
||||||
|
|
||||||
|
static struct event_trigger_ops event_disable_trigger_ops = {
|
||||||
|
.func = event_enable_trigger,
|
||||||
|
.print = event_enable_trigger_print,
|
||||||
|
.init = event_trigger_init,
|
||||||
|
.free = event_enable_trigger_free,
|
||||||
|
};
|
||||||
|
|
||||||
|
static struct event_trigger_ops event_disable_count_trigger_ops = {
|
||||||
|
.func = event_enable_count_trigger,
|
||||||
|
.print = event_enable_trigger_print,
|
||||||
|
.init = event_trigger_init,
|
||||||
|
.free = event_enable_trigger_free,
|
||||||
|
};
|
||||||
|
|
||||||
|
static int
|
||||||
|
event_enable_trigger_func(struct event_command *cmd_ops,
|
||||||
|
struct ftrace_event_file *file,
|
||||||
|
char *glob, char *cmd, char *param)
|
||||||
|
{
|
||||||
|
struct ftrace_event_file *event_enable_file;
|
||||||
|
struct enable_trigger_data *enable_data;
|
||||||
|
struct event_trigger_data *trigger_data;
|
||||||
|
struct event_trigger_ops *trigger_ops;
|
||||||
|
struct trace_array *tr = file->tr;
|
||||||
|
const char *system;
|
||||||
|
const char *event;
|
||||||
|
char *trigger;
|
||||||
|
char *number;
|
||||||
|
bool enable;
|
||||||
|
int ret;
|
||||||
|
|
||||||
|
if (!param)
|
||||||
|
return -EINVAL;
|
||||||
|
|
||||||
|
/* separate the trigger from the filter (s:e:n [if filter]) */
|
||||||
|
trigger = strsep(¶m, " \t");
|
||||||
|
if (!trigger)
|
||||||
|
return -EINVAL;
|
||||||
|
|
||||||
|
system = strsep(&trigger, ":");
|
||||||
|
if (!trigger)
|
||||||
|
return -EINVAL;
|
||||||
|
|
||||||
|
event = strsep(&trigger, ":");
|
||||||
|
|
||||||
|
ret = -EINVAL;
|
||||||
|
event_enable_file = find_event_file(tr, system, event);
|
||||||
|
if (!event_enable_file)
|
||||||
|
goto out;
|
||||||
|
|
||||||
|
enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
|
||||||
|
|
||||||
|
trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
|
||||||
|
|
||||||
|
ret = -ENOMEM;
|
||||||
|
trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
|
||||||
|
if (!trigger_data)
|
||||||
|
goto out;
|
||||||
|
|
||||||
|
enable_data = kzalloc(sizeof(*enable_data), GFP_KERNEL);
|
||||||
|
if (!enable_data) {
|
||||||
|
kfree(trigger_data);
|
||||||
|
goto out;
|
||||||
|
}
|
||||||
|
|
||||||
|
trigger_data->count = -1;
|
||||||
|
trigger_data->ops = trigger_ops;
|
||||||
|
trigger_data->cmd_ops = cmd_ops;
|
||||||
|
INIT_LIST_HEAD(&trigger_data->list);
|
||||||
|
RCU_INIT_POINTER(trigger_data->filter, NULL);
|
||||||
|
|
||||||
|
enable_data->enable = enable;
|
||||||
|
enable_data->file = event_enable_file;
|
||||||
|
trigger_data->private_data = enable_data;
|
||||||
|
|
||||||
|
if (glob[0] == '!') {
|
||||||
|
cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
|
||||||
|
kfree(trigger_data);
|
||||||
|
kfree(enable_data);
|
||||||
|
ret = 0;
|
||||||
|
goto out;
|
||||||
|
}
|
||||||
|
|
||||||
|
if (trigger) {
|
||||||
|
number = strsep(&trigger, ":");
|
||||||
|
|
||||||
|
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, &trigger_data->count);
|
||||||
|
if (ret)
|
||||||
|
goto out_free;
|
||||||
|
}
|
||||||
|
|
||||||
|
if (!param) /* if param is non-empty, it's supposed to be a filter */
|
||||||
|
goto out_reg;
|
||||||
|
|
||||||
|
if (!cmd_ops->set_filter)
|
||||||
|
goto out_reg;
|
||||||
|
|
||||||
|
ret = cmd_ops->set_filter(param, trigger_data, file);
|
||||||
|
if (ret < 0)
|
||||||
|
goto out_free;
|
||||||
|
|
||||||
|
out_reg:
|
||||||
|
/* Don't let event modules unload while probe registered */
|
||||||
|
ret = try_module_get(event_enable_file->event_call->mod);
|
||||||
|
if (!ret) {
|
||||||
|
ret = -EBUSY;
|
||||||
|
goto out_free;
|
||||||
|
}
|
||||||
|
|
||||||
|
ret = trace_event_enable_disable(event_enable_file, 1, 1);
|
||||||
|
if (ret < 0)
|
||||||
|
goto out_put;
|
||||||
|
ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
|
||||||
|
/*
|
||||||
|
* The above returns on success the # of functions enabled,
|
||||||
|
* but if it didn't find any functions it returns zero.
|
||||||
|
* Consider no functions a failure too.
|
||||||
|
*/
|
||||||
|
if (!ret) {
|
||||||
|
ret = -ENOENT;
|
||||||
|
goto out_disable;
|
||||||
|
} else if (ret < 0)
|
||||||
|
goto out_disable;
|
||||||
|
/* Just return zero, not the number of enabled functions */
|
||||||
|
ret = 0;
|
||||||
|
out:
|
||||||
|
return ret;
|
||||||
|
|
||||||
|
out_disable:
|
||||||
|
trace_event_enable_disable(event_enable_file, 0, 1);
|
||||||
|
out_put:
|
||||||
|
module_put(event_enable_file->event_call->mod);
|
||||||
|
out_free:
|
||||||
|
kfree(trigger_data);
|
||||||
|
kfree(enable_data);
|
||||||
|
goto out;
|
||||||
|
}
|
||||||
|
|
||||||
|
static int event_enable_register_trigger(char *glob,
|
||||||
|
struct event_trigger_ops *ops,
|
||||||
|
struct event_trigger_data *data,
|
||||||
|
struct ftrace_event_file *file)
|
||||||
|
{
|
||||||
|
struct enable_trigger_data *enable_data = data->private_data;
|
||||||
|
struct enable_trigger_data *test_enable_data;
|
||||||
|
struct event_trigger_data *test;
|
||||||
|
int ret = 0;
|
||||||
|
|
||||||
|
list_for_each_entry_rcu(test, &file->triggers, list) {
|
||||||
|
test_enable_data = test->private_data;
|
||||||
|
if (test_enable_data &&
|
||||||
|
(test_enable_data->file == enable_data->file)) {
|
||||||
|
ret = -EEXIST;
|
||||||
|
goto out;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
if (data->ops->init) {
|
||||||
|
ret = data->ops->init(data->ops, data);
|
||||||
|
if (ret < 0)
|
||||||
|
goto out;
|
||||||
|
}
|
||||||
|
|
||||||
|
list_add_rcu(&data->list, &file->triggers);
|
||||||
|
ret++;
|
||||||
|
|
||||||
|
if (trace_event_trigger_enable_disable(file, 1) < 0) {
|
||||||
|
list_del_rcu(&data->list);
|
||||||
|
ret--;
|
||||||
|
}
|
||||||
|
out:
|
||||||
|
return ret;
|
||||||
|
}
|
||||||
|
|
||||||
|
static void event_enable_unregister_trigger(char *glob,
|
||||||
|
struct event_trigger_ops *ops,
|
||||||
|
struct event_trigger_data *test,
|
||||||
|
struct ftrace_event_file *file)
|
||||||
|
{
|
||||||
|
struct enable_trigger_data *test_enable_data = test->private_data;
|
||||||
|
struct enable_trigger_data *enable_data;
|
||||||
|
struct event_trigger_data *data;
|
||||||
|
bool unregistered = false;
|
||||||
|
|
||||||
|
list_for_each_entry_rcu(data, &file->triggers, list) {
|
||||||
|
enable_data = data->private_data;
|
||||||
|
if (enable_data &&
|
||||||
|
(enable_data->file == test_enable_data->file)) {
|
||||||
|
unregistered = true;
|
||||||
|
list_del_rcu(&data->list);
|
||||||
|
trace_event_trigger_enable_disable(file, 0);
|
||||||
|
break;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
if (unregistered && data->ops->free)
|
||||||
|
data->ops->free(data->ops, data);
|
||||||
|
}
|
||||||
|
|
||||||
|
static struct event_trigger_ops *
|
||||||
|
event_enable_get_trigger_ops(char *cmd, char *param)
|
||||||
|
{
|
||||||
|
struct event_trigger_ops *ops;
|
||||||
|
bool enable;
|
||||||
|
|
||||||
|
enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
|
||||||
|
|
||||||
|
if (enable)
|
||||||
|
ops = param ? &event_enable_count_trigger_ops :
|
||||||
|
&event_enable_trigger_ops;
|
||||||
|
else
|
||||||
|
ops = param ? &event_disable_count_trigger_ops :
|
||||||
|
&event_disable_trigger_ops;
|
||||||
|
|
||||||
|
return ops;
|
||||||
|
}
|
||||||
|
|
||||||
|
static struct event_command trigger_enable_cmd = {
|
||||||
|
.name = ENABLE_EVENT_STR,
|
||||||
|
.trigger_type = ETT_EVENT_ENABLE,
|
||||||
|
.func = event_enable_trigger_func,
|
||||||
|
.reg = event_enable_register_trigger,
|
||||||
|
.unreg = event_enable_unregister_trigger,
|
||||||
|
.get_trigger_ops = event_enable_get_trigger_ops,
|
||||||
|
};
|
||||||
|
|
||||||
|
static struct event_command trigger_disable_cmd = {
|
||||||
|
.name = DISABLE_EVENT_STR,
|
||||||
|
.trigger_type = ETT_EVENT_ENABLE,
|
||||||
|
.func = event_enable_trigger_func,
|
||||||
|
.reg = event_enable_register_trigger,
|
||||||
|
.unreg = event_enable_unregister_trigger,
|
||||||
|
.get_trigger_ops = event_enable_get_trigger_ops,
|
||||||
|
};
|
||||||
|
|
||||||
|
static __init void unregister_trigger_enable_disable_cmds(void)
|
||||||
|
{
|
||||||
|
unregister_event_command(&trigger_enable_cmd);
|
||||||
|
unregister_event_command(&trigger_disable_cmd);
|
||||||
|
}
|
||||||
|
|
||||||
|
static __init int register_trigger_enable_disable_cmds(void)
|
||||||
|
{
|
||||||
|
int ret;
|
||||||
|
|
||||||
|
ret = register_event_command(&trigger_enable_cmd);
|
||||||
|
if (WARN_ON(ret < 0))
|
||||||
|
return ret;
|
||||||
|
ret = register_event_command(&trigger_disable_cmd);
|
||||||
|
if (WARN_ON(ret < 0))
|
||||||
|
unregister_trigger_enable_disable_cmds();
|
||||||
|
|
||||||
|
return ret;
|
||||||
|
}
|
||||||
|
|
||||||
static __init int register_trigger_traceon_traceoff_cmds(void)
|
static __init int register_trigger_traceon_traceoff_cmds(void)
|
||||||
{
|
{
|
||||||
int ret;
|
int ret;
|
||||||
|
@ -883,6 +1241,7 @@ __init int register_trigger_cmds(void)
|
||||||
register_trigger_traceon_traceoff_cmds();
|
register_trigger_traceon_traceoff_cmds();
|
||||||
register_trigger_snapshot_cmd();
|
register_trigger_snapshot_cmd();
|
||||||
register_trigger_stacktrace_cmd();
|
register_trigger_stacktrace_cmd();
|
||||||
|
register_trigger_enable_disable_cmds();
|
||||||
|
|
||||||
return 0;
|
return 0;
|
||||||
}
|
}
|
||||||
|
|
Loading…
Reference in New Issue