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Commit ceec0b6f authored by Jiri Olsa's avatar Jiri Olsa Committed by Steven Rostedt
Browse files

ftrace, perf: Add open/close tracepoint perf registration actions 

Adding TRACE_REG_PERF_OPEN and TRACE_REG_PERF_CLOSE to differentiate
register/unregister from open/close actions.

The register/unregister actions are invoked for the first/last
tracepoint user when opening/closing the event.

The open/close actions are invoked for each tracepoint user when
opening/closing the event.

Link: http://lkml.kernel.org/r/1329317514-8131-3-git-send-email-jolsa@redhat.com



Acked-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: default avatarJiri Olsa <jolsa@redhat.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent e248491a

include/linux/ftrace_event.h

+4 −2
Original line number Diff line number Diff line
@@ -146,6 +146,8 @@ enum trace_reg { 
	TRACE_REG_UNREGISTER,

	TRACE_REG_PERF_REGISTER,

	TRACE_REG_PERF_UNREGISTER,

	TRACE_REG_PERF_OPEN,

	TRACE_REG_PERF_CLOSE,

};



struct ftrace_event_call;
@@ -157,7 +159,7 @@ struct ftrace_event_class { 
	void			*perf_probe;

#endif

	int			(*reg)(struct ftrace_event_call *event,

				       enum trace_reg type);

				       enum trace_reg type, void *data);

	int			(*define_fields)(struct ftrace_event_call *);

	struct list_head	*(*get_fields)(struct ftrace_event_call *);

	struct list_head	fields;
@@ -165,7 +167,7 @@ struct ftrace_event_class { 
};



extern int ftrace_event_reg(struct ftrace_event_call *event,

			    enum trace_reg type);

			    enum trace_reg type, void *data);



enum {

	TRACE_EVENT_FL_ENABLED_BIT,

kernel/trace/trace_event_perf.c

+75 −41
Original line number Diff line number Diff line
@@ -44,23 +44,17 @@ static int perf_trace_event_perm(struct ftrace_event_call *tp_event, 
	return 0;

}



static int perf_trace_event_init(struct ftrace_event_call *tp_event,

static int perf_trace_event_reg(struct ftrace_event_call *tp_event,

				struct perf_event *p_event)

{

	struct hlist_head __percpu *list;

	int ret;

	int ret = -ENOMEM;

	int cpu;



	ret = perf_trace_event_perm(tp_event, p_event);

	if (ret)

		return ret;



	p_event->tp_event = tp_event;

	if (tp_event->perf_refcount++ > 0)

		return 0;



	ret = -ENOMEM;



	list = alloc_percpu(struct hlist_head);

	if (!list)

		goto fail;
@@ -83,7 +77,7 @@ static int perf_trace_event_init(struct ftrace_event_call *tp_event, 
		}

	}



	ret = tp_event->class->reg(tp_event, TRACE_REG_PERF_REGISTER);

	ret = tp_event->class->reg(tp_event, TRACE_REG_PERF_REGISTER, NULL);

	if (ret)

		goto fail;
@@ -108,6 +102,69 @@ static int perf_trace_event_init(struct ftrace_event_call *tp_event, 
	return ret;

}



static void perf_trace_event_unreg(struct perf_event *p_event)

{

	struct ftrace_event_call *tp_event = p_event->tp_event;

	int i;



	if (--tp_event->perf_refcount > 0)

		goto out;



	tp_event->class->reg(tp_event, TRACE_REG_PERF_UNREGISTER, NULL);



	/*

	 * Ensure our callback won't be called anymore. The buffers

	 * will be freed after that.

	 */

	tracepoint_synchronize_unregister();



	free_percpu(tp_event->perf_events);

	tp_event->perf_events = NULL;



	if (!--total_ref_count) {

		for (i = 0; i < PERF_NR_CONTEXTS; i++) {

			free_percpu(perf_trace_buf[i]);

			perf_trace_buf[i] = NULL;

		}

	}

out:

	module_put(tp_event->mod);

}



static int perf_trace_event_open(struct perf_event *p_event)

{

	struct ftrace_event_call *tp_event = p_event->tp_event;

	return tp_event->class->reg(tp_event, TRACE_REG_PERF_OPEN, p_event);

}



static void perf_trace_event_close(struct perf_event *p_event)

{

	struct ftrace_event_call *tp_event = p_event->tp_event;

	tp_event->class->reg(tp_event, TRACE_REG_PERF_CLOSE, p_event);

}



static int perf_trace_event_init(struct ftrace_event_call *tp_event,

				 struct perf_event *p_event)

{

	int ret;



	ret = perf_trace_event_perm(tp_event, p_event);

	if (ret)

		return ret;



	ret = perf_trace_event_reg(tp_event, p_event);

	if (ret)

		return ret;



	ret = perf_trace_event_open(p_event);

	if (ret) {

		perf_trace_event_unreg(p_event);

		return ret;

	}



	return 0;

}



int perf_trace_init(struct perf_event *p_event)

{

	struct ftrace_event_call *tp_event;
@@ -130,6 +187,14 @@ int perf_trace_init(struct perf_event *p_event) 
	return ret;

}



void perf_trace_destroy(struct perf_event *p_event)

{

	mutex_lock(&event_mutex);

	perf_trace_event_close(p_event);

	perf_trace_event_unreg(p_event);

	mutex_unlock(&event_mutex);

}



int perf_trace_add(struct perf_event *p_event, int flags)

{

	struct ftrace_event_call *tp_event = p_event->tp_event;
@@ -154,37 +219,6 @@ void perf_trace_del(struct perf_event *p_event, int flags) 
	hlist_del_rcu(&p_event->hlist_entry);

}



void perf_trace_destroy(struct perf_event *p_event)

{

	struct ftrace_event_call *tp_event = p_event->tp_event;

	int i;



	mutex_lock(&event_mutex);

	if (--tp_event->perf_refcount > 0)

		goto out;



	tp_event->class->reg(tp_event, TRACE_REG_PERF_UNREGISTER);



	/*

	 * Ensure our callback won't be called anymore. The buffers

	 * will be freed after that.

	 */

	tracepoint_synchronize_unregister();



	free_percpu(tp_event->perf_events);

	tp_event->perf_events = NULL;



	if (!--total_ref_count) {

		for (i = 0; i < PERF_NR_CONTEXTS; i++) {

			free_percpu(perf_trace_buf[i]);

			perf_trace_buf[i] = NULL;

		}

	}

out:

	module_put(tp_event->mod);

	mutex_unlock(&event_mutex);

}



__kprobes void *perf_trace_buf_prepare(int size, unsigned short type,

				       struct pt_regs *regs, int *rctxp)

{

kernel/trace/trace_events.c

+7 −3
Original line number Diff line number Diff line
@@ -147,7 +147,8 @@ int trace_event_raw_init(struct ftrace_event_call *call) 
}

EXPORT_SYMBOL_GPL(trace_event_raw_init);



int ftrace_event_reg(struct ftrace_event_call *call, enum trace_reg type)

int ftrace_event_reg(struct ftrace_event_call *call,

		     enum trace_reg type, void *data)

{

	switch (type) {

	case TRACE_REG_REGISTER:
@@ -170,6 +171,9 @@ int ftrace_event_reg(struct ftrace_event_call *call, enum trace_reg type) 
					    call->class->perf_probe,

					    call);

		return 0;

	case TRACE_REG_PERF_OPEN:

	case TRACE_REG_PERF_CLOSE:

		return 0;

#endif

	}

	return 0;
@@ -209,7 +213,7 @@ static int ftrace_event_enable_disable(struct ftrace_event_call *call, 
				tracing_stop_cmdline_record();

				call->flags &= ~TRACE_EVENT_FL_RECORDED_CMD;

			}

			call->class->reg(call, TRACE_REG_UNREGISTER);

			call->class->reg(call, TRACE_REG_UNREGISTER, NULL);

		}

		break;

	case 1:
@@ -218,7 +222,7 @@ static int ftrace_event_enable_disable(struct ftrace_event_call *call, 
				tracing_start_cmdline_record();

				call->flags |= TRACE_EVENT_FL_RECORDED_CMD;

			}

			ret = call->class->reg(call, TRACE_REG_REGISTER);

			ret = call->class->reg(call, TRACE_REG_REGISTER, NULL);

			if (ret) {

				tracing_stop_cmdline_record();

				pr_info("event trace: Could not enable event "

kernel/trace/trace_kprobe.c

+5 −1
Original line number Diff line number Diff line
@@ -1892,7 +1892,8 @@ static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri, 
#endif	/* CONFIG_PERF_EVENTS */



static __kprobes

int kprobe_register(struct ftrace_event_call *event, enum trace_reg type)

int kprobe_register(struct ftrace_event_call *event,

		    enum trace_reg type, void *data)

{

	struct trace_probe *tp = (struct trace_probe *)event->data;
@@ -1909,6 +1910,9 @@ int kprobe_register(struct ftrace_event_call *event, enum trace_reg type) 
	case TRACE_REG_PERF_UNREGISTER:

		disable_trace_probe(tp, TP_FLAG_PROFILE);

		return 0;

	case TRACE_REG_PERF_OPEN:

	case TRACE_REG_PERF_CLOSE:

		return 0;

#endif

	}

	return 0;

kernel/trace/trace_syscalls.c

+10 −4
Original line number Diff line number Diff line
@@ -17,9 +17,9 @@ static DECLARE_BITMAP(enabled_enter_syscalls, NR_syscalls); 
static DECLARE_BITMAP(enabled_exit_syscalls, NR_syscalls);



static int syscall_enter_register(struct ftrace_event_call *event,

				 enum trace_reg type);

				 enum trace_reg type, void *data);

static int syscall_exit_register(struct ftrace_event_call *event,

				 enum trace_reg type);

				 enum trace_reg type, void *data);



static int syscall_enter_define_fields(struct ftrace_event_call *call);

static int syscall_exit_define_fields(struct ftrace_event_call *call);
@@ -649,7 +649,7 @@ void perf_sysexit_disable(struct ftrace_event_call *call) 
#endif /* CONFIG_PERF_EVENTS */



static int syscall_enter_register(struct ftrace_event_call *event,

				 enum trace_reg type)

				 enum trace_reg type, void *data)

{

	switch (type) {

	case TRACE_REG_REGISTER:
@@ -664,13 +664,16 @@ static int syscall_enter_register(struct ftrace_event_call *event, 
	case TRACE_REG_PERF_UNREGISTER:

		perf_sysenter_disable(event);

		return 0;

	case TRACE_REG_PERF_OPEN:

	case TRACE_REG_PERF_CLOSE:

		return 0;

#endif

	}

	return 0;

}



static int syscall_exit_register(struct ftrace_event_call *event,

				 enum trace_reg type)

				 enum trace_reg type, void *data)

{

	switch (type) {

	case TRACE_REG_REGISTER:
@@ -685,6 +688,9 @@ static int syscall_exit_register(struct ftrace_event_call *event, 
	case TRACE_REG_PERF_UNREGISTER:

		perf_sysexit_disable(event);

		return 0;

	case TRACE_REG_PERF_OPEN:

	case TRACE_REG_PERF_CLOSE:

		return 0;

#endif

	}

	return 0;