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Commit 6fb2915d authored by Li Zefan's avatar Li Zefan Committed by Ingo Molnar
Browse files

tracing/profile: Add filter support 



- Add an ioctl to allocate a filter for a perf event.

- Free the filter when the associated perf event is to be freed.

- Do the filtering in perf_swevent_match().

Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
Acked-by: default avatarPeter Zijlstra <peterz@infradead.org>
Acked-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <4AD69546.8050401@cn.fujitsu.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent b0f1a59a

include/linux/ftrace_event.h

+10 −1
Original line number Diff line number Diff line
@@ -144,7 +144,7 @@ extern char *trace_profile_buf_nmi; 
#define MAX_FILTER_STR_VAL	256	/* Should handle KSYM_SYMBOL_LEN */



extern void destroy_preds(struct ftrace_event_call *call);

extern int filter_match_preds(struct ftrace_event_call *call, void *rec);

extern int filter_match_preds(struct event_filter *filter, void *rec);

extern int filter_current_check_discard(struct ring_buffer *buffer,

					struct ftrace_event_call *call,

					void *rec,
@@ -186,4 +186,13 @@ do { \ 
		__trace_printk(ip, fmt, ##args);			\

} while (0)



#ifdef CONFIG_EVENT_PROFILE

struct perf_event;

extern int ftrace_profile_enable(int event_id);

extern void ftrace_profile_disable(int event_id);

extern int ftrace_profile_set_filter(struct perf_event *event, int event_id,

				     char *filter_str);

extern void ftrace_profile_free_filter(struct perf_event *event);

#endif



#endif /* _LINUX_FTRACE_EVENT_H */

include/linux/perf_counter.h

+1 −0
Original line number Diff line number Diff line
@@ -225,6 +225,7 @@ struct perf_counter_attr { 
#define PERF_COUNTER_IOC_RESET		_IO ('$', 3)

#define PERF_COUNTER_IOC_PERIOD		_IOW('$', 4, u64)

#define PERF_COUNTER_IOC_SET_OUTPUT	_IO ('$', 5)

#define PERF_COUNTER_IOC_SET_FILTER	_IOW('$', 6, char *)



enum perf_counter_ioc_flags {

	PERF_IOC_FLAG_GROUP		= 1U << 0,

include/linux/perf_event.h

+6 −0
Original line number Diff line number Diff line
@@ -221,6 +221,7 @@ struct perf_event_attr { 
#define PERF_EVENT_IOC_RESET		_IO ('$', 3)

#define PERF_EVENT_IOC_PERIOD		_IOW('$', 4, u64)

#define PERF_EVENT_IOC_SET_OUTPUT	_IO ('$', 5)

#define PERF_EVENT_IOC_SET_FILTER	_IOW('$', 6, char *)



enum perf_event_ioc_flags {

	PERF_IOC_FLAG_GROUP		= 1U << 0,
@@ -633,7 +634,12 @@ struct perf_event { 


	struct pid_namespace		*ns;

	u64				id;



#ifdef CONFIG_EVENT_PROFILE

	struct event_filter		*filter;

#endif



#endif /* CONFIG_PERF_EVENTS */

};



/**

kernel/perf_event.c

+73 −7
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#include <linux/anon_inodes.h>

#include <linux/kernel_stat.h>

#include <linux/perf_event.h>

#include <linux/ftrace_event.h>



#include <asm/irq_regs.h>
@@ -1658,6 +1659,8 @@ static struct perf_event_context *find_get_context(pid_t pid, int cpu) 
	return ERR_PTR(err);

}



static void perf_event_free_filter(struct perf_event *event);



static void free_event_rcu(struct rcu_head *head)

{

	struct perf_event *event;
@@ -1665,6 +1668,7 @@ static void free_event_rcu(struct rcu_head *head) 
	event = container_of(head, struct perf_event, rcu_head);

	if (event->ns)

		put_pid_ns(event->ns);

	perf_event_free_filter(event);

	kfree(event);

}
@@ -1974,7 +1978,8 @@ static int perf_event_period(struct perf_event *event, u64 __user *arg) 
	return ret;

}



int perf_event_set_output(struct perf_event *event, int output_fd);

static int perf_event_set_output(struct perf_event *event, int output_fd);

static int perf_event_set_filter(struct perf_event *event, void __user *arg);



static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)

{
@@ -2002,6 +2007,9 @@ static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 
	case PERF_EVENT_IOC_SET_OUTPUT:

		return perf_event_set_output(event, arg);



	case PERF_EVENT_IOC_SET_FILTER:

		return perf_event_set_filter(event, (void __user *)arg);



	default:

		return -ENOTTY;

	}
@@ -3806,9 +3814,14 @@ static int perf_swevent_is_counting(struct perf_event *event) 
	return 1;

}



static int perf_tp_event_match(struct perf_event *event,

				struct perf_sample_data *data);



static int perf_swevent_match(struct perf_event *event,

				enum perf_type_id type,

				u32 event_id, struct pt_regs *regs)

				u32 event_id,

				struct perf_sample_data *data,

				struct pt_regs *regs)

{

	if (!perf_swevent_is_counting(event))

		return 0;
@@ -3826,6 +3839,10 @@ static int perf_swevent_match(struct perf_event *event, 
			return 0;

	}



	if (event->attr.type == PERF_TYPE_TRACEPOINT &&

	    !perf_tp_event_match(event, data))

		return 0;



	return 1;

}
@@ -3842,7 +3859,7 @@ static void perf_swevent_ctx_event(struct perf_event_context *ctx, 


	rcu_read_lock();

	list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {

		if (perf_swevent_match(event, type, event_id, regs))

		if (perf_swevent_match(event, type, event_id, data, regs))

			perf_swevent_add(event, nr, nmi, data, regs);

	}

	rcu_read_unlock();
@@ -4086,6 +4103,7 @@ static const struct pmu perf_ops_task_clock = { 
};



#ifdef CONFIG_EVENT_PROFILE



void perf_tp_event(int event_id, u64 addr, u64 count, void *record,

			  int entry_size)

{
@@ -4109,8 +4127,15 @@ void perf_tp_event(int event_id, u64 addr, u64 count, void *record, 
}

EXPORT_SYMBOL_GPL(perf_tp_event);



extern int ftrace_profile_enable(int);

extern void ftrace_profile_disable(int);

static int perf_tp_event_match(struct perf_event *event,

				struct perf_sample_data *data)

{

	void *record = data->raw->data;



	if (likely(!event->filter) || filter_match_preds(event->filter, record))

		return 1;

	return 0;

}



static void tp_perf_event_destroy(struct perf_event *event)

{
@@ -4135,12 +4160,53 @@ static const struct pmu *tp_perf_event_init(struct perf_event *event) 


	return &perf_ops_generic;

}



static int perf_event_set_filter(struct perf_event *event, void __user *arg)

{

	char *filter_str;

	int ret;



	if (event->attr.type != PERF_TYPE_TRACEPOINT)

		return -EINVAL;



	filter_str = strndup_user(arg, PAGE_SIZE);

	if (IS_ERR(filter_str))

		return PTR_ERR(filter_str);



	ret = ftrace_profile_set_filter(event, event->attr.config, filter_str);



	kfree(filter_str);

	return ret;

}



static void perf_event_free_filter(struct perf_event *event)

{

	ftrace_profile_free_filter(event);

}



#else



static int perf_tp_event_match(struct perf_event *event,

				struct perf_sample_data *data)

{

	return 1;

}



static const struct pmu *tp_perf_event_init(struct perf_event *event)

{

	return NULL;

}

#endif



static int perf_event_set_filter(struct perf_event *event, void __user *arg)

{

	return -ENOENT;

}



static void perf_event_free_filter(struct perf_event *event)

{

}



#endif /* CONFIG_EVENT_PROFILE */



atomic_t perf_swevent_enabled[PERF_COUNT_SW_MAX];
@@ -4394,7 +4460,7 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr, 
	goto out;

}



int perf_event_set_output(struct perf_event *event, int output_fd)

static int perf_event_set_output(struct perf_event *event, int output_fd)

{

	struct perf_event *output_event = NULL;

	struct file *output_file = NULL;

kernel/trace/trace.h

+2 −1
Original line number Diff line number Diff line
@@ -743,7 +743,8 @@ filter_check_discard(struct ftrace_event_call *call, void *rec, 
		     struct ring_buffer *buffer,

		     struct ring_buffer_event *event)

{

	if (unlikely(call->filter_active) && !filter_match_preds(call, rec)) {

	if (unlikely(call->filter_active) &&

	    !filter_match_preds(call->filter, rec)) {

		ring_buffer_discard_commit(buffer, event);

		return 1;

	}