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Commit ff50d991 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Frederic Weisbecker
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tracing: Kprobe tracer assigns new event ids for each event 



Assign new event ids for each kprobes event. This doesn't clear
ring_buffer when unregistering each kprobe event. Thus, if you mind
'Unknown event' messages, clear the buffer manually after changing
kprobe events.

Signed-off-by: default avatarMasami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Przemysław Pawełczyk <przemyslaw@pawelczyk.it>
Cc: Roland McGrath <roland@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
LKML-Reference: <20090813203534.31965.49105.stgit@localhost.localdomain>
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
parent 4263565d

kernel/trace/trace.h

+0 −6
Original line number Diff line number Diff line
@@ -38,8 +38,6 @@ enum trace_type { 
	TRACE_KMEM_FREE,

	TRACE_POWER,

	TRACE_BLK,

	TRACE_KPROBE,

	TRACE_KRETPROBE,



	__TRACE_LAST_TYPE,

};
@@ -343,10 +341,6 @@ extern void __ftrace_bad_type(void); 
			  TRACE_KMEM_ALLOC);	\

		IF_ASSIGN(var, ent, struct kmemtrace_free_entry,	\

			  TRACE_KMEM_FREE);	\

		IF_ASSIGN(var, ent, struct kprobe_trace_entry,		\

			  TRACE_KPROBE);				\

		IF_ASSIGN(var, ent, struct kretprobe_trace_entry,	\

			  TRACE_KRETPROBE);				\

		__ftrace_bad_type();					\

	} while (0)

kernel/trace/trace_kprobe.c

+15 −36
Original line number Diff line number Diff line
@@ -186,6 +186,7 @@ struct trace_probe { 
	};

	const char		*symbol;	/* symbol name */

	struct ftrace_event_call	call;

	struct trace_event		event;

	unsigned int		nr_args;

	struct fetch_func	args[];

};
@@ -795,7 +796,7 @@ static __kprobes int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs) 


	size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args);



	event = trace_current_buffer_lock_reserve(TRACE_KPROBE, size,

	event = trace_current_buffer_lock_reserve(call->id, size,

						  irq_flags, pc);

	if (!event)

		return 0;
@@ -827,7 +828,7 @@ static __kprobes int kretprobe_trace_func(struct kretprobe_instance *ri, 


	size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args);



	event = trace_current_buffer_lock_reserve(TRACE_KRETPROBE, size,

	event = trace_current_buffer_lock_reserve(call->id, size,

						  irq_flags, pc);

	if (!event)

		return 0;
@@ -853,7 +854,7 @@ print_kprobe_event(struct trace_iterator *iter, int flags) 
	struct trace_seq *s = &iter->seq;

	int i;



	trace_assign_type(field, iter->ent);

	field = (struct kprobe_trace_entry *)iter->ent;



	if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))

		goto partial;
@@ -880,7 +881,7 @@ print_kretprobe_event(struct trace_iterator *iter, int flags) 
	struct trace_seq *s = &iter->seq;

	int i;



	trace_assign_type(field, iter->ent);

	field = (struct kretprobe_trace_entry *)iter->ent;



	if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))

		goto partial;
@@ -906,16 +907,6 @@ print_kretprobe_event(struct trace_iterator *iter, int flags) 
	return TRACE_TYPE_PARTIAL_LINE;

}



static struct trace_event kprobe_trace_event = {

	.type	 	= TRACE_KPROBE,

	.trace		= print_kprobe_event,

};



static struct trace_event kretprobe_trace_event = {

	.type	 	= TRACE_KRETPROBE,

	.trace		= print_kretprobe_event,

};



static int probe_event_enable(struct ftrace_event_call *call)

{

	struct trace_probe *tp = (struct trace_probe *)call->data;
@@ -1104,35 +1095,35 @@ static int register_probe_event(struct trace_probe *tp) 
	/* Initialize ftrace_event_call */

	call->system = "kprobes";

	if (probe_is_return(tp)) {

		call->event = &kretprobe_trace_event;

		call->id = TRACE_KRETPROBE;

		tp->event.trace = print_kretprobe_event;

		call->raw_init = probe_event_raw_init;

		call->show_format = kretprobe_event_show_format;

		call->define_fields = kretprobe_event_define_fields;

	} else {

		call->event = &kprobe_trace_event;

		call->id = TRACE_KPROBE;

		tp->event.trace = print_kprobe_event;

		call->raw_init = probe_event_raw_init;

		call->show_format = kprobe_event_show_format;

		call->define_fields = kprobe_event_define_fields;

	}

	call->event = &tp->event;

	call->id = register_ftrace_event(&tp->event);

	if (!call->id)

		return -ENODEV;

	call->enabled = 1;

	call->regfunc = probe_event_enable;

	call->unregfunc = probe_event_disable;

	call->data = tp;

	ret = trace_add_event_call(call);

	if (ret)

	if (ret) {

		pr_info("Failed to register kprobe event: %s\n", call->name);

		unregister_ftrace_event(&tp->event);

	}

	return ret;

}



static void unregister_probe_event(struct trace_probe *tp)

{

	/*

	 * Prevent to unregister event itself because the event is shared

	 * among other probes.

	 */

	tp->call.event = NULL;

	/* tp->event is unregistered in trace_remove_event_call() */

	trace_remove_event_call(&tp->call);

}
@@ -1141,18 +1132,6 @@ static __init int init_kprobe_trace(void) 
{

	struct dentry *d_tracer;

	struct dentry *entry;

	int ret;



	ret = register_ftrace_event(&kprobe_trace_event);

	if (!ret) {

		pr_warning("Could not register kprobe_trace_event type.\n");

		return 0;

	}

	ret = register_ftrace_event(&kretprobe_trace_event);

	if (!ret) {

		pr_warning("Could not register kretprobe_trace_event type.\n");

		return 0;

	}



	d_tracer = tracing_init_dentry();

	if (!d_tracer)