Re: [RFC][PATCH -tip 9/9] tracing: kprobe-tracer plugin supports module_probe

[Masami Hiramatsu <mhiramat@redhat.com>]

Steven Rostedt wrote:
> On Thu, 19 Mar 2009, Masami Hiramatsu wrote:
> 
>> Use register/unregister_module_*probe functions for tracing
>> module .init/.exit functions.
>>
>> Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
>> Cc: Steven Rostedt <rostedt@goodmis.org>
>> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
>> Cc: Ingo Molnar <mingo@elte.hu>
>> ---
>>  kernel/trace/trace_kprobe.c |   15 ++++++++++-----
>>  1 files changed, 10 insertions(+), 5 deletions(-)
>>
>> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
>> index e801e8c..7b7ab53 100644
>> --- a/kernel/trace/trace_kprobe.c
>> +++ b/kernel/trace/trace_kprobe.c
>> @@ -226,6 +226,11 @@ static void free_trace_probe(struct trace_probe *tp)
>>  	kfree(tp);
>>  }
>>
>> +static int activate_handler(void *offset, struct module *mod)
>> +{
>> +	return ((unsigned long)offset == 0) ? 1 : 0;
> 
> This is a strange way to implement:
> 
> 	return !offset;

Yes. Thanks!

> 
> -- Steve
> 
>> +}
>> +
>>  static int register_trace_probe(struct trace_probe *tp)
>>  {
>>  	int ret;
>> @@ -234,9 +239,10 @@ static int register_trace_probe(struct trace_probe *tp)
>>  	list_add_tail(&tp->list, &probe_list);
>>
>>  	if (probe_is_return(tp))
>> -		ret = register_kretprobe(&tp->rp);
>> +		ret = register_module_kretprobe(&tp->rp, activate_handler, 0);
>>  	else
>> -		ret = register_kprobe(&tp->kp);
>> +		ret = register_module_kprobe(&tp->kp, activate_handler,
>> +					     (void *)(tp->kp.offset));
>>
>>  	if (ret) {
>>  		pr_warning("Probe registering error: %d\n", ret);
>> @@ -249,9 +255,9 @@ static int register_trace_probe(struct trace_probe *tp)
>>  static void unregister_trace_probe(struct trace_probe *tp)
>>  {
>>  	if (probe_is_return(tp))
>> -		unregister_kretprobe(&tp->rp);
>> +		unregister_module_kretprobe(&tp->rp);
>>  	else
>> -		unregister_kprobe(&tp->kp);
>> +		unregister_module_kprobe(&tp->kp);
>>  	list_del(&tp->list);
>>  }
>>
>> @@ -301,7 +307,6 @@ static int create_trace_probe(int argc, char **argv)
>>  	} else {
>>  		/* a symbol specified */
>>  		symbol = argv[1];
>> -		/* TODO: support .init module functions */
>>  		tmp = strchr(symbol, '+');
>>  		if (!tmp)
>>  			tmp = strchr(symbol, '-');
>> -- 
>> Masami Hiramatsu
>>
>> Software Engineer
>> Hitachi Computer Products (America) Inc.
>> Software Solutions Division
>>
>> e-mail: mhiramat@redhat.com
>>
>>
>>

-- 
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America) Inc.
Software Solutions Division

e-mail: mhiramat@redhat.com