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Re: [RFC][PATCH -tip 9/9] tracing: kprobe-tracer plugin supports module_probe
- From: Masami Hiramatsu <mhiramat at redhat dot com>
- To: Steven Rostedt <rostedt at goodmis dot org>
- Cc: Ananth N Mavinakayanahalli <ananth at in dot ibm dot com>, Ingo Molnar <mingo at elte dot hu>, systemtap-ml <systemtap at sources dot redhat dot com>, LKML <linux-kernel at vger dot kernel dot org>
- Date: Thu, 19 Mar 2009 23:57:09 -0400
- Subject: Re: [RFC][PATCH -tip 9/9] tracing: kprobe-tracer plugin supports module_probe
- References: <49C2B4D9.6040602@redhat.com> <alpine.DEB.2.00.0903192007380.13615@gandalf.stny.rr.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