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

From: Steven Rostedt
Date: Thu Mar 19 2009 - 20:08:44 EST



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@xxxxxxxxxx>
> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Cc: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxx>
> ---
> 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;

-- 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@xxxxxxxxxx
>
>
>
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