Messages in this thread | | | Date | Sun, 14 May 2023 12:02:36 +0900 | From | Masami Hiramatsu (Google) <> | Subject | Re: [PATCH v9.1 07/11] tracing/probes: Add $$args meta argument for all function args |
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On Fri, 5 May 2023 17:48:56 -0400 Steven Rostedt <rostedt@goodmis.org> wrote:
> On Tue, 2 May 2023 11:18:21 +0900 > "Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote: > > > From: Masami Hiramatsu (Google) <mhiramat@kernel.org> > > > > Add the '$$args' meta fetch argument for function-entry probe events. This > > Hmm, couldn't we just use $args ? That would be different from $arg1, > $arg2, etc. > > The $$ to me would be either the bash pid of current, or perhaps it would > be just to use a dollar sign. I don't see the precedence of $$args being a > "full expand".
OK, I just thought it required a bit special prefix because it will be expanded to several arguments (it is different from other $-params) and, internally, it should be handled in the different path from the other $-params. But the latter is internal reason, we should not care about that. (of course I will leave a comment it.)
Thank you!
> > -- Steve > > > > will be expanded to the all arguments of the function and the tracepoint > > using BTF function argument information. > > > > e.g. > > # echo 'p vfs_read $$args' >> dynamic_events > > # echo 'f vfs_write $$args' >> dynamic_events > > # echo 't sched_overutilized_tp $$args' >> dynamic_events > > # cat dynamic_events > > p:kprobes/p_vfs_read_0 vfs_read file=file buf=buf count=count pos=pos > > f:fprobes/vfs_write__entry vfs_write file=file buf=buf count=count pos=pos > > t:tracepoints/sched_overutilized_tp sched_overutilized_tp rd=rd overutilized=overutilized > > > > Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> > > ---
-- Masami Hiramatsu (Google) <mhiramat@kernel.org>
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