From mboxrd@z Thu Jan  1 00:00:00 1970
From: Namhyung Kim <namhyung@kernel.org>
Subject: Re: [PATCH 17/18] tracing: Add indirect to indirect access for
 function based events
Date: Tue, 13 Feb 2018 18:27:37 +0900
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Cc: linux-kernel@vger.kernel.org,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Ingo Molnar <mingo@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Peter Zijlstra <peterz@infradead.org>,
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        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Clark Williams <williams@redhat.com>,
        Jiri Olsa <jolsa@redhat.com>,
        Daniel Bristot de Oliveira <bristot@redhat.com>,
        Juri Lelli <juri.lelli@redhat.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Alexei Starovoitov <alexei.starovoitov@gmail.com>,
        kernel-team@lge.com
To: Steven Rostedt <rostedt@goodmis.org>
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Hi Steve,

On Mon, Feb 12, 2018 at 12:23:54PM -0500, Steven Rostedt wrote:
> On Mon, 12 Feb 2018 11:15:34 +0900
> Namhyung Kim <namhyung@kernel.org> wrote:
> 
> > > It should have been:
> > > 
> > > 		return process_redirects(arg, val, buf);  
> > 
> > But I think you need to consider data type of the arg when
> > dereferencing the last redirect.
> 
> What for?

Otherwise it'd return a value of unsigned long type regardless of the
type of the arg.  I thought it should have same logic as indirect
args.

But it seems not matter since record_entry() would copy it only for
the arg->size.  Then type check in __get_arg() might be unnecessary
too.

> 
> Also this code has also changed. I haven't posted new patches but my
> latest is in my git tree in the branch ftrace/dynamic-ftrace-events.

I've checked it.  And it seems to have another problem for indirect
(but not redirect) arrays and strings.  Like 'x32[1] foo[2]'?

Thanks,
Namhyung