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Date:   Thu, 11 Oct 2018 23:01:51 -0400
From:   Steven Rostedt <rostedt@goodmis.org>
To:     LKML <linux-kernel@vger.kernel.org>
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@kernel.org>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Andy Lutomirski <luto@amacapital.net>,
        Josh Poimboeuf <jpoimboe@redhat.com>
Subject: Re: [RFC][PATCH] x86: ptrace: Add function argument access API
Message-ID: <20181011230151.25ba36f3@vmware.local.home>
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On Thu, 11 Oct 2018 23:00:21 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:

>   A while ago I posted an RFC patchset for dynamic function based
>   events. But Masami pointed out that this could be done with kprobes
>   with minimal changes. He posted a patch set back in March
>   http://lkml.kernel.org/r/152049860385.7289.14079393589900496424.stgit@devbox
>   I've pulled this in locally, but haven't had the time until recently
>   to look at it seriously. I even plan to talk about these changes in
>   my talk at Open Source Summit in Edinburgh less than two weeks away
>   (talk about conference driven development!).
>   Anyway, the one patch that really needs external approval is the one
>   that creates a new architecture dependent API to retrieve function
>   arguments from pt_regs if the ip is at the start of the function call
>   (via a breakpoint or ftrace fentry). That's this patch.
> 
>   Anyone have any issues with it? If not, I'm going to start doing some
>   serious testing of this code and try to get it into the next merge
>   window.

You can also play with the full repo here:

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git

 branch: ftrace/kprobes

-- Steve