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From: Vaibhav Nagarnaik <vnagarnaik@google.com>
Date: Tue, 28 May 2013 12:34:23 -0700
Message-ID: <CAL26m8+baBm-kcWH96C1oj3rVHoa0Vc=gHshqWAD-BtBd4FJKQ@mail.gmail.com>
Subject: Re: [PATCH] tracing: Fix file mode of free_buffer
To: Wang YanQing <udknight@gmail.com>, Steven Rostedt <rostedt@goodmis.org>,
        =?ISO-8859-1?Q?Fr=E9d=E9ric_Weisbecker?= <fweisbec@gmail.com>,
        Ingo Molnar <mingo@redhat.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Vaibhav Nagarnaik <vnagarnaik@google.com>
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On Sun, May 26, 2013 at 1:52 AM, Wang YanQing <udknight@gmail.com> wrote:
> Commit 4f271a2a60c748599b30bb4dafff30d770439b96
> (tracing: Add a proc file to stop tracing and free buffer)
> implement a method to free up ring buffer in kernel memory
> in the release code path of free_buffer's fd.
>
> Then we don't need read/write support for free_buffer,
> indeed we just have a dummy write fop, and don't implement read fop.
>
> So the 0200 is more reasonable file mode for free_buffer than
> the current file mode 0644.
>
> Signed-off-by: Wang YanQing <udknight@gmail.com>

Acked-by: Vaibhav Nagarnaik <vnagarnaik@google.com>

Vaibhav Nagarnaik


> ---
>  kernel/trace/trace.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index ae6fa2d..02d9875 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -5927,7 +5927,7 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
>         trace_create_file("buffer_total_size_kb", 0444, d_tracer,
>                           tr, &tracing_total_entries_fops);
>
> -       trace_create_file("free_buffer", 0644, d_tracer,
> +       trace_create_file("free_buffer", 0200, d_tracer,
>                           tr, &tracing_free_buffer_fops);
>
>         trace_create_file("trace_marker", 0220, d_tracer,
> --
> 1.7.12.4.dirty