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From:   Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Date:   Thu, 15 Nov 2018 12:12:33 +0200
Message-ID: <CABBYNZJ_TEM18yfO6O4HFdyo7sm-cE8iL4Y8_DEa1e6xZ7a=Bg@mail.gmail.com>
Subject: Re: [PATCH BlueZ] gatt: Ignore SIGPIPE
To:     gbenhaim@augury.com
Cc:     "linux-bluetooth@vger.kernel.org" <linux-bluetooth@vger.kernel.org>
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Sender: linux-bluetooth-owner@vger.kernel.org
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Hi,
On Thu, Nov 15, 2018 at 10:41 AM Gal <gbenhaim@augury.com> wrote:
>
> bluetoothd receives a SIGPIPE and terminates if writing to a pipe that
> was acquired by AcquireNotify and there are no readers. it can be
> reproduced by terminating the reader process without closing the reader
> end of the pipe.
>
> Ignoring the SIGPIPE will cause the write operation to return a
> "io_send: Broken pipe" error which will be logged.
> ---
>  src/gatt-client.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/src/gatt-client.c b/src/gatt-client.c
> index 234f46ed7..236f38ad5 100644
> --- a/src/gatt-client.c
> +++ b/src/gatt-client.c
> @@ -1137,6 +1137,9 @@ static DBusMessage *characteristic_create_pipe(struct characteristic *chrc,
>         if (pipe2(pipefd, O_DIRECT | O_NONBLOCK | O_CLOEXEC) < 0)
>                 return btd_error_failed(msg, strerror(errno));
>
> +       /* Ignore SIGPIPE, a broken pipe error will be returned if the pipe has no readers */
> +       signal(SIGPIPE, SIG_IGN);
> +
>         dir = dbus_message_has_member(msg, "AcquireWrite");
>
>         io = io_new(pipefd[!dir]);
> --
> 2.19.1

I wonder if there is a way to detect that on bluetoothd actually, that
way even if the client don't set it properly it would not make
bluetoothd to exit.


-- 
Luiz Augusto von Dentz