DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 80E47208E3
MIME-Version: 1.0
References: <20181117060024.10390-1-gbenhaim@augury.com> <CAHotPr82XDc9tE_76iknhQtbTjEMzXdQa4HpUy7asTZvwjG5ZQ@mail.gmail.com>
 <CAHotPr9dh7Nz6St10D9LvEUDGrcM29_8CdGivanrw0qzVPb28Q@mail.gmail.com>
 <CABBYNZ+Nkbb2vUXVD6FY4+_ZJEqjgfXh=ONn7JYD9nyrx4E50Q@mail.gmail.com> <CAHotPr-pPNwawo+uU=4QbSNSdNbFcoBbnr-LY_fMiwMQW+1aew@mail.gmail.com>
In-Reply-To: <CAHotPr-pPNwawo+uU=4QbSNSdNbFcoBbnr-LY_fMiwMQW+1aew@mail.gmail.com>
From:   Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Date:   Mon, 19 Nov 2018 12:59:37 +0200
Message-ID: <CABBYNZ+uRoC_Pk8cUTFh6vH4T_xQ+BhQdAuL9-ZTjzfA=qboHQ@mail.gmail.com>
Subject: Re: [PATCH BlueZ] core: Catch SIGPIPE
To:     gbenhaim@augury.com
Cc:     "linux-bluetooth@vger.kernel.org" <linux-bluetooth@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-bluetooth-owner@vger.kernel.org
Precedence: bulk

Im taking care of it, will send the patches when they are ready.
On Mon, Nov 19, 2018 at 11:47 AM Gal Ben Haim <gbenhaim@augury.com> wrote:
>
> are you suggesting to have a single socketpair for both notify_io and
> write_io or 2x socketpair instead of 2x pipe2 ?
>
> On Mon, Nov 19, 2018 at 11:22 AM Luiz Augusto von Dentz
> <luiz.dentz@gmail.com> wrote:
> >
> > Hi Gal,
> >
> > On Sat, Nov 17, 2018 at 10:48 PM Gal Ben Haim <gbenhaim@augury.com> wrote:
> > >
> > > i don't think it works at all... bluetoothd is still exiting with SIGPIPE.
> > > i'm a bit lost with fixing this, I tried few methods that were
> > > suggested here and the only one that actually worked is to ignore the
> > > signal.
> > >
> > > please advise how do you want to proceed with this..
> >
> > We might be better of switching to socketpair instead of pipe2 then,
> > not only we can fix this problem using MSG_NOSIGNAL but also use
> > sendmsg and setting auxiliary data which can be used to set things
> > like the offset.
> >
> > > On Sat, Nov 17, 2018 at 10:41 PM Gal Ben Haim <gbenhaim@augury.com> wrote:
> > > >
> > > > actually it does not log the broken pipe message, is it because errno
> > > > isn't set before the signal handler is done?
> > > > what do you think?
> > > > On Sat, Nov 17, 2018 at 8:00 AM Gal Ben-Haim <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.
> > > > >
> > > > > Catching SIGPIPE will cause the write call to return an EPIPE error
> > > > > which will be logged as "io_send: Broken pipe".
> > > > > ---
> > > > >  src/main.c | 3 +++
> > > > >  1 file changed, 3 insertions(+)
> > > > >
> > > > > diff --git a/src/main.c b/src/main.c
> > > > > index 4716f5388..54cdb8d3f 100644
> > > > > --- a/src/main.c
> > > > > +++ b/src/main.c
> > > > > @@ -533,6 +533,8 @@ static gboolean signal_handler(GIOChannel *channel, GIOCondition cond,
> > > > >         case SIGUSR2:
> > > > >                 __btd_toggle_debug();
> > > > >                 break;
> > > > > +       case SIGPIPE:
> > > > > +               break;
> > > > >         }
> > > > >
> > > > >         return TRUE;
> > > > > @@ -549,6 +551,7 @@ static guint setup_signalfd(void)
> > > > >         sigaddset(&mask, SIGINT);
> > > > >         sigaddset(&mask, SIGTERM);
> > > > >         sigaddset(&mask, SIGUSR2);
> > > > > +       sigaddset(&mask, SIGPIPE);
> > > > >
> > > > >         if (sigprocmask(SIG_BLOCK, &mask, NULL) < 0) {
> > > > >                 perror("Failed to set signal mask");
> > > > > --
> > > > > 2.19.1
> > > > >
> >
> >
> >
> > --
> > Luiz Augusto von Dentz


-- 
Luiz Augusto von Dentz