Re: [PATCH] tty: fix data race in n_tty_receive_buf_common

[Kohli, Gaurav]

On 1/6/2018 1:20 PM, Kohli, Gaurav wrote:

> On 1/6/2018 2:35 AM, Alan Cox wrote:
> > On Sat, 6 Jan 2018 01:54:36 +0530
> > "Kohli, Gaurav" <gkohli@xxxxxxxxxxxxxx> wrote:
> > > Hi Alan,
> > > Sorry correcting the typo here:
> > > +retval =Â tty_ldisc_lock(tty, 5 * HZ);
> > > +if (retval)
> > > +ÂÂÂÂ ÂÂÂ goto err_release_lock;
> > > tty->port->itty = tty;
> > > /*
> > > * Structures all installed ... call the ldisc open routines.
> > > * If we fail here just call release_tty to clean up. No need
> > > * to decrement the use counts, as release_tty doesn't care.
> > > */
> > > retval = tty_ldisc_setup(tty, tty->link);
> > >  Â ÂÂÂ ÂÂÂ if (retval)
> > >  Â ÂÂÂ ÂÂÂ ÂÂÂ goto err_release_tty;
> > > tty_ldisc_unlock(tty);
> > > err_release_tty:
> > > tty_info_ratelimited(tty, "ldisc open failed (%d), clearing slot %d\n",
> > >  Â ÂÂÂ retval, idx);
> > > +err_release_lock;
> > > +tty_unlock(tty);
> > > +release_tty(tty, idx);
> > > +tty_ldisc_unlock(tty);
> > > +return ERR_PTR(retval);
> > Thanks - can you give that a testing since for some reason you seem to be
> > the only system able to hit this and confirm that it's now working
> > properly. Then I'll push it upstream
> > And thanks for doing all the debug work to find this and identify what
> > was going on.
> > Alan
> > --
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> Thanks Alan for your support, yes we will try to reproduce and get back
> to you.
> Ideally it take 2-3 days for issue reproduction, but yes it is
> consistently reproducible.
> Regards
> Gaurav

Hi Alan,
Sorry for the delayed response, as i was waiting for test results.
I have uploaded the new patch v1 as per your suggestions and result 
looks good.

Thanks
Gaurav
>
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