DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org A1FC660314
Subject: Re: [PATCH] tty: fix data race in n_tty_receive_buf_common
To: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Cc: jslaby@suse.com, gregkh@linuxfoundation.org, mikey@neuling.org,
        linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org
References: <1514987332-14122-1-git-send-email-gkohli@codeaurora.org>
 <20180103193807.465e054e@alans-desktop>
 <0a456419-c836-08cf-070b-a254fb702b75@codeaurora.org>
 <20180104110920.169a1fe5@alans-desktop>
 <0dbd1f05-4c94-d1cc-3858-7bd4d38b9212@codeaurora.org>
 <20180104143716.5b09b1c7@alans-desktop>
 <93a7bd73-1123-90a7-b22d-02964ba29fb0@codeaurora.org>
 <999c5499-05c7-4702-77a7-dfb56ba577d2@codeaurora.org>
 <20180105133609.636b2d1f@alans-desktop>
 <a502434e-b534-0e59-fa31-7644a23152eb@codeaurora.org>
 <20180105141504.0e399394@alans-desktop>
 <1097619b-9e03-cba8-e40e-b0c00a53b84c@codeaurora.org>
 <46645a5b-b0d4-35b7-95ac-3606ab9c69d2@codeaurora.org>
 <20180105210529.0264fef0@alans-desktop>
From: "Kohli, Gaurav" <gkohli@codeaurora.org>
Message-ID: <3aa0f202-ac36-2513-22d2-a3164fb44d3f@codeaurora.org>
Date: Sat, 6 Jan 2018 13:20:49 +0530
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On 1/6/2018 2:35 AM, Alan Cox wrote:
> On Sat, 6 Jan 2018 01:54:36 +0530
> "Kohli, Gaurav" <gkohli@codeaurora.org> wrote:
>
>> Hi Alan,
>>
>> Sorry correcting the typo here:
>> +retval =  tty_ldisc_lock(tty, 5 * HZ);
>> +if (retval)
>> +         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);
>>           if (retval)
>>               goto err_release_tty;
>> tty_ldisc_unlock(tty);
>> err_release_tty:
>> tty_info_ratelimited(tty, "ldisc open failed (%d), clearing slot %d\n",
>>       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

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