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From:   Zheyu Ma <zheyuma97@gmail.com>
Date:   Wed, 7 Jul 2021 18:37:52 +0800
Message-ID: <CAMhUBjmsoB5zzqdqs5OKwqNa_twFwxu16pb+OTmUpTwW59sDfQ@mail.gmail.com>
Subject: Re: [PATCH v4] tty: serial: jsm: allocate queue buffer at probe time
To:     Andy Shevchenko <andy.shevchenko@gmail.com>
Cc:     "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        "jirislaby@kernel.org" <jirislaby@kernel.org>,
        "linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
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On Wed, Jul 7, 2021 at 4:14 PM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
>
>
>
> On Monday, July 5, 2021, Zheyu Ma <zheyuma97@gmail.com> wrote:
>>
>> In function 'neo_intr', the driver uses 'ch->ch_equeue' and
>> 'ch->ch_reuque'. These two pointers are initialized in 'jsm_tty_open',
>> but the interrupt handler 'neo_intr' has been registered in the probe
>> progress. If 'jsm_tty_open' has not been called at this time, it will
>> cause null pointer dereference.
>>
>> Once the driver registers the interrupt handler, the driver should be
>> ready to handle it.
>>
>> Fix this by allocating the memory at probe time and not at open time.
>>
>> This log reveals it:
>
>
>
> When doing commit messages try to avoid tons of noise in them, I.e. here is _a lot of useless lines_ from the log, has to be addressed.

Thanks for your advice, I will learn from other commits.

Regards,
Zheyu Ma