Message-ID: <21f01245-9bcf-95fc-7781-a8da02029783@canonical.com>
Date:   Tue, 11 Jan 2022 09:24:37 +0100
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Subject: Re: [PATCH] tty: serial: samsung_tty: Check null pointer after
 calling of_match_node
Content-Language: en-US
To:     Jiasheng Jiang <jiasheng@iscas.ac.cn>, gregkh@linuxfoundation.org,
        jirislaby@kernel.org
Cc:     linux-arm-kernel@lists.infradead.org,
        linux-samsung-soc@vger.kernel.org, linux-serial@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20220111081647.637752-1-jiasheng@iscas.ac.cn>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
In-Reply-To: <20220111081647.637752-1-jiasheng@iscas.ac.cn>
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On 11/01/2022 09:16, Jiasheng Jiang wrote:
> If there is no suitable node, of_match_node() will return NULL pointer.

NAK.

This is not possible. All drivers have such pattern and it was
discouraged to add empty/dead NULL checks.

If you think returning NULL is possible, please explain/document it.

> Therefore it should be better to check it in order to avoid the
> dereference of NULL pointer.
> And the only caller s3c24xx_serial_probe() has already checked the
> return value of the s3c24xx_get_driver_data().
> So the new check can be dealed with.
> 


Best regards,
Krzysztof