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Mon, 03 Mar 2025 09:15:26 +0100 Message-ID: <12050afd-ab60-4bac-bd25-0c3cc925b38b@web.de> Date: Mon, 3 Mar 2025 09:15:14 +0100 Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RESEND] drm/msm/dpu: Delete a variable initialisation before a null pointer check in two functions To: Dan Carpenter , Dmitry Baryshkov , freedreno@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-arm-msm@vger.kernel.org Cc: kernel-janitors@vger.kernel.org, Abhinav Kumar , Archit Taneja , Daniel Vetter , David Airlie , Jeykumar Sankaran , Jordan Crouse , Marijn Suijten , Rob Clark , Sean Paul , Simona Vetter , Vinod Koul , cocci@inria.fr, LKML References: <40c60719-4bfe-b1a4-ead7-724b84637f55@web.de> <1a11455f-ab57-dce0-1677-6beb8492a257@web.de> <13566308-9a80-e4aa-f64e-978c02b1406d@web.de> <54c30a69-71cf-4582-9086-50eb0d39f273@web.de> <29b32b0d-312d-4848-9e26-9e5e76e527a7@stanley.mountain> Content-Language: en-GB From: Markus Elfring In-Reply-To: <29b32b0d-312d-4848-9e26-9e5e76e527a7@stanley.mountain> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:l61V0/AxxnfLP2CwSsghwK08nUFAsuRp8A9xZrnTeiVv24ZQ/3i G3RqnUSDyuxhHQZurimb7PiKwXU+E3AYQdbSIZXeIB08KV04ZaIwwV6knwRGWgTrx/XbTMg CBbyohY7P+EBXFxvTLfoNgfYBAMIogVtGwuVEb013+xJ6c0saMHuLXFWDU4EPclYOhKB/Ey tGrwZLuNRsk+/ZLmwQalw== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:+dEdQWoQ7kU=;IasLY5SUCezkQ/oK2dlxCFJnD1K EJ01spAXIy6+nudFKoE9Ket7tA810fP2bclD61wzlHRGOv4tQIHAjxmFEE2d8kFXsN+a/mPkG FEVtu9wjQZHMXgKSMoC5BPZoDpkzD/U1ZXB1CUWPUuDB0pv7RJq5r/R6B12AP1OMXzCfTU9JD HQKL7MyACkb/xotarJowiXBcVEu/6aHj1Zp36NpLfQeCQEVhsprW05XRB6zJS5J5Glc6AS3Ie uc4MkOzsy8XU3/HU4AS+inJMduJnuSWrdSxzFrNSMYND/jnPk5zOirakBHoh1yny/3+M6oDeY 9Atayo8H9W9OCjxR6DcXcnhUTdAlzZrMlUm9pZKpxtatC3AgFgv1XDDOKcf4yaidQ9xLSr/rn +GqCxAvIKhT+dR3vCubnYfZPN8xmkJxyPgqRYueCCKSBxhqvTzfYv7IKEMxImJWM5wpQvo5fz mgt/io8nxznlCpVV1uZl7qtzsUkOrletjiSuj0aOdQp87vlnvem0wTUWyqLiITCi6Y2NFcZgY +OASaJoFYY3kXCTYlhJWCHe6qXguImSMFZ4YobohpinTpKWiZbTw2cZikfKH6z1fCdTrMd/xA 2jj47hfyTHRDcT1ViLdRrZrNumqNOBggSDj/wCDaLFVXlGV/vZIqRvo5SfOZqDiWj2KMmQnJL bwM0Wis7oqvKHx4WWYMpArgPX9Yv4aNySc+wg4M689OM3e+3vDQBUG+N9LF1C3MC7LGGyoG5f N7xOGsxwTbTlwpJiRk3BjZjdOFgdZgLfzg6gkZQSG6ABrJrKTP6l/K0Po2QG61tOmeRXILOoy 5r1UjE9ozIkmxKQhxRgrZn44y1hHW6/Sx+wb0hm402OQx/ZQ6aA6dlhiYdGICGYHGpcTlmExg 9K8IAbsr4QQpm7X1hHLtmrxfU7NoUzLGnU5twl0X2YskzuQlhbprv4pq3PliEkqOKgWHKnYaI uxDhPlHk3d0UbaV9ognngBO09PQe20k8Cv0i9JB9PkWhY7LySQe01zHatFls93m4uTyZDBkx7 ButtyGSLIyuqZrDn32SlKwjM/H3LhvbD/nAVfC0nDv5QxMgrPd9jQXhi2vAmsm7j/5rveS5ut 4zIqLIODlafpEp/zwlGAqFZBpXsHIDgfS+HgKLLI3wzft0e46RCZ07BYVVN8aJSC54MVKdORR 5DOOgieAt6BNAtTj8hAXKQas//8niv2v7DbX2AFyatHBiySgO2uhFDUnOrXGlgvVoQPMgOdFm xNgbzehk63lnxFNhe3Y2yOuKjXmbhUFzrz4Ojv0zdX7bZdZXJwJM+SklDknLXtWtfkHvT57jt Qs2Q0HSAVP2jzgt785f8S4Woib/Cznidc0aV/A9Zb9zQJ0H8XYRoAUMO83x4+9gEFPgIXeDOP ZbqiAAcogIiZv76m3m2cgXepNh/SPn4ffLOmgAUFkyH/UmqOi7sgcs3Zv1buxi1Si7rTdgDOH +r3VzdjatZdYYDqtQCigjk2oylo8= >>> The address of a data structure member was determined before >>> a corresponding null pointer check in the implementation of >>> the functions =E2=80=9Cdpu_hw_pp_enable_te=E2=80=9D and =E2=80=9Cdpu_h= w_pp_get_vsync_info=E2=80=9D. >>> >>> Thus avoid the risk for undefined behaviour by removing extra >>> initialisations for the variable =E2=80=9Cc=E2=80=9D (also because it = was already >>> reassigned with the same value behind this pointer check). > > There is no undefined behavior here. Will any software development concerns evolve further also according to undesirable null pointer dereferences? https://wiki.sei.cmu.edu/confluence/display/c/EXP34-C.+Do+not+dereference+= null+pointers Regards, Markus