From: Markus Elfring <Markus.Elfring@web.de>
To: Dan Carpenter <dan.carpenter@linaro.org>,
Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
freedreno@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
linux-arm-msm@vger.kernel.org
Cc: kernel-janitors@vger.kernel.org,
Abhinav Kumar <quic_abhinavk@quicinc.com>,
Archit Taneja <architt@codeaurora.org>,
Daniel Vetter <daniel@ffwll.ch>, David Airlie <airlied@gmail.com>,
Jeykumar Sankaran <jsanka@codeaurora.org>,
Jordan Crouse <jordan@cosmicpenguin.net>,
Marijn Suijten <marijn.suijten@somainline.org>,
Rob Clark <robdclark@gmail.com>, Sean Paul <sean@poorly.run>,
Simona Vetter <simona@ffwll.ch>, Vinod Koul <vkoul@kernel.org>,
cocci@inria.fr, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [RESEND] drm/msm/dpu: Delete a variable initialisation before a null pointer check in two functions
Date: Mon, 3 Mar 2025 09:15:14 +0100 [thread overview]
Message-ID: <12050afd-ab60-4bac-bd25-0c3cc925b38b@web.de> (raw)
In-Reply-To: <29b32b0d-312d-4848-9e26-9e5e76e527a7@stanley.mountain>
>>> The address of a data structure member was determined before
>>> a corresponding null pointer check in the implementation of
>>> the functions “dpu_hw_pp_enable_te” and “dpu_hw_pp_get_vsync_info”.
>>>
>>> Thus avoid the risk for undefined behaviour by removing extra
>>> initialisations for the variable “c” (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
next prev parent reply other threads:[~2025-03-03 8:15 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <40c60719-4bfe-b1a4-ead7-724b84637f55@web.de>
[not found] ` <1a11455f-ab57-dce0-1677-6beb8492a257@web.de>
2023-04-11 13:36 ` [PATCH 0/5] drm/amd: Adjustments for three function implementations Markus Elfring
2023-04-11 13:42 ` [PATCH 1/5] drm/amdgpu: Move a variable assignment behind a null pointer check in amdgpu_ras_interrupt_dispatch() Markus Elfring
2023-04-11 13:59 ` Felix Kuehling
2023-04-11 14:45 ` Markus Elfring
2024-09-09 9:42 ` Markus Elfring
2023-04-11 13:43 ` [PATCH 2/5] drm/amd/display: Move three variable assignments behind condition checks in trigger_hotplug() Markus Elfring
2023-04-11 15:04 ` Christian König
2023-05-16 16:40 ` Markus Elfring
2023-04-11 13:46 ` [PATCH 3/5] drm/amd/display: Delete three unnecessary variable initialisations " Markus Elfring
2023-04-11 13:48 ` [PATCH 4/5] drm/amd/display: Delete a redundant statement " Markus Elfring
2023-04-11 13:50 ` [PATCH 5/5] drm/amd/display: Move an expression into a return statement in dcn201_link_encoder_create() Markus Elfring
2024-01-05 19:21 ` [PATCH 0/5] drm/amd: Adjustments for three function implementations Markus Elfring
2023-04-11 16:38 ` [PATCH] drm/msm/dpu: Delete a variable initialisation before a null pointer check in two functions Markus Elfring
2023-04-11 16:43 ` Dmitry Baryshkov
2023-04-11 16:44 ` Abhinav Kumar
2025-03-02 20:56 ` [PATCH RESEND] " Markus Elfring
2025-03-02 23:01 ` Dmitry Baryshkov
2025-03-03 7:14 ` Dan Carpenter
2025-03-03 8:15 ` Markus Elfring [this message]
2025-03-03 8:24 ` [RESEND] " Dan Carpenter
2025-03-05 8:40 ` [RFC] Clarification for “undefined behaviour”? Markus Elfring
2025-03-05 8:51 ` Dan Carpenter
2025-03-05 9:20 ` Markus Elfring
2025-03-05 14:17 ` David Laight
2025-03-05 14:30 ` Dan Carpenter
2025-03-05 21:35 ` David Laight
2023-04-13 19:44 ` [PATCH] video: au1100fb: Move a variable assignment behind a null pointer check in au1100fb_setmode() Markus Elfring
2025-03-02 18:02 ` [PATCH RESEND] " Markus Elfring
2025-03-03 9:19 ` Uwe Kleine-König
2025-03-03 10:08 ` Dan Carpenter
2025-03-03 10:08 ` Dan Carpenter
2025-03-03 10:14 ` Dan Carpenter
2025-03-03 10:30 ` Uwe Kleine-König
2025-03-03 10:36 ` Markus Elfring
2025-03-03 10:53 ` [PATCH RESEND] " Dan Carpenter
2025-03-05 12:14 ` Markus Elfring
2025-03-05 17:07 ` Helge Deller
2025-03-05 17:28 ` Markus Elfring
2025-03-08 21:26 ` [PATCH RESEND] " Helge Deller
2023-04-16 9:30 ` [PATCH 0/9] GPU-DRM-nouveau: Adjustments for seven function implementations Markus Elfring
2023-04-16 9:33 ` [PATCH 1/9] drm/nouveau/debugfs: Move an expression into a function call parameter in nouveau_debugfs_pstate_set() Markus Elfring
2023-04-16 9:36 ` [PATCH 2/9] drm/nouveau/debugfs: Move a variable assignment behind a null pointer check in nouveau_debugfs_pstate_get() Markus Elfring
2023-04-16 9:38 ` [PATCH 3/9] drm/nouveau/debugfs: Use seq_putc() " Markus Elfring
2023-04-16 9:40 ` [PATCH 4/9] drm/nouveau/debugfs: Replace five seq_printf() calls by seq_puts() " Markus Elfring
2023-04-16 9:42 ` [PATCH 5/9] drm/nouveau/bios/power_budget: Move an expression into a macro call parameter in nvbios_power_budget_header() Markus Elfring
2023-04-16 9:44 ` [PATCH 6/9] drm/nouveau/clk: Move a variable assignment behind a null pointer check in nvkm_pstate_new() Markus Elfring
2023-04-16 9:46 ` [PATCH 7/9] drm/nouveau/pci: Move a variable assignment behind condition checks in nvkm_pcie_set_link() Markus Elfring
2023-04-16 9:54 ` [PATCH 8/9] drm/nouveau/pci: Move an expression into a function call parameter " Markus Elfring
2023-04-16 9:56 ` [PATCH 9/9] drm/nouveau/therm: Move an assignment statement behind a null pointer check in two functions Markus Elfring
2023-04-17 16:25 ` [PATCH 0/9] GPU-DRM-nouveau: Adjustments for seven function implementations Karol Herbst
2023-04-16 15:47 ` [PATCH] drm/bridge: it6505: Move a variable assignment behind a null pointer check in receive_timing_debugfs_show() Markus Elfring
2023-04-25 13:30 ` Robert Foss
2023-04-25 14:15 ` Markus Elfring
2023-04-27 15:10 ` Robert Foss
2023-04-27 19:34 ` Markus Elfring
2023-04-28 11:49 ` Robert Foss
2023-04-28 15:55 ` [PATCH resent] " Markus Elfring
2023-04-28 17:27 ` Robert Foss
2023-04-17 9:42 ` [PATCH] drm/mm: Adjust input parameter validation in DECLARE_NEXT_HOLE_ADDR() Markus Elfring
2025-03-03 12:48 ` [PATCH RESEND] " Markus Elfring
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