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From: Mikko Perttunen <cyndis@kapsi.fi>
To: Deepak R Varma <drv@mailo.com>,
	Thierry Reding <thierry.reding@gmail.com>,
	David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	dri-devel@lists.freedesktop.org, linux-tegra@vger.kernel.org,
	linux-kernel@vger.kernel.org
Cc: Saurabh Singh Sengar <ssengar@microsoft.com>,
	Praveen Kumar <kumarpraveen@linux.microsoft.com>
Subject: Re: [PATCH] drm/tegra: submit: No need for Null pointer check before kfree
Date: Wed, 28 Dec 2022 14:28:54 +0200	[thread overview]
Message-ID: <864f2fdd-4289-a178-bbf1-c2a6a579c58c@kapsi.fi> (raw)
In-Reply-To: <Y6sn7XptKyk5cbrA@qemulion>

On 12/27/22 19:14, Deepak R Varma wrote:
> kfree() & vfree() internally perform NULL check on the pointer handed
> to it and take no action if it indeed is NULL. Hence there is no need
> for a pre-check of the memory pointer before handing it to
> kfree()/vfree().
> 
> Issue reported by ifnullfree.cocci Coccinelle semantic patch script.
> 
> Signed-off-by: Deepak R Varma <drv@mailo.com>
> ---
>   drivers/gpu/drm/tegra/submit.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/tegra/submit.c b/drivers/gpu/drm/tegra/submit.c
> index 066f88564169..06f836db99d0 100644
> --- a/drivers/gpu/drm/tegra/submit.c
> +++ b/drivers/gpu/drm/tegra/submit.c
> @@ -680,8 +680,8 @@ int tegra_drm_ioctl_channel_submit(struct drm_device *drm, void *data,
>   		kfree(job_data->used_mappings);
>   	}
> 
> -	if (job_data)
> -		kfree(job_data);
> +	kfree(job_data);
> +
>   put_bo:
>   	gather_bo_put(&bo->base);
>   unlock:
> --
> 2.34.1
> 
> 
> 

It continues to be the case that I think this transform is bad. Same 
applies to the host1x patch.

Mikko

  reply	other threads:[~2022-12-28 12:29 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-12-27 17:14 Deepak R Varma
2022-12-28 12:28 ` Mikko Perttunen [this message]
2022-12-28 13:08   ` Deepak R Varma
2022-12-28 13:17     ` Mikko Perttunen
2022-12-28 13:34       ` Deepak R Varma
2022-12-28 13:48         ` Mikko Perttunen
2022-12-28 14:18           ` Deepak R Varma
2022-12-30  9:15       ` Stanislaw Gruszka
2022-12-30 10:01         ` Mikko Perttunen
2022-12-30 10:03           ` Mikko Perttunen
2023-01-02 18:20             ` Deepak R Varma
2023-01-22 18:18               ` Deepak R Varma
2022-12-30 10:15           ` Stanislaw Gruszka

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