linux-kernel - Re: [PATCH] gpu: host1x: Remove redundant null checks before kfree

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Message-ID: <e46598e5-d680-5ae3-3e4a-ec6e5be5090b@kapsi.fi>
Date:   Thu, 1 Dec 2022 09:48:20 +0200
From:   Mikko Perttunen <cyndis@...si.fi>
To:     zys.zljxml@...il.com, thierry.reding@...il.com, airlied@...il.com,
        daniel@...ll.ch, sumit.semwal@...aro.org, christian.koenig@....com
Cc:     dri-devel@...ts.freedesktop.org, linux-tegra@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-media@...r.kernel.org,
        linaro-mm-sig@...ts.linaro.org,
        Yushan Zhou <katrinzhou@...cent.com>
Subject: Re: [PATCH] gpu: host1x: Remove redundant null checks before kfree

On 12/1/22 03:55, zys.zljxml@...il.com wrote:
> From: Yushan Zhou <katrinzhou@...cent.com>
> 
> Fix the following coccicheck warning:
> ./drivers/gpu/host1x/fence.c:97:2-7: WARNING:
> NULL check before some freeing functions is not needed.
> 
> Signed-off-by: Yushan Zhou <katrinzhou@...cent.com>
> ---
>   drivers/gpu/host1x/fence.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/host1x/fence.c b/drivers/gpu/host1x/fence.c
> index ecab72882192..05b36bfc8b74 100644
> --- a/drivers/gpu/host1x/fence.c
> +++ b/drivers/gpu/host1x/fence.c
> @@ -93,8 +93,7 @@ static void host1x_syncpt_fence_release(struct dma_fence *f)
>   {
>   	struct host1x_syncpt_fence *sf = to_host1x_fence(f);
>   
> -	if (sf->waiter)
> -		kfree(sf->waiter);
> +	kfree(sf->waiter);
>   
>   	dma_fence_free(f);
>   }

I disagree with this coccinelle rule; I think it obfuscates from the 
reader the fact that the pointer could be NULL.

Mikko