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Date: Sun, 31 Dec 2023 17:49:02 +0200
From: Leon Romanovsky <leon@kernel.org>
To: Lin Ma <linma@zju.edu.cn>
Cc: jgg@ziepe.ca, gustavoars@kernel.org, bvanassche@acm.org,
	markzhang@nvidia.com, linux-rdma@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1] RDMA/sa_query: use validate not parser in
 ib_nl_is_good_resolve_resp
Message-ID: <20231231154902.GD6849@unreal>
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 <20231230154422.GB6849@unreal>
 <7d95dbb5.63777.18cbe57e107.Coremail.linma@zju.edu.cn>
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In-Reply-To: <7d95dbb5.63777.18cbe57e107.Coremail.linma@zju.edu.cn>

On Sun, Dec 31, 2023 at 01:27:59PM +0800, Lin Ma wrote:
> Hello Leon,
> 
> > > The attributes array `tb` in ib_nl_is_good_resolve_resp is never used
> > > after the parsing. Therefore use nla_validate_deprecated function here
> > > for improvement.
> > 
> > What did this change improve?
> > 
> 
> To my concern, the nla_validate_deprecated, compared to nla_parse_deprecated,
> will at lease save a memset in function nla_parse_deprecated
> 
> ```
> if (tb)
>     memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
> ```
> 
> Morever, because the `nla_validate_deprecated` just validate the attributes
> array and will not try to retrieve the nla pointers. It shall be faster
> and cleaner here :D.

We don't care about speed in this path.
Let's leave the code as is.

Thanks

> 
> Regards
> Lin