linux-kernel - Re: [PATCH] ksmbd: Remove a redundant zeroing of memory

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Message-ID: <20220323065111.GO3293@kadam>
Date:   Wed, 23 Mar 2022 09:51:11 +0300
From:   Dan Carpenter <dan.carpenter@...cle.com>
To:     Christophe JAILLET <christophe.jaillet@...adoo.fr>
Cc:     Namjae Jeon <linkinjeon@...nel.org>,
        Sergey Senozhatsky <senozhatsky@...omium.org>,
        Steve French <sfrench@...ba.org>,
        Hyunchul Lee <hyc.lee@...il.com>, linux-kernel@...r.kernel.org,
        kernel-janitors@...r.kernel.org, linux-cifs@...r.kernel.org
Subject: Re: [PATCH] ksmbd: Remove a redundant zeroing of memory

On Tue, Mar 22, 2022 at 09:29:51PM +0100, Christophe JAILLET wrote:
> fill_transform_hdr() already call memset(0) on its 1st argument, so there
> is no need to clear it explicitly before calling this function.
> 
> Use kmalloc() instead of kzalloc() to save a few cycles.
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@...adoo.fr>
> ---
> Alternatively, fill_transform_hdr() has only one caller. So its memset()
> could be removed instead and this kzalloc() left as is.
> ---
>  fs/ksmbd/smb2pdu.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
> index bcb98109bac9..0e4f819e5859 100644
> --- a/fs/ksmbd/smb2pdu.c
> +++ b/fs/ksmbd/smb2pdu.c
> @@ -8434,7 +8434,7 @@ int smb3_encrypt_resp(struct ksmbd_work *work)
>  	if (ARRAY_SIZE(iov) < rq_nvec)
>  		return -ENOMEM;
>  
> -	work->tr_buf = kzalloc(sizeof(struct smb2_transform_hdr) + 4, GFP_KERNEL);
> +	work->tr_buf = kmalloc(sizeof(struct smb2_transform_hdr) + 4, GFP_KERNEL);
                                                                 ^^^
fill_transform_hdr() does not clear the last 4 bytes.

regards,
dan carpenter