Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH][next] misc: bcm-vk: Replace zero-length array with
 flexible array member
To:     "Gustavo A. R. Silva" <gustavoars@kernel.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     bcm-kernel-feedback-list@broadcom.com,
        linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
References: <20210514230801.GA35863@embeddedor>
From:   Scott Branden <scott.branden@broadcom.com>
Message-ID: <ae9eb4fd-9109-6650-14bc-74fe71f42850@broadcom.com>
Date:   Fri, 14 May 2021 16:26:02 -0700
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.10.0
MIME-Version: 1.0
In-Reply-To: <20210514230801.GA35863@embeddedor>
Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha-256;
        boundary="000000000000646d7d05c252910a"
Precedence: bulk

--000000000000646d7d05c252910a
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 8bit

Looks fine to me.

On 2021-05-14 4:08 p.m., Gustavo A. R. Silva wrote:
> There is a regular need in the kernel to provide a way to declare
> having a dynamically sized set of trailing elements in a structure.
> Kernel code should always use “flexible array members”[1] for these
> cases. The older style of one-element or zero-length arrays should
> no longer be used[2].
> 
> Also, make use of the struct_size() helper in kzalloc().
> 
> [1] https://en.wikipedia.org/wiki/Flexible_array_member
> [2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays
> 
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Acked-by: Scott Branden <scott.branden@broadcom.com>
> ---
>  drivers/misc/bcm-vk/bcm_vk_msg.c | 3 +--
>  drivers/misc/bcm-vk/bcm_vk_msg.h | 2 +-
>  2 files changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/misc/bcm-vk/bcm_vk_msg.c b/drivers/misc/bcm-vk/bcm_vk_msg.c
> index f40cf08a6192..6efc52b49af6 100644
> --- a/drivers/misc/bcm-vk/bcm_vk_msg.c
> +++ b/drivers/misc/bcm-vk/bcm_vk_msg.c
> @@ -701,8 +701,7 @@ int bcm_vk_send_shutdown_msg(struct bcm_vk *vk, u32 shut_type,
>  		return -EINVAL;
>  	}
>  
> -	entry = kzalloc(sizeof(*entry) +
> -			sizeof(struct vk_msg_blk), GFP_KERNEL);
> +	entry = kzalloc(struct_size(entry, to_v_msg, 1), GFP_KERNEL);
>  	if (!entry)
>  		return -ENOMEM;
>  
> diff --git a/drivers/misc/bcm-vk/bcm_vk_msg.h b/drivers/misc/bcm-vk/bcm_vk_msg.h
> index 4eaad84825d6..56784c8896d8 100644
> --- a/drivers/misc/bcm-vk/bcm_vk_msg.h
> +++ b/drivers/misc/bcm-vk/bcm_vk_msg.h
> @@ -116,7 +116,7 @@ struct bcm_vk_wkent {
>  	u32 usr_msg_id;
>  	u32 to_v_blks;
>  	u32 seq_num;
> -	struct vk_msg_blk to_v_msg[0];
> +	struct vk_msg_blk to_v_msg[];
>  };
>  
>  /* queue stats counters */
> 


--000000000000646d7d05c252910a
Content-Type: application/pkcs7-signature; name="smime.p7s"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="smime.p7s"
Content-Description: S/MIME Cryptographic Signature
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--000000000000646d7d05c252910a--