Received-SPF: pass (google.com: domain of linux-kernel+bounces-135945-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) client-ip=2604:1380:40f1:3f00::1;
Date: Mon, 8 Apr 2024 21:34:59 +0000
From: Justin Stitt <justinstitt@google.com>
To: Erick Archer <erick.archer@outlook.com>
Cc: Long Li <longli@microsoft.com>, Ajay Sharma <sharmaajay@microsoft.com>, 
	"K. Y. Srinivasan" <kys@microsoft.com>, Haiyang Zhang <haiyangz@microsoft.com>, 
	Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>, 
	"David S. Miller" <davem@davemloft.net>, Eric Dumazet <edumazet@google.com>, 
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>, 
	Kees Cook <keescook@chromium.org>, "Gustavo A. R. Silva" <gustavoars@kernel.org>, 
	Nathan Chancellor <nathan@kernel.org>, Nick Desaulniers <ndesaulniers@google.com>, 
	Bill Wendling <morbo@google.com>, Jason Gunthorpe <jgg@ziepe.ca>, 
	Leon Romanovsky <leon@kernel.org>, Shradha Gupta <shradhagupta@linux.microsoft.com>, 
	Konstantin Taranov <kotaranov@microsoft.com>, linux-rdma@vger.kernel.org, linux-hyperv@vger.kernel.org, 
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, 
	llvm@lists.linux.dev
Subject: Re: [PATCH v3 1/3] net: mana: Add flex array to struct
 mana_cfg_rx_steer_req_v2
Message-ID: <zrqicnpeu52n42yulmrupxmrejd7mhbsu35ycd2bgfjz6gmm2a@dtpv5qdxhmnu>
References: <20240406142337.16241-1-erick.archer@outlook.com>
 <AS8PR02MB7237E2900247571C9CB84C678B022@AS8PR02MB7237.eurprd02.prod.outlook.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <AS8PR02MB7237E2900247571C9CB84C678B022@AS8PR02MB7237.eurprd02.prod.outlook.com>

Hi,

On Sat, Apr 06, 2024 at 04:23:35PM +0200, Erick Archer wrote:
> The "struct mana_cfg_rx_steer_req_v2" uses a dynamically sized set of
> trailing elements. Specifically, it uses a "mana_handle_t" array. So,
> use the preferred way in the kernel declaring a flexible array [1].
> 
> At the same time, prepare for the coming implementation by GCC and Clang
> of the __counted_by attribute. Flexible array members annotated with
> __counted_by can have their accesses bounds-checked at run-time via
> CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for
> strcpy/memcpy-family functions).
> 
> This is a previous step to refactor the two consumers of this structure.
> 
>  drivers/infiniband/hw/mana/qp.c
>  drivers/net/ethernet/microsoft/mana/mana_en.c
> 
> The ultimate goal is to avoid the open-coded arithmetic in the memory
> allocator functions [2] using the "struct_size" macro.
> 
> Link: https://www.kernel.org/doc/html/next/process/deprecated.html#zero-length-and-one-element-arrays [1]
> Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [2]
> Signed-off-by: Erick Archer <erick.archer@outlook.com>

I think this could have all been one patch, I found myself jumping
around the three patches here piecing together context.

Reviewed-by: Justin Stitt <justinstitt@google.com>

> ---
>  include/net/mana/mana.h | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
> index 4eeedf14711b..561f6719fb4e 100644
> --- a/include/net/mana/mana.h
> +++ b/include/net/mana/mana.h
> @@ -670,6 +670,7 @@ struct mana_cfg_rx_steer_req_v2 {
>  	u8 hashkey[MANA_HASH_KEY_SIZE];
>  	u8 cqe_coalescing_enable;
>  	u8 reserved2[7];
> +	mana_handle_t indir_tab[] __counted_by(num_indir_entries);
>  }; /* HW DATA */
>  
>  struct mana_cfg_rx_steer_resp {
> -- 
> 2.25.1
> 

Thanks
Justin