Re: [PATCH v2 5/6] bna: Avoid clashing function prototypes

From: Kees Cook <keescook@chromium.org>
To: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Sudarsana Kalluru <skalluru@marvell.com>,
	GR-Linux-NIC-Dev@marvell.com, Rasesh Mody <rmody@marvell.com>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-hardening@vger.kernel.org
Subject: Re: [PATCH v2 5/6] bna: Avoid clashing function prototypes
Date: Sat, 29 Oct 2022 00:12:26 -0700	[thread overview]
Message-ID: <202210290009.C42E731@keescook> (raw)
In-Reply-To: <2812afc0de278b97413a142d39d939a08ac74025.1666894751.git.gustavoars@kernel.org>

On Thu, Oct 27, 2022 at 03:20:47PM -0500, Gustavo A. R. Silva wrote:
> When built with Control Flow Integrity, function prototypes between
> caller and function declaration must match. These mismatches are visible
> at compile time with the new -Wcast-function-type-strict in Clang[1].
> 
> Fix a total of 227 warnings like these:
> 
> drivers/net/ethernet/brocade/bna/bna_enet.c:519:3: warning: cast from 'void (*)(struct bna_ethport *, enum bna_ethport_event)' to 'bfa_fsm_t' (aka 'void (*)(void *, int)') converts to incompatible function type [-Wcast-function-type-strict]
>                 bfa_fsm_set_state(ethport, bna_ethport_sm_down);
>                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> The bna state machine code heavily overloads its state machine functions,
> so these have been separated into their own sets of structs, enums,
> typedefs, and helper functions. There are almost zero binary code changes,
> all seem to be related to header file line numbers changing, or the
> addition of the new stats helper.

This looks like it borrowed from
https://lore.kernel.org/linux-hardening/20220929230334.2109344-1-keescook@chromium.org/
Nice to get a couple hundred more fixed. :)

> [1] https://reviews.llvm.org/D134831
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
> Changes in v2:
>  - None. This patch is new in the series.

This is relatively stand-alone (not an iw_handler patch), so it could
also go separately too.

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook