From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7BDBB17557C; Mon, 9 Sep 2024 08:44:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725871494; cv=none; b=VetptKry2nHjoP5RIHI6DM58jWApLmA4c+U+zKWQnu7KJ7NQvvVFCspvwWuODqzIZy5tk+gnKS6GcLxkzM77ZA3fFlQUHATxJ6ojRapLL2UkvEkNGzuW5Ym8h1IN8jB62UqTZjvxa9SC60lCLK3GcoicQF85covXhX6wdUYnK4E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725871494; c=relaxed/simple; bh=pxwM3hSVCglKIf6EY3IGEl3ujf1W94/lMRDKTRO7k1Q=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=d2/0k8wdaPzh//AjgzqZo+aSh0J6G/z0y0k2Q2BBqBjhvM5rnQP9SbPxjFZyE13FWwT/o9tXhPfVm6wa0KOnMBFCKzFwPxAGv45jHDTHRInhZpn9FBFPBkkMUn+60dwWk/elt7On3H/94EM5BMlvl0UpSUgGVgG5vwWSTLrIlQk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=caX8MYpZ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="caX8MYpZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 27DBDC4CEC5; Mon, 9 Sep 2024 08:44:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725871494; bh=pxwM3hSVCglKIf6EY3IGEl3ujf1W94/lMRDKTRO7k1Q=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=caX8MYpZb9kl5CtRpFChwjoo+mPfLkxCM4HtGqCmEm0QDaIhRoPIprkfXTtm+JAas LmNd9As91CDNi38gy9YLO++ILkd4S0cr7q1S424GVVGq4BoptWsrldGI3pGz+et2V8 qo6Z2VLIUCbTW+fQcZWYx6Bu3vOXTXEdr0yUm33/HMZaallcrdBwEE5B/hyJedujsl vMXHkUd36/2BzPM2fi33MeyJ8MoHEXK4h5TjjhcOfKHjFSmw8K4xNPWLZnjf8nlVqi iHXTe9OQbM5STDecrBzkNQA2XIMM21gDE0b27c27+p4LPDr02+RpIyS3UbkTEVE+j+ JFT7sSQOXZ2Sg== Date: Mon, 9 Sep 2024 09:44:48 +0100 From: Simon Horman To: Nathan Chancellor Cc: Marc Kleine-Budde , kernel@pengutronix.de, Vincent Mailhol , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Heiko Stuebner , linux-can@vger.kernel.org, netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, llvm@lists.linux.dev, patches@lists.linux.dev Subject: Re: [PATCH] can: rockchip_canfd: fix return type of rkcanfd_start_xmit() Message-ID: <20240909084448.GU2097826@kernel.org> References: <20240906-rockchip-canfd-wifpts-v1-1-b1398da865b7@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240906-rockchip-canfd-wifpts-v1-1-b1398da865b7@kernel.org> On Fri, Sep 06, 2024 at 01:26:41PM -0700, Nathan Chancellor wrote: > With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG), > indirect call targets are validated against the expected function > pointer prototype to make sure the call target is valid to help mitigate > ROP attacks. If they are not identical, there is a failure at run time, > which manifests as either a kernel panic or thread getting killed. A > warning in clang aims to catch these at compile time, which reveals: > > drivers/net/can/rockchip/rockchip_canfd-core.c:770:20: error: incompatible function pointer types initializing 'netdev_tx_t (*)(struct sk_buff *, struct net_device *)' (aka 'enum netdev_tx (*)(struct sk_buff *, struct net_device *)') with an expression of type 'int (struct sk_buff *, struct net_device *)' [-Werror,-Wincompatible-function-pointer-types-strict] > 770 | .ndo_start_xmit = rkcanfd_start_xmit, > | ^~~~~~~~~~~~~~~~~~ > > ->ndo_start_xmit() in 'struct net_device_ops' expects a return type of > 'netdev_tx_t', not 'int' (although the types are ABI compatible). Adjust > the return type of rkcanfd_start_xmit() to match the prototype's to > resolve the warning. > > Fixes: ff60bfbaf67f ("can: rockchip_canfd: add driver for Rockchip CAN-FD controller") > Signed-off-by: Nathan Chancellor Thanks, I was able to reproduce this problem at build time and that your patch addresses it. Reviewed-by: Simon Horman