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 5B77719BDD; Thu, 4 May 2023 19:52:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BAB81C4339B; Thu, 4 May 2023 19:52:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1683229941; bh=hveISeaU9FkwcltR0ICWbAguyn61drmwjK/h450Kasw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QDmdAX/1AYyP0EPsy1Fw2jKXaSwAs5E8TSZn30p6xXBiQ90bddh1ax8KsgupL0F97 aDFbWRG9X3RFzh+s9lkgcwklMFHXPilEVbs0DPJLPeSJ+mK//EGMx4x8AzeBXIlyZL h40jivL8QtA8oWaOuA/mFZZ8w2crvZtttMBvyd2WNYkUkPHte3sxrilICOovIYWs3t cLgFGSbqKswtrh+GWfIwqq52AfZiU0C9ScwFqnE3QDjD3TWuce/IFiE4ZUJr0DOXhH vooyJQ8AEBhHbAk0I38EHP+o2CVjgVrZOU/TQGc0bkecwtQlAVSDLR8KCEYBhFM9Nm aTEaT2KhW9wqg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Nathan Chancellor , Horatiu Vultur , Paolo Abeni , Sasha Levin , davem@davemloft.net, edumazet@google.com, kuba@kernel.org, ndesaulniers@google.com, mkl@pengutronix.de, netdev@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH AUTOSEL 4.14 04/13] net: pasemi: Fix return type of pasemi_mac_start_tx() Date: Thu, 4 May 2023 15:51:56 -0400 Message-Id: <20230504195207.3809116-4-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230504195207.3809116-1-sashal@kernel.org> References: <20230504195207.3809116-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Nathan Chancellor [ Upstream commit c8384d4a51e7cb0e6587f3143f29099f202c5de1 ] 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/ethernet/pasemi/pasemi_mac.c:1665:21: 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] .ndo_start_xmit = pasemi_mac_start_tx, ^~~~~~~~~~~~~~~~~~~ 1 error generated. ->ndo_start_xmit() in 'struct net_device_ops' expects a return type of 'netdev_tx_t', not 'int'. Adjust the return type of pasemi_mac_start_tx() to match the prototype's to resolve the warning. While PowerPC does not currently implement support for kCFI, it could in the future, which means this warning becomes a fatal CFI failure at run time. Link: https://github.com/ClangBuiltLinux/linux/issues/1750 Signed-off-by: Nathan Chancellor Reviewed-by: Horatiu Vultur Link: https://lore.kernel.org/r/20230319-pasemi-incompatible-pointer-types-strict-v1-1-1b9459d8aef0@kernel.org Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- drivers/net/ethernet/pasemi/pasemi_mac.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/pasemi/pasemi_mac.c b/drivers/net/ethernet/pasemi/pasemi_mac.c index 6ccdce21ca9b5..c891ee70099a7 100644 --- a/drivers/net/ethernet/pasemi/pasemi_mac.c +++ b/drivers/net/ethernet/pasemi/pasemi_mac.c @@ -1436,7 +1436,7 @@ static void pasemi_mac_queue_csdesc(const struct sk_buff *skb, write_dma_reg(PAS_DMA_TXCHAN_INCR(txring->chan.chno), 2); } -static int pasemi_mac_start_tx(struct sk_buff *skb, struct net_device *dev) +static netdev_tx_t pasemi_mac_start_tx(struct sk_buff *skb, struct net_device *dev) { struct pasemi_mac * const mac = netdev_priv(dev); struct pasemi_mac_txring * const txring = tx_ring(mac); -- 2.39.2