From nobody Thu Oct 2 05:05:17 2025 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 843A7311586; Tue, 23 Sep 2025 06:59:52 +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=1758610792; cv=none; b=a4emeLXSSiteGxnO8i3X+UfKpCJC1VEfqCRk5RI3RkE77z2I8kLliLVi5iaOXo6yP8vnERuULdfZLGXWELBzYdrOqaQYt5XCYGPeciS/Qdkiv9H1GRQ5m8DErzlR9G/Dymu8YSwl39hu6XAMsBIEgYPVQ6WZdEH1N333KfjgQJo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758610792; c=relaxed/simple; bh=YbwnjxfMye/PzcS1THZ1QtGxRafIoeUGUPEkh1iC8L0=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=LW5C2WrNXBmvC0bJpB9gBBMG29PTsFa1GP1bKCMLCUKYPzsGvVxPSuiOgcUmp8CEhGit0uf7sgT1AbqHWjaZG3TKyLgquZi+JMHUEhKuYXoLG04e8tMq4cslJAvnIvGSbXFkAHKRXNFnUpHN6Jr065rdnXAZSrsFrEQ6FAksXwE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=tBB60qv+; 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="tBB60qv+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C7452C116B1; Tue, 23 Sep 2025 06:59:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758610792; bh=YbwnjxfMye/PzcS1THZ1QtGxRafIoeUGUPEkh1iC8L0=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=tBB60qv+uo/+daSANX4YUwMARs93aREqLF1v1USM4r3awAFi4F9Ar49uHhNeWaDkc Af4Zw3zLwZSbtl3YG1VlNrwhtkhKuAqoflNmMQ6j/IDXcEnDzquYAAc85dM7O2b+t/ 2kuNmVIvgROg0BcNGKEauLaOSzspOeNXyWDcOfthB29ckwLRn43ycKUca+Ib0KGZVP hEnhNeXa9UnMqVYgFvG0nqAY9fn9mwsDFHmKRmRHISSosIjeZldEglC8whi5NcsdAD Mbd7/OGkLRL8amgam2vC0uleTBXJyqYImzkgVEANdIs64PpMBrkAo8U6PIrfk72MLb 2teNixUjm/SIQ== From: Vincent Mailhol Date: Tue, 23 Sep 2025 15:58:29 +0900 Subject: [PATCH v4 04/20] can: netlink: refactor can_validate_bittiming() Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250923-canxl-netlink-prep-v4-4-e720d28f66fe@kernel.org> References: <20250923-canxl-netlink-prep-v4-0-e720d28f66fe@kernel.org> In-Reply-To: <20250923-canxl-netlink-prep-v4-0-e720d28f66fe@kernel.org> To: Marc Kleine-Budde , Oliver Hartkopp Cc: Vincent Mailhol , =?utf-8?q?St=C3=A9phane_Grosjean?= , Robert Nawrath , Minh Le , Duy Nguyen , linux-can@vger.kernel.org, linux-kernel@vger.kernel.org X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=2734; i=mailhol@kernel.org; h=from:subject:message-id; bh=YbwnjxfMye/PzcS1THZ1QtGxRafIoeUGUPEkh1iC8L0=; b=owGbwMvMwCV2McXO4Xp97WbG02pJDBmXXPXuqSWyHuHPfcKiJORWsmOZZCvX3btT/glOzkpN/ vrjsDF3RykLgxgXg6yYIsuyck5uhY5C77BDfy1h5rAygQxh4OIUgImUxjAyTLZPXt54pn2F/EHV pJWdx/ZNspGt4Dlf/eb6h+Zi/tR76xn+aVV0+Uzl4n55sJKrUPkj/+t3Fuzzd635lyFeZtnAHtj MBwA= X-Developer-Key: i=mailhol@kernel.org; a=openpgp; fpr=ED8F700574E67F20E574E8E2AB5FEB886DBB99C2 Whenever can_validate_bittiming() is called, it is always preceded by some boilerplate code which was copy pasted all over the place. Move that repeated code directly inside can_validate_bittiming(). Finally, the mempcy() is not needed: the nla attributes are four bytes aligned which is just enough for struct can_bittiming. Add a static_assert() to document that the alignment is correct and just use the pointer returned by nla_data() as-is. Signed-off-by: Vincent Mailhol --- Changelog: v2 -> v3: - add a static_assert() to prove that the alignment is correct. --- drivers/net/can/dev/netlink.c | 36 +++++++++++++++++------------------- 1 file changed, 17 insertions(+), 19 deletions(-) diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c index 248f607e3864ffbda6f0b8daf4e2484179cf9cd5..13555253e789ec6ca9c8c30571c= 990ad6bfde770 100644 --- a/drivers/net/can/dev/netlink.c +++ b/drivers/net/can/dev/netlink.c @@ -36,13 +36,21 @@ static const struct nla_policy can_tdc_policy[IFLA_CAN_= TDC_MAX + 1] =3D { [IFLA_CAN_TDC_TDCF] =3D { .type =3D NLA_U32 }, }; =20 -static int can_validate_bittiming(const struct can_bittiming *bt, - struct netlink_ext_ack *extack) +static int can_validate_bittiming(struct nlattr *data[], + struct netlink_ext_ack *extack, + int ifla_can_bittiming) { + struct can_bittiming *bt; + + if (!data[ifla_can_bittiming]) + return 0; + + static_assert(__alignof__(*bt) <=3D NLA_ALIGNTO); + bt =3D nla_data(data[ifla_can_bittiming]); + /* sample point is in one-tenth of a percent */ if (bt->sample_point >=3D 1000) { NL_SET_ERR_MSG(extack, "sample point must be between 0 and 100%"); - return -EINVAL; } =20 @@ -105,14 +113,9 @@ static int can_validate(struct nlattr *tb[], struct nl= attr *data[], } } =20 - if (data[IFLA_CAN_BITTIMING]) { - struct can_bittiming bt; - - memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt)); - err =3D can_validate_bittiming(&bt, extack); - if (err) - return err; - } + err =3D can_validate_bittiming(data, extack, IFLA_CAN_BITTIMING); + if (err) + return err; =20 if (is_can_fd) { if (!data[IFLA_CAN_BITTIMING] || !data[IFLA_CAN_DATA_BITTIMING]) @@ -124,14 +127,9 @@ static int can_validate(struct nlattr *tb[], struct nl= attr *data[], return -EOPNOTSUPP; } =20 - if (data[IFLA_CAN_DATA_BITTIMING]) { - struct can_bittiming bt; - - memcpy(&bt, nla_data(data[IFLA_CAN_DATA_BITTIMING]), sizeof(bt)); - err =3D can_validate_bittiming(&bt, extack); - if (err) - return err; - } + err =3D can_validate_bittiming(data, extack, IFLA_CAN_DATA_BITTIMING); + if (err) + return err; =20 return 0; } --=20 2.49.1