From nobody Thu Oct 2 05:00:30 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 BE39B30F920; Tue, 23 Sep 2025 05:40:53 +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=1758606053; cv=none; b=ZZpxkr8XLg70boVKAiDaFESdWL6OGUkLU4te7V8yLKYxUUIw7kZFVnmqwzSP19dfPjpbrXiD+zBFcZc+PXbWTtAGhPsQ9q6ZILbSCtc1WunAM9oumGqwHn/9zeLmOfh59XYx5fMRM0sEARemy5h7Y2+SPHcTE+lrL6j/P/OURj4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758606053; c=relaxed/simple; bh=YbwnjxfMye/PzcS1THZ1QtGxRafIoeUGUPEkh1iC8L0=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=RNLZlVCh1eprNDNBdH1Lx337EytbPzRpKeEEoYDEX3/nB5CCYr3RbqQ7094T3FaeZrz8QNfaBSC+uXJXgDdu/SdCt10rkH8n/iQSz+UI8eMghpg4EmkQ/LdPgmBAn5c+s2KFbz28vuWrGCMOqTUpOXmii8Xc0Xw1Q33FBOADXS8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qND9BNll; 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="qND9BNll" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1EFA2C113CF; Tue, 23 Sep 2025 05:40:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758606053; bh=YbwnjxfMye/PzcS1THZ1QtGxRafIoeUGUPEkh1iC8L0=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=qND9BNll6+lABgVv3l3n183eD5kmlls5LNTkwp3ByvQr6k5qs7CoKz/5PzEM/Kfha ZqwzkVIK+67YBHUWbIVNrQSjzoSElUlyv6s3cVZXEFOsW7lNbUUQDIyHT6MMxEPSYY 9lv7Q1nUKwAaZh1TXzzTObxp+shi4Ys/93wXS0gBgnCWbZvyBZbkkP2nlVwaxLksKa 8cAAuF2IuV7Ctb35FqT9n5hYgE3f+mxqWfUVtgInqhqbsOjt8au1zibiO+fPS0/VHf mB8EMRqkWCTTSJjs8XcDceR+i1RyeIFYkmBzAb371YoCxFMMRD6IS9eOoIXXS1gmmi 4xeqCZilj7NXw== From: Vincent Mailhol Date: Tue, 23 Sep 2025 14:39:39 +0900 Subject: [PATCH v3 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-v3-4-87a7684333f3@kernel.org> References: <20250923-canxl-netlink-prep-v3-0-87a7684333f3@kernel.org> In-Reply-To: <20250923-canxl-netlink-prep-v3-0-87a7684333f3@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=owGbwMvMwCV2McXO4Xp97WbG02pJDBmXjDbtjvt+d87tYoVnqe8qZU7Mkth+cLnAqqCWXZMuM Hn3njyzsqOUhUGMi0FWTJFlWTknt0JHoXfYob+WMHNYmUCGMHBxCsBEnKUZGW6+Y93184S/RDSL yxzu0w8kSo1mZ876enPP2eMBnFqiigkM/8v2y7wLktDLuskrGB0xs8rgvX6Ims8d4aeLb93dsFE 1jhUA 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