From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A34F4C48297 for ; Mon, 12 Feb 2024 08:49:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ILcWEc1f+BD4tBTh/9witht4MXUTh/Xn200mxqGEyxA=; b=ra041Mkf4lskeqCYUJFIWHFM9n v/HT38afQoc1dSNQ3EKkZ9wvwhh2qWeF0An5buOS/AbIBO1D89Wgilc2FuAiLm8w/+VJ+s1c7OiRq l5Y2CNuTpwcU8eJTuhD6hKNDEFk84mUyJoiUifYYPtTiI4PjNB2BeN7lmrTAuHKsbi8dixMDlaccC pqcG7jYdkBfS9Ek+2tjPiXs8YBA3kSR82AvvItK6ZAjze4DJzdQzWn358csBIlGhxx+WJL50cfgUE jlu+pbGf5VTn0gLovOTonO4EcLbaM13TNykqB79IRYYhtYbCndh7FBCACGAe64vV+J4YB+pf0ITIZ pSMUDaMg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rZS0G-00000004fF4-1SJv; Mon, 12 Feb 2024 08:49:28 +0000 Received: from madrid.collaboradmins.com ([46.235.227.194]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rZS0C-00000004fE8-1VPr; Mon, 12 Feb 2024 08:49:25 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1707727763; bh=1VsQ4z1r3dEamcItynYxqF1YB4jf1wiMOZfZh4BLL7o=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Z+blcmK+YbesX4oSXgB0nnDs8q8tMFP62tHS9wmWzqmGkKKXHuMZSWX7Z8yIdrc4p M/JFWMrusIALQ6IB+F3V0TjmS8i+tNF2PN2BGVPyGAiBmV7gWLAXNnp499/LPTD6mP OAJ8HA1guaUgHOvm4M521hJpIg3WlL+SPdOQiXMWeVSStXXyCA8hlbJRqH6XZsAn8B /7TwojQIIPzAjm/v5MzpRc5UqricuAvpMtjqtRsPO46vcyrXQTU4V76ntzaicutipQ txstS5dQuLzVmFRUX0WHrnQFDLeaQqcIk6XEwWoJYbKWkNMXZA3RJAnktzJrgdy28d LW1y3zRvkX5hw== Received: from [100.113.186.2] (cola.collaboradmins.com [195.201.22.229]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: kholk11) by madrid.collaboradmins.com (Postfix) with ESMTPSA id 27262378203F; Mon, 12 Feb 2024 08:49:22 +0000 (UTC) Message-ID: <25e10072-30eb-4272-8a89-2c5240d53a1c@collabora.com> Date: Mon, 12 Feb 2024 09:49:21 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] iommu/mtk_iommu: Use devm_kcalloc() instead of devm_kzalloc() Content-Language: en-US To: Erick Archer , Yong Wu , Joerg Roedel , Will Deacon , Robin Murphy , Matthias Brugger , "Gustavo A. R. Silva" , Kees Cook Cc: iommu@lists.linux.dev, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-hardening@vger.kernel.org References: <20240211182250.12656-1-erick.archer@gmx.com> From: AngeloGioacchino Del Regno In-Reply-To: <20240211182250.12656-1-erick.archer@gmx.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240212_004924_568560_E87ADB65 X-CRM114-Status: GOOD ( 18.83 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org Il 11/02/24 19:22, Erick Archer ha scritto: > This is an effort to get rid of all multiplications from allocation > functions in order to prevent integer overflows [1]. > > Here the multiplication is obviously safe because MTK_PROTECT_PA_ALIGN > is defined as a literal value of 256 or 128. > > For the "mtk_iommu.c" file: 256 > For the "mtk_iommu_v1.c" file: 128 > > However, using devm_kcalloc() is more appropriate [2] and improves > readability. This patch has no effect on runtime behavior. > > Link: https://github.com/KSPP/linux/issues/162 [1] > Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [2] > Signed-off-by: Erick Archer Reviewed-by: AngeloGioacchino Del Regno > --- > drivers/iommu/mtk_iommu.c | 2 +- > drivers/iommu/mtk_iommu_v1.c | 4 ++-- > 2 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c > index 7abe9e85a570..9aae6eb604b1 100644 > --- a/drivers/iommu/mtk_iommu.c > +++ b/drivers/iommu/mtk_iommu.c > @@ -1264,7 +1264,7 @@ static int mtk_iommu_probe(struct platform_device *pdev) > data->plat_data = of_device_get_match_data(dev); > > /* Protect memory. HW will access here while translation fault.*/ > - protect = devm_kzalloc(dev, MTK_PROTECT_PA_ALIGN * 2, GFP_KERNEL); > + protect = devm_kcalloc(dev, 2, MTK_PROTECT_PA_ALIGN, GFP_KERNEL); > if (!protect) > return -ENOMEM; > data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN); > diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c > index 25b41222abae..45cd845d153f 100644 > --- a/drivers/iommu/mtk_iommu_v1.c > +++ b/drivers/iommu/mtk_iommu_v1.c > @@ -621,8 +621,8 @@ static int mtk_iommu_v1_probe(struct platform_device *pdev) > data->dev = dev; > > /* Protect memory. HW will access here while translation fault.*/ > - protect = devm_kzalloc(dev, MTK_PROTECT_PA_ALIGN * 2, > - GFP_KERNEL | GFP_DMA); > + protect = devm_kcalloc(dev, 2, MTK_PROTECT_PA_ALIGN, > + GFP_KERNEL | GFP_DMA); > if (!protect) > return -ENOMEM; > data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN); > -- > 2.25.1 >