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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 36125D1CDAB for ; Wed, 3 Dec 2025 23:12:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id BF94B6B0023; Wed, 3 Dec 2025 18:12:41 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id BD0A86B0024; Wed, 3 Dec 2025 18:12:41 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AE64C6B0027; Wed, 3 Dec 2025 18:12:41 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 980096B0023 for ; Wed, 3 Dec 2025 18:12:41 -0500 (EST) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id AEEAC13BB12 for ; Wed, 3 Dec 2025 23:12:37 +0000 (UTC) X-FDA: 84179711154.22.EE043BC Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf16.hostedemail.com (Postfix) with ESMTP id 1BF10180010 for ; Wed, 3 Dec 2025 23:12:35 +0000 (UTC) Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=ECzRbUgV; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf16.hostedemail.com: domain of kees@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=kees@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1764803556; a=rsa-sha256; cv=none; b=YPrfFLnDXOKpn8KmEH1tWSC2e8L2FikWKOpFsS7BqEz0tEnNIJPnTl6aX2jJsyhuEs9VQU 5qpDq/N5XCy4gWQLm0EH/OxnP3gXiIwuuZNGByGlAVS58utSiNvdE3IQILvmOFENEK+7us ulgGTlCFH5Dj2dGY3PUIyyM2VPSLMX8= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=ECzRbUgV; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf16.hostedemail.com: domain of kees@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=kees@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1764803556; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=hr3jB9Go3x/RAch40IxGQsMdKgsJJif2jT6tO/2YTTQ=; b=dAg9Pjg8PzqTo8Mnr7Fc0hAsRkcSdn5anw+zYleT7K9nwix/jzRkUEfUFQByB9c/wUehi9 r5RltKG6kkTb+Wb7pVQ+UNKbDdLw3v64kV2I1k8gbHVqXdoy13RnXgYJVwKyYFDk5thYuj 4wSWlzpI8cV5le+dmkV5ji2YKNWPMI8= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id C2F8E4197C; Wed, 3 Dec 2025 23:12:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 902DBC4CEF5; Wed, 3 Dec 2025 23:12:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764803554; bh=ZPhrI7MQmYmzyNZKm22NDPTdDlwCRn0ToFC4Np+3dp8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ECzRbUgVFXorY0hMDmTNqLr5IhX4IhFOBUqyTHrrZfjh2reDMkbKUjcYvDC2pyaqI uKSGmkeqyC/a7wDkblFIVtyLEdS27sug4U8ux09jwZTHCYCNmtbxnpE3DVv7q2LDi6 B77fX3Io8g2a3BUlYVzNFTy1S1FHA/d8xXXNJdOqjJn20HByJZ687QFMay7OjyJJgT xgFyK8C6Ytj/XEG36LYEoWq6QWwSEw1YC+cyXq8CdGkTgcmjNK1r+o3IUwtDb2F7C3 +Gj57ItT49/fVfUd2NST/8ny+9JMNohAlT6MxME8vdNk8sUcvYFsZSr1OuY4Skry/G 7g7EmfZDRiP9g== Date: Wed, 3 Dec 2025 15:12:34 -0800 From: Kees Cook To: Joe Perches Cc: Vlastimil Babka , Andy Whitcroft , Dwaipayan Ray , Lukas Bulwahn , Randy Dunlap , Miguel Ojeda , Przemek Kitszel , "Gustavo A. R. Silva" , Linus Torvalds , Matthew Wilcox , Christoph Lameter , Marco Elver , Vegard Nossum , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Roman Gushchin , Harry Yoo , Bill Wendling , Justin Stitt , Jann Horn , Greg Kroah-Hartman , Sasha Levin , linux-mm@kvack.org, Nathan Chancellor , Peter Zijlstra , Nick Desaulniers , Jonathan Corbet , Jakub Kicinski , Yafang Shao , Tony Ambardar , Alexander Lobakin , Jan Hendrik Farr , Alexander Potapenko , linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, linux-doc@vger.kernel.org, llvm@lists.linux.dev Subject: Re: [PATCH v5 3/4] checkpatch: Suggest kmalloc_obj family for sizeof allocations Message-ID: <202512031511.ACA8A5DB0@keescook> References: <20251122014258.do.018-kees@kernel.org> <20251122014304.3417954-3-kees@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 1BF10180010 X-Stat-Signature: ckkgk3xhm5af8u7oda93ahx67z3exmwc X-Rspam-User: X-HE-Tag: 1764803555-90154 X-HE-Meta: U2FsdGVkX1/1ZOW7/BEFFMgWMs9ejOC4qlHk0/g+kBijkktP52iEjtoBjH+qjHY7lKtwva80ojvFx0vlrx6y5skR+7YxTaXldzx0txLbcrTeT+7AwTOx84EsFFtg2gfPyDLx7kcSoYes2XkejY45Dcgcowj2TxVH95Pkrcymd+lTmQk/zJNtY9APxCBp7Mq6/i3jWhjRh34pF5SRSM4HmAoNcXfLnsr0auw7x4Ew5R5JZ3Ac8BzsSLiOFwIRs6A/MmLKF3hlAsTFvYauyLDzGck8+KZy0aq6BekFI9CIkxytgpo/IIQU6bEES7tC8L7cammoeCzy7zsdNyn518mMHMQxGzoP9kPIqu9PB3gnaTP9ROc7giBzD4oTuNCba+6HkjTsBfNL4PBtG4hyv9GiADLodd5V/WXRYwwk1txJaGQ/lEKMuhGIiHibFsxJKPY/BhRVL/CE0ixni3MG/TGLNXjXrExfr2dpusTckysc+EYcf2H11zFEldIfExe/XETBfD6CP7ckkhQK3WQ6L6CoI9AseStLeQ5CiqaI6eqh9+ig1NaJG7UD2+mvWhhvE7tOl4sU+LVsV1YKXFUKYYFTsFkZLYYJsVjunlMD/heAVoLYHxheUe+HMecvIKgPbDndTyTXg00cwU2VHRZ8LyuMiAoSowhW+32DpkgXjDynDfTYyi5YZRJy4ZBrqTQgOncEckksc81QOWUUvWFnzhLZMoITj/EjHAT2vZq/wuyGtAHWlvXGTZYmBJPhAMZU8eQJcPP+nqf/ZZ7bRwccl9sXztwF9R9SuDmWrvpmNC6A9Olaxrqd9M+ogb36Vn7AAvbVAi5e7wg5GOAUGHboPj46XOU7YeKfNs0gqqFPM8NvSlY+plWPKMywummHgHfSND1mwlIGrzGhl+DGXXzaUbZmVYo74jXX5VlnxlrKz8+mvuwDqNLYeMNhMmSTilz3TnuRVNd4ZTGVz74h15Ooy51 wXi7de1p MqKCnOvQFyX3E26sL5A6j2jB+D2lg/UU7WHZWNQpH0MNSn4pbDkXJx75m6v0pN/rril1nJBcAFy3GslE= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, Nov 21, 2025 at 08:51:19PM -0800, Joe Perches wrote: > On Fri, 2025-11-21 at 17:42 -0800, Kees Cook wrote: > > To support shifting away from sized allocation towards typed > > allocations, suggest the kmalloc_obj family of macros when a sizeof() is > > present in the argument lists. > [] > > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl > [] > > @@ -7258,17 +7258,42 @@ sub process { > > "Prefer $3(sizeof(*$1)...) over $3($4...)\n" . $herecurr); > > } > > > > -# check for (kv|k)[mz]alloc with multiplies that could be kmalloc_array/kvmalloc_array/kvcalloc/kcalloc > > +# check for (kv|k)[mz]alloc that could be kmalloc_obj/kvmalloc_obj/kzalloc_obj/kvzalloc_obj > > There are _way_ too many of these existing uses to suggest this change > in existing files so please add '&& !$file' to these tests The goal would be to also do the proposed treewide change which gets the vast majority of them converted. -- Kees Cook