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 62CF4CFD36B for ; Tue, 25 Nov 2025 00:30:00 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A1D626B0007; Mon, 24 Nov 2025 19:29:59 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 9F4B46B0023; Mon, 24 Nov 2025 19:29:59 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 909E06B002A; Mon, 24 Nov 2025 19:29:59 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 7E1606B0007 for ; Mon, 24 Nov 2025 19:29:59 -0500 (EST) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 697BD4FA2F for ; Tue, 25 Nov 2025 00:29:56 +0000 (UTC) X-FDA: 84147246792.13.1CDEA3F Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf06.hostedemail.com (Postfix) with ESMTP id C4E19180002 for ; Tue, 25 Nov 2025 00:29:54 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=vP0pDW+B; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf06.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=1764030594; a=rsa-sha256; cv=none; b=0WJJLEXsLA+/zAemCPaSqOfOva1kkQFFX25ZqWJ2YpOPvXctY3eNcooaTJKYPsfBcS41MW 2QZaCh6vmMLnUoG/amz+XpJ9aQDlYDrMwTWVNYxDKZjZqwKBlou5ZDXGZqeNKUoZprmq3I DW3g/bkej2Kk1MwIdvMR2OSrhDhTTCU= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=vP0pDW+B; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf06.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=1764030594; 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=GsQ0Rrft/2zJsF9vIPqGYfKXjTW4MDXp+SfE2VWe7yw=; b=FTIMCR55AI3oHSi2R3yQUNnMFYOyKxMRAz6OQOeadqNcZr4e2yL2N6YmcQBlgCqaYOQ1+X uLgYkY5s2wHApUbnRx8R2no29xqDCxd6EbhvFHcDvQuLgKGT08os9Y5f81OKXJuPJZm3YP EqAnAdHd63YCVvnaHUSOO48A8Ys957E= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 838C4429EF; Tue, 25 Nov 2025 00:29:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 55BD8C4CEF1; Tue, 25 Nov 2025 00:29:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764030593; bh=4uLLAgDc9tGcrBcub+QCJwRh5UloS519zmliLS4+WTI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=vP0pDW+BLmy48fCW+CGIvxSSOBpyZLYqJlIFcgFof2izgXQUBhwAbWrNhiXRBRkXe GG4SgKT9qZsApPZSuXAOjUNhLTFptYI/vhbzI49vtWUzFvUfn/p6YDwl0QxXi513+C Vpg/Fmf9P0BEeHtlxJv8H6UeuikiIv1VjgSQMa+6PjlBo5C3FpmcKscSFnP/utdse5 KZzgwabQE8amERyL/vtIu1c4gltor3c68XQs4cQIeMeTPM7E6vz91pqB7hmuS/+PW2 M9JbOdwp/XqZNni55nZnDncPu+HxP+OkBHc1AIn/vOCItrqo1Ru3C0d84jmTT2dC4q SS3PI2PS8mJ5Q== Date: Mon, 24 Nov 2025 16:29:52 -0800 From: Kees Cook To: Linus Torvalds Cc: Vlastimil Babka , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, "Gustavo A . R . Silva" , Bill Wendling , Justin Stitt , Jann Horn , Przemek Kitszel , Marco Elver , Greg Kroah-Hartman , Sasha Levin , linux-mm@kvack.org, Randy Dunlap , Miguel Ojeda , Matthew Wilcox , Vegard Nossum , Harry Yoo , 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 2/4] slab: Introduce kmalloc_obj() and family Message-ID: <202511241612.6CF90E9@keescook> References: <20251122014258.do.018-kees@kernel.org> <20251122014304.3417954-2-kees@kernel.org> <202511241119.C547DEF80@keescook> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: C4E19180002 X-Stat-Signature: uoduiyxda19sfrw5hxs3majx5wsgkwgc X-Rspam-User: X-HE-Tag: 1764030594-170043 X-HE-Meta: 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 co9S/hM6 Zwn0JVB1Hbo+JJ66iBH4lzwy7mG1ydVXdnkS3Y7ss0AsYYXhLrCQ9xmAEPzfB9xTdpvjf9CDx30YsDeF+M4UXcF+S3IUVXiMPLZVONq7l0MW6615+usWRq9e/xsGeYouOCbee4e+8yS7ysjZvhn9fOFmx0qyFpY2LiCU0wK4mQN2/gjf/owhAM4aQfoQxPJTZoZDk5OFAUlliW42F2jX7giR6pPXOxWmf6CHlmmdt/XRM29s44DQXw2UA5HRI3LgorgWExl4j2UEI/m6qcqf+0b+6qIuYjl/+91nZdPCRn/DtWLy9qYY9Ak9BnOiMGZO1JteXgAElfLGd4hxiCwQtouqHPikfJi8eC7d+L4eI5ugpvmZxe5wZbVcrZ4UqatIOnidnj0Sb1pKbTD1qg3pizh+FlQ== 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 Mon, Nov 24, 2025 at 01:35:12PM -0800, Linus Torvalds wrote: > Those macros are illegible. And 99% of all users DO NOT WANT ANY OF > THAT COMPLEXITY. Okay, I think you're saying "I don't want the common helpers to include the infrastructure for supporting the ..._sz() variants"? > So no. We're not doing *any* of that. You make it simple and targeted > to the *common* case, of you don't do this at all. Because that > over-designed mess that actually turned some users *less* readable, > but one line shorter, was bad. Fair enough. Looking at the treewide change I prepared[1], it's less than 1% of those mechanical replacements: $ git show f79ee96ad6a3 | grep -E 'k.*alloc_(objs?|flex)\(' | wc -l 17473 $ git show f79ee96ad6a3 | grep '_sz(' | wc -l 114 I'll respin without the _sz variants, and try to improve the flex stuff. -Kees [1] https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git/commit/?h=dev/v6.18-rc6/alloc_obj/v5 -- Kees Cook