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]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE74AC3600B for ; Thu, 27 Mar 2025 19:42:30 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 90534280118; Thu, 27 Mar 2025 15:42:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8B264280117; Thu, 27 Mar 2025 15:42:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7795B280118; Thu, 27 Mar 2025 15:42:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 59C3D280117 for ; Thu, 27 Mar 2025 15:42:29 -0400 (EDT) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 93252161697 for ; Thu, 27 Mar 2025 19:42:29 +0000 (UTC) X-FDA: 83268352818.12.446AA12 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf15.hostedemail.com (Postfix) with ESMTP id 3605EA000D for ; Thu, 27 Mar 2025 19:42:26 +0000 (UTC) Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=fowTjCZh; dmarc=none; spf=none (imf15.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1743104548; a=rsa-sha256; cv=none; b=T5U1UOJoHPtbLtDIRgHxVdRyWU+yyCMgMLMn+Gkslc0uURmYK3SZvDnUg8O0f2ElZxOoW/ Qi4VTaKwft9fb13Etda433MkeEVwBB4GeFVPoA3HRdRFOU+Wx9r87EaDIdK7uQ6cra7nad QsslHDC/mUJbfIY+AKMmbih4RccJJ4w= ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=fowTjCZh; dmarc=none; spf=none (imf15.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1743104548; 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=QxApuPwvbMdm/tcX2I8PfZPt6Mt8W2Cnmp2BQW93RHc=; b=WTlLFuhguWK3cqjtDw9iCu1x9tOWb75bRckdTzlrmFnxbMSVLkgQf34rlHhxOUGnt/WXRN VJtWqYlA4ifBU0SseUMO+hN6ItQWTiWqpUIn2DZQ32nT9UjzODNMqYwvbvLN00zGfYcWhY ZeKXf1CvcQMnbTqkbm93klM9Bks6Cnc= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=QxApuPwvbMdm/tcX2I8PfZPt6Mt8W2Cnmp2BQW93RHc=; b=fowTjCZh/e+GKmEDK0YMRnIYmK /Oc5324O6IaG9I1uwb7bVc1qOpmkgPDAHUT8ppVvICTG0wwcQvS+9qU2yaKqO5xAec5HpeK0R8Vtq P5IHBdKUhq4H0N2QRe7LrkkQ/0thifhWAJXITMj8n12n3nVXbdaf4L4nFfreUrRxkPZd6W9SUr4ZD Hlkqdyxt7sbMmRDahXecGIKKe0O2dZGDsDOvtwzbqzV0eBm8n5Jxt75qgPRF5sCS6odokZtLPHTN+ sbPdTUna7cLds8tnopETdwsoikEqIw05Cg0j2ggLoS1n2Ygz02+2ZHq6Xj6byI70Lv8x0aDIkGSL5 +FU4OoNw==; Received: from willy by casper.infradead.org with local (Exim 4.98.1 #2 (Red Hat Linux)) id 1txt7B-00000000usX-17Ii; Thu, 27 Mar 2025 19:42:09 +0000 Date: Thu, 27 Mar 2025 19:42:09 +0000 From: Matthew Wilcox To: Kees Cook Cc: Vlastimil Babka , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, linux-mm@kvack.org, Miguel Ojeda , Nathan Chancellor , Marco Elver , Nick Desaulniers , Przemek Kitszel , linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH 4/5] slab: Set freed variables to NULL by default Message-ID: References: <20250321202620.work.175-kees@kernel.org> <20250321204105.1898507-4-kees@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250321204105.1898507-4-kees@kernel.org> X-Rspamd-Queue-Id: 3605EA000D X-Stat-Signature: kn6h6a8ejo4p9tmmwy6z96bw6rc7zinu X-Rspam-User: X-Rspamd-Server: rspam06 X-HE-Tag: 1743104546-328425 X-HE-Meta: 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 nmC5WTAp 0DQdt+3RCKFalaLTHJ2X9OhJsS2Qo2QCah5JxS7R7TpknrxDHCMt930kJsT3pAfhy1UOWzdPldayIz4hU/yyzgMv3SCGgU4HrExYM92dA04fmkMKDb1feT+5xNe7XOYBFgxAEdaqmxWvX29YWxQkC+PuBYYSksgMIOFifFa5iqcehEk6ZHjMMC02saklcfoAy7sY2a4BREv5IKFqtV11y5Y/UGLTxYoyNLHDYjgKv0UpNi3Vf0lcPEgQxpWEZSaKYoATSXU/KUsoVPD7Rg69AmeC+z276RlGPQsWzwUWEOdFdXM0= 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, Mar 21, 2025 at 01:41:00PM -0700, Kees Cook wrote: > /** > - * kfree - free previously allocated memory > + * __kfree - free previously allocated memory No. After applying this patch, we now have documentation for __kfree -- a function we want precisely 0 people to call directly, and no documentation for kfree(), which is the function we want everybody to use. I don't know what the right solution to kernel documentation is here, but this is definitely not it. Something I've done in the past is to note that kernel-doc ignores preprocessor, so we could do something like: #if 0 /** * kfree - blah blah * @blah: blah * * blah blah blah */ void kfree(const void *object) { } #endif void __kfree(const void *object) { ... } We'd get warnings if people asked the kbuild system to show them all EXPORT_SYMBOL functions which don't have kdoc, but nobody's that invested in having complete documentation. I don't know if this is a good approach to solving the problem.