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 7F94CC8303F for ; Mon, 25 Aug 2025 20:18:30 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B1EDA8E006B; Mon, 25 Aug 2025 16:18:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AF4E88E0038; Mon, 25 Aug 2025 16:18:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A31CE8E006B; Mon, 25 Aug 2025 16:18:29 -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 F037E8E0038 for ; Mon, 25 Aug 2025 16:18:19 -0400 (EDT) Received: from smtpin18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 7859C1A0568 for ; Mon, 25 Aug 2025 20:18:19 +0000 (UTC) X-FDA: 83816391918.18.DC44E4B Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf09.hostedemail.com (Postfix) with ESMTP id DA83614000F for ; Mon, 25 Aug 2025 20:18:17 +0000 (UTC) Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=hFlxFsri; spf=pass (imf09.hostedemail.com: domain of kees@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=kees@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1756153097; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=yNerjuxI+KYbw3mNCEHMV8i09CJJK9GCt86H4fr7e/g=; b=e2t2SnYorU2dJkV41EvBrMRKHuuXgMiQMaCSMEN83I4ChDo8mqJyTDlzvdkuoHuiG2iRKT XIlFP5Cjy8jQsZqpu5pj2taw8+aPp7IxEpZaL06zWviJsYQkOjqeyiN8xAugft0TG0rnjJ t9dq7U04t8fjeJTzmCuiOy1z6Hg8JnA= ARC-Authentication-Results: i=1; imf09.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=hFlxFsri; spf=pass (imf09.hostedemail.com: domain of kees@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=kees@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1756153097; a=rsa-sha256; cv=none; b=hP2Z39Pop/sXWxFu8vjJqB2STFVR3NAKpNK3hDy8UXdM7GqcMtkRP31w8IDIBMfQFLhNF5 BQ5Dz9zFZ09UtMRjDBJhZyUkJP3hGnororuErEJsc38Nk7VmKQ+8VdqeBd89jKP258F3AJ XYQEO2FVrys+gWVyz0su6MK0L1MLq0g= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 47722601E5; Mon, 25 Aug 2025 20:18:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 51237C4CEED; Mon, 25 Aug 2025 20:18:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756153097; bh=yNerjuxI+KYbw3mNCEHMV8i09CJJK9GCt86H4fr7e/g=; h=Date:From:To:CC:Subject:In-Reply-To:References:From; b=hFlxFsrioVHoPBVPmP1nQAdWfA6sGqieK/3eJIPNwb/fgHtGy72TnnSEvhYryibRv GFKFFoV8oSOgWAtWyCNJNocRKr9FJwZ2ZGpaUfnsOhsyI0kupY0SZiqYyBfPilEvcE lC8u05P6vI385iou8sEtH/JARLmrK/KjWR9Gq8DplgFKfLbZgXtCTwPYWtcQRGEdVk RPbLgoMWeYCoQ2qRe5bF0p/PlmOi7wwTGbEdmACDi9xjXr3qRzKZgG4IvzRNF2m7fK PHyxc8DoAeOJeLn60+cbpo9WKw0T1FU8V8yljOwRUbnW4SHutpvZMkzdJxcZLgjaNC 4b0+vQDoj+Kgw== Date: Mon, 25 Aug 2025 16:17:53 -0400 From: Kees Cook To: Marco Elver , elver@google.com CC: linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, "Gustavo A. R. Silva" , "Liam R. Howlett" , Alexander Potapenko , Andrew Morton , Andrey Konovalov , David Hildenbrand , David Rientjes , Dmitry Vyukov , Florent Revest , GONG Ruiqi , Harry Yoo , Jann Horn , Lorenzo Stoakes , Matteo Rizzo , Michal Hocko , Mike Rapoport , Nathan Chancellor , Roman Gushchin , Suren Baghdasaryan , Vlastimil Babka , linux-hardening@vger.kernel.org, linux-mm@kvack.org Subject: =?US-ASCII?Q?Re=3A_=5BPATCH_RFC=5D_slab=3A_support_for_compiler-?= =?US-ASCII?Q?assisted_type-based_slab_cache_partitioning?= User-Agent: K-9 Mail for Android In-Reply-To: <20250825154505.1558444-1-elver@google.com> References: <20250825154505.1558444-1-elver@google.com> Message-ID: <0DC67CE5-6006-4949-A81D-882DBDF4DAC4@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: DA83614000F X-Rspamd-Server: rspam04 X-Rspam-User: X-Stat-Signature: 3nko8go6op9a4esusep1wbzahobubqh7 X-HE-Tag: 1756153097-411714 X-HE-Meta: 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 wef+Au1F 9yStExhnvbQLN4B93haJtTXJaC6Hs0w11C9EhiTmMq0FLpPtqVQJj6iUHvVLLwfGY01JsS/ZDjqtiRzqqedT1/3oRCbbDSvma2ISjmt/i0X/q5uWFUu2FBIGl31PhxRxWuhGwpektGXZuePg0TZbJyAeolaf8ZLdLsMy9YGQFU1rQyjDe7dNuqTY67TyDDLAzxWa+UdsdD2GRaz9HxWv7oWWnwy07VIpHqggn9R5z9na2oS3i1AM2a6x/qUmRe8vK+pLtfQ2rqNV0H63pX+0JJNI3MTibGoeQtvmzl3+92iAsnzs= 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 August 25, 2025 11:44:40 AM EDT, Marco Elver wrote= : >Additionally, when I compile my kernel with -Rpass=3Dalloc-token, which >provides diagnostics where (after dead-code elimination) type inference >failed, I see 966 allocation sites where the compiler failed to identify >a type=2E Some initial review confirms these are mostly variable sized >buffers, but also include structs with trailing flexible length arrays >(the latter could be recognized by the compiler by teaching it to look >more deeply into complex expressions such as those generated by >struct_size)=2E Can the type be extracted from an AST analysis of the lhs? struct foo *p =3D kmalloc(bytes, gfp); Doesn't tell us much from "bytes", but typeof(*p) does=2E=2E=2E --=20 Kees Cook